Meteorological Fun Ahead

It’s still pouring in the Cascades this morning; I see Timberline Lodge has received more than 3″ of rainfall.  I don’t think that happened last winter and I know it didn’t happen during the cold snowy winter of 2007-2008.  Not a perfect pineapple express of course but plenty of very warm rainfall.  The rain will taper off tomorrow morning, but until then it stays very wet up in the mountains with a good surge coming through tonight.

As the rainfall finishes up, we get a glancing blow of arctic air from the big surge headed into the middle of the country.  Models have been very insistent on a dramatic surge of cold/dry air into the Columbia Basin this evening and overnight.  We go from no easterly gradient through the Gorge this evening to 10 millibars or so by midday tomorrow (see image on the left).  On the right you can see the WRF-GFS 5,000′ temp forecast and then you really see the reason for the wind.  Notice a 23 degree temp over Hood River and The Dalles at 5000′ but it’s about 20 degrees warmer over the westside?  So that thick pile of air cascades down into the Gorge west of Cascade Locks like a waterfall (a very loose analogy I know, but that’s how I think of it).  So obviously precipitation type after midnight tonight is a real pain east of Multnomah Falls.  It’ll probably be an instance where it’s light rain, then drops below freezing in spots in the western Gorge, then turns to all snow east of Cascade Locks.  Depending on the changeover time the east end of the Gorge could see an inch or six inches!  Tough call of course.  I do notice the meteogram for The Dalles and Hood River shows temps below freezing all day over there.  It sure wouldn’t hurt to get several inches of snow in 1/2 of the Columbia Basin either since we have many days of easterly wind ahead.

What about here in the Metro Area?  That rainy sloppy junk continues today and tonight, then we gradually just break up tomorrow as the rain ends by midday.  Should brighten up quite a bit later in the day with a bit of downsloping wind.  I’d give it a 10% chance of something frozen (freezing rain only) here in the Metro tomorrow morning, increasing to 50% chance just east of Troutdale/Gresham (Corbett, Washougal hills).  If anything the cold air will be slower to move in than expected.  Then it’s on to a windy and chilly day.  Temps will hold in the lower 40’s all day.  Gusts to 65 mph are likely at the west end of the Gorge and 45 mph Troutdale/Camas/Gresham.  Not sure if we get the “slop-over” of cold air down the west slopes of the Cascades; this model would indicate some.  If so, all of the metro area will be windy, not just east of I-205.  Either way we’re going from warm, humid, and calm today to chilly, dry, and windy tomorrow.

Chief Meteorologist Mark Nelsen

75 Responses to Meteorological Fun Ahead

  1. Christiana in Forest Grove says:

    Okay so wind is moving in a little earlier than expected. What does that mean for snow and freezing rain chances in the valley?

  2. Andrew (Ellensburg, Wa) says:

    Winds have switched to the NE here in Ellensburg, though very light. Still warm, sitting at 36 degrees with a dewpoint of 32.

  3. Rob "Wrath" S.E. Portland says:

    Surface Gradients
    As of 10 PM|Current|Hourly Change
    [Gorge]
    PDX-DLS: -5.5mb | 0.5mb Increase
    TTD-DLS: -5.7mb | 0.5mb Increase

    Sorry, wwm too tired to think.

    Good night all. Hopefully the east wind wakes me up. If so I’ll be back…

  4. wwm says:

    my wind detector (the great and reliable “twig method”) is showing some minor pick up in the east wind. I like that it seems to be earlier than expected.

    question…Is there actually a speed (mph) assigned to each mb? or another way… does each mb represent a mph? so if it is 10 mb is that what 45-50mph?
    and where to where are you getting the 10 or so mbs? is it from the low to the high?

    man, hope thats not too mmuch to reply to.

  5. Rob "Wrath" S.E. Portland says:

    Surface Gradients
    As of 9 PM|Current|Hourly Change
    [Gorge]
    PDX-DLS: -5.0mb | 0.5mb Increase
    TTD-DLS: -5.2mb | 0.4mb Increase

    • stevied (North Portland) says:

      seems to be ramping up nicely

    • Rob "Wrath" S.E. Portland says:

      Yes Sir. Not only that but it’s ahead of tonight’s 00z WRF. Also the cross-section model doesn’t even show east winds developing until 3 AM… Both are wrong.

  6. Rob "Wrath" S.E. Portland says:

    A few excerpts from the evening NWS AFD.

