Tuesday AM update:
Warm advection light snowfall never really materialized even in the far north. We’re not missing out on much as at best it would have been very light. Going forecast still looks good for the system entering the area on Thursday. Snow should begin by Thursday afternoon and continue through Friday with snow showers Friday night and Saturday (possibly lake effect/enhanced south of the GSL). Storm total accumulations should range from 8-16″ with up to 20″ in areas favored by west/northwesterly flow like the Cottonwoods. The secondary storm for Sunday/Monday is looking weaker and more ‘splitty’ and likely won’t bring much more than a few more snow showers. Ridging still looks to take hold of the area again next week, so enjoy the fresh snow while you can. Full details can be found in last night’s discussion…
We are continuing to see a clearer picture in the models with what we can expect late this week in terms of snow, hence the title. We will also finally see some clarity in the valleys when this trough moves through starting on Thursday. The inversions have been awful and have been getting gradually worse. In fact, this is one of the worst cases of inversion we’ve seen in Utah. High temps in the lower valleys haven’t climbed above freezing since before Christmas, and in most cases, they haven’t even been close to freezing. Air quality has become hazardous in many locations as well and this can be dangerous for those with respiratory issues. Good thing there’s an end in sight!
Tonight we will see a plume of warm advection moisture sag into the area where it will remain tomorrow. This will generate enough lift to give most of the Wasatch, especially areas north of I-80, some snow showers. Don’t expect anything more than a few inches in the high elevations–and even this snow will be high density with riming possible.
Wednesday we should see an end to the light snow in advance of the main storm system which will drop into the area late Thursday/Thursday night. Eastern Pacific ridge will be retrograding enough to allow this system to dive down the back side with lots of cold air and sufficient moisture. Good agreement now in the models that the system will stay fairly consolidated as it moves through. The system will stall somewhat over the Wasatch which could lead to higher snowfall totals when and where this takes place. This is also a very cold system with frigid upper air temps forecasted. Snow ratios will easily be around 20:1 so even if the high Wasatch only squeezes out an inch of liquid, we’ll still wind up with decent snow amounts. While model agreement is good right now, don’t have much confidence in it staying that way as the GFS and Euro have been playing tag with each other all week. Therefore decided to not overdue the snow amounts quite yet. Right now, I think it is safe to bet on 8-16″ with up to 20″ in areas favored by a westerly and northwesterly flow. These totals may need to be increased as we approach the event if current trends hold.
Weaker, reinforcing shots of energy should drop into the area through the weekend into early next week with additional snow at times–continuing to add to our totals. Then models are hinting at us ridging up again for a period during the third week of January. Signs in the teleconnections and MJO point to a possible return to stormy weather for the end of the month. Let’s hope so!
Hooray for Snow! It’s been getting a bit firm up der in dem hills! Happy Shredding!