Going Wet

A change in the overall wx pattern is on the way.  A second ☕️, too.

A decent fall storm will begin to move into the PNW, from the NW, later this evening - over Vancouver Is first, then expanding southward into OR by Saturday morning.  The Saturday rain field will be from a warm front, so temps will pop up a bit before dropping on Sunday, as the subsequent cold front moves onshore (most of the precip will likely fall north of Portland into BC.  A good 1/2” or so of precip west side, both WA & OR can be expected.  Some precip will hit east side, well into ID.  Cascade snow, as well.  Drying late Sunday.

Chilly Mon morning to start the work week, maybe a light frost or fog in the usual locations.  The week of Dec 9-13 is charting as dry, chilly, with some fog, for the first 3 days, then increasing chance for rain (north-to-south) overnight Wed the 11th.  The bulk of the precip should fall north of Portland.  Thursday looks mostly dry post-frontal passage after sunrise.  Here’s where it starts to get interesting.  Sip.

Model runs have suggested the potential for a Low pressure system to move “inside the 130” (degrees of latitude, which, if the Low is deep enough, can generate powerful wind events).  For now, we are going say YELLOW ALERT for a wind event over western OR on Friday the 13th.  Rain will increase - from the south before sunrise Fri as the Low pressure center crosses the 130W.  Should model solutions verify, expect southerly winds to increase Friday afternoon, as a possible 988 mb center moves onshore near Astoria.  The barometric pressure gradient could exceed 18-20 mb from the CA border to Astoria around 7pm Friday the 13th.  Note that this isn’t definite, but probable at this time.  Western OR Wind gusts could be the strongest of the year as said Low crosses the Columbia River near Longview around 10 pm.  We’ll leave this here for now; update on Monday. 

Following rain (and wind?) on the 13th, Saturday will be dry, as will early Sunday the 15th.  Another WET storm is charted for Sunday night into Monday, followed by showers Tue evening, moderate rain Wed night the 18th, and a super-wet system on Fri Dec 20.  

Bottom line: a consistently wet December pattern arrives after a 2-3 day dry start next week.  There will be breaks between storms, so flooding issues should not be of concern.  Wind, maybe.  Plenty of mountain snow for Patrons taking to the slopes over the Holidays.  Our annual 'White Watch’ for a possible snowy Christmas will get going next week.