    AREA FORECAST DISCUSSION
    NATIONAL WEATHER SERVICE PORTLAND OR
    834 PM PST TUE JAN 5 2010

    THE NEXT SYSTEM MAY MOVE IN AROUND FRIDAY. THIS SYSTEM HAS A LOT OF WARM AIR ALOFT…BUT WILL LIKELY OVERRUN THE COOL LOW LEVEL AIR MASS THAT IS IN PLACE. WE SHOULD LIKELY SEE WINTRY PRECIPITATION IN THE GORGE…BUT THERE IS A CHANCE OF FREEZING RAIN IN THE NORTHERN VALLEYS AS IT WILL LIKELY BE VERY COOL THURSDAY NIGHT AND FRIDAY MORNING…MORE THAN LIKELY BELOW FREEZING. TOLLESON

    OFFSHORE FLOW CONTINUES SUN NIGHT INTO MON…BUT NEXT SYSTEM IS DUE IN MON NIGHT AND TUE MORNING. MON NIGHT SYSTEM HAS POTENTIAL FOR HIGH WINDS ALONG THE COAST AS IT SWINGS BY TO THE NORTH INSIDE OF 130W…BUT THE DETAILS OF THIS COULD CHANGE SIGNIFICANTLY OVER THE NEXT FEW DAYS SO IT IS NOTHING TO GET OVERLY EXCITED ABOUT. DALTON
    &&

  7. Rob "Wrath" S.E. Portland says:

    Surface Gradient
    As of 8 PM|Current|Hourly Change
    [Gorge]
    PDX-DLS: -4.5mb | 0.6mb Increase
    TTD-DLS: -4.8mb | 0.6mb Increase

  8. Tyler in Hazel Dell says:

    Looks like the COOLER air is into Omak now…
    http://www.wrh.noaa.gov/mesowest/getobext.php?wfo=otx&sid=KOMK&num=72

    Clearing skies, temps and dewpoints dropping

    Haven’t seen a sign any further south than Blue Lake really.

    http://www.wrh.noaa.gov/mesowest/mwmap.php?wfo=otx&map=otxc&list=1&sort=name

    • Rob "Wrath" S.E. Portland says:

      +1 for the Blue Lake reference/report. I agree although pressure is rising in the Columbia Basin.

  9. Rob "Wrath" S.E. Portland says:

    Surface Gradient
    As of 7 PM|Current|Hourly Change
    [Gorge]
    PDX-DLS: -3.9mb | 0.6mb Increase
    TTD-DLS: -4.2mb | 0.5mb Increase
    [Cross-Cascade]
    OTH-GEG: -2.6mb | 0.4mb Increase
    [Fraser River Outflow]
    BLI-YWL: -16.6mb | 1.1mb Increase
    *Strongest of the Winter

  10. Andrew (Ellensburg, Wa) says:

    36 degrees here in Ellensburg, no colder air here yet.

  11. Mr Data says:

    I am more curious as to what it takes to get 50+ *daytime* and sunshine in January for the mid valley?

    I want some warm/sunny weather for even just a tweeny tiny bit.

    • boydo3 N Albany says:

      Actually the coast can have some really nice weather when the H moves over us in the winter, we get a bit of offshore drift. In fact Brookings has hit the seventies under the right conditions this time of year.
      Surf’s up dude!

  12. Mr Data says:

    I just happened to check and it’s now 54F. The artic air is here! 😮

  13. Gordon says:

    So once we get this east wind going it should continue through the end of the work week when another storm comes in about Friday. Thats a good 2-3 days of chilly east winds drying us out and cooling us down. Any chance we get a repeat of the 29th come Friday?

  14. Mr Data says:

    For anyone who cares especally Rob my email is at 86kylexj@wavecable.com now if you wish to chat.

    I promise to not let Monster Tetra take over. 😮

  15. Rob "Wrath" S.E. Portland says:

    Now three consecutive hours with increases in the PDX/TTD-DLS gradient. Definitely beginning now.

    Surface Gradient
    As of 5 PM|Current|Hourly Change
    [Gorge]
    PDX-DLS: -3.0mb | 0.6mb Increase
    TTD-DLS: -3.4mb | 0.7mb Increase

  16. Mr Data says:

    Aloha!

    55F out here and tropical. “55 saves lives.” 😉

    We can’t even GET KPTV or any other station here in Silverton unless we pay a lot of $$$ for cable which has a lot of garbage we don’t like.

    I’d LOVE to be able to watch Mark’s segments but at least I can see his 7-cast.

    • Sandi (Wilsonville) says:

      We cannot watch KPTV either as we didn’t do the digital TV switch nor do we want cable. However, if you go to their website, often there is a video of Mark’s forecast you can watch. Maybe that will help?

  17. Rob "Wrath" S.E. Portland says:

    NE winds have developed here. 4-9mph…. It’s all uphill from here!

  18. Randy says:

    Mark Nelsen is a great meteorologist. I hope KPTV knows how important he is to their station and lines his pockets accordingly. If they ever lost him it would be a big blow to their station.

  19. Rob "Wrath" S.E. Portland says:

    2nd consecutive hour and PDX/TTD-DLS continues to rise…. Hmmmm could be the beginning of the east wind onslaught…

    • Rob "Wrath" S.E. Portland says:

      Yes it is.. That’s quite a bit stronger from the past several runs. Nice trend….

      Oh also did you check out the extended 12z WRF?
      982mb

      Not too bad of a SW-NE trajectory, but would like it further east.

      Also check out the overall pattern.

      Nice trough carved out and strong SW jet also with bitter cold over Alaska. Perhaps by the end of January we return to cold/snowy.

  20. Rob "Wrath" S.E. Portland says:

    Hmmmm this might be interesting, or it could be just a temporary fluctuation.

