December Drenching

The last week for the month will be rather ‘blah’ in the weather dept.  That will change.  Let’s take a look ahead.  Morn’n ☕️ Mug time.

Frosty mornings (low 20s here in the Albany area) will continue much of the week, although temps should begin to tap up a few degrees overnight.  Air quality will continue to deteriorate because of the surface cold air layer trapped under a warmer air ‘blanket’.  By Thursday the 30th, the wx pattern will shift back to the seasonal storms of fall.  Or so the models resolve at this time.

Expect showers to develop sometime during the day Thu, as the first of 3 systems arrives from off the eastern Pacific.  A 'step-up' storm with a bit more moisture and wind action will arrive Fri Dec 1.  Wet day.   The weekend looks damp, as Sat will present more rain/showers and blustery conditions.  Overnight Saturday, a 2nd 'step-up' stronger storm will move rapidly over the PNW.  WINDY.  Sunday looks blustery, chilly & damp at times.   Sunday night presents yet another system, for added precipitation & wind. Top step storm, if you will.

The first work week of December looks VERY WET & STORMY through mid-week; turning showery on Thu.  Colder, with snow levels dropping below the passes.  Fri Dec 8 is trending as the driest day of that week.  Chilly.

Models have shifted back & forth as to the weather over the weekend of Dec 9,10.  Some solutions indicate a break in the wet pattern for a couple days, before a major turn into several days of very drenching rains; other scenarios keep rain over the PNW that weekend, then a drying period thereafter for a few days.  This will get sorted out before the period arrives.  Either way, what follows warrants attention.

For several days now, model runs have presented a string of super wet storms pushing into the PNW, with heavy rainfall across the western region & down into northern CA, as well. It is the timing that varies; not the impact.  WIND will be notable as it accompanies the seemingly unending steady rain.  We’ll have to wait for verification.  Localized flooding will be likely.  

Bottom line: the dry spell of November is coming to an abrupt end.  Various model cumulatives of precip for the first 13 days of December top 6” in the valleys; nearly 10” in our foothills & Cascades; --> as much as 15 inches in the Siskiyou Mountains.  Possible, not definite.