Another Snow “Event”?

Snapshot Drew & I just spent the last 1/2 hour doing some serious surgery on the forecasts…any forecast page that involved the time between 7am and noon tomorrow needed some bandaging or maybe even total replacement.  Some of those forecasts were on life-support anyway.

Up until the 00z model runs, it sure looked like the cold air wasn't going to stick around long, plus the precipitation arrived at the same time the good southerly wind arrives.  Here's what I see now that makes me think a widespread snow is likely in the morning here in the metro area:

1.  Nice dry airmass over us…great for evaporational cooling.

2.  On several mesoscale models, including our RPM, they show the sudden evaporative cooling in the north Valley and Metro area sometime around 8-10am producing a "meso-high" pressure right over us.  This thing was there just a bit on one 12z model, but now I see it on 3 models.  This would imply for a couple hours there may be no or little southerly wind at the surface here in Portland.  That's a big one considering the combination with #3.

3.  A nice burst of moderate precipitation at the same time as #2.

4.  In general it just looks good to my weather eyes for a quick morning snowfall.

One big kink in the plan is that several of the models show warming well up there, maybe above 2,000'.  This may give us ice pellets and/or freezing rain (less likely) at the same time.  My gut feeling is that it'll be all snow, but I thought that once with a system that turned out to be all freezing rain too!  So Drew and I threw some ice pellets or freezing rain pockets in as well.

I still like the idea of gusty southerly wind and rapid warming to around 40 degrees beginning around noon.  I also notice a nice westerly surge through the Gorge at the same time.  This will be the first time The Dalles has been above 35 in about 2 weeks!

Gotta go!  Mark Nelsen

95 Responses to Another Snow “Event”?

  1. J.R. (at parents in happy valley) says:


  2. Tyler in Hazel Dell says:

    Nice catch Mike!
    Maybe some snow Saturday morning??? Hmm
    Who else thinks there is the slightest chance???
    850 MB temps around -6, just light precip though, some east wind. MM-5 GFS shows FROPA around 10 PM Friday night and quick cooling behind it. I don’t see a lot of QPF though.

  3. Tetraforce (The hidden fourth piece of The Triforce says:

    I looked up Ice-Pellets cause I’ve been curious to that term and that’s what it looked like happened in our area. I just didn’t know how to describe it.
    Dad mentioned it was sleeting tiny sized flakes …….Minish sized from the Legend of Zelda series. It was realllllllllllllly tiny.
    At times there was snow mixed in such as when I was in the GED lab.

  4. Tyler in Hazel Dell says:

    Woodland snow…
    Upon arriving at work this morning at 6 in Woodland, there was a ice pellet/snow mix. You could here it hit the windshield. It stuck instantly as the temperature fell to meet the dewpoint and the wind was actually blowing it around for a little bit until it became more wet.
    I say we got about 1.5″ before it switched to rain around 11:40 AM. All roads were fine on the way home minus a little slush in shady areas.

  5. Mike from Orchards says:

    Now I know why my earlier post did not post!….lol
    37.6F here with SSW wind……Looks like the rest of the week will be on again, off again showers with the main storm track to the north….
    I’m getting a little worried Rob “Wrath”…….I think we may be running out of time to get a “S Wind” event this season. I know this it is only late January but weather patterns just have not been condusive for any kind of strong, intense low pressure to develope inside of 140W/N35 area. I know we’ve had some wind “events” in the past in Febuary and even into March..such as March of ’63, but I’m wondering if this is the year with just mostly, cold/snow…..just my thoughts….

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