Thursday, November 24, 2022

Happy Thanksgiving!

 Happy Thanksgiving!

TL;DR: A couple inches of snow freshened up the Wasatch yesterday, now we head into the weekend with sunny skies as we await our next storm on Monday.

Mount Baldy Webcam via Alta.com

Nowcast: Today I am thankful for the deep snowpack we have this early in the season! It's mostly sunny in the mountains today with temperatures not exceeding 30 degrees. Wind is blowing from the North at 10 to 15 mph. High pressuring is building in the region until tomorrow bringing us dry and stable weather.

Short Term: High Pressure has taken a hold on us, giving us some sunny yet cooler days of skiing ahead. Temperatures will rise 5 degrees at all elevations tomorrow and the inversion will continue to build. On Saturday a weak cold front will move through Northern Utah bringing down the temperature with wind  increasing. Likely not enough to blow out the inversion.

GFS 6-hour Averaged Precip Rate via Tropicaltidbits.com

Long Term: The shortwave trough will pass through Sunday afternoon, and any precipitation is expected in the morning if any. Another trough from the the Gulf of Alaska will enter the region Monday morning and will last through the day. It should bring accumulation to the valleys and more to the mountains. Temperatures will be cold, but the mountains could see up to a foot of snow. I'm hoping that low pressure is making its way back into the region to stay.

The backcountry conditions have been stable for a while, but once we get our next storm the danger will rise fast. If you will be traveling in the backcountry make sure you have the proper equipment and know before you go. For the whole avalanche forecast and all things avalanche head over to our friends at the Utah Avalanche Center.

-Ben




Tuesday, November 22, 2022

Still High and Dry Today, But a Break in The Next Few Days

TL;DR:

Sunny and clear today with a few inches of snow coming late Wednesday and Thursday. More snow next week but only 5-10 inches. 


Nowcast:

It is very hazy down in the valley today, but at elevation, it should be clear. The deep inversion that we are experiencing has flipped the temperatures on their heads. Base temps will be around 20°F with peaks being close to 30°F. It will be totally clear today with little to no clouds so be prepared when being out on the snow.

 

Short term:

We have a small short-wave trough moving through late tomorrow that could bring a few inches to the Wasatch. Temps will drop when the front moves in with highs being around 22°F. Clouds will move in Wednesday afternoon and last through Thursday.  I expect only around 1-4 inches of snow depending on elevation.

U of U Atmospheric Science

Long term:

This weekend will remain cold with highs in the mid to high 20s. There won’t be any more precipitation over the weekend but there might be something on Monday and Tuesday of next week. Unfortunately, the main area of vorticity and moisture will hit primarily in southern Utah. We might still get 5-10 inches, but it's still too far out to make an accurate snowfall estimate.

U of U Atmospheric Science


Backcountry comments:

Avalanche danger remains low with the lack of new snowfall. Surface hoar has been seen today throughout the Wasatch. North faces will experience intense sun today so expect slightly softer snow but watch for obstacles that might be lingering under areas with thin cover.

Monday, November 21, 2022

Still Dry.... with Eyes on the Horizon!

TL;DR:


Same ‘ol, same ‘ol … for now, with a chance of a small dusting on thanksgiving eve and potential for more active weather next week.

 

Nowcast:

 

Hazy down here in the valley but looking like a nice day at elevation. Looks to be sunny with no cloud coverage. Temperatures are low this morning with base temperatures below 20°F, midmountain around 20°F, and a bit warmer on the peaks around 27°F. Don’t forget to pack sunscreen and wear some layers!

 

Hidden Peak Webcam via snowbird.com
                    

 

Short term:

 

As the high-pressure system lingers over the Great Basin area, temps will stay cool (highs in the mid 30s °F in the afternoon). Same sub-freezing evenings/nights so be sure to pack handwarmers with your headlamps for you nighttime warriors. There will be an appearance of cloud coverage rolling in tomorrow and a continuation of changes into next week.

 

 

 

 

Long term:

 

Things looking a little less dry with a chance of a light dusting coming in on Wednesday seen on GFS and GDPS models. This storm is not projected to deliver quite the thanksgiving dessert we want, but save some room because more storm cycles have some potential looking into next week. There could be more active weather by next week but there is still disagreement between models.




