Mammoth Mountain Weather Forecast
Including Mammoth Lakes & Bishop, California

September 24th, 2024, at 7:30 AM: Clear skis, along with dry and warm conditions, will prevail over the next week, with increased winds on Wednesday and this upcoming Saturday. Temperatures look to be about 4-7 degrees above average, making for perfect Autumn Weather to get outside and explore. 

Currently, the temperature is 47 degrees up top, with an S wind at 6 MPH, gusting to 8 MPH. Down at the Main Lodge / 8900 elevation level, the temperature is 45 degrees with a W wind at 2 MPH, gusting to 3 MPH at times. 

The temperature is 42 degrees in Mammoth Lakes, 34 degrees at the Mammoth Airport, 35 degrees in Crowley Lake, and 44 degrees in Bishop.

(LIVE) Mammoth Mountain Top of the World Windowcast Webcam

Weather Forecast for Your Adventure

Basic Weather Details into Saturday: For the Main Lodge / 8900 Feet, midday temperatures at the 8900-foot level will be in the mid to upper 60s. Overnight lows will be in the mid to upper 40s. 

The wind forecast for today calls for SE winds at 5-10 MPH with gusts to 15 – 20 MPH over the higher elevations. On Wednesday and Saturday, expect a SW wind at 5-10 MPH with gusts to 15 MPH at the 9000-foot level and gusts up top to 20-30 MPH. 

Midday temperatures in Mammoth Lakes will be in the low to mid-70s. Overnight lows will be in the mid to upper 40s with light winds. For Bishop to Mill Pond, mid-day highs will be in the mid-80s to low 90s, with overnight lows in the low 50s.

NWS Service Forecast for Main Lodge & the Mammoth Lakes Basin @ 8900 Feet in Elevation
NWS Service Forecast for Main Lodge & the Mammoth Lakes Basin @ 8900 Feet in Elevation
Current North East Pacific Infrared Satellite Image
(Live Feed)  North East Pacific Infrared Satellite Image

(Live Feed) Bakersfield Intelicast Rader Image (Live Feed) Bakersfield Intelicast Rader Image[/caption

Mammoth Mountain & Eastern Sierra Weather Discussion & Outlook

Now that Autumn is here, it’s time to enjoy the cooler, drier days before the colder winter weather moves in. When that happens this year is anybody’s guess at this point.

As of Tuesday morning, a strong progressive ridge of high pressure has moved into the Pacific Northwest and will quickly head toward the east by Wednesday. 

In its place, a cutoff low will form off the central and then the southern California coasts Wednesday into Friday. That low will weaken to almost nothing by Friday as a zonal flow with higher heights takes over again by the weekend into next week.

This pattern will be in place for the next 6-10 days; around day 8, the ECM and GEFS have some troughing well off the coast. The GEFS, unlike the ECM, brings weak troughing into the area by Day 11. With the uncertainty in the models, I would say confidence in any outcome beyond day 7 is a bit suspect as of this update.

 Longer Range Fantasy Outlook

Models show October as above-normal in temperature and below-normal in precipitation. The longest-range trend calls for wetter and cooler weather around October 23rd, lasting into early November.

Enjoy the Fall and pray for a significant snowfall in about a month. 

Steve Taylor – the Mammoth Snowman

The next full Mammoth Weather Forecast Update will be Thursday by 5 PM. 

Mammoth Weather Forecast Data from Weather Bell

ECM & GEFS Ensemble Models 500

10-Day ECM 500mb Anomaly GIF: Below is the entire 15-day run of the ECMWF ensemble model. I use this model to tell the Mammoth Weather Story you just read above. Compared to the other models, this solution has been effective more often than others over the years.

10 Day ECMWF 500mb Height Anomaly Outlook
10 Day ECMWF 500mb Height Anomaly Outlook

10-Day GEFS Ensemble 500mb Anomaly GIF: Below is the second most trusted ensemble model that we use that goes out to day 16. Model relaibily beyond day 7 can be very suspect expecialy during the transition seasons of Spring and Fall.  0

GEFS 10 Day 500mb Height Anomaly Outlook
GEFS 10 Day 500mb Height Anomaly Outlook

ECMWF Ensemble Jet Stream Gif

This is the Northern Pacific View of the ECMWF ENSEMBLE Run of the Jet Stream.

Northern Pacific View - ECN ENS - Jet Stream Forecast
Northern Pacific View - ECN ENS - Jet Stream Forecast

Temperature Forecast

Upper-Air Temperature Anomaly GIF: The reds are moving over California, which means above-average temperatures are here again. For now there are no signs of much cooling over the next 10 days.

*Temperature anomaly means a departure from a reference value or long-term average. A positive anomaly indicates that the observed temperature was warmer than the reference value, while a negative anomaly indicates that the observed temperature was cooler than the reference value.

ECN ENS - Upper Air Temperature Anomaly
ECN ENS - Upper Air Temperature Anomaly

The Wind Forecast

The wind forecast for today calls for SE winds at 5-10 MPH with gusts to 15 – 20 MPH over the higher elevations. On Wednesday and Saturday, expect a SW wind at 5-10 MPH with gusts to 15 MPH at the 9000-foot level and gusts up top to 20-30 MPH. 

