Mammoth Mountain Weather
Updated Tuesday, December 30th, at 2 PM
Winter Storm Watch for Friday into Sunday
The next series of storm systems is slated to move into the Mammoth Lakes area. The first one is a Baja Low and is already sending cloudy skies to the area. Light rain and snow showers are expected to start around the first chair on Wednesday, according to the latest HRRR high-resolution model run.
Snow Levels on Wednesday will be high in the warmer airmass of subtropical moisture at 9,000 feet to 10,000 feet, then lower to 8,000 to 9,000 feet by New Year’s Eve. Temps for Wednesday will be in the upper 30s to the lower 40s. Tonight’s overnight lows will be in the lower 20s, and on Wednesday night, lower 30s.
The wet, soggy mess will continue into New Year’s Day with light rain and snow showers. Snow levels are coming down during the day to 7,000 to 8,000 feet. There is a wide spread in snow levels across the models I’m using for both Wednesday and Thursday.
Once the Baja Low is out of here later Thursday, all eyes turn to the developing much colder winter storm for Friday night into Sunday.
Satelight View
Radar View
Mammoth WX Discussion
12-30-25 – The next 10 days look great for snowfall over Mammoth Mountain. The biggest system in the series over the next 10 days is Friday night into Sunday, and then smaller systems beyond that will help keep the snow surface refreshed.
Over the next week, 4-5 inches of water are forecast, adding another 3-4+ feet of base snow in the powder fields of Mammoth Mountain.
I will keep you updated on what to expect…
Ski Ya Later,
Snowman
❓ 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.