Thursday AM update:
Models still looking great for a long duration snow event. Winter storm watches hoisted for almost all Utah mountains. Still looks like no really heavy period of snow, but two or three bouts of moderate snow with additional light snow over a 3+ day period will start to add up. Thus, with a little more confidence decided to up the snowfall totals to 8-16″ with up to 20″ in spots. Valleys will also see decent snow totals of 4-8″ total over the weekend. Should be great stretch of skiing Friday-Monday in the Wasatch! This is the type of storm that can cause a lot of variability in snow totals depending on where bands set up. So wouldn’t be surprised to have some mountain areas with 6″ and others with over 2 feet when all is said and done. Impossible to really say where those areas will be.
Periods of heaviest snow for the Wasatch look to be Friday night and Saturday night. Possibly again on Sunday night with a trailing wave.
Quick look at the long range shows next week we’ll be on the backside of the ridge with possibly a weak impulse dropping down Thursday or Friday of next week. Then perhaps some retrogression and a chance for bigger storms after President’s Day weekend. Stay tuned … More this afternoon!
GFS and NAM continue to advertise a decent storm system for all of Utah Friday-Sunday. The trough will drop into the Great Basin on Thursday night and move toward Utah during the day on Friday. Right now it looks like the Low will track over Central or Southern Utah. This will bring some very good snows to the mountains to our south. Brian Head and Eagle Point should do well. The Wasatch will also do alright. I wouldn’t say I’m comfortable with this forecast as I am still afraid the low will drop too far south, but at this point it looks like a weak surface front will combine with plenty of moisture to bring at least moderate snows to the Wasatch.
Because this isn’t your typical strong cold front type of system, I expect accumulations to be periodic and lighter in nature over the three day period. Rather than one really deep day, there will probably be three days of skiing with at least some fresh snow. Great news for the weekend warriors! And because it will pass just to our south, the counter clockwise rotation of the low may combine with another weak impulse on Sunday to bring decent wrap around moisture to the area. This may favor the Wasatch Back (Park City/Sundance/Uintas) with an atypical easterly flow. It also sets up the potential for strong downslope winds along the Wasatch Front. We’ll have to watch this closely.
As for accumulations, I’ve been putting this off for a day or two longer than I usually do because of the low confidence I have in this type of system. But I think it’s time to make a rough estimate. Right now I think 1-2 feet is possible for the high elevations of Southern Utah. The Wasatch and Uintas to the north stand to see 6-12″ by Sunday. With the slow movement of the system and the fact that cutoff lows like this have a tendency to hammer some areas especially hard, I wouldn’t be surprised to see up to 18″ in select locations of Northern Utah. The valleys of the Wasatch Front will likely see accumulating snow as well — my early guess would be 3-6″. It will also blow out the inversions and the current bout of bad air.
Unfortunately, this system is another “one and done” kind of system. We might see a few weak impulses next week but it looks like we’ll have another break of 7 days or so. MJO, as mentioned yesterday, is in Phase 1. Long-range models are starting to show the pattern transitioning during the third week of February with stronger, undercutting storms hitting the west coast by the last week of the month. Let’s hope so, as we really can’t afford to let Mother Nature take her time.
Also . . .
Here is the latest discussion from the CPC regarding MJO and it’s anticipated effects:
Uncertainty increases in Week-2, (Week after next) but we favor an evolution where the MJO enhanced phase enters the western Indian Ocean and above-median rainfall is favored, albeit only with moderate confidence, for southeast Africa, across Madagascar into the central IO. Tropical cyclogenesis remains favored in the
south-central *IO due to support from dynamical models, even though it is at odds with MJO composites. Elevated chances for below-median rainfall shift slightly
east in Week-2 associated with the MJO eastward propgation and span an area from the central MC, northern Australia into the western Pacific.
Enhanced convection across the southwest Pacific continues to add uncertainty to mid-latitude impacts from this MJO, but it appears that the enhanced convection in this area may begin to decrease by Week-2. For the U.S., the MJO favors, on average, the development of a mean trough across the western U.S. near or just after mid-February suggesting elevated chances for below normal temperatures across parts of the western U.S..
As we approach the end of February, the MJO would favor on average, troughing near or along the west coast and a tendency
toward a mean ridge across the eastern U.S., favoring elevated chances for above-normal temperatures for portions of the east central U.S. and a more
active weather pattern for the western U.S. with enhanced chances for above-median precipitation.
*IO = Indian Ocean