Is it going to snow Friday? Briefly, for some

If you’re looking for a snowstorm, this isn’t the setup for the Portland Metro area, but a lot of us may see snowflakes at least in the air on Friday morning.  Here’s what’s going on this time around:

A cold front drops through our area tomorrow afternoon, with a nice line of showers, dumping snow down to about 1,500′ just before and around sunset.  Then we dry out and turn chilly as a Canadian air mass descends over the Pacific Northwest for tomorrow night and Thursday.

A strong warm front surges right on in over the leftover cold air late Thursday night and early Friday morning.   This sets us up for a (very) brief period of snow at the lowest elevations from the Portland Metro area north into Western Washington.

The change is going to be most dramatic in the mountains.  Government Camp goes from 52 today, to about 35 tomorrow, 28 Thursday, then back up to 40+ Friday and into the weekend.

Timing will be everything with the possible action on Friday morning.  If the precip arrives late, a mixing south wind may start to develop, if the precip arrives early (before 7am), we could all see a dusting briefly.  Luckily we have 2 more days to figure things out.

I do notice on the evening models (especially the WRF-GFS and our RPM), there is little to no mixing until closer to 10am.  They also both show heavier precip to the north of the metro area.  That’s why I mentioned Clark county in these graphics:

MarkSnow_PortlandOutlookPercentages

MarkSnow_PortlandOutlookPercentages2

Whatever happens, by midday the snow level will be jumping to around 8,000′ and it’ll be raining even at the ski resorts!

My gut feeling is that it’s not going to affect anyone’s life much at all from the Columbia River south…we’ll see.

 

By the way here is the snow forecast from our RPM:

RPM_SNOWACCUM

and the 00z WRF-GFS:

wrf_snow
Chief Meteorologist Mark Nelsen

80 Responses to Is it going to snow Friday? Briefly, for some

  1. Punxsutawney aka HIOPHIL in Hillsboro says:

    30.9 even here in Hillsboro and the road is mostly ice. Won’t be long and all of it will be frozen.

  2. boydo3 N Albany says:

    I’m no fan of cold to warm transitions.
    I’ve said this before but, who cares if it snows, only to be rained on before it gets to stick around for a few days? Kinda like having a nice big chocolate bar handed to you, you get a taste, and then it’s ripped away before you can even get a second bite. I could probably come up with a better analogy but it might get censored 😉

  3. pappoose in scappoose says:

    “The chances of snow on Friday morning are now very high and in this blog I will explain why.”

    http://cliffmass.blogspot.com/2013/12/friday-snow-understanding-uncertainties.html

    • chris says:

      so if it comes in a little earlier than expected would that mean higher snow totals or would south winds also come in sooner?

    • Ben T says:

      Excellent question Chris.

    • David B. says:

      As the event has drawn closer, models have generally been forecasting more snow to fall, earlier, before the winds scour the cold air away and change things to rain.

      Earlier this week it was an off chance of there maybe being enough to stick and leave a dusting behind, now the talk is of 2-4 inches. Exciting news, but I will wait until Friday morning before doing any happy dance.

    • pappoose in scappoose says:

      Good news right now is that more moisture is available earlier, as David B. says.

  4. davidbarts says:

    Hmmm….

    THE MM5 SNOW PROGS SEEM REASONABLE. THESE BRING AROUND 4 INCHES OF SNOW TO THE SEATTLE METRO AREA…PERHAPS A BIT MORE TO AREAS NEAR THE CASCADES AND TO THE FAR NORTH. AMOUNTS TAPER TO THE SOUTH WHERE WARM AIR ARRIVES SOONER. TACOMA GETS AROUND 2 INCHES…OLYMPIA AND POINTS SOUTH AROUND 1 INCH. THE CURRENT WINTER STORM WATCH IS GOOD.

    I’m starting to like these forecast amounts!

  5. kcteach says:

    Was 39 at 5pm and now down to 33.2 in Gresham.

  6. down to 30 and icing up here. is that a batch of moisture plunging south from Olympia? their last OBS reported rain. hmm.

  7. Heatblizzard says:

    We seem to become a *colder* version of San Diego lately where the weather remains always the same with very little in the way of actual storms. Instead our excitement or challenge is forecasting cloud coverage.

