Windy pattern returns 5/7-5/15

Tomer’s Take:

  • A powerful jet stream returns to the West through 5/15. It resembles April.
  • The future storm track keeps the bulk of precipitation north of Colorado through 5/15. This leaves Colorado and much of the Intermountain West in a windy pattern.
  • Blowing dust is again possible.
  • The best chances for snow stays in northern UT, WY, ID, MT, and PNW.

Infrared satellite shows the storm track and storm systems lined-up. They’re riding a powerful jet stream.

Infrared satellite 5/6/2022 7am.

Wind Gust Forecast

Forecast (MPH)5/75/85/95/10
Crestone Needle70757060
Quandary Peak50605535
Mount Sneffels60707050
Humphreys Peak65706050
Wheeler Peak50606045
Kings Peak45605555

Jet Stream

A powerful jet stream returns to the West resembling April. It’s following La Nina architecture. The yellow/orange/red colors represent the strongest winds.

GFS interpretation valid 5/8-5/9/2022.

Snow Forecast

5/6-5/15:

Inches of total snow 5/6-5/15.

Everest Weather

Enjoyed a conversation yesterday with Alan Arnette, Michael Fagin, and Marc DeKeyser. The focus is on Everest Weather. Michael and Marc are fellow cohorts who provide weather forecasts and guidance to teams climbing Everest (and other peaks).

You can watch our discussion by clicking here.

Dirty snowpack: Most dust since 2009?

Tomer’s Take:

  • The dust storm on 4/22 was one for the books. Dust was deposited on most of the high mountain snowpack – especially the Southern Mountains.
  • This could be the most significant layer of dust since 2009. Here’s a look back at 2009 in a paper I co-authored.

Dr. McKenzie Skiles at the University of Utah snapped this photo looking into the Wilson Massif in the San Juan Mountains of Colorado.

Dirty, dusty San Juan snowpack, end of April 2022. Dr. McKenzie Skiles.

Here’s a look back at the 4/22 dust storm with wind gusts of 50-90mph. Notice how much dust was entrained on the MODIS satellite image with dust/smoke overlay.

MODIS satellite 4/22 with dust/smoke overlay.

MODIS satellite also has a feature that can look at “Dust Radiative Forcing”. Dust increases radiative forcing and promotes faster melting of the snowpack. Below, is the current satellite image as of 5/2.

Obviously, the Southern Mountains have high amounts of dust. I suspect the Central and Northern Mountains have more dust than what’s being detected. Why? It continues to snow in the Central and Northern Mountains covering up the dust from 4/22. The Southern Mountains have been relatively dry since 4/22 with very little snow. Eventually those dust layers in the Central and Northern Mountains will be revealed as the snow melts.

Below is a look at the current dust radiative forcing versus history. It’s clearly outside of the normal range.

How does this process work? The snowpack melts faster sending water downstream earlier and faster than normal.

Strong wind returns 5/8-5/15

Tomer’s Take:

  • A minor storm system is spinning through the Intermountain West this morning with rain and snow.
  • A larger storm system and dip in the jet stream is waiting in the Gulf of Alaska. This will drive the pattern across the West between 5/8-5/15. Some places get snow while others get mainly wind.
  • The bulk of snow 5/8-5/15 falls in CA, ID, MT, WY, and northern UT.

Infrared satellite shows the storm track and large low pressure in the Gulf of Alaska.

Infrared satellite 5/4/2022 5am.

A large dip in the jet stream and atmospheric pressure anomalies occur across the West 5/8-5/15.

Forecast atmospheric pressure anomalies valid 5/12/2022, GFS interpretation.

Wind Gust Forecast

Forecast (MPH)5/85/95/105/11
Crestone Needle60757575
Quandary Peak45604055
Mount Sneffels65757075
Kings Peak65605555
Wheeler Peak55605050
Mount Whitney80553035

Snow Forecast

5/4-5/13:

Inches of total snow 5/4-5/13.

Snow forecast next 8 days

Tomer’s Take:

  • La Nina continues to anchor the pattern across the West through mid-May. It’s the strongest April/May La Nina since 1999.
  • I’m expecting above normal levels of wind, snow, and rain.
  • Across the Intermountain West, a larger dip in the jet stream and trough of low pressure still possible 5/8-5/13.
  • Conditions might ease the 2nd half of May.

Infrared satellite shows the active storm track and larger low pressure sitting in the Gulf of Alaska. This becomes the dominate force through 5/13.

Infrared satellite 5/3/2022, 6am.

5/8-5/13

Falling pressures are still possible with a dip in the jet stream between 5/8-5/13. Uncertainty remains high regarding precipitation placement. Of higher certainty is strong wind. A trough of this size would deliver abnormally strong wind across the Intermountain West.

Atmospheric pressure anomalies valid 5/9/2022, GFS interpretation.

