Mammoth Mountain Weather Forecast
Monday, October 21st, 2024 @ 10 AM – Good morning, and welcome to our Mammoth Weather Page.
Checking conditions in the area, from Mammoth Lakes down to Bishop, the windowcast shows clear skies with gusty winds over the higher elevations. The temperature is 29 degrees at the top of Mammoth Mountain (11,053 Feet), with an S wind at 43 MPH, gusting to 46 MPH. The wind chill at the top is 12 degrees as of this post.
This week’s weather forecast looks warm and dry, with breezy conditions early in the week. The hoped-for change has been moved to around Monday, the 28th of the month. Hopefully, at that time, cooler weather and some snow showers will arrive.
Short-Term Forecast into Friday: Midday temperatures at the Main Lodge (8,900 Feet) will be in the low to mid-50s today, with upper 50s to lower 60 Tuesday into Friday. The overnight lows will be in the upper 30s to lower 40s into next Wednesday.
The wind forecast for the next few days calls for a SW wind at 5-10 MPH with a gust of 15-20. Above the 10,000-foot level, the wind speed into the early afternoon hours will be in the 25-40 MPH range.
In Mammoth Lakes, midday temperatures will be in the mid- to upper 60s through Friday. The overnight low will be in the low to mid-30s.
For Bishop to Mill Pond, mid-day highs will be in the upper 70s to lower 80s into Friday. Overnight lows will be in the mid-40s. Expect light winds during this time frame.
Mammoth Mountain Extended Outlook Discussion
For the 7-14 Day time frame: The ECM has a deep inside slider that would bring much colder air, breezy conditions, snow showers, and conditions conducive to snowmaking. By Day 12, the model has higher heights with a warm-up and no snowfall.
Looking at the GEFS Ensemble run, it shows what I call a hybrid inside slider that descends more westward than the ECM model.
This pattern would offer the same as the ECM but with a greater potential for several inches of snowfall. This model also differs as it brings a second inside slider with additional light accumulations and very cold air for snowmaking at the end of the run.
Confidence in how all this will work out is low; models are still in transition season, so it’s time to wait and see how it resolves. I have posted both the ECM and the GEFS below so you can see the two solutions that forecaster’s are is dealing with today.
Ultra Fantasy Outlook for November: The month looks to start with the cold and snow showers discussed above. After that, models show seasonal temperatures and drier conditions developing. The data right now is unclear on when to expect any significant changes again after 11/3.
Overall, my outlook for the month would be for 2-3 low-pressure systems to move through the area with moderate to solid ridging between systems. Snowfall is expected to be a bit below average.
There have been six weak La Nina Novembers over the last 24 years; here is what happened with the snowfall on Mammoth Mountain at 9,000 feet.
- 2000-2001 – November Snowfall 22.8
- 2005-2006 – November Snowfall 23.4
- 2008-2009 – November Snowfall 26.5
- 2016-2017 – November Snowfall 19
- 2017-2018 – November Snowfall 34
- 2022-2023 – November Snowfall 61
Looking at all the Fantasy Long Range Outlook data from last week, most of the more extended ensemble models support what we have seen from weak La Nina Novembers from the past.
Steve Taylor – The Mammoth Snowman
Mammoth Weather Forecast Data from Weather Bell
ECMWF Ensemble Jet Stream Gif
This is the Northern Pacific View of the ECMWF ENSEMBLE Run of the Jet Stream.
Temperature Forecast GIF
I am posting both the ECM and the GEFS today out to day 15. You can see the significant differences in the models from Day 8 to 15. The GEFS solution would be best for snowfall and snowmaking; however, for now, I am trusting in the ECM solution, and I hope to be wrong.
*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 southwest flow. Wind speed at the 8900-foot level will be 5-10 MPH with gusts in the 15-25 MPH range during the afternoon. Winds will be gusty at times up to in the 35-40 MPH range this week. I will have more detailed on mountain wind forecasts once the ski area reopens for the winter season.
QPF Forecast
There is no QPF for the next seven days, with just light amounts in the 7-15-day outlook period. Until we see some consensus between the ECM and the GEFS I would not bank on any of these forecast amounts right now.
Snowfall Forecast & Outlook Images
There is a slight chance of snow over the next seven days, with the ECM and GEFS showing dry conditions over Mammoth Mountain.
For week two there will be a change over to cooler weather with possible snow showers at times day 8 out to day 15 if the GEFS verifies. If the ECM verifies there will be less snowfall. Hopefull the NBM model is on to something and will be the winnner of the 3 outlooks below.
Below you will see the ECM, the GEFS and the most favoable for snow the NWS model the NBM. Snowfall total outlooks beyond days 7 are fickel at best and are for an outlook of what might happen not a forecast.
Winter Outlook as of October 11th, 2024
Thinking about potential snowfall and the upcoming winter season is getting exciting. Let’s take a look at what this upcoming snowfall season might hold.
The first issue in looking out into the weather for the snow season in mid-October is simple. Many of the factors that will come into play to influence this upcoming winter won’t be on the table until 4-6 weeks from now.
What we can do is look at the ENSO factor. With the newest seasonal long-range fantasy model run in, the ECMWF Seasonal has a weak La Niña in place through at least January.
During February, the La Nina looks to fade to natural, adding a whole new factor to the second half of the Winter Outlook that we won’t touch this far out.
Below are the winters considered weak La Ninas over the last 30 years. One was a drought season, one an average winter, and four above-average winters. 2023 was the largest winter ever recorded by Mammoth Mountain Ski Patrol and DWP.
- 2000-2001 – Total Snowfall 393
- 2005-2006 – Total Snowfall 578
- 2008-2009 – Total Snowfall 470
- 2016-2017 – Total Snowfall 617
- 2017-2018 – Total Snowfall 262
- 2022-2023 – Total Snowfall 721
The ECMWF Seasonal (see images below) updated this month shows the snow season starting with average snowfall for November and December. Beyond that, snowfall lags below average for January and February, with an average March being shown way out in Weather Model Neverland.
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.
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 with 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
2022-23 Snowfall Total = 717 – Largest Winter Recorded over the last 100 years
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
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
Most Recent Posts
Mammoth Mountain Weather Forecast & Discussion
Steve Taylor the Snowman
December 5, 2024
9:08 am
Read More »
Mammoth Mountain Weather Forecast & Discussion
Steve Taylor the Snowman
November 29, 2024
12:37 pm
Read More »
