Showing posts with label wind. Show all posts
Showing posts with label wind. Show all posts

Friday, October 26, 2012

Thoughts on Sandy

Doomsday scenarios have been playing out for a large portion of the eastern seaboard. There have even been comparisons to the 1991 Perfect Storm that struck New England. Sandy isn't a reprise of that Nor'easter. Sandy is her own storm, like each storm is. All models indicate that Sandy will still be a hurricane when she makes landfall sometime early next week. There is no "Frankenstorm" situation; not even sure what that means. Sandy will be Sandy. Let's break down Sandy and her impacts.

 Sandy has a few things going for her right now. Her current path will take her right along the coastline.

All models bring her right up the coast. She would parallel the coast if it wasn't for factor number 2, the approaching cold front.

 This cold front will aid in bringing Sandy inland. The front will essentially scoop up Sandy and swing her inland.

 There was suspicion as to what the storm will be like at landfall. Will it be a hurricane? Tropical storm? Nor'easter? The high pressure set up to the north of Sandy will help deepen the low pressure at the center of Sandy and the forecast reflects that strengthening. Look for Sandy to make landfall as a category one hurricane.

Now timing and location becomes the next challenge. Guidance is indicating a landfall sometime between Monday A.M. and Tuesday P.M. She may strike anywhere from Delaware to Long Island. The closer we get landfall, the better idea we will have. Either way, the entire east coast needs to take action NOW to avoid disaster LATER.

Potential impacts could cripple a large portion of the east coast as well. With the cold front sweeping through, significant snow accumulations could fall as cold air filters in behind the front. There is plenty of moisture with Sandy, so 6-8 inches of rain as Sandy skirts the Carolinas is not out of the question. Added water from the storm surge may cause devastating flooding for certain places. Storm surge is enhanced by storm winds.


This is a model's forecast for landfall and the impressive wind field associated with Sandy. This is from the European model which has been the most consistent in forecasting landfall. But what is impressive here is the winds. The closer the lines are together, the stronger the winds are. Look how far out the wind field extends! Tropical storm winds may be seen all the way out in Ohio! I like this situation to verify.

A lot is yet to play out. As a forecaster I am anticipating this storm. It could be historic but it will be a deadly one. 

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!