Christmas Eve/Christmas Day snow update

For those hoping for more snow by Christmas morning, we have good news for you.   Are you traveling on Christmas Eve?  When will the snow start?   And how much will it snow?  Let's get started!

TODAY (SATURDAY):

For today (12/23) we are under a dry northerly flow ushering in colder air to the region.  The next system is approaching off the coast as shown below

12z/23rd GFS model forecast of 500mb heights and 700-500mb Relative
Humidity valid 21z (1 PM PST) this afternoon (12/23)

TOMORROW  (CHRISTMAS EVE):

The offshore system begins to spread clouds into the Cascades tomorrow morning as shown below before precipitation begins to spread east in the afternoon and evening.

12z/23rd GFS model forecast of 500mb heights and 700-500mb Relative 
Humidity valid 18z (10 AM PST) Sunday (Christmas Eve)

MONDAY  (CHRISTMAS):

Light snow Monday morning will become focused mainly across SE Washington into North Central Idaho Christmas afternoon.

12z/23rd GFS model forecast of 500mb heights and 700-500mb Relative 
Humidity valid 21z (1 PM PST) Monday (Christmas)

So, have travel plans for Christmas Eve or Christmas Day?  Let's take a closer look at our forecast of snow amounts each 6 hours to get a better idea of when snow will start, and then end.

Sunday (Christmas Eve) Snow amount

4 AM-10 AM

Dry conditions across Central and Eastern Washington into north Idaho.

10 AM-4 PM

Snow spreads into the Cascades and much of Central Washington Sunday afternoon.

4 PM-10 PM

Snow continues to spread northeast, reaching the Spokane/Coeur d'Alene area Sunday evening but with the higher snow intensities around Wenatchee, Yakima, Tri-Cities, and Lewiston.

Christmas Day snow amount

10 PM Christmas Eve - 4 AM Christmas 

Snow over nearly all of the area, except possibly near the Canadian border.  Highest snow intensities over the Palouse, Lewiston-Clarkston Valley, Blue Mountains, and Camas Prairie.

4 AM - 10 AM 

Snow begins to decrease Christmas morning, but still a chance of light snow over most areas.  Steady accumulating snow continues over SE Washington into North Central Idaho.

10 AM - 4 PM

Dry conditions over most of Central, NE Washington, and into the north Idaho Panhandle during Christmas afternoon.

So, how much are we expecting?  Here is our forecast as of 2 PM December 23rd.

The previous blog discussed model uncertainty leading to lower confidence in snow amounts.  Models have come into better agreement, although the European model would support slightly lower amounts than what our current forecast shows.   Snow amounts will continue to be updated as this event evolves.  Please see our web site for the latest forecasts, and winter weather highlights found here