High confidence in the first legitimate cool down for California, snow above 8,000 feet favoring the southern regions. The Rockies see plenty of moisture with a cool-down late this weekend with some areas picking up several inches above 9,000 feet
Short Term Forecast
The fall colors are just starting to peak in some areas in the Northern Rockies. In Utah, the reds are full-on peak with the yellows quickly catching up. Things will change quickly as strong winds and SW flow this weekend bring lots of leaves to the trails (I prefer the yellow brick road after they have fallen) with rain and snow in the forecast.
Below: My ride late Friday in the Emigration Canyon area of Utah near Park City. @powderchasersteve via instagram
Cold air from Canada will bring the highest odds of a decent dump to the Alberta area extending north to south. Upper peaks, especially Banff Sunshine Village might score at the summits.
Below: Decent totals are possible in the SE corner of BC, but especially southern Alberta (Castle Mountain might sneak up a surprise).
California will see its first snowfall primarily above 8,000 feet peaking early Saturday. The models are not in good agreement on who sees the highest totals, but it's likely the southern areas including Mammoth end up the winners. Areas further north towards the I-80 corridor may see significantly less snow. The American GFS shows over a 1/2 in of moisture favoring southern regions, while the European and short-term high-resolution HRR provide slightly higher amounts. Bottom Line: The Sierra will see high-elevation snow from late Friday to Saturday. Southern areas are favored. Higher elevations above 8,000 feet could see 4-8 inches. Areas further north might see significantly less. If it were winter, I would be chasing south if it were mid-winter. Models are not all in agreement so confidence is slightly lower. It's possible some peaks east or south of Mammoth sees 5-11 inches or more.
Below: The southern regions of the Sierra are favored for snow (South of the lake) on this next storm. Decent amounts might be found at the upper peaks (4-8).
The Rockies score decent moisture primarily late Saturday to Monday. The coldest air reaches Utah Sunday night into Monday. Snow levels will initially be above 9500 feet and drive lower late Sunday to Monday (8,000 feet). Montana, Idaho, and Wyoming will get teased at upper elevations with higher moisture totals extending from the Sierra through Utah. Leftovers hit Colorado later this weekend into Monday (Light snow at upper elevations) with slightly warmer temps.
Below: Very generous amounts of moisture are noted for extreme Northern California, Southern Sierra, and central Nevada, extending into areas of Idaho and Northern Utah. An excess of an inch of moisture is possible (We need it). Healthy totals might also fall in the San Juan Range of Colorado or New Mexico (Primarily rain).
Below: University of Utah models taking only the American Model show snow for Alta peaking late Sunday to Monday. Temps are warm until Later Sunday so snow may be confined to the summit initially. NW flow will kick in Monday morning so it's possible higher amounts get reported on Monday with some light snow at lower elevations. Monday should be the best day to hike for some white (Don't try and ski it).
Below: Snow levels are around 9,000 (0 degrees Celsius at 10K) feet early Sunday in Utah with the cold front just approaching by the evening driving snow to mid-mountain or even the base by Monday morning.
Below: General overview of snowfall for the west favoring Canada, extreme northern Montana, Sierra, and Utah. Colorado might play the catch-up game late Sunday or Monday favoring the San Juan ranges. The European model shows healthy moisture in these areas including New Mexico, however, the cold front lags to the north and west so it's possible any snow in the San Juan Range is confirmed to 10K or higher.
The low from this weekend's storm in the Sierra drops south and very slowly progresses over southern Colorado before ejecting north over Colorado early to mid-next week. A secondary low edges into Colorado by Tuesday. The Front Range and areas along I-70 might experience some occasional rain or snow Tuesday-Wednesday. Colder air is noted on the models for this period so some snow is likely in the higher terrain including the Front range and I-70 corridor.
High pressure appears to settle into the west mid to late next week. A very strong low is noted to enter the California Coast in the October 10th or 11th timeframe. This needs to be watched.
Follow my photography on Instagram (Outdoors, Wildlife, Snow) at @powderchasersteve
Bears bears and more bears in my last posts from Alaska.
Thanks for following the Chase forecast- I hope to chase soon!