A Very Early Dry Season Start?

May 2, 2016

11pm Monday…

It’s starting to get dry out there…you know that if you’re a gardener like me.  In the past 16 days Portland has seen less than 1″ of rain.  If you add in the much warmer than normal temps, soils are quickly drying out.  Feels more like June…

What’s ahead?  Unfortunately I see drier than normal or even mainly dry conditions over the next 10+ days.  That takes us to mid-May.  Why?  It’s that persistent upper-level ridging over the Western USA we’ve seen off & on this spring.  It is breaking down right now, we get some normal temps midweek along with some showers, then the ridge pops back up over us this weekend and early next week.

Take a look at the GFS rain forecast for Portland for the past 3.5 days. GFS_precip  Each horizontal line is one run of the model out to 10 days, the most recent forecast is at the bottom.  Incredibly dry isn’t it?  Looks more like July.  All models are staying with the “much drier than normal” theme through mid-month…PDX rain for the next 10 days:

MarkRain_ModelForecasts

Do you realize that 8 monthly record high temperatures have been tied or set in the past two years?  One of those occurred twice (both Oct 2014 & 2015):

AUG 2014
SEPT 2014
OCT 2014
MAR 2015
JUN 2015
OCT 2015
FEB 2016
APR 2016

So when you look at the all-time warmest months here in Portland, 7 of the 12 have occurred in the past two years!  That’s an amazing run of warm weather.  Wow.   A huge climate test will be this fall and winter if/when La Nina conditions take hold.  If we turn cooler than normal with abundant mountain snow that will be great.  If we get a so-so winter with just average winter temps then it’ll be a bit more clear that the warming seen around the globe is beginning to have more of an effect in the Pacific Northwest.  Deep thoughts for 11pm…enjoy the more reasonable temperatures tomorrow!

Chief Meteorologist Mark Nelsen