Warm Summer Weather Here To Stay

July 6, 2012


It’s pretty obvious now that real summer weather has arrived; today was our 3rd day with sunny skies and temperatures have gradually warmed.  Most of the metro area was in the 80-83 degree range.  My little 3 inch high corn plants are FINALLY starting to show signs of life!

With the hot upper level ridge edging a bit closer to us tomorrow and Sunday, temperatures will warm further.  For you real hot weather freaks, I sure don’t see a pattern that would REALLY heat things up (90-105), but we’ll be right up around 90 on Sunday.  Models seem to agree with MOS (Model Output Statistics) output showing mid 80s tomorrow, upper 80s Sunday, then mid 80s Monday.  That drop on Monday is due to a weak marine push started by an upper-level disturbance riding up the west side of the ridge.

Speaking of that, lots of moisture rotating up around the ridge the next few days means increasing thunderstorm action over and east of the Cascades.  Even though I have the week off next week, I won’t be over in Eastern Oregon.  That would have been a great week to be hanging out eastside watching storms fire each day.  Oh well…

As a result, there is a Fire Weather Watch up for most areas east of the Cascades for Sunday-Tuesday.  Thunderstorms are unlikely west of the Cascades, especially after Sunday, since the upper level flow turns more south-southwest. 

The atmosphere remains very warm over us all of next week; with models becoming a bit more variable the latter half of next week.   There are hints that after a warm week ahead, then a bit cooler after about the 15th.  But that’s a long ways away (only 10 days away!).  The 12z ECMWF ensemble chart shows temperatures generally continuing above average, but a notable trend to cooler after late next week, although notice all the variation!  Low confidence after about Day 8 I’d say!

The 18z GFS (ensemble average) is also a bit above average through the 2 week period too.  This model today showed the enormous value of ensemble forecasting.  In the old days (2 years ago) we would have seen only the very hot operational run (blue line) and wondered if a heat wave was 9 days away.  But you can see in the chart that it IS the hottest ensemble member.  Much safer to forecast based on the red line in this case.  Although the 00z has come in MUCH cooler for NEXT weekend, it too may be an outlier…we’ll see.

Enjoy the summery weekend, and if we get lucky, maybe some lightning visible over the Cascades Sunday or Monday evening/overnights.

Chief Meteorologist Mark Nelsen