Mammoth Mountain Weather
Forecast & Discussion
November 3rd, 2025, at 10:30 AM …HIGH WIND WATCH IN EFFECT FROM LATE TUESDAY NIGHT THROUGH LATE WEDNESDAY NIGHT…
WX Summary: Mammoth will get the remnants of a cold front moving through Wednesday afternoon into early Thursday. After that, the area will warm up and dry out again through next weekend.
3 Day Forecast: Look for clear skies today, partly cloudy skies on Tuesday, and midday tempretures in the lower 50s at Main Lodge. Winds will be SW at 5-10 mph with gusts up to 25-30 mph into Tuesday. Overnight lows will be in the upper 30s the next two nights.
On Wednesday, there is a 40% chance of rain or snow showers, with the snow level 8,500 to 9,000 feet, possibly lower to 8,200 feet on Wednesday night. Look for a dusting of snow at Main Lodge, and at best, about an inch of accumulation over the higher elevations with snow ratios at 3 to 1.
Temperatures on Wednesday will drop about 10 degrees, with highs around the Main Lodge in the lower 40s to upper 30s, and overnight lows are expected to drop to around 32.
Snowmaking: Marginal Snowmaking conditions tonight into Wednesday night, and then it will be too warm to blow through next weekend.
Mammoth Weather Discussion
11-3-25 @ 11:37 AM – The strong ridge that has brought the warm days is slowly moving eastward as a low-pressure system approaches southern Oregon and the northern California coast by mid-week.
As the low moves ashore on Wednesday, it will be too far north, so Mammoth will only pick up the tail end of the cold front. This is a warmer Pacific system with higher snow levels and no cold air behind it for snowmaking.
By Thursday into next Weekend, the next strong ridge will build and be right over the area. Over the weekend, the next Pacific low-pressure system will start to push the strong ridge eastward away from Mammoth.
The first low we have next week becomes cutoff and dies off quickly as it pushes the strong ridge off to the east. Expect a slight increase in winds from that system.
By next Tuesday, there is weak ridging for a short time before the next system appears to come into the area around the 13th / 14th of November.
That system has a good chance of giving us a nice dump of snow, with some snowmaking added to the mix. With that said, we need to look at all this with caution, as we are talking about a low that is 10-12 days out. 
Beyond the 14th, both ensembles then have Mammoth in an area of lower heights with more potential snowfall and periods of decent to good snowmaking at night for about a week to ten days.
That’s my Mammoth Weather Story for the day,
Ski Ya Later, Snowman Out. NOAA 6-10 Day & 8-14 Day Outlooks
October Seasonal Model Update – Looking Toward Winter 2025–26
10-5-25 @ 5 PM – The latest ECMWF seasonal update just dropped, and we’ve dug through every chart and model trend to see what this winter might bring to Mammoth Mountain.
The signal this year? A weak La Niña that fades fast — a setup that often means a slow start, followed by a better shot at storms once the pattern relaxes.
That’s a familiar pattern in the Eastern Sierra. Early winter can run lean while the Pacific jet stays aimed a bit north, but once it sags south, things can change in a hurry.
The key question this year isn’t whether storms will come — they will — but when the pattern opens the door and how cold those early ARs run.
Looking for years to match this Fall is tough. Here are the ones that are the closest: 2000-01 (393), 2005-06 (579), 2016-17 (618), and 2017-18 (262).
I will have more information on this in a couple of days, once I have concluded my research on past patterns.
Snowman – Next Model Update on 11/5/25
❓ Top Mammoth Weather Questions (from the Snowman)
When does Mammoth usually get its first snowfall?
Light snow can fall in late September, but consistent snowfall usually begins in late October or early November. Opening Day typically lands between November 10 and Thanksgiving, depending on storm activity and snowmaking.
How does the ENSO pattern affect Mammoth’s late fall and winter weather?
ENSO (El Niño/La Niña) plays a big role in Sierra storm patterns. El Niño winters often bring warmer, wetter storms. La Niña typically favors colder, backloaded seasons with more snow from February through April. Neutral years are the wildcards with high variability.
What is 500mb height and why does it matter?
500mb height maps show atmospheric pressure around 18,000 feet — a critical layer for tracking storm tracks, ridging, and jet stream placement. Watching 500mb patterns helps forecast Mammoth’s incoming storms and long-range trends.
What are the PNA and PDO, and how do they affect Mammoth weather?
The PNA (Pacific-North American Pattern) influences western U.S. ridging and troughing. A negative PNA favors cold, stormy setups. The PDO (Pacific Decadal Oscillation) affects sea surface temperatures in the North Pacific — a negative PDO often aligns with enhanced storm delivery into California during winter.
👉 Want more answers? Check out the full Mammoth Weather FAQ – 50 Expert Answers to learn more about storms, snow, winds, and long-range patterns from a trusted local source.
Author Bio: Steve Taylor, The Mammoth Snowman. Over the last 40+ years, Steve has spent countless hours studying and learning about Mammoth Mountain Weather and Snow Conditions.
Dr. George, Don Marcelin, Howard Sheckter, and Ted Schlaepfer were his weather mentors at that time. Steve used to hang out with Howard in the Weather War room in the early ’90s, getting first-hand knowledge of Mammoth Weather from the (The Dweeb) himself.
Steve has spent countless hours reading, studying, and watching weather discussions from the NWS and multiple Private Weather Forecasters. He is a long-time member of WeatherBell, Weather West, and AccuWeather Pro. Disclaimer: Steve is a hobbyist forecaster with over 35 years of experience reporting recreational weather and travel reports for the Mammoth Lakes area.