Forecast Wind, Freezing Level, and Snow

Tomer’s Take: I’m forecasting three storm systems through 4/29 before high pressure takes control.

My forecast video 4/21:

Wind Forecast

Quandary Peak, CO, Maximum Summit Gust:

4/21: 50mph

4/22: 25mph

4/23: 30mph

4/24: 30mph

Longs Peak, CO, Maximum Summit Gust:

4/21:60mph

4/22: 15mph

4/23: 25mph

4/24: 30mph

Mount Superior, UT, Maximum Summit Gust:

4/21: 35mph, 4-8″

4/22: 25mph, 1-2″

4/23: 15mph

4/24: 20mph, 4-8″

Forecast Freezing Level

Wasatch, Daily Max/Min Levels:

4/21: 7700’/6400′

4/22: 7400’/6400′

4/23: 10200’/8000′

4/24: 10000’/9000′

Colorado’s Central Mountain Zone, Daily Max/Min Levels:

4/21: 7500’/5400′

4/22: 8900’/6600′

4/23: 10900’/8000′

4/24: 10300’/9200′

Forecast Pattern

Forecast jet stream pattern 4/30. Notice the dip in the jet over WY, UT, CO, NM 4/28-4/30. The large ridge to the West will move in after this area of low pressure slides East.

Forecast Timing

Forecast radar/satellite valid 4/21-4/26.

Forecast Totals

4/21-4/23:

4/24-4/30:

Two storm systems through 4/29

Tomer’s Take: Snow accumulation continues across PNW/BC/MT/ID/WY/UT/CO. Two additional storm systems will push season totals further into all-time record territory.

Projected Melt-Out

50th Percentile Projection:

Schofield Pass, CO: June 20 (Dust layer could accelerate)

Red Mountain Pass, CO: June 12 (Dust layer could accelerate)

Forecast Freezing Level

Wasatch, Maximum/Minimum:

4/20: 6100’/5100′

4/21: 7700’/6600′

4/22: 7700’/6600′

4/23: 10500’/8900′

4/24: 9800’/9500′

4/25: 7700’/6400′

Colorado’s Central Mountain Zone, Maximum /Minimum:

4/20: 6100’/3800′

4/21: 8000’/5300′

4/22: 9400’/7100′

4/23: 11000’/8700′

4/24: 10700’/9200′

4/25: 10000’/8200′

Forecast Pattern

Forecast jet stream valid 4/29. Small high pressure ridging over Intermountain West with an area of low pressure off the West Coast.

Forecast Timing

Forecast radar/satellite valid 4/20-4/25.

Forecast Totals

4/20-4/22:

4/23-4/29:

Active pattern through 4/28

Tomer’s Take: I’m forecasting three different storm systems through 4/28 for the PNW/BC/ID/MT/WY/ID/CO/UT.

Alta, UT is reporting 5″ new snow in the last 24 hours. Season total is 885″. Will they make it to 900″ by May 1? Yes

My forecast video 4/19:

Forecast Freezing Level

Wasatch, Maximum Daily Height:

4/19: 5700′

4/20: 6200′

4/21: 7700′

4/22: 7900′

4/23: 10500′

4/24: 10000′

Colorado’s Central Mountain Zone, Maximum Daily Height:

4/19: 8900′

4/20: 6400′

4/21: 8000′

4/22: 9500′

4/23: 11300′

4/24: 11300′

Forecast Pattern

Forecast jet stream valid 4/28. Mixed flow with some strong ridging but also a potential cut-off low off the California coast.

Forecast Timing

Forecast radar/satellite valid 4/19-4/24:

Forecast Totals

4/19-4/21:

4/22-4/28:

Most of the CO snow accumulation occurs 4/25-4/26.

Projected Melt-Out Dates; Four storm systems through 4/28

Tomer’s Take: I’m forecasting four different storm systems for parts of the West through 4/28.

