Monday PM update:
Winter Storm Watch in effect for the Wasatch south of I-80… NWS calling for 1-2 feet of snow by Thursday with 6-12″ north of I-80 in the mountains. I feel that is a bit excessive and still think 6-14″ is more realistic with 4-8″ north of I-80. 12-18″ is possible for some of the high mountains of S. Utah.
Weak system on Thursday night into Friday will keep light snow showers going, mostly in the mountains. Strong storm arrives Saturday. I’m not willing to say it will be “major” just yet, but it definitely has potential. Here is an excerpt from the NWS’s discussion:
CURRENT EUROPEAN AND GFS MODELS INDICATE A VIGOROUS STORM SYSTEM
WILL AFFECT NORTHERN UTAH…PERHAPS WESTERN VALLEYS SOUTH TO CEDAR
CITY…THIS UPCOMING WEEKEND. THIS SYSTEM HAS A VERY NICE MOISTURE
TAP…IN ADDITION TO THE AMBIENT WATER VAPOR LEFT OVER FROM THE
PREVIOUS STORMS…TO AID IN EFFICIENT PRECIPITATION PROCESS. VERY
UNSTABLE WITH 700MB TEMPERATURE NEAR -18C AND 500MB TEMPERATURE NEAR
-37C. THE DYNAMICS ARE ALSO LOOKING STRONG WITH A VERY SHARP COLD
FRONT. LAKE EFFECT WILL ALSO LIKELY BE A CONTRIBUTOR WITH COLD
CONDITIONS…BUT TOO FAR OUT TO ASSESS FLOW PATTERN. IF THIS STORM
PANS OUT AS CURRENTLY ADVERTISED…IT WILL LIKELY BE ONE OF THE BEST
STORMS OF THE SEASON THUS FAR.
Moderate (strong for S. Utah) storm system Tuesday night – Thursday. Whether you have today off from work or not, it might be worthwhile to enjoy the relatively quiet weather we’ll have before things get active tomorrow afternoon. Low pressure system will start dropping down the west coast tonight and then start to move inland tomorrow. An initial flow out of the southwest tomorrow afternoon could fire up some snow showers in Northern Utah. As we head into Tuesday night, the flow will turn southerly as the Low tracks through far southern Utah. This is very similar to the system we had last week and the Wasatch got skunked in the southerly flow, so therefore we are going to tread carefully and only forecast a few inches of new snow by Wednesday morning. During the day on Wednesday the flow will turn more easterly, which could favor the Wasatch Back with some heavier snow, then eventually turn northerly by Wednesday evening, and finally northwesterly Wednesday night. The snow should intensify and become more widespread as the flow finally turns northwesterly. My best guess right now for the Wasatch would be 6-14″ by the end of the day Thursday when the snow winds down. This is a broader range than I usually forecast but that reflects the hard-to-predict nature of relying on wrap-around moisture and orographics for most of the snowfall. There is also the potential for banding to occur which would dump good amounts of snow on one area while other areas see very little. It is impossible to know exactly where those bands will set up. GFS, NAM, and WRF are all suggesting decent snows though, so think all resorts will at least reach the 6″ mark.
Southern Utah, on the other hand, will see most of their snow on Tuesday night and Wednesday as the Low tracks over them. This snow will be heavier and more widespread than in the Wasatch. Eagle Point and Brian Head will likely have very good days on Wednesday with 6-12″ possible.
Thursday night – Friday night will be a bit of a break with periodic light snow likely. The break day will be Friday but a persistent NW flow will keep moisture aimed at N. Utah so we will likely still have off and on light snow in the Wasatch but it doesn’t appear like much in the way of accumulation.
Colder, stronger storm moves in on Saturday. This system is looking very good for potentially significant snow in both the mountains and valleys. GFS and Euro in good agreement with the GEM particularly bullish. Too early to forecast exact amounts but Saturday and especially Sunday could be money for powder hounds like myself. We are talking quintessential deep Utah fluff.
Beyond next weekend, models diverge a bit. GFS flattens the Jet and we go into a moist zonal flow. The Euro keeps the pattern a lot more amped and brings in another very cold system around next Tuesday. No matter what, it still looks to remain active and there is no point fretting about it now with so much active weather in the next 7 days.
P.S. WSF is famous! Well, not really, but I do post these same weather forecasts for OpenSnow.com which is featured in a short article in this week’s Time Magazine about sport-specific weather sites. OpenSnow.com is a collaborative effort to bring quality ski forecasts, made by local weather professionals, to their respective areas. No more automated ski forecasts made by some computer in Atlanta! Great news for myself and my colleagues who work hard to bring you the best forecast possible.