An Unusual Heat Storm

In general, the pacific NW USA endures heat waves in 3-day snips. A lot like snow in that way - extended periods of heat or cold are rare. So we are living through an exception!We're on day seven of temperatures above 90° - and we're expecting one more. Portland's record for 95+ is seven days, and I think that record is at risk.

Our heat storms generally end in one of two ways. The transition that I remember mostly from my youth is a few nice thunderstorms (big ones only by NW USA standards), . Not a massive squall line like the rest of the US gets at the end of a heat wave, though; just storms that form along the Cascades and drift NW to valley-dwellers around sunset. The day after would be cooler as marine air slipped into the valleys.

Nowadays the t-stormy phase gets skipped for the valleys nearly every time, and a strong but dry west wind brings a Marine Push. Wind ramps up late one afternoon and rushes in with cool air, and a cloudless evening in the 60s replaces 80-100° heat. Less exciting but still dramatic. Living here for eight years (north of Portland, aligned with the long lower-Columbia estuary) this has become the default ending.

We had several of these late-day pushes this week, each causing temps to crash in the late afternoon -- but in each case the west wind was stymied and the heat resumed! Forecasts generally agreed that late-week break would arrive Saturday.. no Sunday. Now it is Saturday and it's expected late on Monday. Maybe?

Nearly every day was warmer than even the warmest forecast, and the week's slow cooling became a double peak on Tue and Fri. A couple of 90s then dropping.. well maybe 90 again Fri, or Sat. Oops, today we hit 105° - matching our high during last year's record-crushing Heat Dome, six degrees or more above the forecasts, and the new peak of the week. No push today until 7PM: too little, too late.

 

At least no nearby stations reached 116° like last year, thankfully.. But

 Ugh.

Tomorrow was supposed to be a pinch cooler. So is that 97, or 103°? 

Tune in & find out.