The Heat Wave is Here: 96 degree High in Portland Today

August 15, 2012

A real scorcher today with an afternoon high of 96 here in Portland.  I think this is the only time I remember having low clouds through 9am, then an afternoon high of 96!  That’s because the surface wind flow was turning from onshore to offshore during the morning hours as drier Canadian air was moving down into Eastern Washington and North Central Oregon.   The lowest 1,000′ or so this morning was still mild marine air, but that eroded away as the day went on.  I made the unfortunate (and cheap) choice of NOT using the air conditioning at home today, thinking that if PDX was only going to hit 90 or so, it would only be about 82 here (that’s common).  Well, the mixing from the gusty east wind means that I made it to 89.  It’s really hot inside right now with all the windows wide open.  I’ll crank up that AC tomorrow and Friday though!

The easterly wind hasn’t reached the lowest few hundred feet in most of the metro area, but it will tomorrow, at least east of I-5 and in the hills.  Right now east wind is gusting over 30 mph at times at Vista House.  That ensures a real scorcher tomorrow!  We’ll get even better mixing for another 4-7 degree temperature jump.  That puts most of us in the Western Valleys and Portland Metro somewhere between 99 and 104.

The record high at PDX for tomorrow is 102 and we could reach it, although I’d probably forecast 100 or 101 if I was working tonight.

There are two bright spots:

  1. Dewpoints (moisture in the air) are dropping quickly in the east wind locations so tomorrow should be  “dry heat” as they say.
  2. The heat wave will only last 3 days, since Saturday we will see some marine air work into the Valleys…if we get lucky highs will stay in the upper 80s.

Chief Meteorologist Mark Nelsen