Wind Gust Forecast 5/8-5/11

Forecast (MPH)5/85/95/105/11
Crestone Peak75857585
Quandary Peak50555060
Mount Wilson60656575
Wheeler Peak50555050
Kings Peak60455555
Mount Whitney65553035

Snow Forecast

5/3-5/12:

Inches of total snow 5/3-5/12.

Strongest April/May La Nina since 1999

Tomer’s Take:

  • Nino 3.4 region water temps are currently -1.1C. That’s the coldest water temp in this region since 1999.
  • This anchors the atmosphere and the current pattern continues through May.
  • I’m forecasting an active month of May across the Intermountain West with above normal amounts of rain, snow, and wind.
  • The jet stream is following La Nina architecture and sitting over the PNW, ID, northern Utah, southwest MT, Wyoming, and the Central and Northern Mountains of Colorado.
  • I’m tracking a larger dip in the jet stream between 5/8-5/11. Atmospheric pressure anomalies could run 2-3 standard deviations below the 30 year average. This could translate into heavy mountain snow and strong wind.

Important La Nina update from Philip Klotzbach at CSU:

La Nina Spring & Summer

The latest CPC/IRI forecast from mid April keeps La Nina (blue bars) through Summer and possibly through Fall.

ENSO forecast, Mid-April 2022.

Here’s the model forecast spread. Water temps are already starting colder than what this model suite initialized.

Long running La Nina, the two-year view:

Storm Track

Infrared satellite shows the storm track and large storm system sitting in the Gulf of Alaska. This is the low pressure to watch for 5/8-5/11.

Infrared satellite 5/2/2022 9am.

Below, notice the forecast pressure anomalies around 5/8-5/9 across the Intermountain West. Strong wind, colder temps, and heavy mountain snow if this verifies.

Forecast pressure anomalies around 5/9, GFS interpretation.

Snow Forecast

5/8-5/11:

I took a middle of the road approach to these numbers. It’s still a long way out but there’s potential.

Inches of total snow 5/8-5/11.

Looking back at Winter 2021-2022

Tomer’s Take:

  • Winter started late in many areas with warm/dry weather through most of November and early December.
  • December ended strong in the Sierra and across the Intermountain West with a few moderate to strong atmospheric river (AR) setups.
  • These AR’s hit parts of Colorado hard including above normal snowfall (100″) in Crested Butte.
  • Then the storm track changed and the flow dried up.
  • April delivered one last surge of snow to many places that were in desperate need.
  • April also brought a 100-150mph jet stream that followed La Nina architecture and sat over the Intermountain West for 3 weeks. Abnormally strong winds prevailed.

Forecast vs Reality

Here is the Winter forecast I published in August/September 2021.

Tomer winter forecast 2021-2022.
Tomer winter forecast 2021-2022.

Here are the preliminary season totals for comparison.

Winter 2021-2022 preliminary snow totals.

There were hits and misses. A few highlights:

  • Hit: Below normal snowfall Sierra Mountains
  • Hit: Below normal snowfall Colorado’s Southern Mountains
  • Hit & Miss: Normal snowfall across parts (not all) of Colorado’s Central and Northern Mountains
  • Hit: Above normal snowfall across parts of the PNW
  • Miss: I predicted normal snowfall across the Wasatch
  • Worst Miss: I predicted above normal snowfall in the Tetons
  • Miss: I predicted normal snowfall across Colorado’s Front Range ski areas

A few specifics, snowfall in inches:

LocationActualNormal
Loveland260422
Alta440530
Wolf Creek385430
Steamboat249314
Crested Butte234234
Jackson Hole334526
Park City194355
Snowfall in inches.

Thanks to everyone who read and subscribed to this Blog!

Colorado backcountry skiing 2022.

Season totals, strong wind, and active early May pattern

Tomer’s Take:

  • The storm track continues to favor the West with a few storm systems lined-up through 5/5.
  • The proximity of the jet stream through 5/5 keeps strong wind in the forecast.

Infrared satellite shows the active storm track and storm systems over the Pacific.

Infrared satellite 4/26/2022 6am.

Season Totals 2021-2022

Season Totals 2021-2022.

A few highlights:

  • Alta 440″
  • Wolf Creek 385″
  • Sunshine Village 339″
  • Jackson Hole 334″
  • Winter Park 312″
  • Vail 264″
  • Loveland 262″
  • Steamboat 249″
  • Telluride 246″
  • Crested Butte 234″
  • Park City 194″

Early May

An active jet stream and lower pressures appear to dominate the West through 5/5. If this plays out then the odds of rain/snow in mountainous areas stays high.

Forecast pressure anomalies valid early May 2022, GFS interpretation.

Wind Gust Forecast

In Colorado, the last three weeks have been one for the books. The proximity of the jet stream has followed La Nina architecture. The latest forecasts keep La Nina going strong through Spring into Summer.

Gust (MPH)4/264/274/284/294/30
Crestone Peak6060407055
Quandary Peak3535255040
Kings Peak4545504525
Wheeler Peak4045306040
Mount Whitney3525453030
Grand Teton4535354020

Snow Forecast

4/26-4/30:

Inches of total snow 4/26-4/30.

