Mammoth Mountaineering and Supply

Wednesday – 11-4-2020 @ 9:20 AM – We have a big weather pattern change coming up on Friday, a deep low-pressure system will drop into California.

Friday into at least early next week expect much colder weather with moderate to very strong winds at items along with some beneficial snow showers.

Snowfall amounts will not be large but by late Sunday we could be looking at 6-12 inches of 15-1 ratio snow on the ground from Main Lodge to the top of Mammoth Mountain.

Snowmaking crews are going to get into some serious non-stop action at times right up to the opener with this weather change.

For the next couple of days expect highs on Mammoth Mountain in the 50s with lows in the 30s, in Mammoth Lakes highs will be in the 60s with lows in the 30s. Down in Bishop where they still have peaking Fall colors, it will be in the 70s with lows at night in the 30s to low 40s.

Winds will be light at 5-15 MPH out of the Southwest for the Mammoth Lakes area, which will bring some haze and possible smoke at times back. 

By Friday highs will come down at least 15-20 degrees in all areas of the Eastern Sierra. Mammoth Mountain, Mammoth Lakes and Crowley can expect to be below the freezing mark for several days. 

Winds will be gusting up to 45 mph in many areas, with up to 60 mph gusts possible in wind prone areas. Over the Sierra crest and the top of Mammoth Mountain winds will be up to 100 mph. 

Stay tuned as I will be doing a lot more updates now that we have something to get excited about.

For the most updated forecasts here is the link to the Forecast for Main Lodge from the NWS, and here is the link to the NWS in Reno’s technical discussion.


Below you can take a look at our weather pattern change on both the GFS ensembles and the ECMWF ensembles out to 10 days. Confidence is high now in getting cold air in here that lasts out 10 days. We need these systems to get offshore before they come in to get moderate to heavy amounts of snow. 

Snowmaking Forecast: The pattern that is setting up is going to be very cold for 24 / 7 productive snowmaking for several days and then 12-18 hour runs look likely into the middle of November. It will be fun to watch how much snow they can make over the next couple of weeks. The snowmaking system should be firing up some time on Friday Night. Below are the early morning temperature charts for Saturday and Sunday mornings. 

Snowfall Outlook for the Next 10 Days

Snowfall Outlook for November