Thursday, April 29, 2010

Spring Weather

On the heels of these past two days, I thought I would do a brief analysis of why we are seeing this type of sudden downpours-to-sunshine type weather. For starters, we know that in the Northern Hemisphere we are currently transitioning from winter to summer. This means that the dominating cooler air mass we had over the winter is slowly being replaced by the warmer summer air mass. The clash between the two air masses causes some pretty interesting weather (see: the past few days here in the NW, almost every spring in the Midwest and South).

To get a little more specific, here in Oregon we get a cool onshore flow from the coast that can sometimes gets mixed in with some warmer air that is being forced up from California due to a low that would be located off the Northern California coast. What that leaves us with are these spotty-type clouds which indicate cool, but unstable air. These spotty clouds allow for sun to shine through the clearer areas, and the sun heats the ground surface. As the warmth from the sun heats the ground, it causes the air at the ground to rise. This is called convection: heated air that is forced to rise because it becomes lighter than its surroundings. As that air is warmed and rises, it becomes condensed and clouds form--leading to rain and in our case, downpours. Just how unstable does the atmosphere become? Check out this model representation of yesterday around 5 p.m. This model represents CAPE or Convective Available Potential Energy and measures how unstable and volatile the atmosphere is. As far as CAPE goes, the values expressed are not that high, only in the 100-400 range. Areas in the Plains can see CAPE in the 2000-3000 range. But when mixed with that marine air, what we saw late yesterday afternoon was plenty to trigger some thunderstorms and heavy downpours with hail mixed in. In fact, at 4:50, our radar indicated at least 6 lightning strikes. So you may have noticed that by 7 p.m. last night the showers stopped and there was clearing and some sunshine out there. Why does that happen? We lose our heat source, the sun. With nothing to warm the air, the atmosphere cools. When it cools off, air sinks as it becomes dense and sinking air usually results in high pressure and fair weather. That is exactly what happened yesterday! Look for it to happen again today.

Tuesday, April 20, 2010


I just typed a bunch of random letters, it just so happened to spell the name of that Icelandic volcano that is erupting like a mother as we speak. The "islandmountainglacier volcano" has been spewing for a day shy of a week and it has been hampering travel plans worldwide. But what sort of impact is it having on a climatic scale?

Despite the wide spread impacts, this volcano is not really going to have a long-term impact on the climatologyy of the world. In the past, large eruptions have altered global temperatures by 1-2 degrees Celsius. While this is a pretty good sized eruption, its composition is not one that would alter global temperatures. Take a look at the picture to the left, you can see the grey stream of ash that is pointed like a fire hose to Europe. Many eruptions have Sulfur Dioxide comprised in them and the sulfur acts as a reflecting agent that sends incoming solar radiation from the sun back into space. Large scale eruptions (Vesuvius, St. Helens, Santorini, Etna) spew great amounts of this sulfur dioxide into the atmosphere. That tends to linger and gets dispersed by the global winds and results in the lowering of global temperatures. But Eyjafallajokull is not emitting that much dioxide, so scientists are not expecting any climatic impacts from this eruption. Clearly there will be smaller scale impacts but they will not linger as long as a world wide impact could.

One of those small scale repercussions are thunderstorms. The heat released by the volcano mixes with cold air as well as ice particles colliding cause electrical discharges that result in these awesome lightning displays. These are often refered to as "dirty thunderstorms".

Wednesday, April 14, 2010

Second Season Time!

The end of the Masters always signals the beginning of the Second Season. It is the best time of year, the NHL Playoffs are upon us. It's like the holidays with family, but this time you get to actually punch someone. Let's take a look at the big story lines of this year's playoffs before I get to predictions.

Starting in the East, the big story line is the Washington Capitals. They dominated the regular season with 121 points and the President's Trophy for best record in the NHL. If Ovie and the Caps have ever wanted to win a Cup, now is the year. Everything is in place, but can the goal tending keep pace with the offense? Jose Theodore has a bad history of flubbing it in the playoffs and the young Varlamov was strong last post season, but can he come in cold if needed? It wouldn't surprise me if Theodore and the Caps struggle early. Another thing to watch in the east is Buffalo and their injury roster. Thomas Vanek came back strong from injury in the final two games of the season, scoring 5 goals in three games. Key players Tim Connelly and Jochen Hecht did not play in Buffalo's final weeks worth of games but both have recently practiced. Buffalo will need them both if they want to contend past the opening round.

