Changes next week

After a quiet weather pattern this week, weather changes are on the way.  What kind of changes you ask?  Good question, let's take a look.

We will take a look at a few model solutions for next week but let's begin with today (December 4th).

06z/Dec 4th GFS model of 500mb heights and 250mb wind (image) valid 4 PM December 4th 

This is a pattern typical of El Nino.  The image shows wind speeds up near 30,000 feet MSL with green colors showing winds between 100-140 MPH and orange colors in excess of 140 MPH.  A split jet stream with the southern branch aimed at California and the northern branch staying to our north and east.  Although we are under a weak northerly flow which will bring our region slightly below normal temperatures.

A weak weather system may pass through Saturday for a threat of light snow or flurries.  More significant changes next week.  Check out the pattern for Monday, December 10th.

06z/Dec 4th GFS model of 500mb heights and 250mb wind (image) valid 4 AM December 10th

Noticed a much stronger, consolidated Pacific Jet Stream across most of the Pacific Ocean with a low pressure system off the west coast.  Light precipitation will be possible across Central and Eastern Washington into north Idaho.  It's still a little early to nail down precipitation type so keep checking the forecast for the latest updates as we are monitoring the potential for a wintry mix.

Now look at next Wednesday, December 12th per the GFS model.

12z/Dec 4th GFS model of 500mb heights and 250mb wind (image) valid 4 AM December 12th

Next Wednesday models show the jet stream stretching across all of the Pacific and aimed at Washington, Oregon, and California.  The center of this jet actually had some red colors in there with a maximum value of 225 MPH.  This may bring more significant precipitation to the region including mountain snow, with rain, snow, or a combination of both for the lower elevations.

And it's not just the GFS, here is the Canadian model.

12z/Dec 4th Canadian model of 500mb heights and 250mb wind (image) valid 4 AM December 12th

And finally, the European model.

12z/Dec 4th European model of 500mb heights and 850mb temperature (image) valid 4 AM December 12th

The image is a bit different on this graphic (850mb temperature) but you get the idea with the strong westerly flow noted across all of the Pacific.  So while next week is still a long ways out, the general model agreement gives a boost of a confidence to at least a pattern change.

The 6-10 and 8-14 day outlooks from the Climate Prediction Center for precipitation agree with this idea with elevated odds of wetter than normal.

CPC 6-10 day precipitation outlook issued December 4th valid Dec 10-14, 2018 

CPC 8-14 day precipitation outlook issued December 4th valid Dec 12-18, 2018 

So after a generally dry period through this upcoming Friday, weather changes are likely to follow.