New Snow!

TLDR: 3-9” fell today at various places.  Expect another tr-1” overnight (1-3” favored locations).  Then high pressure with only occasional clouds (Sat, Tue) from dying storms to our north and south for the next 7 days.

The background grey color in the valley today wasn’t too different from the grey over the past few days, but oh what a difference the white flakes in the air and fresh coating of snow made!

As of 4pm it looks like the following amounts have accumulated since sunrise this morning: Upper Little Cottonwood 7-9”, Upper Big Cottonwood 5-7”, Park City area 3-5”, Ogden area 4-6”.  Park city snow stake cameras were even less generous than that.  Since around noon today we’ve been in the post-cold front “hit and miss” regime with moist northwesterly flow, which favors the Cottonwoods.  A few of the flakes this afternoon may have been lake-enhanced as some weak, but relatively well-formed, cloud bands extended southeast of the lake (see below looking southwest from the Univ. of Utah at ~4pm MDT).

20181212_155030

We may get a little more snow this evening but most indicators have the atmosphere drying out in the next couple hours.  One weather model, the experimental FV3, keeps some precipitation coming until about midnight but it is the outlier.  If you believe weather forecasting in general is difficult, try forecasting Great Salt Lake lake-effect snow, which usually humbles even the most seasoned forecaster.  I predict the combo of weak lake-effect and other snow showers will bring another 1-3” overnight to the upper Cottonwood Canyons, with most of that falling before midnight.  Hopefully I’m wrong and we get more!

FV3 3-hour accumulated precipitation valid at 13/0300 UTC.
FV3 3-hour accumulated precipitation valid at 13/0300 UTC.

After tonight things don’t look promising.  High pressure and sun are certain Thu and Fri.  A dying storm skirts to our north early Sat, likely just bringing clouds.  Dry and warming conditions late Sat-Mon are followed by another dying storm that should stay south of us on Tue (again just clouds) with dry and warm after that.  Enjoy the new snow because it’s doubtful we’ll get more in the foreseeable future.

-Tyler

Smog Today, Snow Tomorrow

Lake Bonneville is filled with (cloud) water today. A stratus deck is covering the eastern Great Basin all the way down to Cedar City. Up here along the Wasatch Front, it’s mixed with some pollution, but thankfully the clouds are relatively high (which helps dilute the pollution). And above the clouds in the mountains there is a fantastic undercast. To orient yourself in this image, the Uintas are the broad mountains in the upper right, and the Cottonwoods and Oquirrh Mountains are due west of those.

2018-Dec-11 Terra/MODIS imagery via NASA
2018-Dec-11 Terra/MODIS imagery via NASA

Winds will pick up tonight ahead of the storm, at least in the mountains. In the valleys, the inversion will crack in the morning when the snow gets here. Right now the expected timing is that first flakes will start around 6 AM in the mountains, but it won’t start really picking up until after 8 AM when the front comes through. Snow rates will be pretty high along the front, and 3″ per hour rates are very possible in the intense areas. That’ll make for some gnarly driving conditions going up the canyons in the morning–it’ll probably be safest just to wait until it winds down a bit.

While snow rates may be high, it is a very fast moving storm, and the bulk of it will be done by around noon. The mountains will be the last place to stop snowing and will hold on to some showers for the rest of the afternoon as the Wasatch are wont to do. I’m expecting  5-8″ for most places in the mountains with 7-11″ in the Cottonwoods.

After this storm we’re looking at another dry spell. The next chance of snow is a week from today, and the air will be warm and still until then. There’s even a chance the highest Wasatch peaks will break melting by Friday night. Here’s hoping tomorrow’s storm performs well and gives us a good coating of powder!

This Week: The Bluebird/Snow Day Seesaw

TLDR: The inversion layer should ease away a bit by tomorrow, and a decent snowstorm will bring the goods down to the valley floor. Resorts pull in a good 5 or 6 inches at least. Look forward to a seesaw of bluebird and snow days in the coming week or so.

