Tuesday, December 20, 2011

Snow on Christmas?

We are only 6 days away from Christmas! The big question each time December 25th rolls around is whether or not we will be seeing a white Christmas. Living in Northwest Oregon, we already have a handicap getting snow down to the valley floor. The Pacific Ocean is too close and acts as a moderating influence to our weather. It just keeps temperatures too warm for a persistent snow threat.

Portland's coldest month is January, where the mean average temperature is 39.9 degrees. That is "comfortably" above the freezing mark, making it tough for snow to fall. Let's look over the Cascades at Redmond's coldest month, that's December. The average mean temperature is 32.7 degrees. So why the difference between Portland and Redmond? Elevation plays a key role. Portland sits at roughly 200 feet above sea level. Redmond is at nearly 3,000 feet in elevation. The thermodynamic state of the atmosphere cools as you gain elevation. So you'd expect Redmond to be colder than Portland. Another issue is "continentality".  The land heats and cools much faster than the ocean, so the closer to a body of water you are, the more temperate the climate may be. That is exactly what we deal with here in Portland. We are just close enough to the Pacific Ocean to be impacted by its moderating factors.

So let's answer the question: what is the possibility of a white Christmas in Portland? You actually have a better chance of seeing snow on Christmas if you live in Downtown Portland rather than out near the Portland International Airport. On average, Downtown Portland has a 4% chance of seeing a white Christmas. And at PDX? If you had a worse chance, it'd be no chance... only a 1% chance of seeing the white stuff near the airport. Portland's most recent "white Christmas" was back in 2008, where close to 1" fell on the 25th to go along with the nearly 10" that was already on the ground (as a side note, December 2008 saw 19" of snow!). What about Redmond's chances? Since 1949, Redmond has had 12 white Christmases and on average has a 24% chance of seeing snow on the 25th. 

Just for fun, Portland's snowiest day is January 19th where since 1884 it has snowed 15 times and on average there is a 12% chance for snow that day. 

What does this Christmas have in store? This December has been very dry. The airport has reported only a tenth of an inch of rain through the 19th. That is nearly 3.39 inches below normal. The driest December on record was in 1976 where only 1.38 inches fell. So we are well on our way setting a new record. We remain locked in this very dry weather pattern. All month long, high pressure has been planted out over the Pacific Ocean, leaving us dry. The weather maps continue to hint at this high pressure staying more or less in place.
Christmas Eve Morning
Christmas Morning
Rain by Presents Time
The high pressure clearly shows up on Christmas Eve morning. The ridging sends any rain up over the top of us and keeps us dry and mainly sunny for the 24th. However, a weakness disrupts our nice weather by Christmas morning. That weakness will bring us some showers by the time you are opening presents. But temperatures just won't be cold enough to produce snow. Christmas average temperature in Portland is 45 degrees, I am aiming for 43. So no white Christmas this year!


Wednesday, December 7, 2011

Bowling Season

One of the wildest seasons of college football wrapped up Saturday (The Army Navy game was Saturday--neither will be bowling this season). Things got really interesting this year when LSU beat Alabama 9-6 in overtime. Then talk about who the second best team in the nation REALLY was. Oklahoma State? Stanford? Alabama? Oregon? It was suppose to take a miracle for the Tide to get back into the National Championship picture. And that is exactly what it got! Losses by Oklahoma, Oklahoma State, Oregon, and Stanford all helped the Crimson Tide slide into the #2 spot and wind up with a controversial rematch for the Crystal Ball.

But before we settle who the best of the best are, we must wade through the muck that is the mediocrity bowl-slate (13 teams have the potential to finish below .500). It wouldn't be fun to predict the good bowl games, so I going to break it down all 35 of em. Last years record was 20-15.

New Mexico Bowl-Temple vs. Wyoming
Temple has been an under-the-radar team the last few years. Back-to-back 8-win seasons has the people of Philadelphia thinking twice about the Eagles. Wyoming can't run the ball and they can't stop the run...advantage Owls. Who wins: Temple

Idaho Potato Bowl- Ohio vs. Utah St.
Utah St. had defending national champs Auburn on the ropes with under two minuets to play. Then they choked it away. The Aggies pulled it together and got into a bowl game with the 6th ranked rushing attack in the nation. Ohio is a perennial bowl competitor, but lack success. Who's turning potatoes into fries? Ohio

New Orleans Bowl- SDSU vs. LA-Lafayette
Both teams won 8 games. SDSU did it in a much tougher conference. The Ragin' Cajuns are in their first bowl in 41 years! Who's throwin' beads on Bourbon St? SDSU

Beef O' Brady's Bowl St. Petersburg- Florida International vs. Marshall
Marshall won their last two games to become bowl eligible. Both teams struggle in the offensive category. In a game named Beef O' Brady's, why wouldn't things be offensive? Game lies in the arm of Panthers QB Carrol and WR T.Y. Hilton. Who's got the beef? Florida International

S.D. County Credit Union Poinsettia Bowl- TCU vs. Louisiana Tech
So, TCU wins the Mountain West (welcome to the conference, Boise) and still can't get into the automatic ranks. So they settle for LA Tech. This shouldn't be close. Who's got the better credit score? TCU

Las Vegas Bowl- Boise St. vs. Arizona St.
This one could get ugly. Did the Sun Devils even play a 2nd half of the season? Boise, ranked 7th, will be upset about being left out of the BCS. Who's the high roller? Boise State

Hawaii Bowl- Southern Miss vs. Nevada
Southern Miss cost Conference USA a boatload of cash by beating Houston in the conference championship game. They are a good looking team. Nevada runs the Pistol offense to the T. The Golden Eagles pack a great punch too. This will be a fun game to watch. Mele Kalikimaka to Southern Miss.

Independence Bowl- Missouri vs. UNC
Mizzou bids adieu to the Big 12. UNC put together a decent season under interim Head Coach Everett Withers. Who wins? Missouri

Little Caesars Bowl- Western Michigan vs. Purdue
One of least interesting match-ups this bowl season.  Purdue didn't win back to back games all season. The Broncos won two in a row to get into a bowl. They got a QB who has nearly 3,500 yards passing. Pizza! Pizza! Western Michigan

Belk Bowl- Louisville vs. N.C. State
Louisville competed in the Big East (but who didn't?) N.C. State looked impressive in a stunner over Clemson. The Cardinals were the more consistent of the two teams who both struggle offensively. I have no idea what Belk does...Louisville

Military Bowl- Toledo vs. Air Force
Air Force is the only military team to qualify for a bowl game. Good thing cause this game would be awkward if there wasn't a military school in it. The Falcons can run the ball and Toledo can score lots of different ways. Should be an interesting game. ATTENTION! Toledo

Holiday Bowl- California vs. Texas
The Longhorns struggled and I have no idea why Texas was ranked for most of the season. They weren't very competitive in any of their games against ranked opponents. Cal, Cal, Cal. Somehow, some way, they turned it around in the 2nd half of the season. Remember when Texas head man lobbied for a BCS bowl game over Cal a few years back? Holiday Cheer for Texas

Champ Sports Bowl- Notre Dame vs. Florida State
A classic match-up. Florida State was ranked number five at one point, but lost to Oklahoma, Clemson and Wake Forest in consecutive weeks to put em out of contention. The Irish used two 4-game win streaks to get to a bowl game. Hardly call them a Champ winner Florida State

Valero Alamo Bowl- Washington vs. Baylor
This is the first year in the Alamo Bowl for the Pac-12. Washington played well early under QB Price (who will no doubt be more successful than Jake Locker) but slept walked through the rest of the season. Baylor finished off one of their best seasons and have the best player in college football Robert Griffin III. Who Remembers the Alamo? Baylor


