Mammoth Mountain Weather Forecast & Long Range Outlook
Tuesday, September 3rd, 2024 @ 1 PM: Looking at the current windowcast, skies have cleared out, and most of the haze is gone, as you can see in the live shot below.
Conditions up top during these lunch hours show a temperature of 53 degrees with an S wind at 31 to 47 MPH. The temperature at the Main Lodge is 64 degrees with a WSW wind at 4 MPH, gusting to 18 MPH.
The temperature at Little Eagle Lodge in the upper part of Mammoth Lakes is 68 degrees. Down in the lower elevations, Bishop has an 89-degree temperature at noon.
…Mammoth Mountain and Southern Eastern Sierra Weather Synopsis into next Saturday…
This week, there will be perfect end-of-summer warmth in the area, with a few builds starting around the Wednesday / Thursday time frame. With the build-ups, expect a 10% to 20% chance of a weak thunderstorm over the higher terrain from Bishop Creek Canyon up to Mammoth Mountain and a bit north. By Friday into Saturday, those chances for Thunder Storms will increase to 20-30%.
As of this post, the QPF during this time frame is pretty light, so no moderate or heavy rain is expected. As always, the QPF forecast can change to the wetter side, so make sure to check back for my Thursday afternoon post if you’re going to be out and about Friday into Saturday.
What about snowflakes? Snow Levels look to remain above the 12,000-13,000 foot mark through Saturday; the only dusting showing on the models is down around Mt Whitney.
Here are the details of what you can expect in the High Country into Saturday:
Midday temperatures at the 8900-foot level (Main Lodge / Lake Mary) will be in the low to mid-70s on Friday, with upper 60s on Saturday. Overnight lows will be in the mid-50s.
Winds on Mammoth Mountain will be SW at 10-20 MPH, with gusts to 25-35 MPH at times. Over the higher terrain, look for an increase in winds by Saturday.
In Mammoth Lakes, midday temperatures will be in the mid to upper 70s, with overnight lows in the low to mid-50s. From Crowley Lake to Toms Place, midday temperatures will be in the low 80s. Overnight lows are expected in the upper 40s to lower 50s
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
9-3-2024 @ 1 PM Over the next couple of days, expect more ridging to rebuild over the Eastern Sierra and the Western States, bringing what could be the last real taste of Summer tempratures to the area.
The ridge’s position means that a slight chance of afternoon showers and thunderstorms will pop up again starting about Wednesday. The chance for storms will increase on Friday and Saturday.
By days 7 / 8, the next cut-off low will be off the Northern California coast. That system will end the above-average temperatures and put our area into the just-above-average temperature range.
There will still be some build-ups in the area early next week, and with enough cooler air, there will be a slight dusting of snow down to the 10,000-foot level at some point next week. Confidence in that happening is low, but I will mention it since you will see it on the EDM ENS model down the page.
As we move into September, this month looks slightly above average temperature-wise, with limited precipitation. The best shot for decent precipitation would be from the remnants of a tropical system moving north. However, nothing like that is in the cards at this time.
Please note that with the start of the new month, we are moving into meteorological fall. 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.
Steve Taylor – the Mammoth Snowman – Next Update Thursday by 5 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 others 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 Northern Pacific Wide Angle View of the ECMWF ENSEMBLE Run of the Jet Stream.
Temperature Forecast
Temperature Anomaly GIF: Well above-average temperatures are likely over the next 7 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
The forecast to outlook gif below goes all the way out 10 days on this post. The green you see flashing at times are gusts into the 30-40+ MPH for the top of Mammoth Mountain.
QPF Forecast
This week’s ridging will bring a chance of isolated to scattered Thunder Storms starting Wednesday and lasting into at least early next week.
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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