Good *cough* day everyone *cough*. I hope you had a chance this weekend to make a few turns and enjoy some blue sky. I’ve got news on several upcoming storms this week but first want to highlight an opportunity tomorrow. Think fresh air, totally blue skies, powder flying behind you. Yes, Tuesday’s going to be a good day to be on the slopes if you can catch a break from work. Check out the HRRR forecast below for example:

HRRR Simulated IR
HRRR Simulated IR Imagery, valid 11AM MT Tuesday Dec. 11. Colors are related to cloud top temperatures and can infer the existence of clouds. Light blues and whites suggest no clouds or low clouds. Courtesy tropicaltidbits.com

Infrared imagery can be used to identify both areas of cloudiness and the parts of the country which an astronaut could see through to the surface. Given that, I believe the light blue colors over northern Utah are a mix of clouds and cold surface temperatures. Perhaps by the afternoon resort skies will clear up. Therefore, a trip to the mountains could be a sunny break from the polluted layer we’ve been living in over the past several days. *cough* Speaking of which …


The State of the Atmosphere

The skew-T plot below is a good way to study the inversion layer currently trapping pollution close to the surface in some Wasatch Valleys today. The underlaying haze will sit as deeply as about 1500′ above the surface, where cold surface air is bounded by the base of the inversion layer.

Skew-T
KSLC Radiosonde Skew-T Diagram, 5AM MT Monday Dec. 10. The data are marked by the red line (temperature), green line (dew point), and thin blue line (wet bulb temperature). Vertical Axis relates to height above the surface, horizontal axis is marked with temperatures in deg C. Annotated in red is the layer of the atmosphere where temperature is warming with height i.e. the inversion, blue for cooling i.e. trapped surface air. Annotated in black is the approximate height of each layer. Courtesy NWS SPC.

Tonight

Tonight, this surface layer is flushed somewhat and the overlaying temperature inversion relaxed as a slow-moving cold front passes through northern Utah tonight. This means low-level particulate amounts shouldn’t get much worse before Wednesday. If you look at Tyler’s and Alex’s weekend posts you’ll get the debrief on tonight’s system. Current details haven’t changed much since then.

Further, we can make out this weak front in an afternoon visible image from the GOES-17 satellite. Clouds surround the feature as it crosses the western US.

GOES-17
GOES-17 Visible Satellite Imagery, 2:45 PM MT. Estimated locations of fronts marked with red (warm), blue (cold), and purple (occluded). Annotated with timing of impact at SLC, Utah. Courtesy RAMMB/CIRA at Colorado State University.

Wednesday

Also, note the cyclone centered off the coast of southeast Alaska. This system will hammer the Cascades beginning around midnight tonight, as it pulls in an abundance of moisture from the tropics (the tail of the cyclone marks an atmospheric river that extends southwest to the western tropical Pacific). Next, the interior west gets the leftovers, which won’t bring the snow dump we saw the weekend before last, but should put down snow at all levels in northern Utah and a decent layer of snow in the mountains.

The National Weather Service predicts about 6-12″ in the Wasatch, but I would bump the upper end down an inch or two–say 6-10″–for most ski resorts in the Wasatch. I’ll wait for the high resolution models to come in tomorrow before I’d consider increasing amounts in this range. In any case, northern resorts (Snowbasin, Beaver Mtn …) and Wasatch Back (Park City, Deer Valley …) will be weighted toward the lower end of range and Cottonwood resorts toward the higher end. Locally higher amounts can be expected.


The Week Ahead: Timing

From a broad perspective, this pattern seems to continue for the foreseeable future: A system brings the goods, then a bluebird day or two before another system hits the interior west.

We have tonight’s front and a break tomorrow. Wednesday’s storm, a break Thursday and blue skies Friday are followed by another storm late morning Saturday.  Beyond Saturday could be a break Sunday before another system hits Monday or Tuesday. This last storm is picked up by European and American models and is something to watch through the next week.

Happy skiing,

-marcel

 

 

 

Change Can’t Come Soon Enough

TLDR: 

A Weak cold front passes Mon night into Tue morning with maybe 1” of mountain snow.  The better chance for snow is early Wed throughout Wed.  There’s decent uncertainty with the Wed storm and totals range from 3” to 12+” as of now, so check back as we get closer.

DETAILS:

Conditions are rather miserable along the Wasatch Front but much better in the mountains.  Temperatures today for the most part were a bit warmer in the valleys vs. mountains but that will change for tomorrow (Mon) as most mountain sites will be slightly warmer than the valleys.  Skies will be partly cloudy becoming mostly cloudy by afternoon.  So, head to the mountains if you need a break from the pollution etc. in the valley (just take a bus or carpool).

A relatively dry cold front will move through the area early Tue morning with a chance of maybe 1” of snow with cloudy and windy conditions the rest of Tue.