Forecast Freezing Levels

Wasatch, Maximum height of daily freezing level:

4/18: 7500′

4/19: 6100′

4/20: 6400′

4/21: 8000′

4/22: 9800′

4/23: 10100′

Colorado’s Central Mountain Zone, Maximum height of daily freezing level:

4/18: 11900′

4/19: 8400′

4/20: 6600′

4/21: 8000′

4/22: 10100′

4/23: 11900′

Projected Melt-Out Dates

Bear Lake, RMNP, CO: June 10

Berthoud Pass Summit: June 14

Columbine Pass: June 1

Echo Lake: May 31

High Lonesome: June 15

Independence Pass: May 29

Jones Pass: June 4

Loveland Basin: June 16

Molas Lake: June 5

Rabbit Ears: June 5

Wild Basin: June 6

Forecast Pattern

Forecast jet stream valid 4/27. You can see the final storm system of the cycle 4/27-4/28 sliding through the Intermountain West. Notice the high pressure ridge across the West Coast/PNW.

Forecast Timing

Forecast radar/satellite 4/18-4/23.

Alta, UT

4/18: 6″

4/20: 1″

4/21: 1″

4/22: 1″

4/23: 3″

4/24: 3

Forecast Totals

4/18-4/20:

4/21-4/27:

Pattern through May 1

Tomer’s Take: 3-4 storm systems are lined-up for the West through 4/28. Brief high pressure may develop April 28-May 1.

Will Alta, UT hit 900″ by May 1? Yes, it appears likely.

Will Aspen Highlands, CO hit 450″ by May 1? 50/50 odds.

Will Jackson Hole, WY hit 600″ by May 1? Yes, it appears likely.

Will Wolf Creek Ski Area, CO hit 500″ by May 1? Yes, it appears likely.

Forecast Freezing Level

Wasatch, Maximum Height. This means, the freezing level rises to a maximum level during daytime heating then could re-freeze overnight.

4/17: 11200′

4/18: 7200′

4/19: 6100′

4/20: 6100′

4/21: 7100′

4/22: 8200′

Colorado’s Central Mountain Zone, Maximum Height:

4/17: 12300′

4/18: 11700′

4/19: 8200′

4/20: 6700′

4/21: 6700′

4/22: 8400′

Forecast Pattern

Forecast jet stream valid 4/26. Notice the dip and area of low pressure sliding through the West.

May 1

If high pressure develops across the Intermountain West then it is brief April 28-May 1. It’s followed by lower atmospheric pressure anomalies in the mid-atmosphere by May 2 building over the West Coast.

Below is forecast mid-atmospheric pressure anomalies valid May 1.

Forecast Timing

Forecast radar/satellite valid 4/17-4/22:

Forecast Totals

4/17-4/19:

4/20-4/26:

Three storm systems through 4/25

Tomer’s Take: Active northern jet branch has three additional storm systems lined-up for parts of the West. As mentioned yesterday, Alta, UT could reach 900″. Jackson Hole, WY should easily reach 600″ for the season. High pressure might build for May 1.

My forecast video 4/16:

Forecast Freezing Level

Wasatch, Maximum Height:

4/16: 11300′

4/17: 11200′

4/18: 7900′

4/19: 6400′

4/20: 6600′

4/21: 6200′

Colorado’s Central Mountain Zone, Maximum Height:

4/16: 11200′

4/17: 12300′

4/18: 12100′

4/19: 10900′

4/20: 8400′

4/21: 6600′

Forecast Timing

Forecast radar/satellite valid 4/16-4/21.

Forecast Totals

4/16-4/18:

4/19-4/25:

Alta, UT might hit 900″; Three more storm systems lined-up through 4/24

Tomer’s Take: The pattern is NOT done with the West. I’m forecasting three additional storm systems through 4/24 and about 20 inches of grand total snow at Alta, UT.

My forecast video 4/15:

Aspen Highlands, CO

Aspenweather.net has a great App run by Ryan Boudreau and meteorologist Cory Gates. They’re reporting almost 450 inches of season snow at Aspen Highlands so far. The next storm cycle could push them cleanly to 450 inches.

Screen grab from Aspenweather.net App.

Forecast Timing

Forecast radar/satellite 4/15-4/20.

Forecast Totals

4/15-4/17:

4/18-4/24:

Late April/Early May high pressure ridge?