  8. W7ENK says:

    ABSOLUTELY NOTHING ADVISORY
    NATIONAL WEATHER SERVICE PORTLAND OR
    634 PM PST WED DEC 18 2013

    http://inws.wrh.noaa.gov/weather/alertinfo/13369334

  9. Model Rider says:

    I don’t see how their under a WSW. By looking at radar and satellite it looks pretty scarce. Hmmmm….

  10. Model Rider says:

    The rain just turned to snow in Redmond. With a low of 18 tonight its gonna be really icy under the snow tonight.

    • Timmy_Supercell (Klamath Falls @ 4200') says:

      No moisture down here yet… maybe tonight I’ll see something. Or I could just 100% miss it altogether! It’s happened..

  11. marinersfan85 says:

    Seattle is going to score again. Portland will be left green brown and wet. Portland Oregon Sucks. I miss Seattle. Winter storm watch issued for the Puget Sound.

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

    Looks like once again, Washington will steal our thunder.

    … well, er.. in this case it’s snow 😉

  13. David B. says:

    Hmmmm….

    SAN JUAN COUNTY-WESTERN WHATCOM COUNTY-EAST PUGET SOUND LOWLANDS- WESTERN SKAGIT COUNTY-EVERETT AND VICINITY-SEATTLE/BREMERTON AREA- TACOMA AREA-ADMIRALTY INLET AREA-HOOD CANAL AREA- 323 PM PST WED DEC 18 2013

    …WINTER STORM WATCH IN EFFECT FROM THURSDAY EVENING THROUGH FRIDAY AFTERNOON…

    http://forecast.weather.gov/wwamap/wwatxtget.php?cwa=sew&wwa=winter%20storm%20watch

  14. gidrons says:

    The 12z Euro could give some interesting Christmas eve weather to people above 1000′.

  15. JohnD says:

    I personally am a little bit pumped about the weather
    for the next 36-48 hours. A good little “mini” winter
    pattern is going to ensue (before it warms up again)
    and around here–as we all know–by golly, you have
    to take you you can get. I will be jumping for joy
    if we see even ONE snow shower in the city this
    evening–and you know what?–I think we might!

  16. runrain says:

    Somebody STOP me!

    Blocking Ridge (sung to the tune Silver Bells)

    Blocking ridge, Stubborn ridge,
    Why do you sit there and rile us?

    Sky is clogged, with your fog,
    You simply won’t go away

    Clouds around town, Ski slopes are brown,
    You send weather away,
    And the bloggers are weary and sad

    Arctic winds pass, down to Kansas
    And we can’t get a flake,
    Soon the flowers will all be in bloom!

    Blocking ridge, Stupid ridge,
    What did we do to deserve this?

    Giving fits, it’s the @#$#*,
    This could be a winter bust!

  17. ocpaul says:

    HUMBUG:-/

  18. weathergirl colton1000 ft says:

    Thanks for getting Colton on the map!! LOL.

  19. The same soundings I was looking at yesterday don’t show as much moisture today. Also, the upper levels do start to warm somewhat. No major mixing until the 1 PM sounding when a SW wind develops and a lot of warm air rushes in.

    I don’t think this is at all the type of situation where “cold” air will take longer to scour out. It’s not very cold/dense like we get with arctic air, and there won’t really be any offshore flow either.

  20. schmit44 says:

    12/17/2013 Oregon (All) Temperature Summary

    Warmest:
    High:68 at RED MOUND(1753 ft)
    Low: 52 at RED MOUND(1753 ft)

    Coldest:
    High:19 at NYSSA(2172 ft)
    Low: 4 at Beatty (4320 ft )

    Largest Diurnal Change: 46 degrees
    DW9630 La Pine (58/12 ) (4256 ft )

  21. schmit44 says:

    Our strong blocking ridge has produced an extremely wet and warm 7 day period at Ketchikan, AK. Just a few hours ago it finally dropped to 32 degrees with light snow for the first time in over a week. 15.02″ of rain has fallen in the last 168 hours there.
    http://www.wrh.noaa.gov/mesowest/getobext.php?http://www.wrh.noaa.gov/mesowest/getobext.php?wfo=mso&sid=PAKT&num=168&raw=0&dbn=m&banner=off

  22. Reb G says:

    Been waiting a while to go up snowboarding until some better snow falls…. But even Timberline is not looking good. Any new outlook for snowfall up there?

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

    There’s a chance I may miss it this time. And something about this winter is smelling a lot like summer drought for next year.

  24. dothgrin says:

    And then…yes, it will probably snow Thursday, as schools are either half day or off. Thanks weather. Thanks a lot.

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