Looks Like September (Weatherwise)

August 25, 2013

A busy day today at FOX12 since we not only put a fresh news studio on-air, but also switched the entire news operation to HD.  Hopefully I don’t look too old with the HD cameras.  As one professional told me “HD is great for video, sports, and wide shots, but is no friend to your face!”.

Anyway, we had some rain today!  .08″ at PDX brings the August total to….almost two tenths of an inch.  Don’t worry, there will be more.  We are clearly in a general weather pattern for the next 7-8 days that will produce below average temps and above normal rainfall.  The reason is an upper-level trough that lingers offshore through the week, then totally kicks inland over the Pacific Northwest during the Labor Day Weekend.  Here is the 500mb height anomaly from the 12z ECMWF for midweek.  Quite a deep low offshore for this time of  year:

m500za_f072_bg_NA

Then see what happens next week, models all imply some sort of ridging over the Pacific Northwest…the 00z GFS anomaly map for next Tuesday (AFTER Labor Day!)

m500za_f216_bg_NA

Now the 00z GEM (Canadian) shows the cool upper low over us all week, but, it IS the GEM, so I’ve ignored it.  For now…

The length and intensity of a  possible warm and dry spell after the 2nd of September is definitely up in the air.  Take a look at the 12z ECMWF ensemble chart:

tseries_850t_000-360_Portland

a HUGE variety of solutions…from about average temps to a scorching early September heat wave.  Here’s the 00z GFS ensemble chart…

tseries_850t_000-384_Portland

Same thing, although not quite a disparity between solutions.  The main message is cool for most of the next 7 days, then a bit warmer AFTER the Labor Day Weekend.

Chief Meteorologist Mark Nelsen