Tomer’s Take: Pattern stays active with new snow for PNW/BC/MT/ID/WY/UT/CO/NOCA through 4/21, an additional storm system on/around 4/24, then pattern might transition to a ridge of high pressure late April into early May.

My forecast video 4/14:

Current Setup

Water vapor satellite shows the primary storm track from the Pacific into the PNW.

Forecast Freezing Level

Wasatch, Maximum Height:

4/14: 6600′

4/15: 9400′

4/16: 11500′

4/17: 11500′

4/18: 8400′

4/19: 7700′

Colorado’s Central Mountain Zone, Maximum Height:

4/14: 9900′

4/15: 8200′

4/16: 11700′

4/17: 12600′

4/18: 12100′

4/19: 10500′

Forecast Pattern

Forecast jet stream valid 4/23. Both jets are still active with one additional storm systems 4/23-4/24.

Late April Pattern

Forecast mid-atmospheric pressure anomalies (GEFS) valid 4/29. The high pressure ridge is unmistakable.

Forecast Timing

Forecast radar/satellite valid 4/14-4/19.

Forecast Totals

4/14-4/16:

4/17-4/23:

Pattern through end of April

Tomer’s Take: Freezing levels fall today (4/13) through 4/15 then start rising again with warmer air. Storm track favors PNW/BC/Northern Tier through 4/24 then uncertainty.

One more photo of the dirty snowpack in Colorado…it’s a good one from Nick Green while skiing in Aspen, CO. Thanks Nick!

My blog post yesterday explains this phenomena.

Forecast Freezing Level

Wasatch, Maximum Height:

4/13: 6100′

4/14: 7100′

4/15: 9500′

4/16: 11700′

4/17: 11300′

4/18: 7200′

Colorado’s Central Mountain Zone, Maximum Height:

4/13: 12300′

4/14: 9700′

4/15: 8500′

4/16: 11900′

4/17: 13000′

4/18: 11900′

Forecast Pattern

Forecast jet stream valid 4/22. Northern branch remains active for the PNW/BC/Northern Tier.

Forecast Pattern Late April

Forecast GEFS mid-atmosphere pressure anomalies valid 4/24. This data keeps the unsettled pattern entrenched across the PNW/BC/Northern Tier through 4/24.

Forecast GEFS mid-atmosphere pressure anomalies valid 4/28. This data washes-out the PNW trough and replaces it with a small amount of high pressure ridging across the West.

Forecast Timing

Forecast radar/satellite valid 4/13-4/18.

Forecast Totals

4/13-4/15:

4/16-4/22:

Dirty snow, late April pattern, and snow forecast through 4/21

A high wind event 4/3-4/4 deposited desert dust on Colorado’s snowpack. This seems to occur now every Spring. Dirty snow accelerates the melting of the snowpack by lowering albedo.

I co-authored a peer-reviewed article on Colorado’s Dirty Snowpack in 2010.

Below, MODIS visible satellite shows the brown tint to the snowpack in some places.

MODIS visible satellite 4/10/2023.

Dust aerosols on 4/3 were elevated over the desert southwest. The dominate flow in the upper atmosphere was from the southwest. That’s a perfect transfer conveyor-belt into Colorado on 4/3-4/4.

Dust aerosols 4/3/2023.

Vail’s live cam looking south clearly shows the brown/orange tint to the snowpack.

Vail 4/11/2023.

My forecast video 4/12:

Forecast Pattern

Forecast jet stream valid 4/21. Notice the large trough off the West Coast with support from the Northern Branch.

The Global Forecast System generates a larger, deeper trough. Forecast mid-atmosphere pressure anomalies on 4/20:

Forecast GFS mid-atmosphere pressure anomalies valid 4/20/2023.

Looking even further down the road —> GEFS Forecast mid-atmosphere pressure anomalies:

This would mean a wet/cool forecast for the West Coast.

Forecast Totals

Tetons, WY:

4/12: 3″

4/13: 3″

4/14: 1″

4/18: 4″

4/20: 3″

4/12-4/14:

4/15-4/21: