May's First Half

Normal May pattern ahead, with a mix of mild, dry days and cool, wet days.  Let’s prognosticate on the first half of May.  Grab your Mug.

The weather this week will be ‘orchestrated' by a Low pressure system working south along the PNW coast.  As it drifts south off the CA coast, mid-level moisture will train northward, primarily east of the Cascades, including ID.  Air flow will ‘lift’ up against the eastern slopes of the Cascades, setting off showers & thunderstorms.  Temps will be mild all week, with slightly warmer days late week.  Some of those ‘big storm cells’ forming along the Cascades will drift westward over west side locations.  Late week, the frequency of such drift is likely to increase, esp over NW WA.  Patrons west side may have a decent view of Cascade lightening in the evenings, if not right overhead.  Be safe.

The coming weekend continues to trend to be damp early, turning cooler & a little less wet on Sunday.  A weak system moving in from the Pacific will bring cooler, wet weather later on Mon May 8 and part of Tue.  Dry Wed May 10.  This will set up the potential for a longer period of STORMY May weather, if models verify.  

For 10 days, models suggested dry, mild weather by the weekend of May 13-14, which could still happen by the way, as model projections often revert to earlier solutions.  Back to the forecast:  wet Thu & Fri, May 11,12, with a Low centered over Astoria.  A much stronger storm hits the PNW on Sat & Sunday the 13th & 14th, with drenching rain & notable wind for May.  Yeah, unusual system, but it’s far too out on the timeline to bake into the forecast.  

The week of May 15-19 looks showery to start, dry and rapidly warming by Wed & Thu under a fast-forming ridge of High pressure.  Temps pop back into the 70s to low 80s for a couple of days.  Rain may be possible to end that week.  We’ll see.

(At times, forecasting makes one deficient in B1.)