Armed Forces Bowl- BYU vs. Tulsa
This is a sleeper game. BYU had 9 wins this season but was under the radar because they were an Independent. Tulsa's only conference loss was to Houston. Tulsa can score and should keep this one competitive. Up in Arms Tulsa


New Era Pinstripe Bowl- Rutgers vs. Iowa State
Rutgers is the bigger, stronger team here. Iowa State pulled the huge upset against #2 Oklahoma State to throw the college football world into a spiral only to lose their final two games of the season. Expect Rutgers to pass all over the Cyclones. Now Batting for the Yankees Rutgers


Music City Bowl- Mississippi State vs. Wake Forest
Mississippi State has the misfortune of playing in the SEC West division. You know, with teams like LSU, Alabama, Arkansas and Auburn. Tough to get in a rhythm playing those teams. Wake Forest had a better than expected year, and happy to be back in a bowl game. If the Bulldogs can get the running game going, they can win it. Who's hearing Sweet Music? Mississippi State


Insight Bowl- Iowa vs. Oklahoma
The Sooners are a stranger to non-BCS bowl games. This is only their third non-BCS bowl game in the last 10 years. Iowa won games they shouldn't have and lost games they shouldn't have. Even without standout wide receiver Ryan Broyles, the Sooners should roll. Who wins? Oklahoma


Meineke Car Care Bowl- Texas A&M vs. Northwestern
For some reason, it's always a shock to see NW in a bowl game. But they fought and scrapped this season. Was there a bigger disappointment in college football this season than Texas A&M? Back to back blown leads against Oklahoma St. and Arkansas began the implosion. If Wildcat QB Dan Persa can play the entire game, NW has a shot. The George Foreman goes to Texas A&M


Sun Bowl- Georgia Tech vs. Utah
A pretty good match up in El Paso. Pac-12 newcomers Utah pulled together a strong 2nd half of the season with a stout defense. Georgia Tech can run the ball, they rank 3rd in the NCAA in rushing. A classic game of which will win out. The Sun is shining for Georgia Tech


AutoZone Liberty Bowl- Cincinnati vs. Vanderbilt
Vandy put together one of the more surprising seasons this year, in the SEC no less. This is only their 5th bowl appearance ever. Cincy has a tough streak to them. Give them Liberty Cincy


Kraft Fight Hunger Bowl- Illinois vs. UCLA
Do we HAVE to play this game?? Neither team has a head coach. Illinois won their first 6 games, only to lose their last 6. UCLA actually has a losing record going into this one. The Bruins would have been bowl eligible had USC been able to qualify for the Pac-12 championship game so a bowl game seems fair. Still, most will be fighting boredom watching this one. Serve up some Mac&Cheese to Illinois


Chick-fil-A Bowl- Virginia vs. Auburn
Auburn struggled to find consistency at QB but no one is Cam Newton. Virginia was more successful on the road than the Tigers. But is Virginia ready for this stage? Auburn will be playing in familiar territory in the Georgia Dome. Eat Mor Chikin Auburn

TicketCity Bowl- Penn St. vs. Houston
No doubt Houston had other thoughts than the TicketCity Bowl. Their Conference USA championship loss cost them a BCS game in which they very well could have been the favorite. They settle for a game in Dallas against Penn St. who has a stout defense. I think Keenum is a way better QB than Penn St. has seen all year. Punchin' their Ticket Houston

Outback Bowl- Michigan St. vs. Georgia
A match-up of two conference championship losers. Georgia came on strong to end the season after starting 0-2, winning 10 straight before the SEC championship loss to LSU. Michigan St. couldn't pull another miracle in the Big 10 game. Two great defenses and equal offenses. Who's Going Down Under? Michigan State

Capital One Bowl- Nebraska vs. South Carolina
If Cornhuskers QB Martinez and RB Burkhead click, Nebraska can take this one. But they are so hit-and-miss all season long. South Carolina has a stingy defense with a beast defensive line. Connor Shaw took over nicely at the QB spot for a disappointing Stephen Garcia. Should the Huskers QB/RB tandem fail, the Gamecocks will take over. What's in Your Wallet? South Carolina

Gator Bowl- Ohio St. vs. Florida
I have a tough time with this game. Do two 6-6 teams really deserve a "New Years Day" bowl game? Both had disappointing seasons but Florida may come with a bit more motivation in an attempt to beat the soon-to-be-coached Urban Meyer Buckeyes. This is almost a toss-up. Urban Bowl Winner? Ohio State

Rose Bowl Game- Wisconsin vs. Oregon
This is one of the top 3 match-ups this bowl season. The first BCS game this year features a power offense (Wisky) versus a speed offense (Ducks). If Oregon's surprising D can get a few stops and run around the slower Wisconsin defensive line, Ducks take it. If not, Wisconsin dominates possession and can pull it out. Who's Rosy? Oregon

Tostitos Fiesta Bowl- Oklahoma St. vs. Stanford
In my eyes, this is the best match-up of the season. Oklahoma St. was this close to the National Championship and Stanford could have been in the mix too had they beat Oregon. But with QB's Brandon Weeden and Andrew Luck this one has plenty of points in the offering. I think Justin Blackmon is the difference. The Cardinal don't have that deep threat with Owusu out. Chips n' Dip Oklahoma State

Allstate Sugar Bowl- Michigan vs. Virginia Tech
The most disappointing BCS match-up. Shame on the Sugar Bowl for this selection. Michigan was just good enough to qualify for a spot and Virginia Tech got pounded in the ACC championship game. This should have been Boise St. and Kansas St. But it is all about the money, you know that! Virginia Tech has more talent in this one. Who's In Good Hands? Virginia Tech

Discover Orange Bowl- Clemson vs. West Virginia
How good did Clemson look early in the year? And how quickly that success dropped. But they rebounded to win the ACC bid. West Virginia won the muddled Big East with plenty of help. Clemson definitely has the better team. But if Geno Smith has success passing, the Mountaineers have a shot. Who wins? Clemson

AT&T Cotton Bowl- Arkansas vs. Kansas St.
This is going to be a great game. Kansas State has a hard-nosed offense and coach Snyder always seems to get this team motivated to play. Arkansas was over-shadowed by LSU and Alabama this season. QB Tyler Wilson is playing better than Ryan Mallett had last year. Look for the Razorbacks to pull away late in this one. Who wins? Arkansas

BBVA Compass Bowl- SMU vs. Pittsburgh
Why this game is played so late in the bowl season is beyond me (money, probably). SMU is being rejuvenated by coach June Jones. But unlike the Pony Express, this Mustangs team does it through the air. Pitt never won back-to-back conference games and lost a few games it probably shouldn't have. Compass is Pointing to SMU

GODADDY.com Bowl- Arkansas St. vs. Northern Illinois
An intriguing game to prep you for the National Championship, this bowl features two 10-win teams. Frustrating to know that winning your conference only gets you to the website bowl. Northern Ill. is no stranger to bowl games, but Arkansas St is a 10-win team for the first time in school history. Who gets to Meet Danica Patrick? Northern Illinois

BCS National Championship- LSU vs. Alabama
An SEC team will lose in the title game, you can count on it. Here is my beef with this match-up: This game proves nothing. If LSU wins, they beat Alabama...again. We already knew they could beat Bama (see: Nov. 5th, 9-6 OT). People will cry that Oklahoma State should have had a shot. If Alabama wins, then the series is tied 1-1 and we will never get a 3rd game to see who takes the cake. Nothing is solved in the big picture with this match-up. It just gives the SEC another bragging point. Nonetheless, the game must be played. I expect this game to be different than the first meeting. More points, less defense the second go around. With the game being played in New Orleans, that has to give the edge to LSU. They seem to win one ever five years anyways...


There you have it, all 35 games predicted. Thoughts? See how you do and I'll be back to wrap it all up on January 10th. 






 






Tuesday, November 8, 2011

Oklahoma!

