Mammoth Mountain Weather Forecast & Discussion

October 29th, 2023 @ 5 PM Good evening; for the next 12 hours or so, the cold and dry air in the area will remain. 

Then starting on Monday, the temperatures will be warming up under a developing ridge of high pressure that should be with us through the week.

If you’re going out for an adventure in the Eastern Sierra this week, expect chilly mornings with cool mid-day temperatures typical for late October and early November. For those looking for snow-free fun, this is your week.

5-Day Weather Forecast Details: For Mammoth Mountain, Mammoth Lakes, and the Eastern Sierra, expect mostly clear skies with just a few high clouds around at times.

On Monday, mid-day temperatures out on the Mountain @ the 9000-foot level will be in the upper 40s to lower 50s. 

Night-time lows will be coming up each night, with a low of 28 tonight and then around 32 on Monday night. The rest of the week’s lows will be in the mid-30s.

The Wind Forecast has NE winds at 10-25 MPH, with stronger gusts at times backing off over the next 24 hours and switching to the SW at 5-15 MPH on Tuesday. Expect those lighter winds to be in the area through Friday.

For Mammoth Lakes, mid-day temperatures will be in the mid-50s Monday and then low to mid-60s the rest of the week. Night-time lows will be in the mid to upper 30s this week.

Down at the 4100-foot level in Bishop, mid-day temperatures will be in the upper 50s on Monday, with low to mid-70s starting on Tuesday. Night-time lows will be in the upper 30s to lower 40s.

Snowman out...

USA Satellite - Mammoth Weather Image
USA Satellite – Mammoth Weather Image

 Snowmaking Forecast

10-29-2023 @ 5 PM – A very cold and dry pool of air is still in place over Mammoth Mountain. Snowmaking crews have been able to blow a ton of snow over the last 24 hours. The process is definitely a bit slow when they have to blow on bare dirt, but it looks like they have a decent start on getting Broadway open by the 10th of November.

Moving forward, temperatures will rebound quickly starting Monday. Current data suggest they might be able to blow again Monday night into Tuesday morning with fair to marginal snowmaking conditions. After that, the door to snowmaking will be shut into the following Friday, 11/3.

What happens the following weekend with the snowmaking is unclear from the data we are seeing right now. We will take a look at the snowmaking forecast for next weekend and opening week when I update again in a couple of days.

Mammoth Mountain 10-Day Weather Discussion

10-29-2023 @ 3:30 PM – The only thing to be trusted weather-wise right now is over the next 5 days, ridging will move into the area, and temperatures will warm up again. There are been hints on the models I am showing below of a change in the pattern this upcoming weekend and possibly right around day 10. Confidence is low in any outcome beyond day 5. We can take a look at all this again in a couple of days and see what’s new. Snowman


** 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.

Mammoth Mountain 10-30 Day Fantasy Weather Outlook

October 28th, 2023 @ 5 PM – The longer-range 10-30-Day Fantasy Outlook is calling for below-average snowfall, with temperatures looking just a bit above average now. 

The good news moving forward is there looks to be a change over to a long wave troughing over the West starting sometime during the first full week of November.

While the Ensemble models delay the change a bit, confidence is slowing growing that the pattern will change over to cooler and wetter sooner than later.

There are no signs in the long-range ensembles of anything that could bring in footage yet. It’s very early in the game, and I have seen patterns like this bring in some top-opening storms.

Of course, since this is the Fantasy Outlook period, we are looking for trends, not day-to-day specific details and amounts. Everyone also needs to keep in mind the El Ninos that do turn out to be wet are more backloaded with drier starts to the season possible and snow starting to pick up around the Holidays.

So for now, it’s just wait and see time, I am sure we are going to get into some action here very soon. Weather Patterns can change quickly at this time of year.

Pray for Snow, Snowman

840 Hours Out – ECMWF Extended Ensemble Mean840 Hours Out – GEFS Ext Ensemble Mean

840 Hour Snowfall from the ECMWF Ext. Ensemble Mean

840 Hour Snowfall from the GEFS Ensemble Mean


Temperature Anomaly – ECMWF Ext. Ensemble Mean

ENSO – El Nino / La Nine Outlook – September 26th, 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 on there as of 9-26-23.

> 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.

SSTA Mammoth Weather Forecast
SSTA Mammoth Weather Forecast

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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