Mammoth Mountain Weather Forecast
Saturday, October 19th, 2024 @ 10 AM – This morning, cold air continues to cover the Eastern Sierra, along with strong winds over the Summit of Mammoth Mountain. There is an NNW wind-up Top with gusts to 67 MPH and a temperature of 27 degrees.
Over the weekend, expect winds to back off later this morning into the afternoon hours as the region starts to ridge up again.
As high presure takes control, expect dry conditions with a slow warming trend and breezy afternoon and evening winds over the higher elevations. This pattern will be in place through at least next Wednesday before a cool-down begins.
The next chance for a very light dusting of snow is Friday into Saturday; however, as of this post, confidence is very low in picking up any snow over Mammoth Mountain.
Short-Term Forecast into Wednesday: Midday temperatures at the Main Lodge (8,900 Feet) will be in the low-50s today, with mid-50s Sunday and upper 50s to lower 60s into midweek.
The overnight lows will be in the mid-30s tonight and then upper 30s to lower 40s into next Wednesday.
The wind forecast for the next few days calls for an NE wind at 10-15 MPH with a gust of 20-25 MPH. Above the 10,000-foot level, the wind speed into the early afternoon hours will be 40-50 MPH range.
Sunday into Wednesday, an SW flow will return with winds 5-10 MPH with stronger gusts during the afternoon and evening, especially over the upper mountain.
In Mammoth Lakes, midday temperatures will be in the upper 50s to lower 60s on Monday and then in the upper 60s on Tuesday and Wednesday.
Tonight’s overnight low will be in the low to mid-30s, with upper 30s to lower 40s into Wednesday.
For Bishop to Mill Pond, mid-day highs will be in the lower 70s today and then upper 70s to lower 80s into Wednesday.
Tonight’s overnight lows will be in the upper 30s, and then into midweek, it will be in the low to mid-40s. Expect light winds during this time frame.
Mammoth Mountain Extended Outlook Discussion
For the 7-14 Day time frame, the GEFS and ECM ENS have a low off the Pacific Northwest coast, with some possible very light moisture working its way into the region on Friday (Day 7) into Saturday (Day 8). Tempratures will be warm, so if there is a bit of moisture to work with, snow levels would be very high up in elevation.
After that, expect more tranquil weather until around the 29th or 30th of the month, when the next low will move in as a possible inside slider.
If you look at the image below, you can see that the GEFS is much deeper and colder with that slider over the ECM ENS model run.
If that inside slider pattern happens, it would give the snowmaking crew cooler air to work with, along with some snow showers and possibly several inches of snow if the slider is west enough.
We are in the heart of the transition from Summer to Winter now, so models are getting a bit funky.
Ultra Fantasy Outlook for November: The month starts with the cold and snow showers discussed above. After that, models show seasonal temperatures and drier conditions developing for a time. 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 presure systems to move through the area with moderate to strong 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.
At this point, it’s time to wait and see.
Steve Taylor – The Mammoth Snowman
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 Northern Pacific View of the ECMWF ENSEMBLE Run of the Jet Stream.
Temperature Forecast GIF
*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 15-25 MPH range during the afternoon. Winds will increase in all areas on Thursday and Friday, with gusts in the higher elevations in the 40-50 range.
QPF Forecast
Snowfall Forecast & Outlook Images
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
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