White Christmas Unlikely For Metro Area

9am Saturday

Some of us woke up to a little snow this morning!  Precipitation is dwindling to just about nothing now but as the first cold air poured through the Gorge that area has seen 1-5″ snowfall (as forecast) and even a dusting fell in Portland’s West Hills and far east metro area (Troutdale & Gresham).

Today will be a dry day with increasing sunbreaks & cool temps.  The cold easterly wind will pick up in the Gorge and central/east metro.  Gusts 30-40 mph are likely in the windy parts of the metro area and 60-70 mph in the Gorge by this evening/overnight.

Of course the big question is Sunday and Christmas

THE BIG PICTURE

  1. The chance for a metro area ice or snow storm has gone downhill since yesterday, models are pushing that area of low pressure farther north.  This isn’t a “sure deal”, but models are heading in a warmer direction.  Sorry kids!
  2. Yesterday I gave the metro area a 50/50 chance of widespread snow (A White Christmas). I give it a 20% chance now.  It’s going to be too warm overhead to support snow for most of us in the metro area after the early morning hours.
  3. After some icy spots Sunday AM, most likely driving conditions will be okay Christmas Eve & Day across MOST of the metro area.  Best chance for icy roads midday & beyond would be top of West Hills and east of I-205/into the Gorge.

NOW TO CHRISTMAS MORNING WEST OF THE CASCADES

  • Oregon Coast will be a bit too warm for either freezing rain or snow through this event.  Good driving conditions out there, although the Coast Range could have brief freezing rain or snow around sunrise Sunday and it’ll be a mix of rain/snow through Sunday afternoon over those summits.
  • Dry through late tonight; gusty east wind blows through the Gorge and into metro area…high around 40 today.
  • Around sunrise Sunday. or a bit before, the western valleys will get a brief mix of freezing rain/snow/rain.  Some areas will be a bit too warm and just liquid rain.  We’re talking spotty stuff.  Temperatures hover right around freezing so there should be some spots of ice on roads.  I expect nothing to 1/2″ snow in spots…that’s itThat’s all you get folks! This includes down into the central Willamette Valley and up to Kelso/Longview too.
  • By mid/late morning tomorrow (and for the rest of the day), temperatures will be above freezing in just about all parts of the metro area and roads above freezing as well.  Again, I don’t expect significant travel problems for most of us tomorrow in the lowlands.
  • Tomorrow afternoon steadier precipitation picks up.  By that time temperatures a couple thousand feet overhead will be too warm to support snow.   But to get freezing rain to freeze on roads at that time of day our temperatures would have to be at least down to 30.  That’s not going to happen except right near/in the Gorge and possibly the top of the West Hills.  Thus my reasoning for expecting little/no traffic impacts after early tomorrow.
  • After sunset Christmas Eve and into Christmas Morning temperatures should hover at least a few degrees above freezing in most of the metro area, with freezing rain (ice accretion) continuing only near & in the western Gorge.  I’m thinking mainly right around Troutdale/Gresham/Camas areas
  • Most likely 90% (or more) of the metro area wakes up to 35-40 degree rain showers Christmas morning.

IN THE GORGE & HOOD RIVER VALLEY

  • A snowstorm is coming tomorrow from Multnomah Falls east
  • Expect some light snow right around sunrise, probably less than 1″.
  • Then midday tomorrow through Christmas morning expect 2-6″ new snow.  That should make for a nice 5-10″ snow on the ground for a White Christmas morning…enjoy!
  • Western Gorge will see more freezing rain than snow tomorrow afternoon/evening.  Watch out around Cape Horn, Bridal Veil, & Corbett later tomorrow.

 

Of course all the above points are based on the system moving inland just to the north as shown in this AM’s WRF-GFS model.  You see the surface low up in SW Washington at 7pm tomorrow:

And you see the result in the model snowfall forecast…almost nothing west of the Cascades.  Forecast soundings don’t support snow after early in the morning…the layer of cold air coming through the Gorge is and will continue to be very shallow.

All models seem to be coming into line with this setup (warmer than yesterday’s Euro model).  This is one time the Euro is getting beat by the others…a sad day!

IF FOR SOME REASON MODELS ARE OFF BY 50-100 MILES AND THE LOW MOVES IN SOUTH OF US, WE GET SNOWSTORM TOMORROW AFTERNOON.  But even the Euro doesn’t show that now.

