Changes on the Horizon

May 1, 2006

First the bad news…all long range models have a complete shift in our weather pattern this upcoming weekend.  They show our longwave ridge that’s been prevalent along the West Coast for the past 2 weeks will be replaced by cool troughiness or a strong westerly jet.  That means back to cool & wet April-like weather.  All the more reason to enjoy the rest of THIS week.

I should point out that I had 1/2 blog posting done around 4pm on Saturday as the cold front was moving through.  I too was geeking out like the rest of you with that nice wind switch and temperature drop.  But my power went out briefly right while I was in the middle of the posting!!!  I figured that was a message…stop working on my day off.  But just remember that I was really there with you, racing from window to window to watch the squall blow through.

Tonight we’re back to high pressure, and very DRY high pressure.  Dewpoints are well down into the 20’s this evening.  With pressure gradients going flat and perfectly clear skies, we’ll probably see a light freeze in parts of Washington County and Clark County away from the cities.  Then it’s on to offshore flow through Thursday.  The atmosphere overhead will not be as warm as last week, so even with good offshore flow we will just barely hit 80.  Strong offshore flow in May can push temperatures in Portland to 90 or above.  Not in this case.  850mb temps max out near +10 or so Thursday PM.  If we had a +16 or more, we’d be closer to 90.

Enjoy the sunshine…Mark