GDPS via spotwx


 


 GFS via spotwx
       

Backcountry comments:

 

Loads of surface hoar and faceting have been developed in the snowpack. This yields caution for sluffing of sugary snow, and danger associated with the next significant loading event.


Surface Hoar at Lower Days Fork (Zanetti & Alden)

As always,

 

If you will be traveling in the backcountry make sure you have the proper equipment and know before you go. For the whole avalanche forecast and all things avalanche head over to our friends at the Utah Avalanche Center.

 

 





Saturday, November 19, 2022

Sunny D, Sunny Week.

 

TL;DR:

I Spy With My Little Eye.. Clear Skies that are Blue and Dry.

Nowcast:

If you were outside yesterday or took the dog for a morning walk you might have put an extra jacket on to handle the cold front that passed through Salt Lake City. Valley temperatures are in the low teens and it’s cooler in the parking lots at your favorite skin track or lift line. 


Short term:

Expect today to be similar to yesterday. Twitter is a mess from frantic Elon-emails, and that’s more exciting than the current upper air setup. (Unless you’re in Buffalo/New York and getting feet of snow).

For Utah, Salt Lake, and our favorite Cottonwoods: Mostly clear skies for today, calm winds from valleys and parking lots up to the ridges. Could have some winds from the North at the higher chairs and lunch spots.. keep that windbreaker or extra layer in your pack if you need it.

Enjoy the sun while it’s shining, sunglasses and some SPF will help your day. If skies are clear in the parking lot get your dark lenses out.

Roads should be okay with steady temperatures below freezing, expect ice in the usual spots but relatively clear heading up the canyons.

NAM output courtesy www.spotwx.com, low teens for 'boots on' in the parking lot.. near freezing when chairs stop spinning


Long term:

More of the same this weekend. There’s a low pressure system parked in the Alaskan peninsula, as it marches eastward and makes landfall our Wasatch range could see a light refresh of precipitation.

Timing is down the road and amounts are To Be Determined (TBD) if the arctic air mass continues to be our air-source expect cooler temperatures.

Long range models have Wednesday in sight for a light refill. Great time for beacon practice in the meantime.


Water Vapor courtesy: https://a.atmos.washington.edu/
When will the low move east? Bring us the POW

Backcountry comments:

Today’s recycled powder could cause issues if it continues to cool and facet.. get the goods while you can, more important: check the forecast. Bring your gear, learn how it works, and practice.  

If you will be traveling in the backcountry make sure you have the proper equipment and know before you go. For the whole avalanche forecast and all things avalanche head over to our friends at the Utah Avalanche Center.

Friday, November 18, 2022

Same Old, Same Old

TL;DR: High pressure will build into the region over the next couple of days bringing dry and clear conditions with warming temperatures. A shortwave trough will pass to the north of Utah sometime early next Wednesday just missing us with a chance of precipitation. 


Nowcast: An arctic cold front passed this morning which has dropped temperatures and will limit our daytime high today. A high-pressure ridge sits to the west of Utah waiting to move into the region. Wasatch ski resorts are looking at a high temperature in the upper teens today at the base with a slight wind from the NW. Ridgelines at 9000' can expect to see winds blowing 5-15 mph and 10-20 mph at 11000' with gusts above 25 mph. Expect any cloud coverage to clear throughout the day.


(Alta Ski Resort 10:00 am (Mt Baldy) https://www.alta.com/weather)

Short-Term Forecast: A high-pressure ridge will continue moving into the region bringing warming temperatures, clear skies, and dry conditions through the weekend and early next week. At Wasatch resorts expect daytime highs to hit the low 20's and nighttime lows to be in the mid-low teens.
(NWS Hourly Forecast for Alta, Friday - Monday: https://www.weather.gov/) 


Long-Term Forecast: A shortwave trough will pass to the north of Utah early next Wednesday missing us for a chance of precipitation. High pressure looks to build back into the region up after.
(GFS 500mb Geopotential Height Anomaly Tropical Tidbits: https://www.tropicaltidbits.com/)

For those of you wondering, it looks like our next chance of notable precipitation could be at the very end of the month but it's too early to make any assumptions.

If you are planning on traveling into the backcountry make sure you head to UAC for snow and avalanche conditions to stay safe! #knowbeforeyougo 


Thursday, November 17, 2022

Cold and Dry

TL;DR: We continue to see temperatures that are anomalously cold, under sunny skies.

