Monday PM: Rainier Pattern Ahead

What a dry weekend, a brief downpour in spots Saturday afternoon but so far that has been about it.  PDX has only seen .05″ rain so far for the weekend, although I expect a few showers as we head towards midnight.  I was up at Skibowl sledding with the kids last night and it was perfect on the mountain too with temps in the mid 20s, stars and moon, and perfectly calm wind.

So what happens this week?  Not much the next 3 days.  A cold system is sliding down the coast right now.  Looks like the cold front is offshore and will drag inland between now and 2am.  Then a colder surface low off the northern tip of Vancouver Island slides down towards California late tonight and tomorrow morning.  That does give us light offshore flow tomorrow, but other than some convective showers (hail or thunder?), no solid precipitation to drag the sticking snow level lower than about 1,500′.  Remember that about a week ago it looked like we might be quite close to snow tomorrow morning.

Our first strong storm system in many weeks moves inland Friday, both the GFS and ECMWF show gusty south/southwest wind with that storm.  Not high winds, but a reminder that part of winter wants to stick around a little longer, or at least reappear briefly.

Behind this system we’ve got a very chilly atmosphere for the weekend.  The models are slightly different beyond Saturday, but in agreement that Saturday itself will see 850mb temps somewhere between -5 and -7 with frequent showers.  This COULD bring brief sticking snow to sea level at nighttime this time of year (the -6 or -7), but there is strong onshore southwest wind the whole time, or at least enough to keep the airmass well-mixed.  Take a look at the surface pattern:

slp_120_0000

That’s a lot of isobars!  As a result I think it’s unlikely we get sticking snow below 1,000′ and then only at night.

Models seem to want to be about the same or slightly warmer on Sunday.  The GFS is sending another storm over us, the ECMWF is more showery between systems.  The ECMWF waits until Monday morning to send another rain/wind producer inland, with another run at 850mb temps around -6 again late Monday and early Tuesday.  The GFS brings back the -6 temps by Sunday evening (it’s faster). 

They both spell out the same result:  If you want snow this weekend or early next week at the lowest elevations, it’s going to be tough to do based on current models/maps.  That could change, so no need to lose hope yet.  If you live at 1,000′ in the West Hills?  Maybe a dusting Saturday and/or Monday morning…maybe.

Or, we may just see all sticking snow remain at/above 1,500!  That could happen; look at the 12z ECMWF and 12z GFS ensemble charts:

tseries_850t_000-360_Portland

tseries_850t_000-384_Portland

Two things I see…

  1. One is that on both models through the next 8-9 days not only are no operational runs showing sub -7 degree temps, but none of all the ensemble members are showing it either.  Pretty good agreement there.  There is still a chance of course that if a surface low were to go to our south or a front stalls we could see sticking snow to sea level, but as of now that isn’t shown on any model.
  2. They both show a general upward trend beyond Tuesday the 26th.  Still below average for a few days, so if you count this week and most of NEXT week as chilly, it’s going to be quite a cool end to February.  But beyond that there may be warming back to normal…maybe.  I could see us ending up with normal precipitation by the end of the month too as a wetter pattern settles in too.

Wait, I think I can smell Winter 2012-2013 finishing up in the oven…is that normal March wet weather ready to be served as a side dish?  Could be…

Chief Meteorologist Mark Nelsen

32 Responses to Monday PM: Rainier Pattern Ahead

  1. Jordan (Raleigh Hills, 420') says:

    Fri-Tues looks pretty darn cold and rainy/snowy. 18z GFS (and some earlier runs) sure tries to put flakes in the air at least once for PDX during this time period… maybe we can get one last hoorah before winter is over with…

    • Jordan (Raleigh Hills, 420') says:

      Sun PM/ Mon AM looks particularly interesting on the 18z GFS, I might add. Especially for anybody above 1000ft… we can only hope!

  2. runrain says:

    Looking forward to some nice hail and perhaps a stray snowflake and boom of thunder tomorrow.

