Saturday, November 22, 2008

Showers and Sunbreaks




Today is classic postfrontal conditions around here. Showers and sunbreaks. Interestingly, this is completely different than the eastern part of the country...there when a front goes through temps fall, skies clear, and precipitation is over. The reason we have a lot of our showers after frontal passage? The Pacific Ocean. As cold air from Alaska and Asia passes over the relatively warm waters of the Pacific it destabilizes since there is a lot of temp change with elevation. Just like your hot cereal pot as you put it on the stove and the bottom warms.
Take a look at the latest visible satellite image...you see the white speckled area....that is the instability showers coming in. Those showers will be moving in today...and there will be showers...and snow showers in the mountains. We can catch a few of them as well...although there will be some rainshadowing from the Olympics. With westerly flow on the coast, we have had a weak Puget Sound convergence zone and that may rev up a bit later....so if you are in some steady rain showers in the seattle area...go north or south and you should be able to get out of it...

The surface data plot (see attached) shows weak winds over the region, with showers over the coast, NW Washington, and in the mountains.

Tomorrow is looking dry...everywhere in the region. And still no major weather next week....

1 comment:

Keeping one's head above water said...

it was interesting that north of chehalis it was black and gloomy and chehalis got just a few sprinkles.