Cold Start to 2017 Looking Likely

Wednesday, December 28, 2016 at 6:45 am

Summary:

A very weak system is brushing far northern Utah bringing cloud cover and a few light snow showers.  Weather should remain calm through the end of 2016.  We will start next week with chances for snow and increasingly cold temperatures.

Details:

Very light snow showers have been moving periodically through northern Utah overnight into this morning associated with the brush-by system we’ve mentioned the last few days.  As expected, highest totals were for farthest north ski areas.  Beaver Mountain reporting 3″ of new snow.  PowMow at 2″.  Most other locations either reporting nothing new, or just a dusting.  We should clear out later today and remain quiet weather-wise through the end of the calendar year.

After New Year, things get more interesting.  A ridge will amplify up the west coast and into the Gulf of Alaska.  This is going to send cold air and weak impulses down the backside of the ridge into the interior West.  Models have been consistent with bringing chances for snow back to the region for the first half of next week, but aren’t generating much significant snowfall.  The 18z GFS operational run yesterday briefly gave me hope that they were trending a bit more organized, but the 00z and 06z runs today went back to a weaker solution.  Overall, there’s just very little agreement, from Sunday night thru Wednesday of next week, ensembles generate anywhere for 0.5″ to 3″ of liquid for the Upper Cottonwoods:

Univ of Utah

So it’s likely we’ll get something, but when and exactly how much remains to be seen.

What we do have more confidence in is the cold, arctic air.  Model runs have showed 700mb temps bottoming out between -18C and -24C.  The former would be cold.  The latter would be close to record cold.  The CPC has clearly seen this chance for frigid air in their 6-10 day forecast:

My experience with these super cold airmasses is that they generally struggle with moisture necessary to generate significant snowfall.  Which is why I think lighter snow is more likely for early next week.

Long Range:

Almost zero confidence in the long range.  ECMWF ensembles generally keep troughing around thru the first two weeks of January, which would suggest chances for storms.  GFS has, at times, indicated that the amplified ridge off the west coast could be undercut by the southern jet.  Perhaps a combination of moisture and cold air… that would be nice.  But at this point it’s all just speculation.

WSF





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  • Brian Belt

    Evan, There use to be a link in the right side of your page with photos that were tagged to wasatchsnowforcast via instagram and other social media sites, what happened to that?