Recall spring and early summer here in the Pacific Northwest....
Portland had one of the worst springs of all-time! It ranked as the 4th coldest and 2nd wettest spring on record. The average temperature for the 2011 spring period (March-May) was 49 degrees. We received 14.41" of rain as well, 0.9" shy of tying the all-time record. Given the two, I'd say that's a pretty miserable stretch.

While we "suffered" here in the Pac NW, it compares very little to what the Sooner State has endured since January 1. Oklahoma has gone through a variable mixed bag of extremes this year. Let's review:

February 10:
In Northeast Oklahoma, Nowata recorded the state's coldest temperature ever when the mercury disappeared to minus 31 degrees Fahrenheit! That record stood for 64 years and previously was minus 27 degrees.  Also ending that day was the new state record for snowfall in 24 hours. Just to the Southeast of Nowata, 27" of the white stuff fell in Spavinaw! Winter Canadian air was to blame for these winter records.

Let me draw your attention to the top left map. This is the setup for February 9th. Notice that over Oklahoma, the pink colors are moving from the north to the south. This indicates very cold temperatures in the atmosphere above, an "arctic outbreak". Those temperatures above translate into cold temperatures at the surface. The map on the bottom right displays relative humidity through roughly half the atmosphere. The pink colors indicate a "dry" atmosphere, or low humidity levels. The brighter blues tell us that the atmosphere is saturated and wet. The more saturated the air is, the more likely precipitation is to fall. There is a bulls-eye of high saturation over Oklahoma on the 9th. Combined with the cold temperatures, we get the beginning of a record snow event!

February 9 setup

On the 10th, notice that Oklahoma looses it's moisture source. The record 27" of snow fell out of that saturated air but dried out quickly after. When the atmosphere is dry, that typically means there are no clouds in the sky. A clear sky allows heat from the day to escape out to space and rapidly cool temperatures at the surface. This is how you drop temperatures to minus 31 degrees!
February 10 setup

May 23:
Oklahoma lies in the middle of what is known as Tornado Alley. More tornadoes occur here than anywhere else in the world! The threats from tornadoes includes hail and high winds. State records were set in both categories in a two day span beginning on the 23rd. A record 6" hailstone fell in Guetbo. Below damage to a roof of a car that collected the hailstone.

May 24:
A tornado outbreak near El Reno caused a scientific wind gauge to record a wind gust of 151 miles per hour as the tornado passed. That gust crushes the previous record of 113 miles per hour that was set back in 1994.







July:
A majority of the country baked this summer in record heat. Oklahoma was at the top of that list.
Temperatures Compared From Average

 Oklahoma averaged a July temperature of 88.9 degrees. This is not the average high temperature. It is the average temperature felt at any point in Oklahoma for the month! It has never been that hot in any state for any month, ever! Truly remarkable.

Summer: 
The summer never provided relief for Oklahoma. Mark Shafer, director of climate services for the Oklahoma Climatological Survey said that at one point 99% of Oklahoma was experiencing severe drought.

November 5:
From the non-weather department but still significant and record-setting: Oklahoma experienced its strongest earthquake on record. A 5.9 magnitude earthquake struck near Sparks. It was a shallow earthquake, which allows the earthquake waves to travel longer distances. Earthquakes are nothing new to Oklahoma. Given the states proximity to one of the United State's major fault lines, the New Madrid fault, earthquakes from that seismic zone probably impacted Oklahoma in the past. There are several known fault lines in Oklahoma and while it is not in a perceived "earthquake zone", its location still can produce sizable quakes.

2011 has been a torture on Oklahomans. What does all this extreme record-setting phenomena mean? I wish I had an answer for that but I'll let you draw your own conclusions!





Monday, October 17, 2011

Tragedy in IndyCar

Sunday was supposed to be a day of racing celebration. The final race of the 2011 IndyCar in Las Vegas was set up to be a good one. A championship on the line with two men battling it out for the top spot. Danica Patrick was making her final start as an IndyCar driver before making the full time switch to NASCAR next season. Dan Wheldon had just agreed to become Patrick's replacement for next season. Wheldon also had a personal challenge on the line: win the race and get a $5 Million bonus. 11 laps in, things took a horrific turn.

On lap 12, there was a 15-car crash that sent multiple cars flying through the air like toothpicks blown in the wind and ignited several fires. As the dust settled, attention turned to one car, Dan Wheldon's. Hope turned to fear when Wheldon was air lifted from the track to a nearby hospital.About two hours later, IndyCar CEO Randy Bernard was the one who broke the horrific news, "IndyCar is very sad to announce that Dan Wheldon has passed away from unsurvivable injuries,". Wheldon became the fourth driver in IndyCar to die from an accident on the track since 1996.

Wheldon's death sparks memories of Dale Earnhardt's fatal crash at Daytona in 2001. Earnhardt was a NASCAR champion. Wheldon was an IndyCar champion. He won the 2011 Indy 500, the most famous of all American races. He won the same race in 2005 en route to the tour championship. Racing has lost another champion.

Crashes are part of racing. At speeds of over 200 miles per hour, decisions are split and can be costly. Safety is of paramount importance at those speeds. IndyCar and NASCAR have taken all precautions to ensure the well-being of their athletes. In my opinion, there was nothing that could have been done in order to avoid this tragedy.  It truly is amazing that more deaths do not result from some of the crashes. That is a testament to the rules and regulations put into place by racing officials.

There is nothing more sobering than death. As the news of this tragedy came down amongst the drivers on the track, a championship was the last thing on their minds. Pit road was overrun with emotion. The drivers voted to not finish the race. Instead, they returned to their cars and did a five lap tribute for Wheldon. A classy move by the drivers and IndyCar as a whole.

Death continues to remind us what we take for granted. Dan Wheldon's life should be celebrated. He was a man who was widely liked among other racers in IndyCar. He was successful at what he did and died doing what he loved. Each racer knows that their life is on the line each time they get behind the wheel and death can show up around every turn.

Dan Wheldon was 33.

Monday, September 26, 2011

Joplin, Revisited

The NWS put out their final assessment of the infamous EF-5 Joplin tornado that occurred on May 22.

The report didn't touch much on the final death toll. 159 people lost their lives in the tragedy, the most from a single tornado since 1953. The report also didn't cover the damages caused.

What the report did cover, in great detail, was the processes that lead up to the warnings being issued ahead of the tornado and the response the citizens took to protect themselves. The findings of the report are somewhat surprising!

The NWS Assessment team took an ethnographic approach to conducting some of it's research. The report stated that ethnographic techniques were used to, "Understand residents points of view regarding the process of warning receptions to warning responses and how decisions were made."

I am big fan of this approach. It definitely helps to know your target audience, in any situation! Understanding the thought process of the citizens is a huge first step to improving warning timing and distribution. Over 100 people were interviewed for the report. One of the more important findings was how the people in the path of the twister processed the warning information.

In this day and age, social networking is huge. Facebook, Twitter and text messaging are huge communication tools. These are great ways to get information out. Meteorologist James Spann, who covers the Birmingham, Alabama market, has utilized these tools about as well as anyone can. He sends out tweets and posts that pertain to weather watches and warnings in any part of his television viewing market. There is great potential in social networking when it comes to severe weather. The problem with it is two-fold. First, not everyone uses social media. Those who don't would then have to find their warning information elsewhere. The second problem to this is validity. Not everyone who is posting about a tornado or thunderstorms are trained experts. So there could be a lot of false information flying around out there.

Social media can be one method of risk awareness. What are others? Many towns in Tornado and Dixie alley have tornado sirens. Weather radios are common as well in these parts. T.V. weather reports are the best way to get access to severe weather information. In Joplin, it is "community policy to sound sirens when a tornado is moving towards Joplin OR a severe thunderstorm with expected winds to exceed 75 m.p.h." This causes a big problem.