So continue on with your normal pre-Christmas & Christmas plans but keep a close eye on the forecast, this blog, & temperature around your home.

Chief Meteorologist Mark Nelsen

 

 

104 Responses to White Christmas Unlikely For Metro Area

  1. specialK says:

    Sleet/ZR innner SE PDX now…. coming down nicely.

  2. Nahtalkin says:

    Sleet and ZR

  3. Alohabb says:

    It’s coming down at a good rate here. Mostly sleet. But that east wind is still really strong. Should make tonight even more interesting

  4. ocpaul says:

    Freezing rain at 300′ in Oregon City. 32.5 temp

  5. W7ENK says:

    0835: Sleet just started falling in Milwaukie.

  6. Alohabb says:

    Freezing rain/sleet falling at a good rate in Aloha.

  7. White Christmas Advisory up this way:
    http://forecast.weather.gov/showsigwx.php?warnzone=WAZ559&warncounty=WAC035&firewxzone=WAZ654&local_place1=Bainbridge%20Island%20WA&product1=Winter+Weather+Advisory&lat=47.628&lon=-122.5216

    Though there’s caveats with it. The low is forecast to come in just barely south of me. Any northward deviation and this one’s probably gonna mostly bust for me. And the models are seldom exactly right, and to further erode confidence in that forecast they’re disagreeing somewhat on the storm track. Euro is the most bullish on snow for me.

    Nothing to do really but wait and see.

  8. Garrison - Aumsville says:

    Freezing rain for the past hour here 10 miles SE of Salem

  9. TruckinAint4Sissies says:

    From Weather Underground:
    “… Winter Weather Advisory remains in effect until 10 PM PST this
    evening…

    what… mixed precipitation expected. Some snow and sleet may mix
    in with the freezing rain Sunday morning and early afternoon,
    but the main round of freezing rain is not expected until late
    Sunday afternoon and evening. Total ice accumulations of up to
    two tenths of an inch are expected. Greatest ice accumulation
    expected east of I-205 and across The West Hills. Little to no
    snow accumulation expected. However, there is a small chance
    precipitation stays as snow through Sunday evening, which could
    bring snow accumulations of up to 2 inches.
    Where… in Oregon, greater Portland Metro area. In Washington,
    Greater Vancouver area.
    When… 8 am to 10 PM today.
    Additional details… temperatures are expected to warm above
    freezing in places like Hillsboro and downtown Portland Sunday
    evening, but the east pdx Metro and West Hills of pdx may hold
    onto below freezing temperatures until late Sunday night.

    Precautionary/preparedness actions…

    A Winter Weather Advisory means that periods of snow, sleet or
    freezing rain will cause travel difficulties. Be prepared for
    slippery roads and limited visibilities, and use caution while
    driving. The latest Road conditions for the state you are calling
    from can be obtained by calling 5 1 1.”

  10. Well everyone have a Merry Christmas! I probably won’t be in much today or tomorrow.

    At least whatever moisture breaks through from the moisture working up the valley should be snow this morning. NWS still going brief mix this afternoon to rain with the main moisture. They still mentioned the wrench that is the EURO/GEM going into Lincoln City. But for thr moment it still seems thr northly track has the highest odds.

    If nothing else enjoy the next 8-10 hours. 😁

    • Side note, there is a warm finger over Salem… Mornings sounding shows it above freezing (both wet bulb & temp) around 1000′.

      I miss the temp gauges on the tower which gave us a great temp profile over Portland.

  11. Sprayandpay says:

    This site and Fan Fiction.net are not that far apart other then the fact that you may actually find some good fanfiction in there despite all the 12 year olds pounding on keyboards (or are they monkeys on keyboards?) I’ll let you decide.

    It’s okay to disagree about models (as models these days are pretty much broken with old data not fit for the modern climate regime) but when it resorts to name calling then name calling about the name calling all over junk science that’s too far and most people don’t have time to wade thru all that.

    This is where a mod needs to step in and clean up a lot of posts. Too bad Mark doesn’t do that and often goes after legit users who have vast knowledge so people like DJ Droppings AKA Rob Wrath go away and people like Weather Phil will never poke their face in here.

    It’s a cluster trap. This blog is like when Seattle or DC has a snow day and a few centimeters of snow screws everything up and a run on bread,milk and toiletries after five flurries fall.

%d bloggers like this: