A Wet Week Ahead; Chilly Start to Spring Break

A very nice looking low pressure center will be spinning up quickly the next 24 hours well offshore and head for northern Vancouver Island. Even with a forecast pressure around 985 millibars, it’s too far to the northwest to give us real strong wind either at the Coast or here in the Valleys. That said, gusts 60+ at the Coast and 30-40 mph are likely later Tuesday night and very early Wednesday morning just ahead of the cold front passage. We’ve seen very few (maybe only 1 or 2?) of these strong low pressure centers since late December, so it’ll be a refreshing change. Ahead of this we get a good 6-7 millibars easterly gradient developing through the Columbia River Gorge by sunrise. So those of you out in Corbett and Washougal expect to hear the wind roaring with gusts up around 50+ mph in the next 12 hours. Luckily this time of year the afternoon heating east of the Cascades doesn’t allow the high pressure to linger east side long so that wind will be gone by evening.

Plenty of rain with this system tomorrow and especially tomorrow night and Wednesday.  This is good news because:  1) We’re well below average January-March, and,  2) I just planted 100 Douglas Firs and they need a good soaking to settle in!

What caught my eye today and this evening is how cold the two upper-level troughs are going to be after the cold front passes through. The first comes through early Thursday morning, the 2nd late Thursday night and Friday morning. The NAM model has been “over-chilling” 850mb temps recently; not sure why. For example last weekend it was forecasting around a -7 or -8 and we bottomed out at -6 Saturday morning (or was it Sunday?). Anyway, it’s saying -7 to -8.5 now with a 2nd trough late Thursday night!  The GFS and ECMWF are a bit more reasonable in the -6 to -7 range.  That temp combined with showers could easily allow sticking snow down to 1,000′ or even a little below in the overnight hours.  The issue for Wednesday night is that we still have breezy southwest wind (onshore flow) and showers seem to taper off during the overnight hours.  Then on Thursday night surface high pressure is building in from the SW so we may not have much of any moisture.  It’s something to keep an eye on but I think lack of moisture is going to be an issue if you want anything more than a dusting down to 1,000′. 

Forget about sticking snow in the city of course…it’s too late for that unless we have some sort of solid and heavy precipitation with those chilly upper-level temps.

Friday between 2-4pm Spring Break begins for most Oregon schools and it appears to start chilly.  Not much rain this upcoming weekend but definitely cool.  Good for skiing! 

Models do imply more reasonable temps, but not necessarily dry beyond Sunday.  Here is the 18z GFS ensemble chart, click for a “non-gray” view:

tseries_850t_000-384_Portland

You can see temps go to average or a bit above for next week, so Spring Break may not be a total loss.  But what would that week be without some hail, gusty wind, and occasional downpours?  I spent every Spring Break week of my school career (except one) somewhere between Seattle and Salem and I think I remember 1, or MAYBE 2 that had some sort of sunny and warm weather.

Chief Meteorologist Mark Nelsen

 

45 Responses to A Wet Week Ahead; Chilly Start to Spring Break

  1. Longview - 400 ft says:

    The radar is showing the Portland area is going to get hit with a major heavy shower. In fact, Mark has just mentioned it on the news. Get ready!!!!

  2. cgavic says:

    Correction. Temp was 46. Now 40 degs at 1, 100 ft sandy.

  3. cgavic says:

    46 and rain up at our place in sandy

  4. GTS1K says:

    Dang… 40.4 – raining steadily and heartily last couple of hours. East wind still in charge, here.

  5. W7ENK says:

    Sounds like Seattle gets all the fun tonight… again. 😦

    • W7ENK says:

      Yup.

    • Garron near Washington Square says:

      …And NWS suggesting windy conditions Wilsonville south. So, what’s on the whine list under our ever encompassing dome? I’ll take a case of the bitter stuff for next winter, just in case. Something besides south winds must be able to penetrate this? Oh, wait, south wind only makes it through the dome if there’s a chance for a snow event. Only Commander Adama would know how to break through the shield!

  6. Sapo says:

    This run looks slightly colder than the 18z from yesterday…

    Interesting.

  7. runrain says:

    The rain is having a tough time breaking through to the valley. And some turd is burning brush in Happy Valley and clogging the entire valley in a thick layer of smoke! I hope they are enjoying smoking out all the kids playing at recess. I also would advise against anyone with respiratory problems from going outside here. It is really bad! Surprised the fire department hasn’t addressed this.

  8. vernonia1 says:

    3 broken ribs HURT!!! 😦

  9. W7ENK says:

    LIGHT BREEZE WATCH
    NATIONAL WEATHER SERVICE PORTLAND OR
    1103 AM PDT TUE MAR 19 2013

    http://inws.wrh.noaa.gov/weather/alertinfo/9681624

  10. 32 here this morning, first freeze since the 10th.

    Looking at the last two years, my last freeze was May 1st in 2011 and May 10th in 2012.

    For my Vancouver station, the average last frost in the last 17 years is April 7th.

  11. W7ENK says:

    Hey, someone’s gotta highball this locomotive down the track… she’s been sitting on the siding for three months, all fired up with nowhere to go!

    All aboard! 😆

  12. Choo Choo!

    ♪♫♪ Play that funky music ♪♫♪

  13. runrain says:

    East winds already kickin’ up out there.

  14. bgb41 says:

    3/18/2013 Oregon (All) Temperature Summary

    Warmest:
    High:64 at AGNESS2( 247 ft)
    Low: 46 at Brookings Airpor(459 ft)

    Coldest:
    High:24 at HOWARD Mt Howard(8150 ft)
    Low: 10 at CRAZYMAN FLAT (6100 ft )

    Largest Diurnal Change: 39 degrees
    NORTH FORK MALHE (64/25 ) (3270 ft )
    Lorella (54/15) (4160 ft)
    CHRISTMAS VALLEY (52/13) (4360 ft)

    Heaviest Rainfall:
    0.80″ at HEBOWX Mt. Hebo(3160ft)

  15. TracyEllen Carson Webb says:

    So don’t put the umbrellas in storage yet?!

  16. 850mb temps of -8c in the last 10 days of March is COLD!

    Not only that, but it looks like we get borderline arctic air sliding down from Canada on Friday and Saturday, with 850mb temps possibly as low as -9c in the Columbia Basin by Saturday morning. Of course this time of year high temps will be well into the 40s, but still….

    https://www.facebook.com/notes/karl-s-bonner/late-march-arctic-event/10151483901882767

  17. Whu…hello…… (looks around) first? nah…couldn’t be..

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