Cold Air Still on Track

It’s like the good old days; checking out model updates for weather 5 days from now while totally missing the one day forecast.  As I suspected (but didn’t forecast), the low clouds that developed over us 24 hours ago just sat in the Valley all day.  So on the last day of November with onshore flow and no mixing of any sort, what oh what did I think would clear us out???  I don’t know.  But it did make for a great timelapse from our skycam at 1900′ in the West Hills.  It was above the cloud cover all day.

A bit of a change in the short term is strong easterly flow through the Gorge developing tomorrow afternoon and continuing through Thursday, or Friday.  This appears to be a classic chilly December east wind too.  So after a high near 50 tomorrow I think we’ll be cooler Wednesday and Thursday, with much colder nights where the wind goes calm.  Basically it’s going to get chilly, sunny, and windy for a few days.

Of great interest is the long range of course.  The usual twists and turns keep showing up in various models and model runs within the same models. 

The GENERAL pattern appears to  look like this:  We will see a shot of some sort of cold airmass this weekend and early next week.  Then we go into a much wetter pattern sometime next week as a warmer jet moves in.  My gut feeling is that it’ll be an El Nino-ish warm jet.  Of course the details are the BIG issue.  How cold?  When does it arrive?  When does moisture return?  Or is the ECMWF right (all by itself up through 12z today), showing troughing much farther offshore which doesn’t allow a blast of cold air.  For example, the 12z ECMWF showed 850 mb temps Sunday morning around -3.  The GFS at 12/18z showed -10 or so.  of There is SOME support so far for that warmer solution.  The new 00z NAM is tilting that direction.  More thoughts tomorrow, and Wednesday, and Thursday etc…

Chief Meteorologist Mark Nelsen

183 Responses to Cold Air Still on Track

  1. Pat -n- Metzger says:

    Shouldn’t we have some sort of frozen precip. sometime, even in a transition event? So it is only a matter of time?

  2. steve says:

    Hey Katu showing snow Monday and Tuesday of next week

  3. norman brwon says:

    a so how cold could it get and do u see any snow in any of the modals?.. and what the 12z modal say..

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

    There’s a new post 😉

    12z is MUCH COLDER!

  5. NR says:

    at 126hr it looks like the cold air dropping down is only a cut off from the main cold air that remains in Canada.

  6. Boydo3 says:

    Like sitting on your board waiting for that perfect wave. Even if it isn’t perfect you’ll ride cause it looks pretty damn good!

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

    A nice 12z run and where is everyone? lol…

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

    Hour 120

    Already -10 to -11c 850mb!

  9. Tyler in Hazel Dell says:

    East wind picking up at Corbett…all since 7 AM…

    http://www.wrh.noaa.gov/mesowest/getobext.php?sid=C2664&table=1&banner=off

    • Rob "Wrath" S.E. Portland says:

      Ya!

      Tyler, are we having a conversation. Seems like it. 😮 …

      East wind meeting at Crown Point next Monday?

  10. Tyler in Hazel Dell says:

    12z is much quicker with the cold punch vs. the 6z

    Shows thickness around 527 vs 533 on the 0z at 10 PM Friday.

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

    OKay there we go…. Hmmm

    Hour90

    850mb temps -6c by Saturday afternoon. Correct me if I’m wrong, no really please do. I think that’s a little colder than 0z at the same time frame.

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

    Ugh!

    Stuck on HR48 forever LOL
    I’ve clicked refresh 75 times I bet.

  13. Timmy_Supercell (Hillsboro) says:

    It seems things are getting even more interesting…. Temperatures on 00z sure did look brisk.

  14. Tyler in Hazel Dell says:

    Hmmm look…Offshore/outflow at Bellingham…

    http://www.wrh.noaa.gov/mesowest/getobext.php?wfo=sew&sid=KBLI&num=72

  15. Boydo3 says:

    The 0z euro shows a low sweeping in from the wsw next mon. tue. The 0z gfs shows nothing in that time but has us cold and dry. Wonder what scenario would prevail. A combo would be good!

  16. Ryan (Walnut Grove) says:

    Hmmm… It seems people are getting dangerously close to wish-casting right now.