When the sirens go off, what are they warning for?!?! There is a large difference between a severe thunderstorm with damaging winds and a tornado. While both can be destructive, a tornado is far more deadly than strong winds. There needs to be clarification between the two events. The people in Joplin on May 22nd had to process two different blasts of the siren. This should have been all it took for people to act. However, the report found out that people acted, "after processing a variable number of risk signals...". In a deadly, EF-5 tornado situation, people can not afford to take time and contemplate a "variable number" of warnings. There were many reports that people did not act until they visibly saw the tornado! Why weren't the sirens enough?

Several people who were interviewed said that tornado sirens have lost their credibility. A few of the responses show why:
 "the sirens have gone off so many times before"
"bombarded with sirens so often that we don't pay attention"
"...[the sirens] go off for dark clouds"

These responses go to show that people who live in tornado-prone areas are probably desensitized to the sirens. Folks would point to data to prove why they treat the sirens with such complacency. In all tornado warnings issued by the NWS nationally, it was found that over 75% of the warnings were false alarms. That information was averaged over roughly the last 4 years. So it is easy to see why people assume that a tornado siren is just someone crying wolf! But here is the bottom line, every environment is different. On this particular day, the environment was primed and ready to fire off dangerous, long-track storms. So you just don't mess with weather, even if it means you have to take to safety for 20 minuets or so.

What needs to be done to prevent this confusion and complacency again? It is critical that the NWS, media members and community officials are on the same page when it comes to warnings and stressing immediate action. Sirens need to be blasted for one type of event only. A reverse-911 action plan may help as well. Anything that puts emphasis on the danger of the situation and allows enough time for action to be taken.

This problem of complacency runs far past tornadoes and Joplin, Missouri. When faced with an approaching hurricane, several people disregard warnings and evacuation requests to ride out the storm because they think that the weather man is wrong, or that it would never happen to them. It is downright foolish to challenge mother nature. The minuet you don't respect it, it can take your life. 

Here is the link to the full NWS Joplin Tornado Assessment









Wednesday, September 14, 2011

La Nina Returns?

NOAA has put out a La Nina Advisory for the 2011 winter season. That's right folks, La Nina appears to have re-developed and is here to stay a bit longer than first thought.

What exactly does La Nina mean, you may be asking? It essentially is a cooling of Sea Surface Temperatures (SST) in the central and eastern portions of the tropical Pacific Ocean. The set up has warmer than average SST's over the western Pacific and cooler than average SST's in the central and eastern Pacific. La Nina typically occurs ever 3-5 years but consecutive episodes occur nearly 50% of the time, according to the NOAA Climate Prediction Center. While La Nina stems from the anomalies of SST's, its impacts go way beyond ocean temperatures.

Sea Surface Temperatures showing a cooler eastern Pacific which signals a La Nina return. Via NOAA CPC.
Winter of 2010 in the United States was a record-setting one. High snowfall totals lead to record Spring flooding and severe weather that was off the charts! The exceptional drought that is on-going in the South...yup, put that one on La Nina. Wichita Falls, TX became the first location with 100 days at or above 100 degrees this year! So the news that La Nina has reformed does not offer much in the way of relief.

What can we expect for winter 2011? Average La Nina winters cause wetter than normal conditions here in the Pacific Northwest and can often expect cooler than average temperatures, too. La Nina doesn't offer much drought relief during the winter months either for those in the South and Southwest,
“This means drought is likely to continue in the drought-stricken states of Texas, Oklahoma and New Mexico,” said Mike Halpert, deputy director of the Climate Prediction Center.  
 
Typical La Nina setup
Beyond the upcoming winter, it is tough to tell just how long and strong La Nina will be. Should it last into next Summer, it could mean another active hurricane season. During the 2010-11 La Nina conditions, forecasters predicted a very active tropics with 14-19 named tropical storms. As of today, we are sitting at 14 named storms this season. Pretty good, huh? With those cold waters in the Pacific, oceans try to balance out by warming up the tropical Atlantic waters to above average temperatures. So, if La Nina lingers around for another Summer, things could be active again.


With La Nina's anticipated return, records could fall again this winter. That would not be welcome news to most.





Tuesday, September 6, 2011

Tropical Patterns

Katia has reached major hurricane status in the Atlantic. After Irene lashed the Carolinas and skirted the Northeast, Katia has a lot of east-coasters holding their breath. As Katia formed, I had mentioned that the storm track appeared to take it out to sea and avoid being the second storm to hit the east coast in a month. So far, so good. Here are computer models for Katia's track.

All models have the storm re-curving out to sea. However, a common issue with tropical forecast is that a forecaster may wind up "riding" the models and forecasting what the computers spit out. When it comes to tropical forecasting, patterns almost work better than guidance.

Gut feelings often can be the best forecasting tool, assuming you have knowledge of the situation. Now, being from the Pacific Northwest, I obviously have little knowledge of topical histories. But having picked up a few hints along my studies have helped me to generate some opinions about the 2011 tropical season. My gut instinct was that Katia would curve out to sea. Here is why I stated that.

Take a look at Katia's actual track below.
Let's take a look at where Katia formed. Katia got tropical depression status at roughly 26 degrees West latitude and a day later was a tropical storm at roughly 33 degrees West latitude. So Katia formed rather quickly off the west coast of Africa. Through historical observations made, it has been determined that 90% of all tropical cyclones that develop EAST of 35 degrees West latitude will RE-CURVE off to sea. That is the exact situation we have with Katia. This was my first clue.

My second clue came through a process called teleconnectoins. Meteorologists use teleconnections in order to "anticipate" what may come down the road for a specific location but is used in the most general sense. The basics of this is this: what is occurring in the western Pacific (off coast of China/Japan) will occur on the U.S. east coast roughly 6-10 days later. Nothing is specific, it just assumes general trough/ridge patterns. Teleconnections can help forecast the track of a storm brewing in the Atlantic. When Katia formed, I took a look at what was occurring in the western Pacific. A trough was located just off the coast of Japan. So I inferred that this trough would generally move eastward and ultimately pull Katia out to sea when she wanders towards the U.S. coast!

I've been told it's better to go down on your own forecast than someone else's. So I decided to own my gut instinct and say what I thought; Katia will miss the U.S. and re-curve out to sea. I'm more than happy to live and die by my own forecast. That was a valuable advice given to me by one of my teachers whom I greatly respect.

Looking ahead, we have a new tropical disturbance developing in the east Pacific. Invest-95 has a high probability of becoming a tropical cyclone. Let's compare the track of Katia to that of Invest-95. 

Invest-95 has formed a little south of Katia's track, and is forecasted to track a bit north of Irene's path. Lots of time however for Invest-95 to change, so I'm not making a call on this yet.





Monday, August 22, 2011

Hello, Irene

Here we go! Hurricane Irene has taken shape and developed into a category one hurricane. Irene has already pounded Puerto Rico with strong winds and heavy rains that have left some 800,000 people without power.

At its current location, Hurricane Irene is traversing the most hostile location for a storm. The islands of Puerto Rico, Haiti, Dominican Republic and Cuba are all road-blocks for any tropical system that passes them. Their mountainous terrains threaten to rip apart the structure of any well developed storm. Just a month or so ago, Tropical Storm Emily found this out. Emily wandered into Hispaniola and was all but destroyed by Haiti and the Dominican Republic.

However, with Irene, we have a different and more dangerous situation playing out. Irene has taken a more northerly track as a tropical storm. It has just brushed Puerto Rico and during that time strengthened from a Tropical Storm into a Hurricane. What stands in Irenes' way now? Below, current National Weather Service track has it moving northwesterly, its next stop in the Bahamas.

Current models back the NWS forecast. A big blocking ridge over the central U.S. will prevent Irene from moving west in the Gulf of Mexico. A trough over the mid-Atlantic will allow Irene to cut a path along that trough and "feel" its way into making a South Carolina landfall.

