Slow Weekend

December 29, 2006

Things are looking real slow the next 3 days weatherwise.  Several weak systems move into our West Coast ridge and die a slow death.  Today’s system was amazingly well predicted by models.  Our RPM showed solid rain on the coast late this morning, then brief rain in the western valleys and no rain making it to the Cascades.  Radar loops this afternoon showed exactly that scenario occurring.  It knocked down the easterly pressure gradient from around 11millibars PDX-DLS to only 2 mb.  That gradient should recover to 6-8 mb. again tonight/tomorrow, so the wind will make a recovery, but only in the usual "Gorge-influenced" spots.
2 obvious changes in long-range maps tonight:

1.  Back to active westerly flow along with fast moving waves/troughs…good system comes through Wednesday.
2.  Chilly trough slides into Northwest (and out again quickly) Thursday.  850mb temps on all models briefly dip to -6 or -7.  Most likely a hilltop snow event with strong onshore flow, definitely not a widespread snow producer at sea level.
3.  Wait, I only said two but I thought of another.  Long range GFS in 12-16 day period has tried to send some sort of very cold air our way in the last 3 runs.  This is way out in la-la-land of course but bears watching.  I DID notice that 00z Canadian dumps the cold air out over the Pacific at 10 days instead of down towards us.
Mark