Cool Afternoon

A brief post for now, then more detail on tomorrow night’s system later when I have more time.

As expected, arctic front has just turned into more of a "northerly drift" across the metro area.  At 2pm temps range from 32 up at Kelso to 40 or so down towards Aurora/Salem.  Visible satellite picture shows the edge of the northerly breezes moving down into the Willamette Valley.  And it really is a "drift", very little movement out there.  But mesoscale models never showed a good push from the north.  What they do continue to show though is a good easterly gradient developing through the Gorge overnight.  Of course as that begins we have calm winds here in the metro area for a very cold night, then the Gorge wind spreads across the city tomorrow.  35 seems like a good high since The Dalles should stay around 28.  I am impressed by how cold that arctic airmass was.  12 at Bellingham with the northeast wind raging this morning, and widespread dewpoints below zero in north central Washingotn.  Too bad it isn’t like previous ice storms where that cold air really gets sucked down through the Gorge.  On that note…I have lots of thoughts about tomorrow night, but it’s off to a news meeting because all the newsies want to know the scoop…Mark

304 Responses to Cool Afternoon

  1. Jeremy says:

    Have you considered doing a half-hour or so NW weather show Saturday mornings? Something a bit more technical that pouring water on 28 degree concrete and reporting on it throughout the 10pm news?
    Your blog proves there are hundreds of wx nerds (I included) that would enjoy a more detailed look at NW WX. I love the science.
    The forecast is for the masses. The process to create the forecast is what I’m interested in. The classic ingredients for valley snow or a winter flood, the unpredictability of a summer upper level low, where the models leave off and talent takes over.
    What the heck is the difference between the MM5-GFS and the MM5-NAM?

  2. -100F says:

    I agree, all I want now is 1-2 inches of snow…

  3. luvrydog says:

    Andrew…I think has to do with the wierd pattern…temps not dropping dramatically and at the same time, people are starting to question tomorrow night. I also think it has to do with the fact that the arctic air didn’t make the full intrusion yet that everyone thought it was going to…What I’m worried about is how boring the next week looks after tomorrow…bleah. Looks like we might end up in a ridge or split flow…and we all know that is crap for us weather fans!!!

  4. Matthias - North Portland says:

    New post…Mark says no snow and a VERY brief freezing rain event (if at all). What a bust.

  5. mback says:

    New blog

  6. muxpux says:

    this is a wierd pattern. supposed arctic air over us, and even with radiational cooling with the snow cover up here. only down to 27 after a high of 32 at the Kelso Airport.
    even Abernathy MTN, just NW of town here at 2,000 feet jumped from 15 to 18 in one hour. the 3mph Weast wind may have something to do with it, but its been light out of the east, and their temp has been falling most of the day.
    ive got overcast skies up here in longview btw. was just clear an hour ago. hmmm.

  7. Justin says:

    i’m not exactly ecstatic either about tomorrow night, I stand by what I said earlier. even if everything works out to a tee, I’d say December 18, 2005 at best, 1-2” of snow and a little more sleet/zr. Still, 2” of snow sounds pretty damn nice right about now. I’d definitely take it.
    BTW, now completely overcast here. Really interesting, seeing as many thought that this would be the ‘clear point’ and that the clouds wouldn’t start to filter in until tomorrow afternoon or evening. Definitely do think sub freezing highs are looking more likely, and you can probably scratch those 14-15 degree lows I was hoping for.

  8. Rob *Southeast Portland* says:

    Me either Jacob, not just yet anyhow.

  9. Rob *Southeast Portland* says:

    30.4F Clear skies. My coldest temp yet.
    Wind E 10-18mph
    So my temperature is falling even with the wind. To me that means the Gorge is getting colder so when the offshore flow really getting strong by tomorrow we “should” be firmly entrenched in cold air say Salem north, but especially PDX/Vancouver metro area, and likely in east county/western Gorge.

  10. jacob BPA says:

    IM not totaly sold until I see Wed night temps and dew point we want our dew points in the mid teens the East wind will lower the Dew points

  11. Tyler in Vancouver says:

    Getting ready to head to work here. 27.9 here, DP 25.

  12. Jerry says:

    Mark didnt sound to thrilled about tomorrow nights event.

  13. Andrew---Ellensburg, Wa and Portrland, Or says:

    Not many people posting tonight…

  14. 25 & steady here now
    Sure cloudy out there

  15. J.R. says:

    28.9 here in happy valley near 600ft

  16. mtgirl says:

    23 at 1400ft Chehalem mt

  17. jacob BPA says:

    Days 5-8 look to be interesting
    And the Eastside of the State won’t see a big warm up so our little pool of cold air should somewhat stay intact over there.
    Nothing truly jumps out right now check back Friday

  18. Rob *Southeast Portland* says:

    Jacob talked this morning briefly about the jet earlier for next week.
    This post reflects on that
    This is in the “la-la land” area, but check out the MRF 300mb jet stream model.
    Jet goes right up to SE Alaska/Yukon Territory, then blasts straight S over Washington/Oregon.
    That would be fun.