Way out west, plenty of surprises blessed the top 8. Detroit struggles early cost them a top three seed but they are still the most dangerous team I think in the west. Colorado turned it around after a league-worst finish last year so that is good for them. Phoenix nabbed their first playoff spot in 10 years amid turmoil of ownership. The biggest story is the San Jose Sharks. They have dominated the west for the last two seasons, yet they have failed to make it past the second round in the playoffs. "Jumbo Joe" Thornton is the leader of this team but always seems to flop in the playoffs. He, along with Russian goalie Evgeni Nabokov, will need to step up for the Sharks. Nabokov was picked apart by the Canadians in the Olympics and he can not afford to struggle on a big stage again. Prediction time:
1. San Jose vs. 8. Colorado
San Jose HAS to win a 1st round series eventually. Colorado faded toward the end. Sharks in 5.
2. Chicago vs. 7. Nashville
Blackhawks are loaded with young talent. Nashville is scrappy. Hawks win on home ice in 7.
3. Vancouver vs. 6. Los Angeles
Remember that guy who won a gold medal between the pipes. Luongo is too good. 'Nucks in 6.
4. Phoenix vs. 5. Detroit
The Red Wings are the scariest team in the playoffs. Phoenix is good but inexperienced. Experience wins out. Detroit in 6.
1. Washington vs. 8. Montreal
No brainer. Caps too talented and Montreal can't score. Caps in 5.
2. New Jersey vs. 7. Philadelphia
The Devils defense will win out over physical Philly. Devils in 6.
3. Buffalo vs. 6. Boston
Miller is America's boy. He wants to get a silver cup to match is medal. Buffalo in 6.
4. Pittsburgh vs. 5. Ottawa
Barry Melrose says if Ottawa wins, it proves God is a Canadian. But God isn't Canadian. Pens in 6.
1. San Jose vs. 5. Detroit
Uh oh. Red hot Detroit runs into San Jose. Wings steal one in San Jose and win the series in 6.
2. Chicago vs. 3. Vancouver
This series boils down to if the Hawks can stop Henrik Sedin and get the puck past Luongo. I see an upset here. 'Couve in 6.
1. Washington vs. 4. Pittsburgh
The match up every NHL fan wants to see. Sid the Kid versus The Great 8. Ovie and the Caps took all four games in the season series, and they take this one. Caps in 5.
2. New Jersey vs. 3. Buffalo
This is speed versus defense. Buffalo can slow it down if needed. Two outstanding goaltenders in this one. Buffalo has more firepower and pull it out in 7.
Conference Finals
3. Vancouver vs. 5. Detroit
Vancouver back with home ice is tough to beat. The offense will overwhelm Detroit who has to cool off at some point. Canucks will win in 7.
1. Washington vs. 3. Buffalo
Ovie never played Miller in the Olympics. It would have been an great game. Two high-octane offenses here, Caps outscore the Sabres. Caps in 6.
Stanley Cup Finals
Washington Capitals vs. Vancouver Canucks
An awesome final. These two teams are capable of winning the cup. Washington can put shots on net like no other team in the league. That will be key for the Caps if they want to win, the more shots at Luongo the more likely they find holes in his armor. Capitals will win Lord Stanley's Cup in 6 games and Ovechkin will be the Conn Smythe Trophy as the Finals MVP.

Thursday, April 8, 2010

Forecast FAIL!

For the first time in six months, I failed at my job. I completely botched yesterday's forecast.

Showing up to work and already having a general idea of what the day will bring is pretty standard for me. I walked into work yesterday morning anticipating a break from all the rain and wind and cold (you probably are in the same boat). I may have just relied on what I looked at the previous day, as Tuesday's model runs were showing some ridging (high pressure) settling in. I took that to the bank. Wednesday morning came, and things looked pretty much the same. That ridge in the 500mb chart (left), which is basically a map that shows where the greatest amount of energy half way in the atmosphere, was still there. But the forecast did not hold up. So what happened?

A large cloud shield was up near Vancouver Island yesterday morning, here is the snapshot of that. The sharp edge on the back side of the shield indicates the location of the jet stream, or the direction in which the storm SHOULD have gone. It looked as though it would push north, leaving us with pleasant weather. But as the day progressed, the clouds pushed eastward instead of north. The ridge that I was counting on had failed me and it was game over. Instead of the decent, dry weather, those clouds brought cooler and a bit more showery conditions.

It was really the first time I had been completely incorrect with a forecast. I have missed temps in the past, but never temps AND conditions. But hey, luckily I work in a field where you can still get paid to be wrong (but I don't support being wrong).