This forecast track will keep Irene away from those big islands in the Caribbean and allow the hurricane to move over very warm waters. The warm waters act like fuel to the storm and will allow it to develop and intensify. In fact, the NWS is currently showing Irene making landfall as a major hurricane (in order for a storm to be classified as a "major hurricane", wind speeds must reach 110mph or greater).

A lot can happen between now and Irenes' landfall, which is sometime Saturday morning. Models are changing hourly for this storm so it will be important to keep an eye on the changing conditions. But for the first time since 2009, the United States is looking at our first serious hurricane landfall!

Monday, August 1, 2011

Emily Taking Shape in the Atlantic?

It is a long ways out (meteorologically speaking) but a great tropical system is about to take shape in the tropical Atlantic. Long range models are showing a well-developed center of low pressure forming and making landfall on the southern tip of the Florida panhandle. This storm, should it become a tropical depression/storm/hurricane will be the 5th such storm this season. Storms are named once they reach a Tropical Depression status with a distinctive closed circulation. Should this disturbance reach that stage and from all indications it will, Emily will be its name!

What kind of shot does Emily have of actually making a U.S. landfall? Let's take a look.

Here is a look at the precipitation forecast from today that is valid for this Thursday. Notice the high precipitation forecast down in the Caribbean near the Dominican Republic. By this point, Emily should be at the least a Tropical Storm. The wild card to development is whether or not the storm makes landfall on Hispaniola. If it does, Emily could be torn apart by the friction of the land. But hurricanes don't like to be on land, so sometimes a storm will shift its path to avoid land and actually just skirts right around it. If that happens, the storm will have more chances to intensify in the warm waters.
This forecast is valid for Saturday morning. Clearly the model is showing Emily making landfall in southern Florida. But is there a shot that Emily misses the Unites States entirely and just swings out to the open Atlantic? Of course, but the "steering mechanism" reinforces a U.S. landfall.
The 500mb map shows us "roughly" where systems will go. Two things to note in this map, valid for Friday. One: The high pressure over the a bulk of the South. Circulation around the high pressure is in a clockwise patter. You can visualize air moving around the central area of high pressure. Winds will "pull" Emily onshore, giving us the landfall the models have shown above.
The second point is the ridge of high pressure that is building up in the New England area. This is critical to storm intensification. Higher pressures to the north means lower pressures to the south and that helps deepen the low that enters the Caribbean/Gulf of Mexico region. These two points back up the prediction of Emily making an intense landfall.

But just a few days later, things appear to change. This map is valid for next Monday, a week out. The high pressure region over the South has disappeared, due to Emily interacting at close range with the high pressure area. Along with the weakening high pressure, a trough just off the N.E. Atlantic coast has developed. Notice the wind barbs are showing a westerly flow. Emily will "feel" this trough and hitch a ride with it. Eventually, Emily will be pulled out to the Atlantic.
The precipitation map valid for next Monday does show Emily moving back over Atlantic waters and a rapid weakening of the storm will continue. The evolution of Emily will depend on several things, most of which I have mentioned. Land and intensification play roles, but so does storm speed (fast or slow moving) and water temperature. Nearly 7 days out however, Emily may become the first named storm in nearly 2 years to make landfall in the United States!

Friday, July 15, 2011

No End In Sight

The Pacific Northwest continues to be mired in a Spring-like run of weather in the middle of Summer. Today marks the first day that average temperatures should reach 80 degrees, yet we are currently in a stretch of 8 consecutive days below 80 degrees. And then comes even worse news: there isn't an end on the horizon. Let's see why:


Above is our trusty 500mb chart. This is a set up known as the "Omega Block" because the graph resembles the Greek letter Omega. It is caused by a large ridge of high pressure over the Central U.S. and troughs on either side of the ridge. Under a ridge this big, hot air is sinking to the ground, resulting in scorching temperatures that have brought several days of triple digits. All we are stuck with is cool, gray conditions and some rain this week. That huge ridge blocks systems that typically track north into Canada but are now forced down into our backyard. This Omega Block has been set up for the better part of a week now and things aren't changing a whole lot.
This map is an anomaly chart that shows the average 500 mb lines from multiple model runs with different starting parameters. It basically gives us a an idea of where ridges and troughs will be 8-14 days in the future. Notice the big ridge over the Central U.S. has subsided a bit but the general trough in the NW/ridge in the East pattern still exists. That's not a welcoming sign for a return to Summer!
Here is a temperature probability map that correlates with the 500mb map 8-14 days out. I think this is pretty self-explanatory. Blues mean below average, red above. Yadda yadda yadda. Summer appears to be on hold until further notice. Maybe it's time to take a vacation...

Wednesday, July 6, 2011

Arizona Duststorm

A huge and rare weather phenomena occurred this week in Phoenix, Arizona. The storm has an odd name too, one that we LOVE to say around the station here. The event is known as a "haboob". The haboob originates from Arabic and is common in arid regions of the world like Saudi Arabia and the Sahara desert. The giant cloud of dust is rather impressive and can cause near-black out conditions with zero visibility. Check out this video time-lapse on Scott Wood's photography page:
http://www.scottwoodphotography.com/Weather/2011StormChasing/15913598_nN77g#1370278891_RDCLM67

Really incredible! But how exactly do these "haboobs" develop? The geography of the Phoenix area is set up just right for these events. During the summer seasons, a monsoon develops. People often mistake monsoon with a very intense period of heavy rainfall. In fact, the monsoon is a seasonal reversal of wind patterns. The heavy rainfall is just a result. In Arizona, the Summer monsoon winds come off the moist Gulf of California from the Southwest and push up against the Colorado Plateau, to the Northeast of Phoenix. As this moist, gulf air is forced to rise up the plateau, thunderstorms are generated over the top of the dusty plateau. These thunderstorms can be very intense and produce lots of rainfall in a short period of time. That rainfall eventually cools the center of the thunderstorm and forces cold air to rush out of the bottom of the storm, known as a downdraft. This downdraft, which acts like a mini-cold front, picks up all that dust and sand on top of the plateau and forces it down towards the Phoenix area! Thus, a resulting haboob. Here is an image of the setup for the haboob:
Following the dust storm, Phoenix was rocked with a pretty good thunderstorm. Those storms were sparked from the continued moist SW flow colliding with the rain-cooled downdraft air rushing out of the older thunderstorms over the plateau. They converge right over Phoenix and huge thunderstorms result! Again, this all results from the Summer monsoon in the Southwest! Monsoons occur all over the world, the most famous being the South Asian monsoon in India and Myanmar. Summer monsoons are critical in delivering rain for the growing seasons in that part of the world. Winter monsoons exist as well in South Asia. High pressure over the Tibetan Plateau keeps things cold and dry. All over the world, the monsoon creates unique and wild weather!

Tuesday, June 28, 2011

Summer BEFORE July 4th?

Summer officially started June 21st. But here in the Pacific Northwest, residents often live by the creed, "Summer actually starts on the 5th of July". It has been a decent start to the Summer here in Portland. A 80 degree day here or there. But even better news is showing up on the weather maps! Let's take a look.

Our first bit of evidence is the 500mb map. This is halfway up the atmosphere and shows us overall ridge (good) and trough (bad) patterns.

Here is the 500mb map valid last night for July 4th around 11 a.m. Look at the ridge that covers most of the West and extends all the way into northern Canada! This is a great set up for a nice stretch of warm, sunny conditions! Other maps re-enforce this fact.

