Sprinkles of The White

Posted by Rufus La Lone on

Monday December 13
A chilly, damp period is ahead, with some areas in the immediate future getting a sprinkle or two of The White.  What about your morn’n Mug location?  Let’s take a gander. This will be complicated, so stick with us, please.
Cool week ahead, with periods of showers & snow showers in the mountains.  For Tue & Wed this week, an approaching Low may draw colder air out from the Columbia River Gorge, and when combined with the coldest air aloft compared to the past few days, could bring on The White (1” or so) for a brief spell in portions of the Willamette Valley & higher chance around Hood River.  This system may also sprinkle The White around Chehalis, maybe north into portions of the SE area of the Puget Sound.  All iffy, and short-lived, but fun to witness, if verified.  Bellingham north Patrons should receive some precip, but whether or not stays as snow to the surface is iffy for now.  Any Patron around the PNW sipping their morn’n beverage above 500’ or so Tue & Wed should enjoy a short-shot of The White.  Mountain passes will be definitely requiring tire attention.
Thu into Fri should warm at the surface, moving chance for snowfall above 1,500-2,500 ft or so.  The next organized disturbance is modeled to arrive later Fri into Sat.  This will be rain at the surface, heavy snow in the mountains.  Sunday Dec 19 is trending generally dry & chilly; frost if the sky clears in your area.  
Christmas Week is beginning to look quite interesting.  Monday will usher in a chance for The White south of Salem before the surface air warms, as a system tracks off the coast of Oregon, drawing colder air in from the E/NE.  An outflow wind is possible from both Gaps - Fraser & Columbia River - but not super strong at this time (definitely could become an issues around Christmas - read on).  Tue & Wed Dec 21-22 are trending relatively DRY & chilly.  Thursday Dec 16 looks damp as a system moves in from the NW.  Not seeing snow risks quite yet, but Nature’s Christmas surprise may be just around corner.
Christmas Eve & Christmas Weekend:  the stage is being set - per model scenarios - for a very impactful WINTER STORM event (remember we talked about stages for snow last week?).  At that time, we had NOT been discussing an Arctic Outbreak-type of winter event, but now that is trending as POSSIBLE for the Big Holiday period.  Models hint of a High pressure Dome of 1044-1048 mb developing over the Yukon and moving south.  Should this actually take place, the pressure difference between interior BC and the Olympic Range could be huge - meaning powerful outflow winds from the Fraser River Gap.  (Outflow winds much colder than what we discussed on last Saturday’s Farm Show on KGMI 750 Talk Radio.)  Model runs suggest a rather deep Low pressure cell dropping south, right along the BC/WA coast, at the same time as that cold DOME figuratively drops into place.  As we mentioned in our last report, we all know the drill, if that happens.  Moisture, subfreezing outflow air - SNOW.  Back to the forecast —
Fri Dec 24.  Rain & wind increasing from Thu system as the surface Low moves south along the OR coast.  Air will turn snow-cold first over NW WA, Vancouver Is., SW BC as this event gets underway on Christmas Eve.  It is possible for the precip to turn from rain/showers north of Salem to all snow at some point overnight Thu into early Christmas Eve.  Odd movement of that Low - it may shift south near Brookings, then back north again - still off the coast - before literally “parking” itself just west of Vancouver Island.  Oh my, if this verifies, all that moisture will first turn back to rain at the surface, before swinging back to The White as Santa makes his jolly way across the rooftops.  Based on current model trends, SNOW is possible from Eugene all the way north into BC on Christmas Day.  Really?  Remember, just a crazy forecast for now, but seriously, we have not seen this pattern for Christmas on the model charts in years.  Ponder Point for sure.  Some solutions keep the NE cold air flow strong through that weekend; others place the coldest portions of that High Dome east of the Rockies, with enough drawn into the eastern basins of WA/OR to hold snow at the surface as possible after Christmas.
Monday Dec 27: another Low may follow a similar path as the Christmas Eve Low, and add to the moisture source, along with increasing E-NE outflow winds for more snow at low elevations, esp for NW WA.  Southerly winds should lift snow up off the surface over Willamette Valley, Portland at that time.  It may set up a FREEZING RAIN event for Salem north into Longview.  Double oh my, if this verifies.
NOTE: we do not take this kind of forecast lightly, as long-term Patrons understand.  This could ALL change back to ’normal’ mild Christmas weather, as you know, but it would be unwise NOT to heed what could be a reality, esp given the large numbers of folks traveling about the area during the big holiday.  Any amount of surface snow will challenge holiday travel.  We’ll monitor this closely the next several days.
“Before you give somebody a piece of your mind, be sure you can get by with what you have left."
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