Tomer’s Take: Off/on light snow continues today in CO. This storm system then races into the Northeast and delivers moderate to heavy snow accumulation at the ski areas of VT, NH, and ME between PM 11/21-11/22.

What’s next? A strong Canadian cold front dives south through MT, WY, UT, CO, and NM with much colder air and snow accumulation 11/23-11/25.

Snowbird, UT is reporting 21″ in 48 hours.

Loveland, CO picked up about 6″ and it’s still snowing.

Current Setup

Water vapor satellite shows the current departing area of low pressure and what’s next in the north Pacific.

Orange/red = drier air aloft.

Forecast Jet Stream

Valid 11/24. Canadian cold front moving south through CO into NM. Door is wide open for much colder air for MT, WY, UT, CO, NM.

Valid 11/29. Storm track favors the PNW/BC.

Forecast Radar & Satellite

Forecast Snow Totals

MT Snow: 11/23-11/24

WY Snow: 11/23-11/24

UT Snow: PM 11/23-11/24

CO Snow: PM 11/23-11/24

NM Snow: 11/24-11/25

Tomer’s Take: Snow continues 11/19 in UT, and Colorado through 11/20. The next storm system arrives 11/23-11/24 with much colder air and snow accumulation for MT, WY, UT, CO, and NM. Heavy accumulation and double digit accumulation possible in a few areas.

My forecast video:

Snow continues at Aspen/Snowmass with additional accumulation likely through 11/20.

Forecast Radar & Satellite

Forecast Snow Totals

UT Snow: 11/19, AM 11/20, PM 11/23-11/24.

CO Snow: 11/19, 11/20, PM 11/23-11/24.

NM Snow: 11/24-11/25.

Tomer’s Take: The next storm system hits UT, WY, and CO between 11/18-11/20. Heavy snow appears likely for the Wasatch. Another storm system races through with even colder air 11/23-11/24.

My forecast video:

Current Setup

Water vapor satellite shows the slow moving deep trough moving into CA directing atmospheric traffic. But, also notice the Polar Jet has cut-off the trough, reestablishing the storm track into the PNW.

Forecast Jet Stream

Valid 11/19. Cold front slides north to south from MT, WY, UT, and CO.

Valid 11/23. Storm system and cold front hits ID, MT, WY, UT and CO.

Forecast Radar and Satellite

Forecast Snowfall

*Update 2:30pm 11/17.

UT snow occurs afternoon 11/18 through 11/19.

CO snow occurs afternoon 11/18 through 11/20.

*Update 2:30pm 11/17.

UT snow occurs 11/23-11/24, 11/25-11/26.

CO snow occurs 11/23-11/24, 11/25-11/26.

Tomer’s Take: Three different storm systems are lined-up through Thanksgiving. My forecast totals have increased for the Wasatch. The third storm system 11/23-11/24 is trending slightly stronger.

2 inches of new snow (so far) is being reported at Alta, UT. Snow is also moving into Colorado’s Central and Northern Mountains.

It just started snowing at Aspen/Snowmass.

Current Setup

Water vapor satellite shows a deep trough on/around CA directing atmospheric traffic.

Forecast Jet Stream

Valid 11/19. Amplified jet with energy dropping north to south through MT, WY, UT, CO, NM.

Valid 11/23. Notice the dip in the jet supporting the 3rd storm system 11/23-11/24.

Forecast Radar & Satellite

Forecast Snowfall

UT Snowfall: 11/16, PM 11/18, 11/19, AM 11/20.

CO Snowfall: 11/16, PM 11/18, 11/19, 11/20.

Thanksgiving snow forecast totals.

Tomer’s Take: A large trough of low pressure approaching CA dictates the flow of business across the West through 11/20. Two cold fronts mesh with energy from this trough generating snow for ID, WY, UT, MT, CO, NM. A third storm system tracks across the PNW, ID, MT, UT, WY, CO 11/23-11/24.

My forecast video:

Current Setup

Water vapor satellite shows a large trough of low pressure approaching CA.

Orange/red = drier air aloft.

Forecast Jet Stream

Valid 11/19. Energy slides down from MT, WY, UT, CO, NM.

Valid 11/23. Third storm system delivers light snow to PNW/BC/Banff, ID, MT, UT, WY, CO through 11/24.

Forecast Radar & Satellite

Forecast Snowfall

*Updated 2:30pm 11/15.

Utah Snow: 11/16, 11/18-11/19.

Colorado Snow: 11/16, 11/18-11/20.

Wyoming Snow: 11/16, 11/18-11/19.

*Updated 2:30pm 11/15.

Tomer’s Take: I’m tracking a large CA trough of low pressure and two cold fronts coming out of the PNW. The interaction should generate snow for PNW, BC, Banff, MT, ID, WY, UT, CO, and NM.

My forecast video:

Current Setup

Water vapor satellite shows the large CA trough. It really dictates the near future.

Forecast Jet Stream

Valid 11/19. Powerful and amplified jet stream. The bulk of energy drops north to south through MT, WY, UT, CO, NM. Look for low pressure development in eastern Colorado.

Valid 11/23. A cold front is dropping north to south from Canada through MT, WY, and eventually CO.

Forecast Radar & Satellite

Forecast Snowfall

*Updated 3pm 11/14.

Valid 11/14-11/17. The snow in UT and CO occurs on the 11/16.