The map above is our 850mb map. We use this map to locate areas of warm air and areas of cold air. We can track their movement with this map. The red contours on the map are isotherms, lines of constant temperature, in degrees Celsius. Temperatures at the 850mb level loosely translate to specific temperatures at the surface. This map, again valid last night (June 27th) shows the conditions for late morning on the 4th. The 15-degree isotherm is just to our east. If we estimate the 850 temp to be about 14 degrees Celsius above Portland, that would translate to an 80-degree day! Plenty of time for it to change, one way or another, but the warm temperature fits the above 500mb map we looked at!
Here is your surface map for the Fourth of July! Looks awesome! Precipitation is nowhere to be seen. Also not the high pressure system out off the southern Oregon coast. That helps send any sort of wet systems well to our north! Any time we see surface pressure around 1020, that means good things. The 1020 isobar (lines of constant pressure) is right in our neighborhood. Average surface pressure is right around 1013. The higher the pressure, the better the conditions!

We have concluded our investigative work! Weather forecasting works like an investigation. Start with one map, and try to find validations on all the others. In our 4th of July case, things are lining up in a good way! Maybe this year, Summer in the NW starts early!

Friday, June 17, 2011

Waiting For Arlene

Many of you may not know who Arlene is. That's ok, she was overshadowed by some of her more famous sisters. She last showed up in June of 2005. She came to the Southern U.S. from Honduras and killed a person. She was the first of her kind that year, many others followed and did far worse things.

Of course I am talking about Tropical Storm Arlene. She made landfall about 6 years ago to the date. For a tropical storm, she was a large one. Just missing hurricane status. But she ushered in one of the most active and historic hurricane seasons on record! Her more famous sisters are known as Hurricane Katrina and Hurricane Rita. There were 26 named storms in 2005, so many that we ran out of names and had to use names from the Greek alphabet for the remaining storms.

2011 tropical season is underway, it began June 1st. So far, the Atlantic basin has been quiet. But forecasters have warned that it will not remain that way as the season progresses. The Climate Prediction Center says the Atlantic will see 12-18 named storms, 6-10 of which may reach hurricane status (sustained winds over 1 minuet that measure at least 74 m.p.h). Of the named storms, the CPD says that 3 to 6 of them may become major hurricanes (Cat. 3 or higher, winds at least 111 m.p.h.). This would equate to what is referred to as a "hyper-active" hurricane season. 2005 definitely qualifies as a hyper-active season, and we just endured one last year. 2010 was an active, yet rare year. 19 named storms in the Atlantic and NOT ONE of those storms made landfall in the U.S. This is very rare.

Your probably asking yourself, "How can they forecast an entire hurricane season when they can't even predict the weather 36 hours out?!". There are signs but before I talk about those that are scientific, I want to just brush over a little research I did.

The U.S. has had a wild Spring. A record amount of tornadoes and severe weather in general across much of the country has us praying for that Summer weather to give us a break. I decided to look at past Springs and the amount of severe weather and compare it to the following Hurricane Season.

Last year, we had 1,543 reported tornadoes. As I mentioned above, 2010 had 19 named storms but none made landfall. 2009 had 1,305 tornadoes and nine named storms (1 landfall). 1,685 tornadoes were reported in 2008 and we had 16 named tropical storms that Summer (3 landfalls). 1,102 tornadoes and 15 named storms (1 landfall) in 2007. 1,117 tornadoes and nine named storms for 2006. Our active hurricane season in 2005 (26 named, five landfalls!) only had 1,262 tornado reports. Finally, 1,820 tornadoes were reported in 2004 with 15 named storms (three landfalls). Breaking down the stats, it is somewhat difficult to draw correlations between active Springs and Summers. So far this year, there have been 1,482 preliminary tornado reports. Those haven't been all confirmed yet. But still a high number. What will that translate into for this Summer?

Let's talk about trends that DO correlate to an active tropical season. We will begin with sea water temperatures. Warm water is "fuel" to a hurricane so the warmer the water, the better a chance to get storms to fire up and strengthen. The Atlantic waters are impacted by what happens off of our coast here in the Pacific. Our cool Spring can be credited to the cool, La Nina conditions. The La Nina typically gives us cooler than normal ocean waters here in the Pacific. The main goal of the ocean is to balance itself out. If we have a cold Pacific, the oceans will make up for it by having a warm Atlantic. Warm waters in the Atlantic means a good amount of "fuel" for storms this Summer!

Warm surface waters mean provide the atmosphere with a lot of uplift. When the sun strikes the warm waters and warms the air around it, that air will begin to lift. And guess what lift means for storms? You got it! Rising motions in the atmosphere help aid hurricanes and all storms for that matter! Now we have warm waters in the Atlantic and that means plenty of uplift for our storms.

Here is a map of 2010 and the storm tracks of those 19 storms that Summer.
Note how many made their way into the Gulf of Mexico. As only one storm tracked into the Gulf, that could mean a lot of untapped energy will remain for this hurricane season. As a tropical storm or hurricane makes its way through the warm Gulf, it feeds off the warm waters. When that warm surface waters get used up, the ocean pulls up cooler water from below to replace that warm water. The more storms that track through the Gulf, the less fuel for the next storms to use. With only one storm moving through that area last year, that could mean plenty of leftover energy just waiting to be used this year!

So there are the "proven", scientific reasons as to why we could see a very active, fun but dangerous 2011 Atlantic Hurricane Season.

Friday, June 3, 2011

Portland's Spring Weather: In Pictures

One of my favorite parts about my job are the viewer emails that we receive on a daily basis. Most emails are VERY opinionated stances on stories or programming (one of my personal favorites being a complaint about the station not airing a classic Perry Mason re-run. You know, the one where Perry wins the case?). Those emails are a story for another day. But during crazy weather times, which we have had plenty so far this year, we do receive some very cool photos! I thought I would share a few of them with you all.

This first photo was taken earlier this Spring. These are some of the most unique cloud forms, it's easy to see why! Sometimes referred to as flying saucers or "the mothership", the scientific name for these clouds is "lenticular clouds". They form over hills or mountains as moisture in the atmosphere is forced to rise over the geographical barrier and forms a cloud. The size of the cloud is normally determined by the jet stream above, causing shear to the cloud, or tearing of the cloud. In the above photo, you can see the jet stream is pushing the cloud from the left side of the photo to the right. Look at the top right-hand side of the cloud. You can see the tops of the cloud being pushed down-wind (to the right). These clouds will appear stationary, giving it that hovering, "mothership" look. In fact, the cloud is repeatedly fed moisture from the air and just re-generates a new cloud. As the air moves down the back side of the hill or mountain, the moisture in the air evaporates, thus no cloud! If you look towards Mt. Hood on a clear day, you can often see a "cap" over the top of the mountain. The cool thing about lenticular clouds is that they don't generate any precipitation and are typically a sign of fair conditions!

Our next photo depicts a visually stunning but dangerous cloud!
This photo was sent in from Woodburn. But it looks very similar to a cloud that people in the South and Midwest have seen lately. I am fairly certain that this is a cloud known as a "wall cloud". The reason why I am not 100% sure is that in order to confirm it, there would have to be rotation. But judging from the photo, I feel confident that this is a rare wall cloud in Oregon! Why is this cloud rare in Oregon? Because we only average 2 tornadoes a year! This low-hanging cloud formation is often a significant indicator of a tornado. This storm setup has a large amount of air at the surface being sucked into the storm. Imagine air from the left side of the photo being sucked into the central portion of the storm. As the air gets sucked into the storm, it quickly cools and condenses into a cloud that forms at a lower elevation. Research has shown that the lower the level of the wall cloud, the more likely a tornado is to spawn. All that being said, this storm did not tornado. The environment has to be just right and most times the ingredients just aren't there for the development of tornadoes. But if you notice this low-hanging cloud in the future...probably best to take cover, just to be safe!

