Warm, Then Cool

October 11, 2006

Allright, I win last night, but you 80 naysayers won today.  We were warmer overnight, but could only reach 76 at PDX today.  Obviously that 80 at the end of September will be the last of the year, especially looking at next weeks maps.

Ridging GRADUALLY weakens overhead the next 3 days, and by Saturday we have weak onshore flow.  That can make for a tricky forecast since any low clouds that develop this time of year are very hard to break up with the weak sunshine.

Nice cold front later Sunday and Monday should give us a good soaking.  Maybe up to .50" even in the lowlands.

Evening models have come around to a developing upper-level high over the Gulf of Alaska next week linking up with ridging developing again well offshore.  That digs a surge of cold air south out of Western Canada down over us.  Just 4 weeks from now I’d be thinking we could be in a snow pattern, or an early season arctic air outbreak.  But this time of year it should just turn chilly and breezy once the east wind arrives by midweek.  I’m discounting the -9 850mb temp to the GFS’s usual zeal for cold air in the long range.  A -7 to -8 after Halloween is cold enough to give us snow if we have moisture…Mark