Mammoth Mountain Weather Forecast & Long Range Outlook
Saturday, August 31st, 2024 @ 12:30 PM: Looking at the current windowcast, there are a few clouds from Mammoth Mountain down to the Bishop area. It’s a perfect day for end-of-summer fun in the Eastern Sierra.
Conditions up top during these lunch hours show a temperature of 58 degrees with an SSW wind at 11 to 20 MPH. Down at the Main Lodge, the temperature is 68 degrees with an SSW wind at 3 MPH, gusting to 9 MPH. Last but not least, the temperature at Little Eagle Lodge in the upper part of Mammoth Lakes is 73 degrees.
…Mammoth Mountain and Southern Eastern Sierra Weather Synopsis into next Wednesday…
Expect above-average temperatures into Monday, with some warming Tuesday through next Friday. Skies will be pt cloudy, with a few isolated showers possible in the high country this weekend. There is also a possibility of a few small build-ups into next week, but overall, skies should be mostly clear by Monday.
The ECM ENS, like other models, has a cut-off low coming into the area and weakening and dying over the next 48-72 hours.
That COL will bring in a few afternoon clouds with a slight chance of showers today and possibly a few very light isolated showers for the higher terrain on Sunday.
QPF output from the ECM shows light precipitation amounts at .01 to .10. Snow levels would be well above the 12,000-foot mark.
Look for increased winds in the area this weekend and Labor Day from the COL. Above the 9500 level, gusts out of the SW from 25 MPH to 35 MPH could occur into Monday afternoon.
Here are the details of what you can expect in the High Country into Labor Day: Midday temperatures at the 8900-foot level (Main Lodge / Lake Mary) will be in the low to mid-60s.
Overnight lows will be in the mid to upper 40s. Winds on Mammoth Mountain and in the high country will switch to the N to NE today at 5-10 MPH, with gusts up to 15-25+ MPH at times. Friday into Labor Day, winds will be SW at 10-20 with gusts to 25-35 MPH at times.
In Mammoth Lakes, midday temperatures will be in the mid to upper 70s, with overnight lows in the lower 50s. From Crowley Lake to Toms Place, midday temperatures will be in the low 80s. Overnight lows are expected in the mid to upper 40s.
For the Bishop to Millpond areas, expect mid-day temperatures in the mid-90s and overnight lows into the mid-50s.
Mammoth Mountain Extended Fantasy Weather Discussion
8-31-2024 @ 1 PM After the current cut-off low moves out on Monday/Tuesday, you can expect more ridging to rebuild over the Eastern Sierra.
The ridging will bring dry conditions to the area, with warming temperatures in the 7-10 day weather forecast period.
Looking at this morning’s ECM run, limited moisture will make its way into the area, so just a few isolated builds up with a small chance of any thunderstorms are in the long-range outlook.
As we move into September, you can expect just above-average temperatures for at least the first half of the month. Beyond that, continued drier and warmer conditions are more likely to prevail.
Please note that we are moving into meteorological fall with the start of the new month. Models can get a bit weird over the next 6-8 weeks as they are entering the transition season from Summer to the next Snowfall season, which will hopefully start in late October or early November.
For many years of September past, the first small Fall system moves through around the 21st of September, give or take a few days. Signs are showing off and on in the longer-range ECM Weekly model, with that scenario returning in 2024.
Steve Taylor – the Mammoth Snowman – Next Update Tuesday by 4 PM
ECM & GEFS Ensemble Models 500
15-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 not over the years.
16-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.
ECMWF Ensemble Jet Stream Gif
This is the Pacific Wide Angle View of the ECMWF ENSEMBLE Run of the Jet Stream. You can see increased upper winds associated with the Cut Off Low (COL) just off the coast Sunday into Monday.
Temperature Forecast
Temperature Anomaly GIF: Above-average temperatures are likely over the next 7-10 Days from Mammoth Mountain down into the Bishop area.
*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.
The Wind Forecast
Winds will remain in the lighter range over the next 24 hours and then slowly increase, with moderate winds expected on Sunday into next Tuesday. Peak wind gusts below are showing up on Monday.
QPF Forecast
That cut-off low shows a low QPF forecast for Saturday and Sunday, with a slight chance of isolated showers on Monday over the higher terrain.
Snowfall Forecast
Just a tiny dusting of snow is showing up around the Mt. Whitney area; all other locations and elevations are too warm for snow from this weak cut-off low to move through.
Precipital Water Anomaly
There is enough moisture around for some isolated showers in the next few days. When you see the green on the map below, there is a chance for build-ups and isolated precipitation.
45-Day Long Range Fantasy Outlook
This is the long-range ultra fantasy 45-day model run. These longer-range ensembles are good for examining long-range trends in the overall weather pattern. They should never be used or considered a forecast.
Over the next 45 days, the weather is looking about what I would expect for September in the Eastern Sierra: dry with above-average temperatures. Let’s hope for a dusting of snow again around the third week of September.
45-Day Fantasy Snowfall Outlook
The ECM has a very light dusting in the third week of September and another in early October. These are the ultra-fantasy model runs, so keep this in mind.
First Look at Snowfall Season 2024-25
8-31-2024 – 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
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
El Nino - La Nina - Neutral Watch
Last Update from DWP Precipitation for Mammoth Pass & the Eastern Sierra
* Mammoth Mountain and Eastern Sierra Weather is updated several times a week by local Steve Taylor. 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 the 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 & 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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