The final picture I have today could be considered a cloud "relative" of the wall cloud.
What we are looking at are the low-hanging clouds at the base of the ominous dark cloud. The clouds appear right above the rooftops of the buildings in Vancouver. While very similar to a wall cloud, these clouds known as "scud" are actually smaller, often rugged individual clouds. Scud clouds form when moist, cool air falls out of the storm, this is known as the outflow. The outflow forces the warmer air around the outside of the storm to rise. As the warmer air rises, it cools and forms a cloud. So these Scud clouds are indicators of a cool outflow from the storm!
It is easier to make out the individual clouds in this photo. They just kind of linger around the base of the storm. Because they hang around the base of the storm, they often times get confused as wall clouds. This is not the case as Scud clouds do not spawn tornadoes.

There was a brief look at what has been happening around Portland this spring. The wall and scud clouds are very rare for Oregon and the NW as a whole but do occur. Lenticular clouds, on the other hand, are quite common for us. The Cascade mountain range offers us plenty of opportunities for lenticular development on top of all those mountains!

Wednesday, May 11, 2011

The Rainshadow

This LandSat image is of the northern end of the big island of Hawaii. LandSat images are an awesome way for meteorologists to analyze the impacts of weather. So what is so cool about this picture? Take a look at the vegetation differences from the northeast side of the island to the west end. A stark difference between lush greens and drought-like conditions. What causes this phenomena to occur so close together? It's known as the "Rainshadow" effect.
The Rainshadow is caused by two things: topography and prevailing winds. In this photo, the dominant winds are coming from the northeast and moving directly across to the west of the island. The prevailing winds encounter the land and it's topography. On Hawaii, winds meet the mountains of Mauna Kea to the south and Kohala to the north. The winds are forced to ride up and over the mountains. That process is called orographic lift.




As the prevailing winds are forced UP the mountain, that air will begin to cool. This side of the mountain is called the "windward" side. As the air rises and cools, it will condense and begin to form a cloud. We even see some clouds forming in the image. If and when the clouds cool enough, they will begin to dump rain as it continues to rise over the mountains. With all the rain that occurs on the windward side of the mountain, that provides ample water to keep the vegetation nice and green!
The prevailing wind is now on its way down the back side of the mountains, or the "leeward" side. Here, the opposite of the "windward" process takes place. As air sinks, it warms up. The air running down the leeward side of the mountain has thus lost all of its precipitation and is beginning to warm up, resulting in drier conditions. This process explains why it is so dry on the back side of the mountains! Sometimes, this whole process can lead to severe droughts near and behind mountainous terrains.

The Rainshadow phenomena occurs all over the world, including right here in Oregon! Our dominant wind pattern is from the west off the Pacific and to the east. Add the coastal mountain range and the larger Cascade range and presto, we have a rainshadow!
The dominant rainshadow is in Central Oregon. This is what gives places like Bend such a desert-like climate. The rainshadow isn't as dominant between the coastal range and the Cascades, but it is evident when you look at rain totals around the metro area. In large rain events, higher rain totals normally are expected EAST of the Portland-metro area into the foothills of the Cascades because that air is beginning to ride up the Cascades.

Wednesday, May 4, 2011

The Super Outbreak Aftermath

The dust is settling from the late April tornado super-outbreak. It will go down as one of the worst outbreaks in U.S. history. In fact, the April 27-28th outbreak will set the bar for most tornadoes in a single outbreak. As National Weather Service offices across Mississippi, Alabama and Georgia conduct damage surveys of the deadly super-outbreak, official numbers are still coming in. Initial raw data from the two days reported some 269 tornadoes alone. After the NWS surveys, the official number of tornadoes that actually occurred reached 153. That tops a 37-year old record of 148 tornadoes in April of 1974. Deaths from this outbreak have reached a staggering 340 and we are lucky that, given the severity of the storms, it was only that much. The most deadly tornado outbreak came from the infamous 1925 Tri-State outbreak that ravaged Missouri, Illinois and Indiana and left 695 dead.

NOAA complied satellite images into a movie that tracts the outbreak. The video is awesome.


NWS Offices have distributed some great information in regards to several of the hardest hit areas. As of May 3rd, there have been two EF-5 tornadoes reported from April's super-outbreak. As I detailed in my last entry, the EF scale is not based on wind speeds like the Saffir-Simpson scale used to determine hurricane category strength. Rather, the tornadoes receive their ratings after the storm is over and is based on how much the tornado "eats" or destroys. One of those EF-5 tornadoes ripped through Northern Alabama and hit the town of Hackleburg. The NWS put wind speeds of that tornado at around 200 miles per hour. By comparison, for a hurricane to reach its strongest category strength of Cat-5, its wind speeds only need to be 156 miles per hour. So this tornado is doing some SERIOUS damage. At least 25 fatalities were reported from the Hackleburg EF-5 and surveys put the damage path 25.5 miles long and 3/4 mile wide! The EF-5 monster was on the ground for only 23 minuets but managed to toss cars 150-200 yards into the air!

A more deadly EF-4 tornado hit Tuscaloosa, Alabama and stretched Northeastward into Birmingham. I was watching The Weather Channel as this monster moved through Birmingham and the images were awesome from a weather standpoint, horrific from a human standpoint. NWS reports have this EF-4 with winds up to 190 miles per hour. The death toll reached 65 from this one tornado, making it the deadliest single tornado since May of 1955 when 80 people were killed in Kansas. The Tuscaloosa tornado traveled about 80 miles in close to an hour and a half. It was believed to have a damage width of 1.5 miles! The storm that spawned this tornado began in Mississippi and was sustained all the way to North Carolina. The tornado itself did not last that long but the storm that spawned it dropped several different twisters.

Take a look at some imagery from these two tornadoes. This Google map shows the path's of all tornadoes confirmed so far by the NWS across the Gulf coast states. The pink trail in Northern Alabama is the EF-5 and it also gives a good idea of how far the Tuscaloosa tornado traveled. It is rare that a tornado is sustained for an hour and a half. Most tornadoes have a life span on the matter of a few minuets so this was one powerful twister.
Landsat images are helpful in locating tornado tracks. NASA released this image of the damage path left by the Tuscaloosa tornado. Note the other tracks from different tornadoes on the image as well.

The Super-outbreak also tormented Georgia. The NWS in Peachtree City, GA put out great information regarding the outbreak in their state. One EF-4 and four EF-3 tornadoes were reported by the NWS office.

The Catoosa County EF-4 tornado touched down just after 8 p.m. on the 27th and ultimately had a damage path 13 miles long and 1/3 wide. Here is an image of the track and intensity.

And another image of the damage path taken by the surveyors:
Seven deaths and more than three times as many injuries resulted from the Catoosa twister.

Another tornado, this one an EF-3 rating, hit Bartow, Cherokee and Picknes counties. The tornado touched down just before 9:30 p.m. and had winds that topped out at 150 miles per hour. No deaths were reported and only 3 injuries. Check out the 23 mile-long path of this storm:

A huge tool in the fight to forecast tornadoes is radar. We use reflectivity to determine where precipitation is falling and how heavy it is. Tornadoes have specific characteristics that show up on radar, the most dominant being what is called a "hook echo". Here is the radar image of the B-C-P tornado:
The intense reds, whites and some pink show the heaviest areas of rain. Note how the radar image has a "hook" to it in Northeast Bartow county. That is a textbook "hook echo" and is a sign that the environment may be tornadic because the winds are wrapping the rain around a center of rotation in a counterclockwise direction.

Also detectable on this radar image is a "V-notch". Note how the precipitation out in front of the hook echo takes on a V-like formation. This indicates strong upper-level winds that are running into the storm's updraft from the surface. The westerly winds hit this updraft and must move around it, thus fanning out precipitation to either side of the storm and creating a V-like echo on radar. Strong upper level winds are critical for tornado development.

