This WINTER IS OVER Post

I have enough confidence (after perusing maps & models) this evening to safely say that winter is over here in the lowest elevations of southwest Washington and western Oregon.  So what the heck does that mean?  There is no sign of an outbreak of cold arctic air in the next two weeks (through the end of February), and strong hints that doesn’t even occur in the three-week period ending the first weekend of March either based on the 15 day runs of the GFS/GEM/ECMWF models. 

So it’s probably better wording to say the THREAT OF WINTER WEATHER in the lowlands is finished:

Without the blast of cold air from the north, a prolonged cold spell, or significant snow or ice storm won’t happen.  Also, with no heavy rain through the end of the month and low snow levels most of the time, we are done with flooding too.

So this is likely going to go down as a La Nina Winter without an outbreak of cold arctic air here in the Pacific Northwest…although that hasn’t been too unusual lately.  Assuming we don’t have a freak occurrence in the next 3 weeks, only 1 out of the last 5 La Nina winters have produced an arctic outbreak (last winter, 2010-2011).    The 5 La Nina winters before that all had at least one event.  Strange eh?

So what is still on the way?  The LONG SPRING begins…several episodes of snow down to at least 1,500′ over the next two weeks, possibly lower about a week from Friday and maybe in the last couple days of the month.

Could we still get snow here in the cities such as Longview, Vancouver, Portland, or Salem?  Sure!  But it would be a brief wet snow that is on the lawns in the mornings and gone in the afternoon…similar to what we saw for a few days late last February.  But as of now that is unlikely in the next 7-10 days at least.

So go ahead and turn on your outdoor water, uncover the faucets, and for the love of all things weather, please take off your studded tires if you have no plans to leave the lowest elevations in the next 3 weeks.  I just turned on my outdoor faucets today.

Those of you looking at maps/models closely probably wonder why I would “pull the plug” on winter when the 12z ECMWF showed arctic air quite close at Day 10?  I almost decided against doing it today, but then noticed two things:

1.  The ECMWF 850mb ensemble chart showed only 1 or two members out of 51 going for anything colder than about a -8 degree temp.  Also, note that the average gradually rises after Day 11. 

2.  The 500mb anomaly map from the 12z ECMWF on Day 10:


Looks great doesn’t it? Strong ridge way offshore and a cold trough that has dropped right in over the top of us. But it’s a transient pattern; here is Day 15 (5 days later):


The ridging has flattened and shifted much farther to the west, trough has filled, and we are back to just a little cooler than average on March 1st.  Not unlike what the 00z GFS shows, lots of cool troughs coming at us from the west beyond Day 10 with hilltop and foothill snow at times, but just cool rain showers in the lowest elevations.  This is a classic late winter/early spring La Nina pattern.  Yes, I realize the GFS has been unreliable much of this winter, but in this case it’s quite similar to the ECMWF the past few days.  This pattern (beyond Day 10) is also what the ECMWF has been showing for several weeks in the weekly maps too.

Hot off the press…the 00z GFS ensemble chart showing the dips in the 850mb temps as the cold troughs come through with -5 to -7 degree values.  One this coming Saturday, then 6 days later (next Friday), then again 4 days later on the 29th.  Followed 3 days later by one more….you get the idea.  You can infer that some ensemble members must be trying to build the ridge closer to us beyond Day 10 since some of the values are up in the 0 to +10 range.

Chief Meteorologist Mark Nelsen

 

47 Responses to This WINTER IS OVER Post

  1. Andrew (Portland....Sylvan Highlands ~800 feet) says:

    The 18z keeps the chilly temps around for the weekend, though not nearly as cold as what has been shown in earlier runs. Looks like PDX bottoms out around -5. Could be a very nice event for those close to and above 1500 feet, maybe even around 1,000 feet if the moisture is steady and heavy enough to pull down some of the colder air above. Long range shows 850mb’s dropping to -8 over PDX next weekend, could get very interesting.

    • Andrew (Portland....Sylvan Highlands ~800 feet) says:

      NWS mentions that the snow level may drop as low as 500 feet Friday night and Saturday with all elevations having the chance to see some wet flakes mixing in.