Some light snow is possible overnight Tue-Wed as a better storm approaches and arrives early Wed with precipitation through much of the day.  This fast-moving storm will be accompanied by windy conditions, but snow amounts from the different forecast models and ensemble members span a wide spread as of this writing.  The graphic Alex posted yesterday hasn’t changed much so depending on the storm moisture and trajectory, we could see 2-6” or 8-14”.  Below are the SREF ensemble members to give an idea of the spread and likely precipitation accumulations.  Check back tomorrow to see if models and ensembles begin to converge on a solution.

usw_pic

LONG RANGE:

High pressure will build back in Thu-Fri with a storm beginning to impact the west on Sat, but this far out the Sat storm appears to deteriorate by the time it hits northern UT.

-TKW

Colder Tonight

Not very much has been happening this weekend weather-wise. A shot of cold air moved through the mountains, and temperatures are dropping from near-melting to well below freezing tonight. Alta Base reached up to 32°F this afternoon, but it will plummet down into the teens and maybe single digits overnight. But the winds have been calm, and it’s been pretty dark with some clouds and long midwinter nights.

The cold won’t last long though as warm moves in in the next few days ahead of the next storm. By the end of the day Sunday the resorts will be flirting with the melting line, and by Monday temperatures should be above 32°F in the afternoon. The warmth will be accompanied by clearer skies and even calmer winds (and thickening pollution in the urban area). Later in the day Monday high clouds will move in from the north as the midweek storm approaches Utah.

The next storm will be a two-parter. The first part will be Tuesday, but it won’t bring more than clouds and some flurries. The second part is a fast-moving storm bringing cold air and snow to northern Utah. To show the current state of thinking about this storm, I’d like to draw attention to the graph below showing a few dozen model simulations of precipitation in the Cottonwoods. Each line represents one ensemble member’s accumulated precipitation/snowfall, and all of the thick lines are ensemble means of one kind or another.

Modeled Potential Precipitation at Alta this week, via University of Utah Dept. of Atmospheric Sciences
Modeled Potential Precipitation at Alta this week, via University of Utah Dept. of Atmospheric Sciences

Notice how the means don’t have very many actual model lines near them. That shows that there are really two dominant possibilities of what could happen. One is represented by all the model lines grouped together at the bottom in the  1-6″ range. In that scenario the storm stays mainly to our north. The other possibility is that northern Utah takes a direct hit, and those model lines cluster around 12-16″ (with some outliers going higher).

Right now I’m leaning towards the higher solution, but it is too early to really say much of anything. This storm would be Wednesday, and today is just Saturday. In the meantime we get to enjoy what we have and hope the snowmakers are taking advantage of tonight’s chill.

East coast kind of day

Well, today certainly felt like I was skiing back home. I’m not entirely sure if I mean that in a positive way but being raised an east coast skier certainly makes it easier to put up with rugged snow conditions. The sun over the past few days has done its work, crusting exposed southerly slopes, and its absence today kept the resort groomers pretty firm.

Alta Webcam Friday Afternoon (12/7)
Alta Webcam Friday Afternoon (12/7)

The mountains may receive just a trace of snow overnight tonight before the ridge begins to dominate the synoptic setup and the tap shuts off. That’s not to say the column is devoid of moisture, but there’s not much to make it productive, and drier air filtering in at mid to upper levels will quickly dominate. A stubborn, shallow, broken cloud layer will likely stick around throughout the better part of Saturday, beginning to clear out in the early evening and overnight. By Sunday, subsidence under the building ridge just upstream dominates, and temperatures will warm under sunny skies. The ridge is evident in both the 500 (not shown) and 700 mb (shown below) flow fields, with the axis more or less to our west early Sunday. The lack of white shading indicates low 700 mb relative humidity, helping to prevent any cloud development.

GFS 700 mb streamlines (showing wind/flow pattern) and relative humidity (shaded)
GFS 700 mb streamlines (showing wind/flow pattern) and relative humidity (shaded) at 5AM MT Sunday 12/9

If you’ve lived here long enough, you know ridging in the winter time commonly comes with surface high pressure and strong temperature inversions, capping the valley air and allowing pollutants to accumulate. As Taylor previously indicated, these conditions will likely worsen in the valley through the weekend and into early next week until we get a significant trough passage to help mix out the stable layer and cold air pooled within the valley. Please, do your best to reduce emissions by carpooling and other environmentally conscious decisions. “What you burn is what you breathe!”