*Updated 3pm 11/14.

Valid 11/18-11/23. UT snow occurs 11/18-11/19, and CO snow occurs 11/19-11/20.

Tomer’s Take: I’m forecasting three different storm systems through 11/22. Heavy snow appears likely. The first low originates in CA (where totals will be low) and tracks through UT, AZ, NM, and CO. This first trough greases the skids. The 2nd low races from the PNW through ID, MT, WY, UT, and CO to fill the void. The third low is a major storm system that nails the PNW and BC and then tracks through Banff, ID, MT, WY, UT, and CO.

Current Setup

Water vapor satellite shows a large trough of low pressure digging south towards the CA coast. Once upon a time this storm system looked like it might drop heavy snow in the Sierra. Not now. Why? Lack of atmospheric river contribution and trajectory. But, it will grease the skids for two additional storm systems in the PNW.

Forecast Jet Stream

Valid 11/17. First large tough slowly moving onshore into CA.

Valid 11/19. Powerful jet stream acting like a conveyor belt for two additional areas of low pressure. This WNW flow will guide heavy snow through PNW/BC, ID, MT, WY, UT, and CO.

Valid 11/22. Jet orientation after the 3rd and final low of this storm cycle. Low exits through CO.

Forecast Radar & Satellite

Forecast Snowfall

*Updated 4pm 11/13.

*Updated 4pm 11/13.

Windy Period 11/19-11/21

Max gusts (mph) –>

Kings Peak, UT

11/19: 50mph

11/20: 40mph

11/21: 55mph

Longs Peak, CO

11/19: 55mph

11/20: 50mph

11/21: 85mph

Quandary Peak, CO

11/19: 50mph

11/20: 50mph

11/21: 55mph

Mount Rainier, WA

11/19: 45mph

11/20: 85mph

11/21: 85mph

Tomer’s Take: What once looked like a significant snow event for CA has changed. Why? Weak atmospheric river (AR) contribution and poor trough trajectory.

Looking down the road, this initial trough will grease the skids for two additional areas of low pressure originating in the PNW that look more robust for the PNW, BC, ID, MT, WY, UT, CO between 11/18-11/22.

My forecast video:

Forecast Atmospheric River

Valid next 10 days from ECMWF, Integrated Vapor Transport (IVT) for 38N/123W (Around San Francisco coast).

Only looking at weak atmospheric river contribution 11/14-11/17.

Forecast Jet Stream

Valid 11/15. I sizable trough off the CA coast but it lacks atmospheric river contribution.

Valid 11/21. This impressive pattern appears to send robust moisture, cold air, and dynamics from the PNW/BC straight into the Interior Rockies.

Forecast Radar & Satellite

Forecast Snowfall

Tomer’s Take: Snowfall continues to trend down for CA and the Interior Rockies 11/13-11/18. Trough trajectory and weak atmospheric river (AR) intensity are two limiting factors. A larger trough of low pressure across the West might be possible after 11/18. That said, heavy snow is likely for BC and higher elevations of the PNW with a couple feet of accumulation possible.

Clear Opening Day morning at Loveland Ski Area. Colorado is in for a 7-10 day dry stretch. I’m not forecasting any significant snow until 11/18 or later.

Heavy snow starts this afternoon/tonight in Whistler/Blackcomb and continues all night into 11/11. A 2nd burst of snow likely PM 11/12 and AM 11/13. Morning cam:

Current Setup

Water vapor satellite shows a large trough of low pressure hitting AK, BC and eventually PNW.

Orange/red = drier air aloft.

Forecast Atmospheric River

Forecast Integrated Vapor Transport (IVT) for 38N/123W (San Francisco coast) next 10 days. Notice one spike in intensity then a low level of contribution.

Forecast Jet Stream

Valid 11/15. Trough is further West off CA coast versus previous forecast solutions.

Valid 11/19. Exciting area of low pressure through CO/NM plus active jet in PNW with developing trough.

Forecast Snowfall

*Update 2pm 11/10.

Valid 11/10-11/13 mid-mountain. Big totals in BC/PNW higher terrain.

*Update 2pm 11/10.

Valid 11/14-11/18 mid-mountain.

Tomer’s Take: The next pattern shift continues to trend weaker on/after 11/13-11/18 for CA and the Interior Rockies. The main beneficiaries of heavy snow are ski areas in the PNW/BC. Optimism three to four days ago for heavy snow was predicated on a moderate to strong intensity atmospheric river (AR) contribution. That does not appear to be realistic now.

A few inches of new snow fell at Loveland, A-Basin, and Vail. Spectacular view from Vail this morning:

Current Setup

Infrared satellite shows a large trough of low pressure hitting AK, BC, and eventually the PNW.

Forecast Atmospheric River

Forecast ECMWF Integrated Vapor Transport (IVT) valid for the San Francisco lat/lon only favors weak AR contribution.

Forecast Jet Stream

Valid 11/15. A large trough of low pressure dives south from the PNW/BC towards the CA coast.

Valid 11/18. An area of low pressure exits through CO/NM. A powerful jet stream continues to favor the PNW/BC.

Forecast Radar & Satellite

Forecast Snowfall

*Update 2pm 11/9.

Valid 11/9-11/12. Heavy snow is likely in BC/PNW.

*Update 2pm 11/9.

Valid 11/13-11/17.