Major Cold

The winds have subsided now as the strong low has moved east. There are a lot of lessons regarding that low and intense winds it produced...not the least, it being a good example of the difficulty of forecasting rapidly developing systems over the oceans. On one hand, the computer models were extraordinary...predicting the rapid development of an intense low from nothing, days in advance. The problem was the track...and keep in mind that we were only talking about a 100 mile error of the models a day before. Meteorologists do better than economists...at least we saw it coming! The low brought max 40-60 mph gusts in the interior and some gusts to 80-90 mph on the coast. There was some light snow last night at higher interior elevations...but nothing serious. And a key issue is that the road surfaces are relatively warm since our air temps have been fairly warm. This protection will be gone in a few days.
The big...and serious story...now is the cold. We are about to go into the most significant cold spell in years, and you should prepare for it. Remove hoses from exterior pipes, wrap vulnerable pipes, leave water dripping in vulnerable areas..you know what I am talking about.
Today, we have some residual moisture from the storm, but will progressively dry during the day (see radar image). The air is fairly warm right now, with onshore flow from the ocean. The freezing level is about 2000 ft over Puget Sound, snow level about 1000 ft. Today the cold air will start to move in...and particularly tonight. We will get into the mid and upper 30s today, but tonight temps will drop in the 20s. Cool air will start to push into the Fraser RIver valley and strong outflow will begin..with NE winds moving SE over Bellingham, over the San Juans and then will hit the Olympics. This can produce upslope flow and snow on the NE side of the Olympics...so those near Sequim and Port Angeles should prepare for it. I have inserted a series of model output below showing sea level pressure and low level temps...you can see the cold pushing in. Note also that even colder air will be east of the Cascades...next week they will have HIGHS in the single digits and subzero minima. A large pressure difference will develop across the Cascades (due to the colder, denser air east of the crest)...and this will produce strong easterly winds in the Columbia Gorge. I love how everything happens at once in these intense weather periods.
What about snow in the lowlands? By later today the air will be cool enough for snow almost everywhere...but it will be generally dry..a disappointment for the kids. A disturbance from the north will increase the chances of clouds and precip (snow) tonight...BUT by that time there will be a strong easterly, downslope component off the Cascades. I suspect the result will be little, if any snow, east of the Sound and light snow (0-3 inches) on the western side and over the Olympic Peninsula.
Then we settle down to an extended cold period that could last a week. There is a possibility of light snow midweek...but lets wait to talk about that.

PS: Several has asked me about getting the book in times of the holidays....particularly since amazon and barnes.com are temp out. Several local bookstores have lots of books...including university book store...and several, like UBS, ship...just like amazon. A number of barnes and noble locations have books. 5000 more books were printed in the past week...and should be getting into the system by the end of next week. Anway, check my web page (click on book icon) to get more info on availablility issues.