    PDX/TTD-DLS increased 1mb the past hour. WRF/models didn’t show easterly flow developing until 7-10 PM. OTH-GEG cross cascade gradient also turned flat/very light offshore. Looking at the Mesowest page northerly winds are increasing over north central Washington and the Columbia Basin with a few locations at/over 40mph. Dewpoints are beginning to fall as well. If easterly offshore flow is already beginning to develop this could be 4-8 hours ahead of the WRF. Wondering if this might signal a bit stronger cold push into Eastern Washington….

    • JohnD says:

      Rob,
      What are the implications of your comments?–e.g. just a longer period of slightly cooler winds?–or–is there any potential what-so-ever for an East Portland “Big Event” of the kind that Steve Pierce was alluding to on Sunday?
      Thanks.

    • Rob "Wrath" S.E. Portland says:

      I think east of I-205 45-55mph possible as the time height/cross section model shows now with 50kts sustained just off the surface. As far as a wintry event… Not likely. I suppose we could flirt with ZR though.

  21. Rob "Wrath" S.E. Portland says:

    Sure would be nice to see tonight’s 00z WRF add 1-3 more mb, or a stronger inversion.

    Yes I know. “You’re crazy, Rob! Isn’t 80+mph gusts enough?”

    The answer to that is “No! 90+mph or I’m going home!”

  22. Debbie Taylor says:

    A balmy day in Beaverton- 54 degrees! However, I see that it’s only 43-45 at my home in Fairview! I’m ready for the wind and to see some blue skies for a bit- bring it!

  23. Steve Pierce (Vancouver, WA.) says:

    ** VISTA HOUSE WIND ALERT **

    I have had a good look at the latest meso-scale models this morning. If you want to experience some extreme wind, some of us are attempting to pull together a group of folks to meet at the Vista House (Crown Point) tomorrow (Wednesday) at 1pm. Based on latest model projections, I would expect to see wind speeds in excess of 80mph there tomorrow.

    Anyone have an hour to spare tomorrow about that time? Let’s do it.

    SP

  24. Steve Pierce (Vancouver, WA.) says:

    ** WEATHER WEENIE ALERT **

    For all the unemployed, self-employed, part-time employed, swing shift employed, graveyard employed, folks on vacation, independently wealthy, stay at home parents, etc….

    I have had a good look at the latest meso-scale models this morning. If you want to experience some extreme wind, some of us are attempting to pull together a group of folks to meet at the Vista House (Crown Point) tomorrow (Wednesday) at 1pm. Based on latest model projections, I would expect to see wind speeds in excess of hurricane force (likely 80-85mph) there tomorrow.

    Hope to see you up there Wednesday at 1pm!

    SP

  25. Mr Data says:

    What does it take for us to have 50+ and sunshine in January without south winds to cheat us?

  26. Mr Data says:

    South winds here and 54F after a low of 53F.

    Talk about Tropical! 😮 It’s global warming here all right. 🙂

  27. Rob "Wrath" S.E. Portland says:

    I see the BLI-YWL Fraser River Outflow gradient is up over 14mb nearing 15 now. North winds blowing across north central Washington too. Seems to me the modified arctic air is moving south slowly out of southern British Columbia about 120 miles north of the Canadian border.

  28. Good update Mark!

    Just bring on the east winds!

    49.5F

  29. Rob "Wrath" S.E. Portland says:

    Mark, thanks for the update.

  30. Gidrons says:

    Guess which part of the continental US that this National Weather Service forecast is for:

    SHORT TERM [TODAY AND TONIGHT] CLEAR…DRY AND COLD DESCRIBE
    CONDITIONS THROUGH TONIGHT. DEEP LAYER NORTHWESTERLY WINDS CONTINUE
    TO USHER PROGRESSIVELY COLDER AND DRIER AIR INTO THE REGION AS A
    LONGWAVE TROF PATTERN PERSISTS ….

    FRIDAY…SATURDAY AND SUNDAY COLD WITH NEXT ARCTIC RIDGE MAKING ITS
    IMPACT ACROSS . NIGHTTIME MINS DURING THIS PERIOD BECOMING
    BITTERLY COLD. CONSIDERING THE OFFICIAL FORECAST…WILL LIKELY HAVE
    TO CONTEND WITH DANGEROUS WIND CHILLS WITH THESE RANGING FROM NEAR
    ZERO TO 10 ABOVE. WILL CONTINUE TO HIGHLIGHT THURSDAYS WINTRY
    WEATHER PRECIPITATION POTENTIAL AND STEP UP WORDING ON WEEKEND WIND
    CHILLS IN THE LOCAL HAZARDOUS WEATHER

  31. WEATHERDAN says:

    Boring weather for the next 10 days. Then it looks like temps go down to average. But I still see no chance of cold weather next 16 days. However axis of cold air shifts to Rockies late in the time frame. This is the first time recently I’ve seen even a hint of a Western cooldown though.

  32. Bobbo says:

    10% chance for FZR? woooooooooooo hoooooooooooo!!!!!!!!

  33. Gidrons says:

    No Boring Larry
    You were not the first this time
    but thanks for playing

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