      SNOW LEVEL WILL BE MAINLY ABOVE THE CASCADE PASSES WITH THE FRONTAL
      PRECIPITATION…THOUGH THE SKI RESORTS WILL BE MOSTLY SNOW…AND SNOW
      LEVELS WILL BE DROPPING THROUGH THE EVENING…SO THE SNOW WILL LIKELY
      GET DOWN TO THE PASSES WITH SOME OF THIS PRECIP. THEN WE GET INTO
      THE DRY SLOT OF THE OCCLUDING SYSTEM FRIDAY EVENING…THEN COLD CORE
      ALOFT SPREADS IN OVERNIGHT. IT IS AT THIS TIME THAT WE HAVE A CHANCE
      FOR SOME THUNDERSTORMS IN THE COASTAL WATERS AND ALONG THE
      COAST/COAST RANGE AS WE GET INTO A LITTLE DEEPER LAYER MOISTURE FOR
      POTENTIAL CHARGE SEPARATION. STRONG COLD ADVECTION BEHIND THE FRONT
      DURING THIS TIME…THICKNESS METHODS AND 850/925 TEMPS SUGGEST THAT
      SNOW LEVELS WILL DROP SHARPLY AND GENERALLY BE AROUND 1500 FEET. THAT
      SAID…EXPECT IT TO VARY CONSIDERABLY ON SATURDAY AS HEAVIER SHOWERS
      EASILY LOWER THAT SNOW LEVEL AT TIMES TO 1000 FEET…POSSIBLY TO 500
      FT. EXPECT WET SNOWFLAKES MIXED IN JUST ABOUT ANYWHERE.

  2. W7ENK says:

    This should be interesting to attend, if any of you can make it…

    http://www.omsi.edu/node/1007

  3. runrain says:

    I know its a LOOOONG way out but I was thinking that, with the 50th anniversary of the Columbus Day Storm coming up on October 12th this year, we should plan a weather blog gathering and share memories and/or experience them from those who remember. I would be happy to reserve the banquet room at Stark St. Pizza. Oct 12 is on a Friday this year which happens to be the exact day of the week the storm hit. Even the time of day will be close (a 6pm start). All those who remember (myself and Boring Larry are two I know) can write a brief summary of what they remember of the storm. I would be happy to read the submissions to the group, which can also be from friends and family of bloggers. I also have a book that local printer Gann Publishing put out documenting the storm that I can share. It would be a fun and interesting evening and maybe we can even conduct it with flashlights and candles to similate the loss of power during the storm :)

    Thoughts?

  4. W7ENK says:

    Interesting post and long discussion about AGW over on Cliff Mass’ blog.

    http://cliffmass.blogspot.com/2012/02/will-we-do-anything-about-global.html

    Chuck Weise chimed in, lots of people trying to hand him his @$$, but he’s standing his ground strong… Rough crowd overt there!

  5. CHECK THIS OUT GUYS accuweather is say that there is 1.6 inches of snow on the way for gresham!!! CLICK ON THE LINK

    http://www.accuweather.com/en/us/gresham-or/97030/daily-weather-forecast/335312?day=3

  6. Andrew (Portland....Sylvan Highlands ~800 feet) says:

    So what your saying is IF we manage to pull off a system that drops a fast 1-2 inches to the valley floor end of February or early march then you have completely busted?

  7. PDX Weather Nut says:

    Winter is over? Seems like winter never “started” in the first place this year.

  8. WEATHERDAN says:

    The odds would favor a warmer spring and summer weather pattern than the last two years. Of course considering how cool the last two summers have been that isn’t saying much. This year Salem should hit 100+ at least once. 1 is our long term average. Last years maximum was 96. Normal maximum is 101. As for 90+ days this year, I feel about 16-19 days. Normal is 16, and last year we had 17 days. All but 4 however were in the low 90,s. 80+ days should be somewhere between 60-65 days. Normal is 58 and last year we had 59 days. 70+ days. Normal is 120, last year was 119. My estimate this year is 124-128. In other words slightly warmer than last year, but nothing to get too exited about. I do feel we will have a better chance to see a few thunderstorms than we did last year. Don’t look for a warm spring. But I think we will eke out a few more nice days than last spring. On a scale of 1-10 2010 being a 4 and last year being a 5. This summer will be about a 6. Of course I could be completely wrong.

