Mammoth Mountain & Eastern Sierra Weather Forecast
- …………..……………….................…………10-21-21 @ 2:41 PM ............WINTER STORM WATCH IN EFFECT FROM SUNDAY AFTERNOON THROUGH MONDAY EVENING ABOVE 9000 FEET............Snowfall Amounts of 2-3 Feet of Heavy Sierra Cement our expected at this time......... Mammoth Mountain is set to Open October 29th......... Ski ya Later Snowman.........
Mammoth Mountain & Eastern Sierra Recreational Weather Forecast
10-20-21 4:56 PM Update – The next couple of days will be the calm before the series of storms that have hit to our north start to move more south. How far south the main AR band reaches is in question at this time.
For now, the forecast calls for pt cloudy skies on Thursday. Then on Friday into early Sunday there is a chance of rain and snow showers before the Main system moves into the area late in the weekend. For the details of that event read down the page to the Storm Update section.
Here is the forecast for Thursday into Saturday.
Temperatures: On Thursday highs at the Main Lodge and in the Mammoth Lakes Basin will be in the upper 40s to low 50s. Then low 40s through the weekend. Night times lows will be in the low to mid-30s tonight through the weekend.
For Mammoth Lakes, highs will be in the upper 50s Thursday and then low 50s into Sunday. Nighttime lows will be in the low to mid-30s through the weekend.
48 Hour Precipitation & Snowfall Forecast: Thru Friday afternoon Mammoth Mountain will be south of the main precipitation. As of now expect there could be a chance of showers later on Friday just after the forecast below expires.
Snowmaking: All the cold air is gone for now so now snowmaking for a bit. They had a great run for mid October. Will be watching for the next round of cold air to invade the area.
From NWS Reno Disclaimer: In the past, we have seen great model agreement days out only to see significant changes as the event nears with the emergence of finer-scale details.
This is especially true of atmospheric rivers as a shift of 50-100 miles in the core of the moisture feed (still quite possible) can affect precipitation amounts and higher elevation snowfall dramatically.
Today’s Weather Story and The 10 Day Outlook
10-20-21 @ 3:57 PM Storm Discussion for Sunday and Monday
Good afternoon, looking at all the data here on Wednesday and it’s clear that there is confusion between the US models and EU Models.
Our GEFS & GFS slams the AR right into Mammoth Mountain with 6-10 inches of QPF.
The EU that was also looking large yesterday as now backed off with the AR north of the area and 2-3 inches of water.
AR forecast has the main band coming in the perfect spot to brings the heavy precipitation right into Mammoth.
The other issue is snow levels, they are looking a bit too high right now. Just a few years back we had a storm in the early season that left 10 inches of snow at Main and 5 feet up top.
I will take a look again on Thursday and have a brief update with what’s going on and what we might expect.
Yes, I did message Ted the WeatherGuy and this was his reply on the big system:
“Too much uncertainty to call that right now.”
Here are the GEFS and the EPS Models side by side going out the next 150 hours.
Here are the Snowfall and QPF Outlooks for the up coming storm and AR feed. As you can see there is great disagreement in the forecasted amounts of precipitation.
Here is the WPC run on the event for precipitation. Here is the AR outlook for Sunday/Monday from this mornings runs.
Fantasy Long Range Weather Outlook
10-18-2021 EPS is showing ridging out at the end of the month with a new low lurking in the Gulf of Alaska. This model goes out to 16 days.
The GEFS has done a good job with the long-range outlooks over the last 6 weeks. Here is the most current fantasy run out to 840 hours.
This run shows us ending our 21-day cycle of cool unsettled weather ending with the next 21-day cycle being on the dry side.
Right at the end of the run below the next wet cycle moves in for a nice big refresher. (Yes this is a fantasy outlook and not a forecast folks. I do agree with a drying trend to start the first half of November.)
ECMWF Seasonal Ensemble Mean – Monthly Update from 10-1-2021
The MOJO Outlook
MJO Phase and Temperatures
MJO Phase and Precipitation
Mammoth Mountain and Eastern Sierra Weather Posts
Who Are We?
Steve Taylor – Mammoth Snowman – Over the last 30+ years, Snowman has spent countless hours studying and learning about Mammoth Mountain Weather and Snow Conditions first hand. He has been skiing around the hill with marked ski poles since March of 1991 so he can measure the fresh snowfall amounts out on the hill.
Snowman started blogging this information back in 1990 on the old Mammoth BBS system, then the RSN Forums and then on to MammothSnowman.com in 2004 with Video & Photo Blog report. (No YouTube back then). Facebook got added to the fold back in 2008 and then the Facebook Group in 2016.
Reports, videos, and photos from the website have been featured on both local TV Stations here in Mammoth, along with AP, Fox, ABC, CBS, and NBC News.