Nowcast: As of 11:00 a.m. mountain time, temperatures at mountain crest level remain in in the teens, with base temperatures in the 20s and light winds. Skies are clear. Mountains have not reported any new snowfall since last Thursday (Nov. 10).


It's a bluebird day at Park City Mountain Resort for the resort's second day of the season (Source: Park City Mountain Resort)

Short-Term Forecast: A weak cold front will bring a shift in winds from southerly to northerly, and a reinforcing shot of cold air early on Friday. This wave will not bring any precipitation to our region, just cool temperatures and increased clouds at low levels. Notice how in the time height section shown below (where time progresses from right to left), the blue line, which indicates the freezing level, drops quickly on Friday morning and remains very low all day on Friday. This is due to our weak cold front progressing southwards.

(Source: University of Utah Department of Atmospheric Science)

For the mountains, this will mean temperatures just above 0 °F on Friday morning.

Mid-Term Forecast: In the wake of this wave of energy, a ridge will redevelop by Sunday, and it will be centered over our region. The black contours in the plot below indicate the height of the 500 mbar level in the atmosphere. The large spacing between those contours in Utah indicates a strong ridge.

(Source: University of Utah Department of Atmospheric Science)

This will cause warming temperatures at the end of the weekend and the start of next week. Beyond that, there are signs of a pattern shift, but it is beyond the range of forecast confidence.

Fortunately, we have an excellent base for mid-November, and new resorts are opening each week. Enjoy the great early season skiing!





Wednesday, November 16, 2022

Persistence

TLDR; Clear skies will prevail with temperatures staying 5-10 degrees F below average for this time of year. A weak, moisture-starved shortwave trough will move through the region at the end of the work week with very little precipitation potential.


Nowcast

At the two open resorts in Big Cottonwood Canyon, temperatures are in the low 20s at lower elevations (~8000ft) and mid-teens at upper elevations (~9500-10,000ft). Skies are a deep blue this morning with hardly a cloud in sight over the Central Wasatch. Winds are calm to 10mph at the highest elevations. A dark goggle lens and plenty of sunscreen should definitely be on hand for those heading up to the mountains today. Enjoy the sun! 

Cloud-free skies prevail over northern Utah this morning, as seen from the NASA GOES-EAST satellite. Image courtesy of the College of DuPage.

Short Term

Not much in the way of significant changes to our weather over the next 36 hours as we remain in between a region of high pressure in the Gulf of Alaska and low pressure over the Eastern US. We will see gradual warming tomorrow in the range of 2-4 degrees F before cooler weather arrives Friday morning. A weak shortwave trough (a relatively small region of low pressure, a weak wave pattern that moves around larger scale features) will be moving through the region Friday morning cooling temperatures ~10 degrees F and increasing cloud cover. In the image below, the axis (center) of the trough at 5am MST November 18 is drawn in red.

500mb (~5500m above sea level) Geopotential Heights and Wind Barbs from GFS Model, Valid 5am MST November 18. Image courtesy of Tropical Tidbits.



The two crucial ingredients to produce precipitation for significant winter precipitation are dynamics and moisture. Simplified, dynamics can just be interpreted as upward motion in the atmosphere. Without significant upward motion, it is difficult to condense water vapor into clouds. This storm lacks both significant dynamics and moisture; Any precipitation with this event will likely amount to little more than a trace and will be confined to the highest elevations.

As some of you may have noticed, even with our notable dearth of precipitation in the last week, temperatures have remained below average. Why could this be? One key to this lasting cold is the origin of our current airmass. Let's take a look.

NOAA Hysplit Ensemble, 72hr Backward Trajectory Valid 5pm MST November 14, 2022. Image courtesy of NOAA Air Resources Laboratory.


The above plot takes the airmass that was located 500m above the surface at Alta and runs the model in reverse for 72 hours to see where it likely came from. The different lines are different possible solutions from different models in the ensemble. As you can see, the majority of the solutions are showing our airmass' origin to be interior Canada, dropping down from the North. Air from interior Canada this time of year is typically much cooler than our usual air masses in Northern Utah during periods of high pressure, as is the case here. 


Long Term

While we will likely remain dry for the next week, there is the potential for precipitation to make its return to Northern Utah in the 8-14 day outlook. The Climate Prediction Center is forecasting an elevated chance of above-average precipitation for our region. While this is by no means a certainty, it does mean the dice are loaded in our favor for the November 23 - 29 period.