  3. Ben T says:

    We need a snow and “glice” storm.

  4. Greg Carstens says:

    Mark

    There is a nice stacking pattern as I like to call it going on in the far North Pacific. Systems keep forming east of the Kamchatka Peninsula (East of Russia in the Pacific Ocean). A new 968 millibar low was taking shape there this morning. Basically anywhere from Adak to Anchorage have been getting slammed over the last week or so as the systems leap over the top of a 1037 millibar high that has sharpened this morning and even retrograded a bit in what we like to call the sweet spot for cold systems to slide down our coastline. It still appears at this time and even TWC mentions it as well that California looks like it will see the brunt of the action. At the very least around cool and showery I think and the NWS Digital Forecast Datebase had snow levels for the next week at anywhere from 1,000 to 2,000 feet. I am in your corner and am cautiously expecting very little if anything to happen up this way. Some where I heard a mention of a heavy shower possibly lowering the snow level even down further but I see that idea even being a lucky hit for anyone. Yep best chance at least for right now is above 1,000 feet with 850 temps at -6 C.

    By the way, my analysis for the far Western Pacific off Kamchatka comes from the NOAA Ocean Prediction Center current surface analysis. 🙂

  5. W7ENK says:

    COLD RAIN WARNING
    NATIONAL WEATHER SERVICE PORTLAND OR
    251 PM PST MON FEB 18 2013

    http://inws.wrh.noaa.gov/weather/alertinfo/9275027

    • JJ97222 says:

      I love that cold rain warning, well as most kids are finishing their basketball seasons and gym time like clock work we can see the beginning of winter when the daffodils are 8 inches out of the ground with weeds and crab grass just waiting for next eight weeks of rain to flourish. Baseball anyone?

  6. EY (Oak Grove) says:

    Cool, wet end to February? Yeah, I could get behind that.

    Potential uptick to normal temperatures for March? Yeah, I could get behind that.

    12z GFS Operational saying 850mb temps at 10C by the 4th of March? I can only dream.

    I think someone in the Metro area is going to see sticking snow, and many more are going to see some snowflakes in the air.

  7. PDX Weather Nut says:

    Same old thing … never snows in PDX anymore. Last real snow was in Dec. 2008. Pretty sad “winter”.

  8. Dave in SW PDX (235') says:

    These should do nicely:

    http://tinyurl.com/azoypol

  9. bgb41 says:

    Typo on paragraph #1

  10. Timmy_Supercell (Klamath Falls @ 4200') says:

    Tonight and into tomorrow I stumble upon a chance of snow. Not too much moisture content to speak of, so I may only get an inch (give or take) out of it.

    After that, snow quiets back down. Spring comes back.

    • Timmy_Supercell (Klamath Falls @ 4200') says:

      Looking back at last February; I had easily over 1 foot of snow pack. This is a whole different story 😛

    • PDX Weather Nut says:

      Spring? It’s February.

    • Timmy_Supercell (Klamath Falls @ 4200') says:

      Last weeks of weather here is identical to the average April here. Enough to categorize it as a fake Spring ^_^

    • Timmy_Supercell (Klamath Falls @ 4200') says:

      *Last 2 weeks of weather..*

      alright, enough typos Timmy… no edit button here.

  11. W7ENK says:

    Rainier, like the mountain or the beer?

    • Dave in SW PDX (235') says:

      Ha! That’s exactly what went through my mind as I read the title of this post.

    • gidrons says:

      BTW, what ever happened to those chickens you were babysitting? Or should I ask, how did they taste?

    • W7ENK says:

      They tasted great! 😆

      No, my neighbor came home from Boston, was home for about a week, then went to India for two weeks on business. But, they let me pet them now, and they even started laying, or one of them did — probably the big one, the other one is molting and looks like it flew through a wood chipper. o_O

      Thankfully, they’re not my responsibility anymore!

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