Mammoth Mountain Weather Forecast from the Snowman
Steve Taylor the Snowman
October 8, 2024
8:46 am
Read More »
Mammoth Mountain Weather Forecast
Including Mammoth Lakes & Bishop, California
Tuesday, September 10th, 2024 @ 3 PM – The area has mostly clear skies with some haze from dissipated wildfire smoke from the south.
It feels like early Fall up in the high country, and the lower elevations from Crowley down to Bishop are also starting to cool off a bit.
Checking area weather stations up top this afternoon, the temperature is 53 degrees with an S wind at 30 MPH, gusting to 47 MPH at times. Down at the Main Lodge / 8900 Foot level, the temperature is 62 degrees with a WSW wind at 5 MPH, gusting to 21 MPH at times.
The temperature is 71 degrees down in Mammoth Lakes, 81 degrees in Crowley Lake, and 91 degrees in Bishop.
Synopsis: The Fall Season’s first “inside slider” will be making its way into the Great Basin over the next 24-48 hours. For our region, expect very dry conditions (Red Flag Warning) with breezy to gusty winds, especially over the high country on Wednesday.
Expect cooler days with lighter winds under clear skies by Thursday, Friday, and Saturday. 
Mostly clear skies are in the forecast on Wednesday, with midday temperatures at the 8900-foot level (Main Lodge / Lake Mary), which will be in the upper 50s to lower 60s. Winds will be 10-25 MPH with gusts over the higher terrain 45 to 60 MPH.
Thursday into Saturday, midday temperatures will be in the low to mid-60s, with overnight lows in the 40s under clear skies. Winds on Mammoth Mountain and over the higher elevations will be SW at 5-10 MPH, with gusts up to 20 MPH during the afternoons.
Midday temperatures in Mammoth Lakes will be in the mid-to-upper 60s on Wednesday, then upper 60s to lower 70s Thursday into Saturday.
Overnight lows will be in the low to mid-50s, then dropping into the lower 40s. The wind will be out of the SW at 5-10 MPH, with gusts to 15 MPH, except on Wednesday, when gusts will be 20-30 MPH.
Midday temperatures from Crowley Lake to Toms Place will be in the low to mid-70s, with overnight lows dropping into the mid-30s to lower 40s. Winds will be SW at 10-15 MPH, with gusts on Wednesday of 20-30 MPH.
For Bishop to Mill Pond, a high of 92 is expected on Wednesday, followed by low to mid-80s Thursday into Saturday. Overnight lows will fall into the low to mid-40s, and valley winds will be 5-15 mph, with gusts to 25+ MPH possible at times.
Snowman
Mammoth Mountain Weather Outlook & Discussion
9-10-2024 @ 4 PM – The warmth of Summer is looking to be coming to an end as two weather systems are heading into the area over the next week.
The first system enters the area on Wednesday as a dry inside slider. Expect breezy conditions throughout the region, with moderate to strong winds over the upper terrain on Mammoth Mountain.
There will be a lull in the action Thursday into next Saturday, but you will notice it’s much cooler from Mammoth Mountain to Mammoth Lakes and Bishop.
So, system one takes us from Summer to Fall with pleasant daytime temperatures and cooler nights to end the week and start the weekend.
The second following system will come in from the West later on Sunday. That trajectory should bring in a bit of moisture with the low. If this system pans out, it will bring the second dusting of snow to Mammoth Mountain. (The last 1-2 inches fell on August 24th.)
The other thing to note about low number two is that it will be in no hurry to vacate the area; as you can see in image two just below, it hangs around all week.
However, the low does set up residence on the west side of the Great Basin so that the Eastern Sierra will remain cooler and blustery, with a chance of light snow showers next Tuesday and possibly Thursday.
The snow levels out that far are sketchy, but they look to be above the 8500-9500-foot level. Of course, we can fine-tune the details in the next several updates.
Confidence in the first system is high, but the second system’s track and moisture are still somewhat in doubt.
In the longer-range fantasy outlook period for the last week of September, the EPS model predicts higher heights again for what would be considered Indian Summer Weather. That is assuming next week’s system does bring a dusting to the high country.
While the area will warm up again, it will be late September, so temperatures won’t be as warm as in early September.
Looking way out into the Fantasy Forecast for Octobers weather trends, we see warm, dry days. The one thing that could change would be a Typhoon merging with the westerlies and sending some energy and much-needed moisture our way.
That type of weather pattern is more likely for Mammoth from around mid-October into early November. It’s a short window, but sometimes we get blessed and go from dirt to snow base fast from that type of Senecio.
If that does not happen, October might be the perfect month for hiking and more mountain biking.
Have a great day and enjoy the weather, Steve Taylor – the Mammoth Snowman
Next Weather Page Update by 5 PM Thursday
Mammoth Weather Forecast Data
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 Eastern Pacific View of the ECMWF ENSEMBLE Run of the Jet Stream.
Temperature Forecast
Temperature Anomaly GIF: Over the next week, expect a slow cooldown, as shown below, with the blues moving over California. The cooler weather looks to be in the area for the next 10-14 days before there is a bit of a warm-up again. You can kiss the heat of Summer goodbye this week in the Southern Eastern Sierra.
*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
Gusts on Wednesday look to be NW to N at 45-60 MPH over the top and near area ridges. By Thursday winds over Mammoth Mountain and the higher elevations will be SW at 5-10 MPH, with gusts up to 25-35 MPH during the afternoons.
QPF Forecast
ECM ENS takes the track of the inside slider a bit too far east for any QPF from this system. Most models have the same outcome; however, the GFS had a trace of precipitation, as did the CMC this morning.
Snowfall Forecast
The ECM ENS shows no snow this week, while the NBM model has some light snowflakes across the Central Sierra Crest on Wednesday. The exact track of the inside slider will determine if there are any snowflakes. If that track does get closer to the Eastern Sierra, then the ECM will start to pick up on it, but for now, the low is still a bit far to the east.
The is what you see in the image below with 1-3 inches possible for some of the higher terrain. The ground is warm don’t expect more then a dusting to 1/2 inch ina few isolated areas above 9500 to 10,000 feet. This is still out at Day 7 so confidence is a bit low.
Precipitable Water Anomaly
As the inside slider drops into the great basin, all the moisture in the area gets suppressed to our south. The second low brings with it a slight tao of moisture. Hoefully it’s enough to get the ground white again for at least a few hours.
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 into mid October in the Eastern Sierra: dry with above-average temperatures. Let’s hope for a dusting of snow again around the third week of September and again early to mid October.
45-Day Fantasy Snowfall Outlook
The ECMWF EXT ENS still has a dusting for later in September, with more snow at some point in October. These would just be dusting and would melt off on contact or possibly hang around for a couple of hours.
Once the mid October hits any snow that does fall should hang around on north facing slopes. In the past there have been several October openers when the energy from a Typhone gets caught up on the Jet Stream and heads in the Sierra. Those system never show up in the long range so let’s hope we start to see something like that set up after mid October. Just a dream….
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.
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
Most Recent Posts
Mammoth Mountain Weather Forecast from the Snowman
Steve Taylor the Snowman
October 6, 2024
8:04 am
Read More »
Mammoth Mountain Weather Forecast from the Snowman
Steve Taylor the Snowman
September 30, 2024
7:57 am
Read More »
*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.
——————-
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
