ECMWF Says Ridging Continues Through March

March 5, 2015

4pm Thursday…

The Euro model says spring is already here and we’re jumping right into typical April conditions over the next few weeks.

The last time we saw a warmer/drier than average March was 8 years ago…in 2007.  I suppose we are due.

An interesting ECMWF monthly run last night.  It implies that we might see our warmest March in years.

There is one map for each of the next 4 weeks, showing 500 millibar height from all the ensemble members and the anomaly (colored areas).  Warm colors mean higher than normal heights and cold the opposite.

Week 1:  We already know what’s happening over the next week or so.  Strong ridging now continues through Tuesday, then a system to our southwest kicks out over the top of us as ANOTHER ridge pops back up over us late next week.


Week 2:  This takes us into the first part of Oregon’s Spring Break.  Look at the ridging over Alaska and extending down into the western USA.


Week 3:  The rest of Spring Break.  Looks like ridging still hanging in tight, although slightly farther west and north.  Maybe a bit cooler, but still drier than normal.


Week 4:  Through the first week of April.  Same pattern.


By the way, the GEM and GFS both agree through 15 days out…the farthest we can see on those models.  They show the same ridging on Friday, the 20th of the month

gem_fri_20 gfs_fri_20

More on the ski season a bit later…

Chief Meteorologist Mark Nelsen

4 Sunny Weekends? It Might Hit 70 This Time Too!

March 4, 2015

Wednesday 7pm…

Do you realize we are forecasting a 4th consecutive sunny weekend?  Amazing for late February and early March!

Starting with Valentine’s Day we have seen mostly sunny skies each weekend day. That’s due to nearly constant upper-level ridging hanging around near the West Coast over the past month.  During that time we’ve seen less than 1/2″ of rain!

With the increasing sun angle and day length, we’re getting more energy down here at the ground so that means warmer temps this weekend.  We may hit 70 either Saturday, Sunday, or Monday.  But it wouldn’t be a record because we’ve been even warmer in early March as mentioned in Monday’s post.  We don’t appear to get good offshore (easterly) flow over the weekend, which should keep high temperatures from reaching the 75 we saw back in 2005 despite the 850mb temps forecast to be about the same as 2005.  So to summarize…


  • Warmest we’ve seen so far this year
  • Good chance we touch 70 either Saturday or Sunday
  • Light wind continues, including in the Gorge
  • Overnight temperatures will gradually warm too

It’s very obvious that we have no rain, and hardly any clouds, on the way through Tuesday of next week.  We have some rain in our 7 Day forecast for Wednesday, but is that the beginning of “the big change”?  It doesn’t appear that way for now.  Models have been consistently backing off on cool and wet weather later next week and beyond.  Just 1-2 days ago the GFS models was giving us snow down around 2,000′ or even lower in the extended range.  As of today though all of our long-range models show some wet weather later next week but then a return to upper-level ridging of some sort after the 15th.  Take a look at the ECMWF & GFS 500mb height anomaly for 9 days from now…next Friday, the 13th:



Then a week later, Thursday the 19th.  Including the GEM too…this is just as Oregon’s Spring Break is about to kick in…




The all show either normal or above normal upper-level heights over the Pacific Northwest.  No sign of a big turnaround to a wet pattern.

So enjoy the unusually sunny early March weather…it might not happen for another 10 years!

Chief Meteorologist Mark Nelsen

A Look Ahead and ECMWF Maps

March 2, 2015

11pm Monday…

As I was making the forecast today I realized that in March I’ve never put so many sunny orbs on the 7 Day Forecast.  This is what I ended up with:

7 Day

Why?  Same old story we’ve seen off and on all winter.  Ridge of high pressure in the upper atmosphere near the West Coast for the next 7-9 days.  Both the GFS and ECMWF have rain returning around next Wednesday.    Note the very warm temperatures late this week and the arrival of rain the middle of next week on the GFS meteogram


Is this an unprecedented March weather pattern?  No, it happened exactly 10 years ago!  March 2005 was incredibly warm to start.  In fact the record high temperatures from the 7th to the 11th still to this day are from that “heat wave”.  That was after a terrible ski season.  Actually this winter is matching 2004-2005 quite well so far.  What happened after all the sunny and warm weather?  It rained for the next 6 weeks starting around the 15th of the month.  By the way, the 850mb temperatures during the period below were between +7 and +11 deg. C.  That tells me that if offshore flow develops over the coming weekend or early next week we could get into the 70s…stay tuned!


There is no sign that a significant turn to cool and wet weather is on the way.  Last night’s ECMWF monthly run keeps some sort of upper-level ridging nearby through the end of the month.  Take a look at the 4 weekly maps:





Notice that on none of these maps do you see a cool and wet westerly flow with a trough over us.  So the chance for the closed ski areas reopening this year seems to be heading downhill.  And the chance for the ski season even turning “okay” is not looking so great either.  I see the fresh 00z GFS looks cold and wet later next week, but it is…the GFS.  The ensemble chart shows the 10-15 day period is much colder on the operational run than the ensembles.  So that colder solution is unlikely.

Enjoy the constant sunshine the next few days!

By the way, I had a great time at the Pacific Northwest Weather Conference over the weekend.  Great talks by different professors, government folks, and some Canadians too,  All dealt with Northwest weather.  I also ran into a bunch of different TV personalities and we talked “shop” of course.


Do you recognize some of these people? Top row: Jennifer Gray-CNN, Chris Warren-Weather Channel,   Larry Schick-Army Corps of Engineers (KING-TV for a long time), Sam Argier-KIRO, Nick Allard-KGW.  Bottom row: MJ McDermott-KCPQ, Rich Marriott-KING, Me (didn’t want to comb hair).

Chief Meteorologist Mark Nelsen