Another product that meteorologists use on radar is called "storm relative velocity". It basically shows where winds are moving towards and away from a radar site. It allows us to see inside the storm and indicate areas were winds may be moving in opposite directions right next to each other, giving us a strong indication of rotation. On the image below from the same EF-3 event, areas of red are winds moving away from the radar site and areas of green are winds moving towards the radar site:
Notice the areas of green smack in the middle of all the red. That is a textbook indication that there is rotation in the area, possibly leading to a tornado. In this case, an EF-3 tornado resulted.

So those are some tools that can be used to identify severe weather. The creation of radar has increased severe weather safety over the years and has helped in the further understanding of how tornadoes work. All the above information has been provided by various National Weather Service offices including the photos. The statistics are staggering yet, it could have been so much worse if not for inventions such as radar and warning systems. This definitely puts April's Super-outbreak into perspective and displays the awesome power of Mother Nature.



Wednesday, April 27, 2011

Severe Weather

We here in the Pacific Northwest are moaning and groaning about below average temperatures and wet weather. Meanwhile, the Midwest, Southeast and Ohio Valley are being pounded with round after round of severe weather. It is just one wave after another of tornadoes, hail and damaging winds for these states. By the way, many of these states endured record snowfall totals during this past winter. Breaks in the weather have come at days at a time, but no real relief has been offered since the beginning of April. The numbers from the Storm Prediction Center really tell it all.

Here are preliminary tornado reports over the last 5 days. Keep in mind these are preliminary, and will take a while to officially be confirmed:Tuesday, April 26: 54 tornado reports Monday, 25: 44- one tornado may receive a EF-5 rating in Arkansas. Sunday, 24: 13 Saturday, 23: 9 Friday, 22: 28
That is an ugly stretch of storms. They were spread out across all of the Midwest and South. But that stretch of 5 days does not compare to reports a few days earlier. On April 19th, the SPC had
77 reports of tornadoes mainly in Missouri, Indiana, Illinois and Ohio. That was the third-highest total for the month so far. A few days earlier on the 16th, 139 unconfirmed tornado reports across North Carolina and Virginia. And the most reports of tornadoes for April came on the 15th when 146 reports came in from Mississippi and Alabama. In all, 654 reports have been made for the month of April, according to the Storm Prediction Center. Again, they are preliminary and it is possible that not all will be confirmed as tornadoes.Take a look at this map that shows the distribution of tornadoes so far this year (notice one in Oregon! It received an EF-0 rating). Often times, severe wind damage can be confused as tornado damage. It is the job of the NWS to analyze storm damage in person. This process is what gives us tornado ratings. Often people think that the Enhanced Fujita ranking system is based upon wind speeds when it actually is based upon damage.
How does this April's reports compare Aprils' past? In 2009, 226 tornadoes were confirmed. The 3 year average for April is 185 tornadoes. So, should all 654 reports be confirmed, that would be more than twice the 3-year average for the month of April! Incredible.
What's even more incredible is that the peak tornado season hasn't even started yet! That
distinction belongs to May with a 3-year average of 322 tornado reports. May also holds the all-time record for tornado reports of 543 in 2003.
What is the possibility of all 654 April reports this year being confirmed? Given the large number of reports, it would be hard to imagine that all of them were tornadoes. But all we have to do is look at January 2011 for evidence to the contrary. There were 10 preliminary reports of tornadoes this January. The actual report of tornadoes by NOAA was 16 (that also stands as the total number of official tornadoes so far this year, but February doesn't have official totals yet). So it is possible that these reports will be confirmed.
Along with severe weather comes loss of life. Over the decades of weather reporting and forecasting, deaths resulting from severe weather has improved greatly. More information at the fingertips of forecasters means improved warning systems. But the shear amount of storms this Spring season is starting to take its toll. April 2011 has 43 confirmed deaths from tornadoes. The 3-year average is only 6.
So WHY is all this happening? Let's take a look at the charts and find some similarities between April 15, 16, and 19.
Here are the charts for the 15th around 5 a.m.

The maps we want to analyze are the two upper maps. The one on the left is the 850mb map. Look towards the Gulf Coast. Notice how warm, moist air is pouring in off the gulf into Louisiana and Mississippi indicated by the warmer colors. That causes instability and uplift in the atmosphere. The map to the right is the 300mb map. This shows the position of the jet stream. A strong, westerly stream is preferred for severe weather. That is exactly what we have. Lots of warm air, plus strong westerly jet is a great recipe for storms. Watch this as it moves east on the 16th. Here is the setup for April 16th around 5 a.m.

Now all the action has swung to the east. Cold stable air is now pouring into Louisiana and Mississippi a day after the severe storms and the warm moist air is now being forced up the eastern Atlantic. This was an interesting situation where the warm Gulf moisture was being sucked up and mixed in with the warm Atlantic moisture off the east coast. The warm air, plus a strong jet stream on the 300mb map that is evident over the Carolinas spawned a tornado outbreak of record proportions in North Carolina. It definitely helped that the storms really were initiated the day before over the south and continued as they migrated towards the east. But another thing that aided these storms the Appalachian Mountains. As air descends down the mountains, it is forced to stretch. Imagine an ice skater that is spinning. As the skater pulls their arms in, they spin faster and faster. This is conservation of momentum. That is what the air is doing as it travels down the back side of the Appalachians. The air is warming, compressing and spins a bit faster in order to conserve energy. A perfect setup for tornadoes. A few days later, it was the Ohio Valley's turn.
Here is the setup for April 19th
Overall, this setup isn't much different than the initial outbreak on the 15th. There is a tighter low over the central part of the country again that is pulling the warm air from the south. The broad cool air stretches east-west along Ohio, Indiana, Illinois. That is our target. A strong jet stream just to the north of those states helps enhance the storms. The main factor though is the tight gradient between the warm and cold air. In the lower left hand map, you see surface pressure plotted. The main feature is that low. The bulge in the isobars protruding eastward is the warm front. It shows up nicely on the 850mb map as well, huh? This system resulted in those 77 tornado reports!
So knowing that April could set a record for confirmed tornadoes, what does that mean for May when historically we see the most tornadoes? We don't know. The broad scale weather pattern is always changing. We can only see 3-5 days out in regards to issuing credible severe weather threats. So in that sense, there is no use in forecasting out any further. In my eyes, it is smart to only look ahead one day at a time. As of today, looking ahead shows a slight break for tomorrow. A break which will be much needed for many as clean up efforts have been hampered by more storms. The actual number of tornadoes will take a while to be confirmed but given what is going on, take solace in the rain and mid-50's.

****UPDATE****
Yesterday's storms that ripped through the South added to what will no doubt become a historic and infamous April. Various reports have the death toll reaching 194 as of 6 a.m. this morning. No doubt that number will rise as the clean up effort begins in earnest this morning. I would assume that there would be potential for an EF-4 or even EF-5 rating out of this outbreak given the reports and videos.
There have been 162 reports of tornadoes from yesterday, making it the most so far this year. As I mentioned yesterday, most likely not all will be confirmed as tornadoes and some reports may even be of the same tornado. While watching coverage yesterday, news stations in Birmingham, Alabama caught a twister that may have been on the ground for 45 minuets! It is tough to put this event into words, so I'll let the pictures do the talking.

Tornado caught in Tuscaloosa, Alabama- one of the hardest hit areas- via Crimson Tide Productions:

4-27-11 Tornado Tuscaloosa, Al from Crimson Tide Productions on Vimeo.



A days worth of action caught by the guys from TornadoVideosdotnet-


Photo snapped by a reporter for WBRC as people take shelter in Cullman, AL
http://twitpic.com/4q93rs

Another video from Tuscaloosa. Not sure who to give credit to, but it isn't me...


An image from Twitter of the damage from Tuscaloosa, completely demolished- via @danamlewis
http://www.twitpic.com/4qaxnn

This monster skirts just past Bryant-Denny Stadium, home of the Crimson Tide-via Clay Hasenfuss

Tuscaloosa Tornado (4/26/2011) by sportsxbrooks