Ok, ok, I know you all want to hear about the next storm. It’s still too far out to even hint at total accumulations, but let’s see what we’re working with. Spaghetti plots (aptly named) are a great way to help visualize model uncertainty. The trough that is expected to pass through the region on Tuesday is present in most of the GEFS members, with a few suggesting the development of a closed low over central California. The model mean develops a fairly shallow trough that is a little too far to the north to be a big producer for us here in Utah. The trough does continue to amplify (strengthen) as it moves through and off to our east on Wednesday, but it is a case of too little too late, it seems. A second, slightly more amplified trough enters the region late Wednesday and makes its passage on Thursday, bringing the potential for a more significant dose of mountain snow.

GEFS Ensemble 500 mb heights showing the uncertainty associated with the amplitude of the trough passing through on Tuesday.
GEFS Ensemble 500 mb heights showing the uncertainty associated with the amplitude of the trough passing through on Tuesday.

With that framework in mind, yes, we can take a (cautious) look at the plumes to summarize the outcome of the ensemble forecast (leaving out a lot of in-between detail here).

NAEFS (GEFS+CMCE) ensemble plumes showing QPF and Snow through Thursday.
NAEFS (GEFS+CMCE) ensemble plumes for upper BCC highlighting the spread in QPF and Snow through Thursday.

While the model mean can be helpful, it can hide a lot of the story. As a consequence of the more northerly track in the GEFS, most members are constrained to less than 0.6” of water accumulated during the Tuesday-Thursday period. A few optimistic GEFS and CMCE members go high, but we will likely see those solutions drop out in the coming days. Too soon to say much more.

-Mike

Channel Your Inner Clark Griswold

TLDR: Tonight into early tomorrow, a quick moving system will graze the southern portion of the state. This system could result in a few inches of high elevation snow and light low elevation rain in the southern third of the state. Don’t expect much in terms of accumulations in our neck of the woods. A ridge builds in for the weekend.  Our next chance of unsettled weather arrives next Tuesday.


Sunny skies and a building inversion are whats on tap for this weekend.. Not ideal, but perhaps time to get into the holiday spirit. With only 19 days til Christmas, this quiet weather pattern might be a good excuse to drag out those decorations and channel a festive mindset more like Clark Griswold and less like the Grinch (I know no snow = no fun, but we can all try, right?).

tenor

 

Short Term Forecast (Thursday Evening – Saturday Morning):
In the overnight hours, an upper-level trough will make its way across the southern portion of Utah en route to wreak havoc on the southern plains and eastern third of the U.S.  Compared to the forecasted impacts for the rest of the country, this will be essentially a non-event for us folks in Utah give the current lack of moisture in the western U.S. Below is a forecast of available moisture in the atmosphere.  Note the greys and browns over Utah, showing very dry air, while the brighter colors over Texas show an airmass with potent moisture advancing into the southern plains.

18Z GFS Precipitable water valid Friday 5 am MST
18Z GFS Precipitable water forecast. Valid Friday 5 am MST (via models.weatherbell.com)

Winter storm advisories (purple-shaded counties) and watches (dark blue-shaded counties) cover the southern plains in anticipation of the low interacting with a moist airmass originating from the Gulf of Mexico. Flood watches have also been issued for southeast Texas where temperatures will remain above freezing throughout the duration of the event.

Current weather alerts via weather.gov
Current weather alerts (via weather.gov)

In comparison, we are looking at light precipitation across southern Utah.  Given the track of the progressing upper-level low, there won’t be much (if anything) in the way of precipitation for the northern portions of the state. Ski areas in southwestern Utah, like Brian Head, will likely pick up 3-6″ of new snow from the advancing system.  Rain at lower elevations will be light to moderate through the morning. The 18Z GFS total precipitation solution is showing measurable precipitation forecasted for the Cottonwoods, but I think that is relatively unrealistic.  I think 0-2″ is a reasonable expectation through Friday.

18 Z GFS Total Precipitation through Saturday at 5 am (via models.weatherbell.com)
18 Z GFS Total Precipitation through Saturday at 5 am (via models.weatherbell.com)

3-5 Day Forecast (Saturday – Tuesday):
Over the weekend, quiescent weather will prevail, but air quality is likely to deteriorate. The combination of snow cover, cold surface temperatures, low wind, and low sun angle will aid in the development of a dreaded temperature inversion, which will result in a build up of pollutants in the surrounding valleys. The air quality is expected to be poor enough by Saturday that sensitive groups (asthmatics, eldery, etc.) could be impacted, as forecasted by the Utah Department of Environmental Quality

Salt Lake Valley air quality forecast (via air.utah.gov)
Salt Lake Valley air quality forecast (via air.utah.gov)

Luckily, the inversions rarely impact the high elevations, so get up to the mountains and go ski the excellent early season conditions.

