The Big Chill Will Strike the Northwest

If anyone thought that La Nina would sneak away with little notice, the latest model predictions should disabuse you of that opinion:  an extraordinary cold wave will occur next week, with several daily cold records destined to be broken.

But there is more:  huge additional snowfalls will occur over the mountains of the entire West Coast.

Let me start with the predictions at Seattle and Pasco, WA for the next week, based on the National Weather Service Blend of Models predictions.

There will be warming over the weekend into Monday, with a transition occurring on Tuesday as modified Arctic air pushes in. 

  The highs on Wednesday through Friday will be in the 30s, and the lows will be at freezing or below every night, bottoming out at 22F Friday morning.


For Pasco, even colder, with temperatures dropping into the low teens.

Now let me show you the maps of pressure and temperature (at around 2500 ft), which will give you a good feeling about how the Arctic is coming to us!  I have waited until now to provide this discussion--holding off until we are close enough in time to have some confidence in the forecast.

Let's start on Tuesday morning at 4 AM (purple and blue are the coldest temperatures).   Very cold air is poised to enter the NW...with the most frigid temperatures east of the Rockies. At this time, a cold front has just moved through western Washington.


By Wednesday morning, extremely cold air is moving southward east of the Rockies, with very cold air entering eastern Washington through the Okanagan drainage. Modified Arctic air is over the entire Northwest.  Frigid northeasterly winds will be pushing through the Fraser River Valley towards Bellingham.

Pretty much the same story for Thursday morning, but colder.  Life-threatening conditions in Montana.   Any Chinese balloons falling there at this time would be all iced up.


Even COLDER on Friday morning, but a front with warmer air is approaching!


What about snow?    The predicted snowfall total through 4 PM Monday is substantial (feet) in the central to northern Cascades, southern BC, and in the Rockies.


And as the cold air pushes southward, substantial snow will move into Oregon and California, particularly in high terrain. Great news for California's water supply this year.


At this point, there are no predicted major lowlands snowstorms, but a relatively modest change in the forecast could alter that.   We are plenty cold enough for snow... the moisture is missing!

The European Center is going for about an inch at SEATAC later next week, while the National Weather Service GFS model has about half a foot (but it is snow-crazy). 

In any case, the region should prepare for the cold.   Homeless folks need to be brought inside, pets should be kept indorros, and hoses should be disconnected from their faucets.  Get the thermal underwear out and stock up on hot chocolate and coffee.

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