    • PDX Weather Nut says:

      Might be a hot summer. Normal number of 90+ degree days in PDX is twelve I believe, might be a bit more in Salem. People seem to forget just how hot the summer of 2010 was here. Temperatures near 110 degrees on occasion!

    • chris s says:

      Pdx weathernut, i believe you mean 2009 for the 110 weather, it was at the end of July.

  9. 12z euro ops run has ~-10c 850 temps SEA on 2/26. I love it. It ain’t over till it’s over! Yeah, climatology/regression to the mean will likely this late Feb blast before it starts, but somebody’s feelin a wee bit nervous about their Nostradamesque proclamation of the end if winter? Come on, we all know only marmots/groundhogs have that magical ability!

  10. NWS..where do they get these #’s ??? Snow level Friday nite 1,700′ & Sat 1,400′ How about just above 1,000′ ??? :)

    • pappoose in scappoose says:

      Always crazy fun discussing the snow levels. My particular favorite is 150′. Most of you have heard my joy when I hear of this prediction. I can go up on the hill behind the house and climb a tree and I’M IN THE SNOW!!!

  11. stormblown says:

    Mark, ruling out 2” snow falls doesnt seem wise considering it can snow that much at 34 degrees.

    Also, is it my imagination or has there been a serious lack of ice storms(freezing rain) in Portland the last 10 yrs when compared to the same period 10-20 years ago?

    • PDX Weather Nut says:

      That’s true. More so with snowfall than ice storms but quite noticeable over the long term. Last real snowfall in town was in December of 2008.

  12. Austin(Cornelius) says:

    Mark…your not old. -_-
    “I feel old when I get out of bed.”
    yeah well stop complaining…old is when you have an oxygen tank, and live at the nursery home. Whaa whaa whaa. PUT A FORK IN IT UNTIL YOU HIT YOUR MID SIXTYS!!!!

  13. bgb41 says:

    2/16/2012 Oregon (All) Temperature Summary

    Warmest:
    High:55 at AGNESS2( 247 ft) & Brookings (US 10(150 ft) & CW3485 Port Orfo(400 ft) & DUNES(120 ft)
    Low: 37 at OCNSID Oceanside(22 ft) & Meno(98 ft) & ROCKWY Rockaway(450 ft)

    Coldest:
    High:19 at HOWARD Mt Howard(8150 ft)
    Low: 3 at Mazama (4590 ft )

    Largest Diurnal Change: 37 degrees
    Sand Creek (US 9 (42/5 ) (4525 ft )

    Heaviest Rainfall:
    0.41″ at YELLOWSTONE MTN.(3080ft)

  14. Sharin Pease says:

    Oh, Mark….I sure hope you are wrong with this. I LOVE THE SNOW, RAIN and HAIL. I really do! Born and raised here in Portland, Oregon and I can remember having snow fall in the 3rd week of March during spring break back in 1961 or 1962. I haven’t given up yet and I continue to do my “SNOW DANCE!”

    PLEASE BE WRONG!!!!

  15. g says:

    Mark doesn’t look a day over 30.

  16. Stick a fork in it, take tires off, uncover faucets, pretty safe bet…. Hope you have some Tabasco in the fridge to help drown the taste of the nasty crow you’ll have to eat on the outside (way outside) chance you’re wrong. There are old weathermen, and bold weathermen, but no old bold weathermen! Plenty of bold weathermen ate crow this non-winter.

  17. Mark, looks like the Gorge is not out of the picture. What’s your take?

  18. Karl Bonner says:

    La-la ridge closer! La-la ridge closer! LA-LA RIDGE CLOSER!!!

  19. Patrick Timm says:

    Well Puget Sound got an arctic blast so not all of the Pacific Northwest escaped one this La Nina.

    • Mark Nelsen says:

      They sure got a nice snow & ice storm, but even Seattle only made it down to 26 this winter and during that event, so I think you’d have to say it only made it into Northwest Washington.

  20. W7ENK says:

    OMG, you officially pulled the trigger!! O_O

  21. B1900 Pilot says:

    Primero. I’m ready to put the fork, knife, and spoon into this unexciting winter.

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