If the holiday wasn’t busy enough, the weather department will really get busy this week. By now you have heard or seen the possibility of snow and cold for Christmas and beyond. We briefly discussed it here the other day.
First let’s quickly explain the wet snow on Saturday. We had a cold front pass through late in the day, but it was unusual in the way it performed. We could call it an “annafront,” which combines heavy precipitation and dynamic cooling. Snow aloft falls rapidly and melts as it falls and changes to rain. This process utilized thermal energy to cool the lower regions of the air which allowed the snow to fall basically to sea level at temperatures above freezing. Instead of brisk west to northwest winds which follow normal cold fronts, in this case the winds became calm.
The foothills and areas east of I-205 scored the most snow with big wet flakes falling on the west side. There it was conversational snow as we call it and many saw none of it if you retired early for the night. I think I can recall this event happening less than a dozen times in my lifetime. Amazing and fun and, of course, short-lived. Get you in the holiday spirit?
Back to the future — a decent day today with more clouds and rain Wednesday and Thursday continuing into Friday. Meanwhile, a cold arctic air mass gathers strength over southern British Columbia and heads our way. We will get some of this cold air flowing out over the ocean and back inland as snow showers. More cold air settles in the Columbia Basin and heads down the Gorge eventually.
