A Classic Windy March Day Ahead

Gusty windy, sunshine, downpours, and temperatures not TOO chilly should really make it feel like March today.  Not one of those gloomy and rainy days, but an invigorating, refreshingly wet day. 

Did I “sell” that well?  I’m up early for my last school visit “field trip”.  I’m headed down the Valley to Trinity Lutheran Preschool in Mt. Angel and Aumsville Elementary (Toto!).  All that and back to Portland by 3pm.

Check out the nice curl of low pressure west of Astoria.  Looking at the IR loop you can see it has reached it’s maximum depth and is beginning to fill; good news since it’s a little farther south than expected.  The low is going to stretch a bit as it moves onshore.  In fact we are going to see the southern part of it drag across NW Oregon midday-early afternoon.  It’s called the “bent-back occlusion”.  THAT gives us a renewed surge of SW wind on the Coast and our strongest wind in the Valleys…sometime between Noon-2pm.  I like the term “poisonous tail of the bent-back occlusion”…sounds dangerous.  It’s an old saying in the Pacific Northwest referring to these situations.  We had one of those give us damaging wind back in November 2006 I think.  As that passes through, models show 13-15 mb. gradient from Olympia to Eugene, which gives a general guide of 40 mph gusts.  The icing on the cake this time of year is lots of mixing due to the warm sun inbetween showers.  The mixing allows stronger winds a few thousand feet overhead to show up at the surface, especially with heavy showers between the sunbreaks.  We will see some gusts in the 40-50 mph range.  Not a huge windstorm, but “Wind Advisory Worthy”, and enough for a tree or powerline to go down here or there.  Especially since we haven’t even seen a gust over 50 mph at PDX this winter!  It hasn’t been a big year for south wind at all (again).   By 5pm it’s all over and we finally get a dry day Friday!

Chief Meteorologist Mark Nelsen