5/1-5/5:

Inches of total snow 5/1-5/5.

Colorado Dust Storm on 4/22: One for the books

Tomer’s Take:

  • Friday 4/22/2022 was a day for the books. Wildfire danger hit “Very Extreme” for the first time in a decade.
  • Dewpoint and relative humidity values dropped into the single digits.
  • Record high of 89 in Denver. All-time April record is 90.
  • A major dust storm developed as wind gusts reached hurricane force for 5 hours in some places. This was essentially a Dust Hurricane.
  • A layer of dust was deposited on Colorado’s high mountain snowpack. This will have important Spring melt implications.
  • The jet stream has taken up residence in Colorado for the last 3 weeks. On 4/22 it delivered with 100mph winds aloft.

Look at this monster low pressure, 980mb on 4/23 at 11am. It extends from Canada to the Mexico border.

Infrared satellite 4/23/2022 11am.

Below is a visible satellite image (True Color VIIRS) and aerosol depth algorithm overlay (MODIS) from 4/22 afternoon. It’s used to estimate atmospheric aerosols – in this case it’s mostly dust and smoke represented in the yellow/orange/red colors.

This dust also reached the high mountain snowpack. Atmospheric flow through 14,000ft was consistent out of the southwest all afternoon.

This dust layer will accelerate the Spring melt.

For more background, I co-authored a paper in the NWA Journal of Operational Meteorology in 2010 on dirty snow/dust storms in Colorado.

Visible satellite and AOD overlay from 4/22/2022 afternoon. Dust/smoke/aerosols represented in yellow/orange/red colors.

Photo of the dust on Vail’s Back Bowls from Patrick McCarthy:

Max Gusts 4/22

  • 10-Mile Range: 70mph
  • Red Mountain Pass: 86mph
  • Monarch Mountain: 72mph
  • Wolf Creek Pass: 71mph
  • West Elks: 60mph+
  • Sangre De Cristo High Peaks: 90mph (estimate)
  • Rocky Flats: 90mph
  • NE Plains, Otis: 86mph
  • Buckley AFB: 74mph
  • Buena Vista: 72mph
  • Air Force Academy: 71mph

Below, wind history from Breckenridge Peak 8 on the 10-Mile Range, 12,998ft. Notice three straight days of 60mph+ wind gusts.

Peak 8 of the 10-Mile Range, Wind History 4/2022.

Dust Storm

Here’s video from my colleague Courtney Fromm:

Severe Weather CO/KS

My good friend Ryan Kushner went storm chasing on 4/22. He didn’t see any tornadoes (there were several reported in KS) but says they saw a big lightning show. He says blowing dust was a major problem.

Ryan Kushner and Jenn Mravich at Mount Sunflower, KS.

Weekend snow and wind

Tomer’s Take:

  • Major storm system continues across the West through 4/24 with strong wind and heavy snow at higher elevations. Then the storm track shifts and favors the PNW through the end of April
  • A storm system with snow tracks across MT, ID, WY around April 30-May 1.

Infrared satellite shows the storm track and major low pressure system hitting California’s High Sierra with heavy snow and wind. Also notice the major low pressure in the Gulf of Alaska. It’s part of the pattern change favoring the PNW through the end of April.

Infrared satellite 4/22/2022 5am.

Wind Gust Forecast

Gust (MPH)4/224/234/24
Crestone Peak906530
Quandary Peak506020
Longs Peak407540
Kings Peak455030
Wheeler Peak656540
Mount Whitney403025

After 4/24

High pressure rebuilds across the Intermountain West. Lower pressure anomalies move into the PNW.

Forecast pressure anomalies valid 4/27/2022, GFS interpretation.

5/1

Notice the lower pressure anomalies moving through MT, WY, ID between 4/30-5/1.

Forecast pressure anomalies valid 4/30/2022.

Snow Forecast

4/22-4/24:

Inches of total snow 4/22-4/24.

4/25-5/1:

Inches of total snow 4/25-5/1.

Last gasp of April

Tomer’s Take

  • One last storm major system through 4/24 for the Intermountain West then the pattern shifts favoring the PNW.
  • Precipitation starts as rain in many mountain valleys before changing to snow.

Infrared satellite shows the storm track and large Pacific storm system moving into California. The 2nd Pacific storm system takes a more northern track into the Gulf of Alaska and is part of the pattern change next week.

Infrared satellite 4/21/2022 5am.

Next Week

High pressure rebuilds next week across the Intermountain West. Lower pressure anomalies move to the PNW.

Forecast pressure anomalies valid 4/27/2022, GFS interpretation.

Wind Gust Forecast

Gust (MPH)4/214/224/234/24
Crestone Needle45855530
Quandary Peak35505530
Grand Teton40354030
Kings Peak55505030
Wheeler Peak35655035
Mount Whitney60453030

Snow Forecast

4/21-4/24:

Inches of total snow 4/21-4/24.

4/25-4/30:

Inches of total snow 4/25-4/30.