Cold & Showery

April 16, 2007

SnapshotSunday was a nice break from the cold & showery weather, but you knew it couldn’t last long during this cool/wet April.  A nice cold front passed overhead this evening and appears to be in the eastern 1/3rd of the state.
Behind the front, cold and unstable air is just about to move onto the Coastline.  We haven’t had many of these "episodes" this Spring season.  Lifted Index, a measure of instability in the atmosphere, goes down to right around zero by tomorrow afternoon west of the Cascades.  That plus some CAPE up to about 200 or so should give us a good chance for strong convection.  Of course this time of year that means heavy showers with possible hail or thunder too.  This cold upper-level trough coming inland tomorrow and Wednesday will sit directly over us Thursday and Friday.  Models keep just about all moisture those two days down to our south.  That seems a bit hard to believe with chilly air sitting overhead, but I’ll go with it for now.
A new trough arrives in the Pacific Northwest Saturday.  I don’t see any dramatic changes early next week.  The 00z Canadian has a bit more ridging over us, but the 00z GFS stays cool, or at most average temperature-wise over us next week…Mark