Mammoth Mountain Weather Forecast & Discusion
Steve Taylor the Snowman
January 16, 2025
6:15 am
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Mammoth Mountain Weather Forecast
Including Mammoth Lakes & Bishop, California
Tuesday, October 8th, 2024 @ 7 AM Good morning. High pressure continues to bring warm and dry conditions to the area while a week short wave off the coast spins in some clouds from the southwest. There is a 10-20% chance of a light shower over the high country today.
By Thursday, a weak cutoff low will be approaching the Northern California coast. That low will start to affect the weather, with more clouds, a cooling trend, and breezy conditions in most locations. The upcoming weekend should be a nice one with perfect Fall Color Viewing Weather.
Looking at the windowcast and current conditions, you will find that Mammoth Mountain and the Southern Eastern Sierra are under pt cloudy skies.
Checking up Top (11,053 Feet), the temperature is 43 degrees, with an NNW wind at 8 MPH gusting to 9 MPH. The Wind Chill is 38 degrees, with an RH of 50% and DP of 26.
Down at the Main Lodge (8900 Feet), the temperature is 48 degrees, and the SW wind is 1 MPH, gusting to 3 MPH at times. In Mammoth Lakes, the temperature is 46 degrees, the Mammoth Airport is 40 degrees, with 45 degrees in Crowley Lake and a 53 down in Bishop.
Mammoth Weather Forecast for Your Adventure
Basic Weather Details into Saturday: For Tuesday expect pt cloudy skies with a 10% chance of a light shower. Skies will be clear on Wednesday, with partly cloudy conditions on Thursday and Friday. Expect clear skies over the weekend.
For the Main Lodge area, midday temperatures at the 8900-foot level will be in the mid-60s into Wednesday, then lower into the upper 50s to lower 60s on Thursday and upper 50s this weekend.
The wind forecast for the next few days calls for a southwest flow. Winds will be light during the overnight hours and then increase during the late morning and afternoon hours.
Wind Speed at the 8900-foot level will be 5-10 MPH, with gusts in the 15-20 MPH range during the afternoon hours. Wind gusts up top will be a bit stronger, at 20-30 MPH at times.
In Mammoth Lakes, midday temperatures will be in the upper 60s to lower 70s and then lower 60s Thursday into the weekend. Overnight lows will be in the mid-upper 40s with light winds.
For Bishop to Mill Pond, mid-day highs will be in the mid- to upper 80s into Friday, with lower 80s this weekend. Overnight lows will be in the upper 40s to lower 50s.
Mammoth Mountain Area Forecast Discussion
Warm & dry days continue under higher heights from a ridge of high pressure centered just to the east of the Eastern Sierra Region.
The next weak upstream low will cut off and approach the northern California coast Thursday into Friday. The low will weaken, and weak troughing will influence the area into the weekend.
Temperatures will fall later in the week into the weekend, but they will still be above seasonal averages. Conditions will remain dry for at least the next week to 10 days.
The good news is that if you like cooler and possibly wetter weather, the longer range continues to show a change right around the 19th to the 23rd of the month. As of now, that’s when we could see the next dusting of snow on the ground.
Looking into the weather trends in the Ultra Fantasy Outlook period for the first two weeks of November, cooler weather with snow showers shows up on the ECM, GEFS, and CFS long-range fantasy models. (The model images below are just long-range trends and are not a forecast.)
Steve Taylor – The Mammoth Snowman
The next full weather page update will be on Thursday, October 8th, by 5 PM.
Mammoth Weather Forecast Data from Weather Bell
ECM Ensemble Model 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.
ECMWF Ensemble Jet Stream Gif
This is the Eastern Pacific View of the ECMWF ENSEMBLE Run of the Jet Stream.
Temperature Forecast
Upper-Air Temperature Anomaly GIF: We are starting to see a nice cool down in the upper air temperature anomaly by the end of the weekend. Let’s hope that comes through.
*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 wind forecast for the next few days calls for a west-to-south-west flow. Wind Speed at the 8900-foot level will be 5-10 MPH with gusts in the 15-20 MPH range during the afternoon hours. Wind gusts up top will be a bit stronger at 20-30 MPH at times.
QPF Forecast
After a chance of some showers today, the area looks dry out over the next 7 to 10 days. After that, we should see more in the QPF Outlook very soon.
Snowfall Forecast
Most models show the area getting little to no snowfall over the next ten days, which is typical for early October. The ECM model below has dusting over the higher peaks of Inyo County later today.
Precipitable Water Anomaly
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. You can see a pattern change from the 19th to the 23rd of October.
46-Day Ultra Fantasy Snowfall Outlook
These long-range snowfall outlooks are good for trends. They should never be considered a forecast. One thing I see in the long-range trend here is a change to colder and snowier weather around the 19th to 23rd of October into the second week of November. We see this to varying degrees in all the longer-range ensemble models.
Second Look at Snowfall Season 2024-25
10-6-2024 – Time to take a look at the long-range data and see how the trends are developing for the upcoming snow season.
The newest seasonal long-range fantasy model runs are in as of 10/5. The ECMWF Seasonal has a weak La Nine in place for the November-January period; beyond that, conditions rapidly change to the natural range. With the (flip-flopping) CFS having a more moderate La Nina through January.
Besides the SST forecast, many other variables will affect the outcome of the upcoming winter. Many of those factors are impossible to gauge this far out.
So, if we assume the ECMWF is close to right on the SSTs, the snowfall season based on the past more then likely will be below the average mark (50% chance), with a 25% chance of being around average and a 25% chance of being above average.
Several very big winters have come from weak La Ninas over the last 25 years. (See the La Nina Winter Chart down the page.)
The ECMWF Seasonal has the snow season starting with average snowfall for November and December, with January into February being drier, with an average March and April. Confindence in this long range outlook is low as the last run had a well below normal winter. Going to be intresting to see what the outcome will be on the next update on 11/5 is.
Here is the CFS precipitation outlook for November through January as of 10/6/24. Take it with a grain of salt, as this model constantly changes its outcomes.
Temprature-wise, many La Nina years have also turned out to be colder than average. The troughs affecting the Eastern Sierra are, more often than not, inside sliders.
Those types of weather systems are drier and colder than you’re used to seeing on Mammoth Mountain.
However, the current ECM Seasonal model shows the area’s temperatures averaging above average each month this winter. Go figure; it seems like the model is still struggling with what might come our way over the next few months.
As we wait for the snow season, remember that La Ninas are much like El Nino winters. There is no one specific outcome; you can get massive snowfall or a total bust. It’s all fun to watch, especially when it ends with a deep base on Mammoth Mountain.
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 next update for this snowfall section will be 11/6/24.
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
Last Update from DWP Precipitation for Mammoth Pass & the Eastern Sierra
*Mammoth Mountain and Eastern Sierra Weather is updated on 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. Snowman
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