Major Winter Events Probable

You’ll need a hot refill in that Mug for this one.  A change is in the works for a wild winter ride coming soon.  As a caution, remember that all of our long-range forecasts are never absolutely guaranteed to take place, as Nature does its own thing relative to what computer models may project.  Our premise is to be prepared, just in case.  That said, here goes - - - 

Rain returns tonight, after a few showers today.  As the front moves onshore overnight tonight, temps will drop and snow will begin over the Cascades.  The cold front will drop south into CA, as well.  Showers may linger on Sunday, with a chilly afternoon - highs in the 40s.  Mountain snow will be evident.  A weak system will bring additional precipitation overnight Sunday into Monday the 8th.  

Monday night through Tue will be the first big change.  A stronger, colder system begins to move in, with cold air support on the back side.  Expect moderate rain at the surface, with 1-3 feet of snow in the mountains, and a decent shot of snow over the coast range is possible overnight Tue.  It will be windy.  The stage is being set.

A secondary front may form and head for ‘landfall’ Wednesday morning around Astoria.  WINDY & wet in western OR.  Showers in WA.  Cold Arctic air will begin to shift south out of Canada. The Yukon Dome we always refer to is modeled at the 1048-1052 mb level.  Fraser Gap outflow will begin.   A Low will position just west of Vancouver Island on Thu, setting up those strong Fraser Gap winds & much colder temps.  SNOW will be in play now, as the Arctic air makes its way through the Gap into western WA.  That Low will draw Arctic air over the eastern Pacific to pick up moisture, allowing for snowfall down to the surface, or nearly so, for portions of northern OR by overnight Thu.  A southerly breeze may hold snow off valley floors early in the event, but that will change by Fri.

Friday Jan 12. ✲ SNOW showers possible everywhere, with dangerously strong outflow winds in Whatcom County.  The PNW should begin to ‘dry down’ as the Arctic air will be dry.  Temps may not climb out of the 30s on Saturday & Sunday.  The Fraser, and to a lesser extend, the Columbia Gap winds will lessen during the weekend.  Snow showers possible on Sunday Jan 14 across western WA & OR.

Folks, the air mass is charted - by some models - to be quite cold for the PNW.  Lots of variance in that projection, but we have to warn Patrons to prep their water systems, plumbing, etc for subfreezing temps that may last for several days.  This storm next week could just be the first shot.  Oh, California will also be impacted as the Arctic air modifies a bit heading south, but will remain cold enough to initiate snow showers at low elevations in northern CA.   

Overnight Sunday Jan 14 into Monday, cold winds out of the east will increase again for the Fraser & Columbia Gaps.  At the same time, a storm system will begin to approach the west coast of WA, OR & CA.  This is where the situation looks wild.  SNOW at first, followed by freezing rain, and BACK TO SNOW again (!?). The storm may track south of WA, and over western OR.  Simultaneously, cold Arctic air will also be re-enforced by another cold wave out of the Canadian interior.  Rain and/or snow for western valleys, with the chance of all snow for the Portland area (Columbian Outflow) and Puget Sound (Fraser Outflow) during the Tue/Wed Jan 16,17 period.  If this verifies, MULTIPLE INCHES of snow will be the battle, as well as freezing rain.  

Cold Arctic air will continue to be in play as the week of Jan 15-19 ends.  A Low positioned west of Vancouver Island may form, adding moisture over the top of the cold air at the surface.  Broad areas of SNOW probable Thu AND Fri to end the week.  Again, this is WAY out there on the charts, but worthy of mention and ponder.  Cold air may remain in place through the weekend of Jan 20,21.  We’ll see.

In Summary: model solutions range from wet, 40+ degree weather, to COLD, snowy and subfreezing conditions across the entire PNW during the period discussed above.  What we have outlined above is highly probable, so warrants this forecast discussion, as so many businesses, schools, agencies, farmers, cattlemen etc need to prepare just in case.

The Weather Café®️will keep you posted with special statements during the upcoming time frame of events.  More importantly, heed Nat’l Wx Service watches and warnings.  Even if surface snows do not fall, transportation in & out of the PNW by road will be dangerous because of packed snow on the highways.  Air travel may be impacted, if surface snow develops.  Deliveries may be impacted.  You know the drill.