What a Weekend! Mild Weather Will Continue

March 9, 2015

I can’t believe we’ve seen four consecutive sunny weekends.  This weekend topped them all; more like a nice May weekend than early March!  We hit 68 Saturday and 69 Sunday in Portland.  In fact today (at 69) was the 6th day at/above 60 degrees.

Looking ahead, temperatures look very mild for the next 7-10 days, and likely beyond.  This isn’t going to be like any March we’ve seen in many years.  We get one wet system Wednesday, and then some more this coming weekend.  We actually need the rain, since we’ve only seen .43″ in Portland in the last month…crazy stuff for this time of year!

The reason we’ll stay mild (although with rain at times) is the same we’ve seen all winter long.  Actually much of the last two winters and parts of the warm season too.  Upper-level ridging wants to continue along the western coast of North America or in the Gulf of Alaska.  That keeps storms away and weakens those that do move through the ridge.  Take a look at the 15 day 500mb height anomaly map from the 12z GFS, GEM, and ECMWF.  This is the ensemble average of all the runs from each model for Tuesday the 24th.  That’s in the middle of Oregon’s Spring Break:

ecm_15day_tue_24

gem_15day_tue_24

gfs_15day_tue_24

Surprising how similar they are isn’t it?  All show the ridging centered to our north/northwest.  This may allow some precipitation into California at times, but in general it’s a warmer and drier than normal pattern like we’ve seen.

BIG PICTURE:  THIS IS A YEAR WITH A VERY EARLY START TO SPRING AND THERE’S NO SIGN OF A RETURN TO AN EXTENDED PERIOD OF WET AND COOL WEATHER.

The 00z ECMWF monthly run is almost the same.  The maps above end at the end of week #2, so I’ll just show you week #3 and week #4:

500za_week3_bg_NA

500za_week4_bg_NA

Same story continues through the first week of April.  Cold trough in the east and mild ridging along the West Coast.  The heights weaken a bit over Alaska.

By the way, I think it’s unlikely any of the closed ski resorts will reopen and it’s even possible skiing goes down to just higher slopes of the other ski areas with the warmer than normal weather continuing.  Much of the precipitation the next 7 days will fall as rain at the base of Meadows and Timberline:

MarkSnow_MtHoodFcst_2013

Chief Meteorologist Mark Nelsen