A Dry? Weekend Arrives

May 11, 2007

Fflood1_2Fflood2_2I found these two images on the NWS website.  They show how destructive flash flooding can be.   Click on them to get a closer look.  Here’s a link to the NWS web site  Flash Floods .  Now on to our current weather.  Water Vapor loop has looked very impressive this afternoon/evening with a nice closed low/trough moving towards the Coast.  But the last few hours I’ve become far more confident on model’s insistence that we’ll see no significant rain or thunderstorms from this.  Apparently most of the moisture is quite high up.  No model has good instability for tomorrow and lifted indexes are quite high which doesn’t help either.  The trough moves through quickly and is out of here by Sunday.
Ridging builds in quickly for Monday and Tuesday.  I just bumped up the Monday forecast temperature based on the MM5.  Easterly flow develops during the day Monday, with some east wind maybe even making it out of the Gorge.  That plus 850mb temps rising to +12 C in the afternoon should push our high to the warmest so far this season.  My "magic chart" based on past 850mb temps vs. PDX high shows a high around 81-83 Monday too.  So confidence is high on that.  IF a late Tuesday marine push holds off long enough, mid 80’s are likely that day.  Then cooler with a quick, but possibly dry trough passage for midweek…our dry spell is going to continue.  Before Mom gets here this weekend I guess I better get the drip watering system working for the season.  The garden is going to need it..Mark