  19. timmy - scappoose says:

    26 here

  20. mback says:

    WWM. That is funny!! Frost. LOL. I love it. Sounds like we all want the samething at least hu? 27.8 and stil dropping under clear skies.

  21. Rob *Southeast Portland* says:

    Offshore flow is finally kicked in.
    Corbett NE12 G26(which I know is light for them)
    Rooster Rock ESE 13mph
    Humidity levels should really start falling off overnight as well as much lower dewpoint F’s

  22. w.w.m. says:

    Jacob, you guys see anything long term that looks promising? 7-10 day trend? any more cold spells? snow? ice? East wind? frost even? anything?

  23. mback says:

    Derek, you out there buddy?

  24. jacob BPA says:

    You better Stay up late to see snow tommorow Im looking at this and it sure looks that Freezing Rain will Be in the Morning Hope for the Moisture to come in around Midnight WED

  25. mback says:

    Also, 28 and still dropping here in Gresham.

  26. Rob *Southeast Portland* says:

    Low pressure is exiting has exited Idaho moving into Montana. Higher pressure should begin to build more rapidly in the Columbia Basin/NE Washington, so the offshore flow should really get going by morning.

  27. mback says:

    Question. If the east winds do pick up and we get a bit of frozen precip. on wed/thurs. and we freeze Thursday night, gradually warm on Friday, then get brushed by the other system in the Pacific which warms us up a little bit more, could this be the gradual warm up that is in Mark’s 7 day?

  28. Winter weather monster says:

    Well, finally am starting to see a bit more east wind. (troutdale /gresham boarder) nothing to yell about yet but the neighbors flag is starting to do a light dance every now and then,Id say 5-8 mph from east. Also 29.0 here. was cooler earlier, then went to 31.0. Last hour back down to 29.0.

  29. Tyler in Vancouver says:

    I do see some good news in terms of offshore flow developing. Even though the wind at Troutdale is fairly light, the humidity and dewpoint are dropping, good signs of cold/dry air moving in.
    27.5 here, DP 25.

  30. mback says:

    Hmmm, after seeing what I just saw, it sounds as if Mark is thinking we won’t get much precip. on Wed/Thurs.

  31. muxpux *Longview* says:

    26.3 here in Longview according to my thermo.
    also, found a weather reporter whos records are posted on the NWS website. its 1.5 miles away as the crow flies, and same elevation.
    they are reporting 24 degrees and a DP of 18.
    the kelso airport, 2.5 miles as the crow flies (but along the cowlitz river) is reporting 27 with a DP of 21.
    either way. from JUST south of longview northward, there is a nice blanket of snow on the ground. wierd thing happened. it fell as wet snow yesterday and last night. then today with the “drier” air and very cold air, now the top part of the snow is powder, and the bottom is icy. i know it isnt really a “wierd” thing, but found it odd.
    also. i was very pleased to see portland get no snow with this. although i did see PDX got a snow shower during my lunch break. i work down on Columbia BLVD. near the Humane Society.
    for once Longview got all the luck. im sure you guys will get it all next time.

  32. Bryan**Wilsonville** says:

    31* winds ne at 6 mostly cloudy 210ft

  33. mback says:

    Good point Justin and thinking back, weren’t the east winds forecasted for Wednesday anyway? I actually can remember some forecasts said Thursday so maybe things are just going as planned.

  34. Matthew says:

    When the air above, starts warming up, then that signals that warm air is over running it. Not a good sign if the warm air keeps going down the chain. All snow storms I’ve seen, had the whole layer below freezing. See the base of these clouds go from 6,000 to 10,000 or around 800 millibars-700 millibars. So 850 tells how warm the airmass is up to a little over 5,000 feet. It can go up or down based on the air mass/pressure. If the temp is rising at 1,800 feeet that is not a good sign for tomarrow to be all snow. I don’t care if there is a 100 mph east wind moving through the gorge, if the cold air layer is only a few thousand feet thick, then expect the snow to melt before it reachs the valley. Sleet is a deep low level layer of at least 500 feet deep near he surface…Freezing rain falls when just the surface is freezing.
    The Atmosphere is layers, and its important to watch. On the other hand, the latest 850 temps show -9c…So its more then cold enough up at 5k. This warm layer must be near 2,000 feet. Or around 900 millibars???
    We will see.

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