Hot Offshore Flow Ends: Marine Push in Valley This Evening

August 16, 2012

It hit 100 in Portland today, our 2nd 100 of the season.  Most likely we won’t hit 100 again this year.  Not a guarantee, but the weather pattern looks significantly cooler for the next 7+ days starting Saturday.  In fact someone mentioned that right now we are in the warmest August on record.  Well, that’s with the hottest part of the month most likely behind us and the cooler pattern ahead.  It’s very unlikely we’re going to see that warm average temp hold up.

I also think we probably won’t hit 100 tomorrow, more like 96-98?  That’s just my “shoot from the hip” analysis.  I’ve found that without offshore (easterly) windflow it’s very tough to get out of the mid 90s once we hit the latter half of August.  Look at today; with almost perfect conditions we just barely hit 100.  It would have taken a warmer upper-level atmosphere to push us up into the 102-105 range; I mentioned that on a posting earlier this week.  There seemed to be some wishcasting going on too. 

This evening a very obvious marine push is in progress.  McMinnville is running 10 degrees cooler than at 9pm last night.  Corvallis has a west wind gusting to 24 mph. That plus a totally calm western Gorge indicates that even though the heat wave isn’t over, it sure won’t be as hot or hotter tomorrow.  When is the last time you saw a push into the Valley during a heat wave and then warmer temps the next day?  It doesn’t happen.  Thus a slightly cooler (but still hot!) day tomorrow.

Saturday and Sunday we get back to our usual marine-influenced summer weather with highs only 80-87 or so.  So this will be a 3 day heat wave; pretty typical for summertime here.

Speaking of the marine push, I spent 1pm-6pm at Cannon Beach.  A hot drive over there with no cooling until the turnoff to Saddle Mtn about 10 miles east of the coastline.  The fog/clouds thickened all afternoon on the beach; and by 4pm I said “forget this!” as I was cold in my shirt and shorts.  Then a slow warmup on the 60 miles back to the metro area. 

Chief Meteorologist Mark Nelsen