    It will certainly get cold and there will be the possibility of a transition event giving us a day of snow (possibly)… But, There is nothing in the model data thus far that screams epic snowstorm which has been bantered about on occasion here.

    I do know the EURO has gone nuts with the potential for it. But, at last check the GFS, NAM, and ECMWF aren’t indicating anything major. I didn’t see the 00Z ECMWF but wasn’t the 18Z indicating temps no where near what the other models where kicking out?

    • Rob "Wrath" S.E. Portland says:

      Ryan,

      Last night’s 0z GFS was great, 0z GEM was solid, and 0z EURO was AMAZING. Also 0z GFS ensembles shows much colder solutions.

      Of course wish-casting or overly getting ones hopes up might be weather suicide right now.

  17. Tyler in Hazel Dell says:

    Rob, I’m curious…yesterday I was mentioning one of the models showing a major warm up after a short bout with cold air, starting about next Thursday. You said that was too far out to worry about.

    However, you just said

    “The systems after the 9th will likely be moving in from the southwest meaning they will continue to pull very cold air through the Gorge.”

    Isn’t that too far away to worry about???

    • Rob "Wrath" S.E. Portland says:

      Ah yeah of course.. Was just hypothetically speaking about a possible scenario.

    • Rob "Wrath" S.E. Portland says:

      Based off the 6z GFS… Let’s just get the cold air well in place (3-5) days before we can discuss those type of details.

    • Ryan (Walnut Grove) says:

      But will we have that much cold air on the east side of the state? It’s the first really cold air mass to enter the east side so it won’t be all that established yet.

    • Rob "Wrath" S.E. Portland says:

      Usually with 3+ days of east winds 30+mph that does the trick. I know it’s all about baby steps. Get the cold into the Columbia Basin. Develop a strong east wind. Establish thick cold low level air mass. Then the real wild card MOISTURE.

  18. JHills says:

    Rob, when do you sleep? LOL! Thanks to you and everyone for all the insight and information you post on the blog – My work doesn’t allow me much time to pour over model data etc but i truly enjoy the recaps and opinions you guys provide! Keep it up and fingers crossed for the weekend..

    • Rob "Wrath" S.E. Portland says:

      I slept 7 hours Monday, but last night sleep wasn’t an option unfortunately. Of course whenever there is an impending weather event my weather weenie geek syndrome kicks in full gear and with that type of adrenaline pumping through me sleeping isn’t important. 🙂

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

    I’m sure hoping today’s 12z GFS/EURO are as epic as last night’s. The only reason I say hoping is because we’ve seen models tease us into believing something and then POOF take it right away. As I said a few hours ago the agreement last night gives me confidence.

    • Snow-Zone/Monmouth-Elv200' says:

      Yes, I want cold, snow arctic blasts. Each day the models need make this look more and more like a done deal, set and sealed no questions asked.

  20. stevied (North Portland) says:

    something new… 12z NAM forms a low Fri morning over NW tip of Wash and brings moisture in

  21. threefeetofsnowplease! says:

    Isn’t the 12z coming out soon?

