Here is a plot of the temperatures at Sea-Tac Airport for the past 12 weeks, with the normal high (red) and low (blue) temperatures shown.
The freezing level dropped below 3000 feet today and the snow level dipped to around 1500 feet for a short time. Imagine that. Paradise, on Mount Rainier, received over half a foot before it warmed a bit. Here is a shot there near sunset today.
The NW Avalanche Center even has a high avalanche danger out for tomorrow. First one this year?
The NW Avalanche folks have had plenty of time to repair instruments and complete advanced training this year.
And take a look at the 500 hPa weather map for this morning. A trough of low pressure over our region. Haven't seen that in a while.
But don't worry, the ridge from hell (actually from the tropics) is coming back with a vengeance.
A strong WARM front is right offshore and will move in tonight. To illustrate this, here is the forecast for 11 PM tonight of sea level pressure (solid lines), surface winds, and low-level temperatures. Look along the coast. You see the shift from SE to SW winds, a kink in the pressure lines, and a transition from cold (green) to warmer (yellow) temperatures...that is the warm front.
It seems a normal spring pattern, but the current avalanche hazard is actually an indication of abnormality, by two things.
ReplyDelete1) the drought and high FL generated widespread surface crusts that has prevailed most of the season.
2) another bout of unseasonably high FL for the forecast. High even under the prevailing zonalflow and higher yet with the upcoming SW flow.
The CB's and spring showers are typical but the warmth is not, no matter which sector it comes from. If you ask me anyway. Your thoughts?
It's not the first 'High' danger rating this year from NWAC, but they sure have been rare.
ReplyDeleteJanuary 18, 2015: http://www.nwac.us/avalanche-forecast/avalanche-region-forecast/1085/
For several hours today there has been a very distinct rain shadow from Olympia to Tacoma. I don't recall this happening very often, especially when winds don't appear to be from the NW.
ReplyDeleteThank you for unabashedly referring to the perpetual-motion, heat-generating, winter-ruining dynamo by a rather accurate name: "The Ridge From Hell".
ReplyDeleteSomewhat related: Lee Grenci has an interesting post up about snowmelt due to rainfall, and how it doesn't happen quite the way most people think.
ReplyDeletehttp://www.wunderground.com/blog/24hourprof/comment.html?entrynum=108
-Douglas
Sorry slightly OT but I thought Cliff would be interested in new study supporting Cliff's evaluation of Jennifer Francis's research on Jet Stream wobble and colder winters.
ReplyDelete'Climate Change Is Not Causing Extreme Winters'
http://www.science20.com/news_articles/climate_change_is_not_causing_extreme_winters-154455?utm_source=twitterfeed&utm_medium=twitter
P.S. If Cliff is ever interested in submitting article to Science 2.0 contact Hank Campbell to discuss.