Mammoth Mountain Weather Forecast & Discussion

November 15th, 2023 @ 11:30 AM – Mammoth Weather 5-Day Forecast: A cut-off low will continue to be the weather story for California and Mammoth Weather watchers.

These systems can drive you nuts trying to nail down any details as they are cut off from the jet stream. The current cut-off low off the coast of California is one of the more frustrating systems that we have had to deal with in a long time.

As of Noon on Wednesday, the COL is expected to continue to rotate off the coast into Friday, and then it will quickly weaken and move into and through California by Saturday night.

In the process of the low spinning around, it will send some waves of snowfall toward Mammoth Mountain this afternoon, tonight, and then again on Friday into Saturday.

Some of our High-Resolution models, as storms approach, have Mammoth Mountain picking up some snowfall over the next 24 hours. At Main Lodge, snowfall in the 1-2 inch range is expected, with 3-5+ inches up top. One of the models had up to 8 inches at some locations along the Sierra Crest near Mammoth Mountain.

The next wave for Friday is in question, with some of the High-Resolution models picking up on 1/2+ inch QPF amounts that could add up to 3-6+ inches of additional snowfall by mid-day Saturday.

NWS Forecast for the 8900 Foot level at Main Lodge
NWS Forecast for the 8900 Foot level at Main Lodge

Thursday into Sunday Weather Forecast Details: At the Main Lodge, expect pt cloudy skies on Thursday with cloudy skies and a chance of snow showers on Friday and Saturday. Snow levels will be in the 8000-9000 foot range, with any snow that does accumulate expected to be low ratio base snow. 

Mid-day temperatures will be in the low to mid-40s on Thursday, with highs in the mid to upper 30s Friday into Sunday. Early morning lows will be in the upper 20s to lower 30s.

SW  winds will be 15-30 –15 MPH with gusts up to 30- 40 MPH around Main Lodge and MC Coy Station with gusts to 50 MPH above the 10,000-foot level.

Here is the Current Satellite View at 11:30 AM
Here is the Current Satellite View at 11:30 AM
This Chart shows 10-1 Ratios - Expect around 5-1 Ratios from tonight's wave if it happens.
This Chart shows 10-1 Ratios – Expect around 5-1 Ratios from tonight’s wave if it happens.

Mammoth Mountain 6-10-Day Weather Discussion

10-12-2023 @ 3:22 PM – A deep low-pressure system will cut off from the jet stream and drop down and off the coast of California over the next few days. This system being a cut of low makes it very hard to forecast.

These cut-off lows are always a woe for weather forecasters and model riders trying to figure out how much snow Mammoth Mountain might pick up; this one is no exception.

As of this Sunday afternoon, the forecast position of the cut-off low will keep most of the heavy precipitation off the coast of California.

The low will be slow to move and is forecasted to finally push inland over Southern California at the end of this upcoming week into next weekend. Yes, this one is moving slowly.

By next Sunday, the area will come under some short wave ridging at day. Then, way off in Fantasy Land at days 9 and 10, the ECMWF Ensemble Mean has a deep inside slider set up in the great basin. That will usher in some cold air for snowmaking crews right before Thanksgiving.

Ultra Fantasy Outlook For the Thanksgiving 4-Day Holiday… The ECMWF Ensemble Mean turns the inside slider at days 9 and 10 into a hybrid slider. It will usher in a period of cold air along with numerous snow showers at times through the Thanksgiving Holiday Period.

If that hybrid slider slides just off the coast, Mammoth could pick up several feet of snow, as shown on the ECMWF Control Run Below. Of course, this way out in the future is just an outlook, not a forecast.

Pray for Snow, Snowman @mammothsnowman

The content on this Mammoth Weather Page is from Steve Taylor (Snowman), Ted S (CCM), NWS Reno / Hanford / Vegas. Model Images from Weather Bell with on Hill WX data from the Mammoth Mountain Ski Patrol.

Mammoth Mountain 10-30 Day Fantasy Weather Outlook

** Weather Disclaimer: The Fantasy Outlooks are “Outlooks, Not Forecasts.” Some years, the wet patterns that appear in these longer range outlooks pan out; other times, the changes are always out in the fantasy period and never make it to the short-term forecast period. When all the ensemble models have agreement on wet or dry patterns, more often than not, they do seem to pan out more often then not.

11-12-2023 @ 5 PM – The longer-range 10-30-Day Fantasy Outlook is calling for below-average snowfall, with temperatures looking a bit warmer then we like for consistent snowmaking.

Pray for Snow, Snowman @mammothsnowman – Next 30 Day Outlook Update on Sunday 11-16 @ 6 PM

840 Hours Out – ECMWF Extended Ensemble Mean

840 Hours Out – GEFS Extended Ensemble Mean

Snowfall from the ECMWF Ext. Ensemble Mean

Snowfall from the GEFS Ext. Ensemble Mean

ECMWF – Seasonal Mean Precipitation Outlook – 11-5-2023

ENSO – El Nino / La Nina Outlook – November 12th, 2023

El Niño Update: The current El Nino is in the strong category. How the event affects Mammoth Mountain and the Eastern Sierra this winter is uncertain. There are a lot of variables with this particular El Nino event that have not been seen during other strong events. Take a look at the video below for more information.

There are not a lot of strong El Ninos to look back at, so it’s hard to trust any of the long-range data right now. Past El Niño winters have been slow to start, so don’t be surprised if the Eastern Sierra sees below-average rain and snowfall this Fall. 

The video below is new from Mike Discussing the most current El Nino Data. All the images in this section have been updated, with what’s the most recent as of 11-12-23.

>>>> 9-29-23 – To note, El Niño winters can be slow to start, so don’t be surprised if the Eastern Sierra sees below-average rain and snowfall this Fall.

Current Weather and Information Posts

Author – Steve Taylor – The 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 in 2004 with Video & Photo Blog reports. (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 and Bishop, along with KTLA, AP, Fox, ABC, CBS, and NBC News.

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