It was another fantastic spring day across the region wasn’t it? Just a few thin high clouds drifting lazily by at times. We made it to 68 in Portland, just a few notches down from the 71 yesterday (March 31st). Salem and Eugene were a bit warmer than yesterday.
In my opinion, we’ve had a great start to spring if you like to get outdoors. March was drier than average, with plenty of partly cloudy or sunny days. It was our 7th driest on record at PDX (out of 81), and the 2nd driest during a La Niña winter/spring.
Just as interesting? We’ve now gone through four consecutive years with drier than normal conditions in March. Payback will be a real tough in some future March!
And you can see most of the West has been quite dry this past month
What about temperatures? A bit cooler than average. Not a huge departure, but most of Oregon has been cooler than normal.
Is this unusual? Not really. Looking back at past La Nina springs, there is a very strong signal for cooler than normal across the Pacific Northwest. This is a composite of April-June temperatures for the last 20 La Nina springs. Pretty clear signal isn’t it?
One would think a cool spring would also be wet, but that’s not the case. April through June precipitation from those same 20 springs…well below average.
I don’t mind these springs too much; plenty of sunny or partly cloudy days mixed in with the wet days. Plenty of chilly nights and late frosts (like this year), but a cold/clear night is followed by very strong April/May sunshine too!
Snowpack is still running well ahead of average in northern Oregon; no significant spring melt yet due to the cooler temps. Southern Oregon is not in good shape as of April 1st. Lots of drought issues are likely across the Klamath and Good Lake basins
April is what I call the “greening up” month west of the Cascades. Most deciduous shrubs and trees come alive this month; bare of foliage to start, then flush with fresh leaves & green by April 30th. It’s very dramatic in the woods around my home. Right now the ground is pretty much bare and bright sunshine makes it down to the forest floor. But four weeks from now all the ferns will have popped out of the ground, alder/maple trees will be leafed out. It turns darker and shady in the woods from that point through October.
Portland’s average high temperature rises from 59 > 64, and we typically see 5 days at/above 70 degrees. Last year we made it to 76 degrees late in the month
We have also entered the drier half of the year…just barely. April is slightly drier than October in a typical year as the rainy season slowly winds down
In the short term, we’ve got a dying cold front that brings a few sprinkles to the northern Oregon coastline tomorrow. Then (unfortunately) on Easter a splitting upper-level trough brings another dying front overhead. Lots of clouds that day but not much rain! The fresh 00z GRAF model shows how little rain we expect through Sunday afternoon. If there is no color on this map, that means less than 0.10″ precipitation.
The result? Not much rain and temperatures near normal for this first week of April. And…
EASTER WILL NOT BE A WASHOUT, JUST LOTS OF CLOUDS PLUS A FEW SPRINKLES OR A SHOWER
Chief Meteorologist Mark Nelsen