  22. PaulB/Eugene says:

    From SFO AFD:
    FOLLOWING THE GEM AND ECMWF WOULD BRING RAIN CHANCES TO NORTHERN
    CALIFORNIA BY SUNDAY…ESPECIALLY LATER IN THE DAY AND HAVE KEPT
    POPS IN THE CHANCE CATEGORY. MODEL SOLUTIONS ACTUALLY BRING WARM
    ADVECTION RAINS ONSHORE SOMETIME SUNDAY EVENING BUT ENOUGH
    UNCERTAINTY TO AT LEAST MENTION RAIN CHANCES DURING THE DAY SUNDAY.
    RAIN CHANCES THEN INCREASE OVERNIGHT SUNDAY INTO MONDAY. THE EURO
    HASN`T REALLY WAVERED OVER THE LAST THREE MODEL RUNS WITH TWO
    RELATIVELY WEAKER STORMS SUNDAY NIGHT THROUGH TUESDAY WITH THE
    REMNANTS OF FORMER SUPER-TYPHOON NIDA ARRIVING ON WEDNESDAY. AGAIN
    THE GEM MODEL IS VERY SIMILAR TO THE EURO IN TIMING AND INTENSITY
    WITH AT LEAST TWO ~980-985 MB LOWS PASSING WEST OF CAPE MENDOCINO
    MONDAY THROUGH WEDS OF NEXT WEEK. THE ONLY THING KEEPING CONFIDENCE
    DOWN SLIGHTLY IS THE FACT THAT THE GFS MODEL KEEPS THINGS DRY UNTIL
    WEDS. CONSENSUS IN HOUSE AND WITH NEIGHBORING OFFICES IS TO DISREGARD
    THIS AND WOULD EXPECT TO SEE NEW RUNS OF THE GFS TREND MORE IN LINE
    WITH THE EURO. ITS GETTING HARD NOT TO START DRAWING ANALOGIES TO THE
    OCTOBER EVENT WITH ANOTHER RE-CURVING FORMER TYPHOON TAKING AIM AT
    THE CENTRAL COAST AND NORTHERN CALIFORNIA. TO GIVE AN IDEA ON
    RAINFALL POTENTIAL…AND THESE ARE VERY COARSE AND PRELIMINARY AT
    THIS TIME THE ECMWF GIVES 4 DAY STORM TOTALS OF 5-7 INCHES IN THE
    HILLS WITH WIDESPREAD 3 TO 5 INCH RAIN TOTALS FOR THE VALLEYS. OVER
    IN THE SIERRA THE LATEST RUNS GIVE STORM TOTAL QPF OF NEARLY 19
    INCHES OF LIQUID PRECIP. STILL WAY TOO EARLY TO GET SPECIFIC BUT
    OBVIOUSLY THE SANTA CRUZ MOUNTAINS AND BIG SUR COAST COULD REALLY GET
    NAILED AGAIN. AS WITH THE OCTOBER STORM WILL EVENTUALLY HAVE TO LOOK
    INTO WIND AND BIG SWELL POTENTIAL AS WELL. ITS NOT TOO EARLY TO START
    YOUR STORM PREPARATIONS.

    • Rob "Wrath" S.E. Portland says:

      Hmmmm interest read. Sounds like the southern jet is going to be monstrous… Which will probably keep the lows south of PDX allowing arctic air to overspread the PNW…. Just my thoughts based on the SFO AFD.

      Paul, in reading Seattle’s NWS I got a sense that the system on Friday may drop much further down the Coast which would lead to the onset of colder temps arriving sooner I’d say Saturday instead of Sunday afternoon.

      Any thoughts?

    • Rob "Wrath" S.E. Portland says:

      Interesting*

    • Snow-Zone/Monmouth-Elv200' says:

      Oh forget talking inches of rain, snow…. wouldn’t there be feet of snow if we had arctic air firmly in place and the lows tracked south?

  23. Timmy_Supercell (Hillsboro) says:

    Looks like i missed a couple of posts, went to bed early last night…

  24. JHills says:

    Just up watching KGW and they introduced Rod Hill as the newest member of their weather staff… Good to see him back on the scene!

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

    Oh no:o

    It was Cherie from Vernonia b-day yesterday.

    Happy belated B-day!

  26. Annie in Vancouver says:

    42.8
    has gotten very foggy here in the past hour or two. Can’t see much beyond about 100 feet.

    … And up with a sick toddler. Good times 😉

    • Rob "Wrath" S.E. Portland says:

      Ah sorry to hear that.

      41.9f here light fog.

      East wind will be developing before noon.

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

    Annie in Vancouver Says:
    December 1, 2009 at 3:42 am

    Doesn’t that say Troutdale will be dry the whole time it’s cold enough to snow though?
    ———————————-
    Yeah until the 9th-10th…

    Remember 2 things
    If an arctic air mass is in place for 3+ days with constant east winds models will try to move out that air mass too soon. Also models don’t see the Gorge and don’t handle the depth of cold air very well either.

    • Rob "Wrath" S.E. Portland says:

      One more thing I noticed. The systems after the 9th will likely be moving in from the southwest meaning they will continue to pull very cold air through the Gorge. Models sometimes try to weaken that too soon as well.