ECM ENS Wind Forecast
ECM ENS Wind Forecast

QPF Forecast

The following ten days is looking dry, with no rain or snow in sight at this time.

NBM - QPF Forecast
NBM - QPF Forecast

Snowfall Forecast

Most models show the area getting no snowfall over the next ten days, which is pretty typical for late September into early October.

NBM - Snowfall Forecast
NBM - Snowfall Forecast

Precipitable Water Anomaly

ECN ENS - Precipitable Water Anomaly
ECN ENS - Precipitable Water Anomaly
6-10 Temperature Outlook
6-10 Temperature Outlook
6-10 Temperature Outlook
6-10 Day Precipitation Outlook
6-10 Temperature Outlook
8-14 Day Temperature Outlook
6-10 Temperature Outlook
8-14 Day Precipitation Outlook

45-Day Long Range Fantasy Outlook

This is the long-range ultra fantasy 45-day model run. These longer-range ensembles are suitable for examining long-range trends in the overall weather pattern. They should never be used or considered a forecast. We see below higher hights with drier weather in the region through most of October. 

10-45 Day 500mb Height Anomaly Outlook - ECMWF Weeklies
10-45 Day 500mb Height Anomaly Outlook - ECMWF Weeklies

46-Day Fantasy Snowfall Outlook

These long-range snowfall outlooks are good for trends, and should never be considered a forecast. One thing I see in the long-range is a change to colder and snowier weather around 10/23 into the first week of November. 

46 Day Fantasy Snowfall Outlook from the ECM Weeklies
46 Day Fantasy Snowfall Outlook from the ECM Weeklies

First Look at Snowfall Season 2024-25

9-5-2024 – When looking ahead to the next snowfall season, predicting what might happen is difficult at this time of year. If a weak La Nina does form (66%), there is a good chance we will have a drier-than-average snowfall season. 

However, several very big winters have come from weak La Ninas over the last 25 years. (See the La Nina Winter chart down the page.) Everyone must also remember that many other factors are at play than just warm or cooler water along the Pacific equator. 

For now, Ted (Powder Forecast) and I are not forecasting what the winter might be like. We will better understand how this may play out in late October / early November. As we have all seen in the past, patterns can quickly flip and change in late December and January. 

La Nina seasons are like El Nino and can bring drought, moderate winters, or large ones. Many factors are at play, and the situation can change as the winter season starts to ramp up in mid-to-late December.

Let’s keep the positive vibes that Mammoth Mountain gets a perfect winter, with moderate amounts of powder snow mixed in with some dry periods and endless wind-buff days.  

Steve Taylor – The Mammoth Snowman 

PS The new runs of the ECMWF Seasonal come out for forecasters on the 5th of each month. 

Weather Bell Winter Snowfall Outlook 2025
Weather Bell Winter Snowfall Outlook 2025
September 5th Update - ECMWF Seasonal Precipitation Oct - December 2024
September 5th Update - ECMWF Seasonal Precipitation Oct - December 2024
CanSips Seasonal Precipitation October - December 2024
CanSips Seasonal Precipitation October - December 2024

La Nina Years Snowfall Totals for Mammoth Mountain

Weak La Nina
1971-72 Snowfall Total = 268 with 139 in December
1984-85 Snowfall Total = 236
2000-01 Snowfall Total = 393 with 124 in February
2005-06 Snowfall Total = 578 with 4 100+ inch snowfall months
2008-09 Snowfall Total = 470 with 2 100+ inch snowfall months
2016-17 Snowfall Total = 617 with 245 January 163 February
2017-18 Snowfall Total = 262 with 142 in March

Moderate La Nina
1970-71 Snowfall Total = 255
1995-96 Snowfall Total = 321
2011-12 Snowfall Total = 263
2020-21 Snowfall Total = 244.5
2021-22 Snowfall Total = 260

Strong La Nina
1973-74 Snowfall Total = 306
1975-76 Snowfall Total = 197
1988-89 Snowfall Total = 251
1998-99 Snowfall Total = 323
1999-00 Snowfall Total = 382
2007-08 Snowfall Total = 333
2010-11 Snowfall Total = 668
2022-2023 Snowfall Total = 717 – Largest Winter Recorded over the last 100 years

ENSO Watch

Global SST Temperature Anomaly

Last Update from DWP Precipitation for Mammoth Pass & the Eastern Sierra

Most Recent Posts

*Mammoth Mountain and Eastern Sierra Weather is updated Sunday, Tuesday & Thursday by local Steve Taylor, the Mammoth Snowman. The goal is to provide detailed weather forecasts presented in an easy-to-read format. This isn’t a Hype, one-and-done model-run website. It’s just the basic facts from how I see it after 40 years of being involved in local weather and recreation. And yes, I use Weather Bell for my forecasting data.

 

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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 MammothSnowman.com in 2004 with Video and photo Blog reports. (There was No YouTube back then.) Facebook was added to the fold in 2008, and the Facebook Group was added in 2016. 

Reports, videos, and photos from the website have been featured on local TV Stations here in Mammoth and Bishop, as well as KTLA, AP, Fox, ABC, CBS, and NBC News.

Click Here to Learn More About the People Who Make MammothSnowman.com a Reality