Cold Nights & Warm Days

August 30, 2006

Classic early September weather coming up just as we enter…September.  Funny how that works.

Trough has moved on east this evening and showers are finished.  Clearing skies tonight + cold & dry airmass means widespread 40’s.  I wouldn’t be surprised to see Battle Ground or Forest Grove down slightly below 40 degrees tonight.
Offshore flow begins tomorrow under a building upper level ridge with light easterly wind through the Gorge, but northerly wind will continue in the Valley.  This should keep temperatures from getting above 80.
Friday a different story with our first strong easterly flow of the early Fall season.  MM5-UW shows 4-6 millibars easterly pressure gradient through the Gorge.  In the warm season this should send gusty east wind out across the metro area during the day Friday.  Peak gusts probably 25-30 mph.  40-45 mph more likely at the west end of the Gorge.  I used to hate that when I lived in a windy spot near Corbett because it would knock down my corn before it was ready in September….But I digress.  Thermal trough with much lighter easterly wind will sit over us all day Saturday, so that should be the warmest day.
A change in the maps means not so hot the rest of the weekend, but more warm/hot weather later next week.  The ridge is going to get knocked down and pushed east a bit Sunday-Tuesday, then it rebounds right over us Wednesday-late next week.  It all adds up to a bunch more summer…Mark