    • Annie in Vancouver says:

      Ahhhh, yes – I forgot about that! Thank you Rob!

    • Rob "Wrath" S.E. Portland says:

      You’re welcome.

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

    AREA FORECAST DISCUSSION
    NATIONAL WEATHER SERVICE PORTLAND OR
    211 AM PST TUE DEC 1 2009

    .LONG TERM…AFTER FAIRLY GOOD AGREEMENT IN THE SHORT TERM…THE MEDIUM RANGE MODELS DIVERGE SIGNIFICANTLY EARLY IN THE LONGER TERM PERIOD…ESPECIALLY THE NCEP GFS MODEL. THE 00Z GFS TAKES A SHORT WAVE OVER THE WEST COAST RIDGE INLAND WELL TO OUR NORTH ON FRIDAY… LEAVING US DRY. IT ATTEMPTS TO TURN THE LOW LEVEL FLOW BRIEFLY ONSHORE BEFORE TURNING IT STRONGLY OFFSHORE AGAIN THIS WEEKEND AND EARLY NEXT WEEK.

    THE ECMWF…CANADIAN…AND EVEN THE NAM12 BRING A SYSTEM DOWN FROM THE NORTHWEST ON FRIDAY WITH SOME COLD VALLEY RAIN AND MOUNTAIN SNOW. WILL POSSIBLY NEED TO UP POPS FOR FRIDAY IF THESE TRENDS CONTINUE. THE CANADIAN AND ECMWF BOTH THEN SHOW A CUT BACK SYSTEM INTERACTING WITH SOME SOUTHERN STREAM ENERGY AND MOISTURE EARLY NEXT WEEK WITH A LOW SETTING UP OFF THE COAST.

    THIS COULD BE AN INTERESTING PATTERN DEVELOPMENT WITH OFFSHORE FLOW THROUGH THE GORGE. CURRENT FORECASTS TAKE A CONSERVATIVE APPROACH AND WILL CONTINUE THAT FOR NOW…BUT WILL NEED TO MONITOR HOW THIS DEVELOPS. TOLLESON
    &&

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

    Okay out to day 8… I don’t bother looking further.

    All in all a “decent” 6z GFS run. It wasn’t outstanding. As I said I’m not concerned as this isn’t a major model run there isn’t as much info, variables, etc. that goes into the 6z/18z which is why often forecasts are based off of the 12z/0z GFS, 12z/0z EURO, or even a blend of the two. Also ensemble members weigh heavily on trends which you then will see the operational models shift to.

    The trend that matters are the 0z GFS is on board. 0z EURO on board, 0z GEM on board, and 0z GFS ensembles on board.

    Hoping 12z GFS later this morning is as kind as last night’s 0z set of models.

    Good night all.

  30. Mixer Mixing Mixed Yevgeniy Mixed Mixing Mixer says:

    check out that LOW FORMING A H192!!!

    • Azzurri says:

      Days 12-15=Pineapple Express? From frigid and snowy to balmy and….floody? Should be rather exciting the next few weeks.

  31. muxpux says:

    HR 144 has the -12 line right over top of us….

  32. Annie in Vancouver says:

    Does anyone happen to know if any local or online colleges/schools offer a meterorology class or course for total amateurs like myself? I *really* wanna learn, learn, learn – but am finding it difficult to DIY-it online by myself. For every one thing I learn, it seems to bring up 20 more questions.

    Or, really any type of resource that’ll teach the basics up to being able to read & understand maps?

    THANKS! I know this is sorta off subject… 🙂

    • Azzurri says:

      You can perhaps take a beginners course on the atmosphere but meteorology involves a strenuous amount of physics, calculus and some chemistry.

    • Ryan (Walnut Grove) says:

      There has been talk off and on about the AMS holding a “weather boot camp.” Last mention it was a possibility for this coming spring.

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

    Okay that’s MUCH better…

    -12c over PDX by late Sunday night.

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

    Well to HR 132 things definitely have slid off to the east… But no way I am panicking yet given the solid model agreement with last night’s 0z GFS/EURO/GEM.

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