Our next chance of unsettled weather arrives on Tuesday which should not only flush out the valley pollutants, but drop some new snow on the mountains! Enjoy a bluebird weekend!

– Taylor

Settled weather moves in

TLDR: Low level moisture will linger through late week with mostly cloudy conditions and very light mountain snow accumulations (slightly more snow for southern Utah/Brian Head). Then, settled weather moves in over the weekend with sunny, bluebird days for the mountains and valley haze as high pressure builds in. This ridged pattern looks to dominate over our area for awhile until possibly next week Tuesday when models indicate a possible trough making its way through Utah.


TODAY

Ok so it’s been an interesting past couple of weeks, wouldn’t you say? Several systems have come through Utah, providing us with plenty of mountain snow for most of our resorts. And just this morning, we had a band of snow move through northern Utah associated with a mid level deformation axis extending from an upper level low off the coast of California. This produced an additional 1-2″ of snow across the upper Cottonwoods and Park City ski area, with little to no accumulations elsewhere.

Webcam at Park City Mountain Resort's Crescent Ridge at 3:00 PM MST
Webcam at Park City Mountain Resort’s Crescent Ridge at 3:00 PM MST. Image courtesy of parkcitymountain.com

Throughout the day, it’s been cloudy with low level moisture and very light low level winds as promised by the GFS time-height forecast chart Lucas shared yesterday. Above is an eastward facing webcam image from Park City Mountain Resort’s Crescent Ridge this afternoon showing pleasant but cloudy conditions at the mountain. Below is a southward facing webcam time lapse from the University of Utah’s William Browning Building (chpc.utah.edu) this afternoon, showing a steady stream of mid-upper level moisture flowing from out of the southwest ahead of that upper level low off the California coast. Note the valley haze and periods of low level moisture condensing into low stratus clouds over the Salt Lake Valley.


Thursday – Friday

We’ll be stuck in somewhat zonal (west to east) flow over the next couple of days in northern Utah as the low pressure system currently just off the California coast slides well to our south and east. So, expect cloudy conditions with maybe a snow shower or two in the northern Utah mountain resorts during this time, but don’t expect to see much in the way of accumulation. However, in southern Utah things should be a bit more interesting as shortwaves ahead of that low pressure system should be able to draw more moisture into that region. Brian Head should see increasing snow shower activity Thursday afternoon and evening, with the bulk of snow activity occurring Thursday night into Friday morning, winding down by Friday evening. Expect 2-3″ of snow Thursday through Friday evening.

THE WEEKEND!

As a ridge builds in from the west, expect the middle and upper level moisture to move out, and sunny skies to make their way in over Utah. While beautiful blue bird conditions should exist for the mountain resorts this weekend, valley haze associated with trapped moisture and particulate matter (…pollution) will pay us a pretty lengthy visit as a low level inversion (temperatures increasing with height) sets in. Below is a forecast sounding from weathernerds.org showing a weak inversion Saturday morning. Unfortunately, we could see some valley low stratus/fog associated with the inversion this go around, especially Sunday through Monday. Great excuse to get up to the mountains and ski under near perfect conditions!

Weathernerds 12z 5 Dec GFS forecast sounding valid Saturday morning at 12Z (5 am MST) over Salt Lake City. Note the low level inversion, where the red line indicates warming with height from the surface (850 hPa) to approximately 800 hPa (~6,500 ft above sea level). You can tell this is an inversion by the way the red line is tilted slightly to the right compared with the light brown lines (temperatures) going from bottom left to top right. Image courtesy of  weathernerds.org by Matt Onderlinde.

Early Next Week

High pressure should stick around until about Tuesday next week when a trough looks like it could make its into northern Utah. Right now the ECMWF has this as a rather strong, compact wave that would definitely break up the inversion and likely provide the mountains and valleys with precipitation. Below is the ECMWF 500 hPa relative vorticity, height and streamline forecast for 18Z 11 Dec (11 am MST next Tuesday morning) where it shows this trough entering into northern Utah with strong relative vorticity values and cyclonic flow.

ecmwf_z500_vort_west_26
12Z 5 Dec ECMWF 500 hPa relative vorticity, height and streamline forecast for 18Z 11 Dec (11 am MST next Tuesday morning). Image courtesy of models.weatherbell.com

While we wait to see what happens with the potential next system on Tuesday, stay out of the valley smog and enjoy mountain sun and snow this weekend!

-Pete

Early sunsets and late-week moisture

Temperatures started off chilly all across the region this morning thanks to a combination of recent snow cover, clear skies, and cold air advection in the wake of our weekend storm. A view of minimum temperatures since midnight from MesoWest shows many of our mountainous areas near or below zero degrees Fahrenheit, with some especially cool observations well below zero of -11 F in the northern part of Snyderville Basin near Kimball Junction,  -7 F  at Cardiff in Big Cottonwood Canyon, and -8 F at Trial Lake in the Uinta Mountains. The famously cold Peter Sinks dipped to -34 F overnight.

Minimum temperatures (F) since midnight across the Central Wasatch and Eastern Uintas. (mesowest.utah.edu).
Minimum temperatures (F) since midnight across the Central Wasatch and Eastern Uintas. (mesowest.utah.edu).

As we approach the northern hemisphere winter solstice later this month, days are becoming shorter and nights are becoming longer, however, we get to experience our earliest sunsets of the year over the next several days with sundown just before 5:00pm MST. You might ask: “Why is our earliest sunset several days before the winter solstice?” It has to do with the tilt of the earth and how time is kept, and is nicely summarized here. The same goes with our latest sunrise, which occurs several days after the winter solstice in the beginning of January.

Salt Lake City sunrise and sunset times from timeanddate.com. Our earliest sunsets of the year are this week.
Salt Lake City sunrise and sunset times from timeanddate.com. Our earliest sunsets of the year are this week. Explore more at: Time and Date.

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Short Range Forecast (Wednesday – Friday)

While the temperatures were frigid this morning a rebound will occur starting tomorrow – especially for the higher terrain in the region.  The storm system impacting southern California at present time will eject warmer and moister air into the region from the southwest during the morning hours tomorrow. This should allow for some nice orographic precipitation to pop up over the mountains resulting in a bit of light snow. However, don’t expect much in terms of snowfall – maybe up to a couple of inches during the day tomorrow for our mountains. Some more moisture looks like it will be in place during the day on Thursday, but it’ll be still somewhat unexciting (maybe up to another couple inches) as the brunt of the storm passes well to our south. Drying out will start to occur for the weekend along with intensification of inversion conditions.

GFS time-height section for the rest of the week. Expect more moist/cloudy conditions for the remainder of the work week, with clearing for the weekend and intensifying inversion conditions. (weather.utah.edu)
GFS time-height section for the rest of the week. Expect more moist/cloudy conditions for the remainder of the work week, with clearing for the weekend and intensifying inversion conditions.
(weather.utah.edu)

__________________________________________

Weekend and beyond

Beyond our weak surges of moisture during the rest of the week, calm weather will be the case for the weekend and into next week.  Potential for a more active weather period begins midweek next week around the 11th/12th of December, as seen below in the GFS ensemble viewer from wetterzentrale.de. Enjoy the great early-season conditions under the sun this weekend!

Lucas

Sunshine and Powder

As this crazy storm cycle winds down, we get to enjoy some December sun for a bit. The Cottonwood ski resorts are reporting 9-15″ over the weekend, and more showers fell this morning adding to the total. Now high pressure has built in and the sun has come out in the valley. We’ll get to enjoy another day of sunshine tomorrow before the clouds come in again.

Scattered clouds over Utah with clear skies upstream
Scattered clouds over Utah with clear skies upstream. GOES-East imagery via RAMMB/CIRA

The next storm system is similar to some of the ones we saw last week but weaker. A storm is approaching California from the west, and it will bring significant rainfall to parts of the southwest. There will also be precipitation at the boundary between this moist storm air and cold air that moved in with the last storm. Unfortunately, this boundary will be to our north, so the best snowfall totals will go to the Bear River Mountains. Down here it’ll start some showers in the mountains to keep things fresh and then move on. Not that places further north will get very much–just a few inches. At the very least this storm should help stir up the stagnant air a bit. The graphic below shows how relatively moist the atmosphere will be Wednesday afternoon, and the snow will be where the moisture is.

GFS Model PWAT with hand-drawn circle showing where greatest chances for snow is
GFS Model PWAT with hand-drawn circle showing where greatest chances for snow is. Via WeatherBell

After Wednesday, there will be a few more days of clouds and light showers as the storm system passes to our south. Then high pressure builds in for the weekend again and we’ll get some more December sunshine.