Weather Update — October 20, 2026

Transcript

My friends…

It’s always a beautiful day here in the Eastern Sierra. I’m Noé from eastsideweather.com, here for MammothFM in the Eastern Sierra, coming atcha with your local weather report…

Our storm is still scheduled to arrive in a few days. Some isolated showers will be possible on Tuesday, and then by Wednesday afternoon the main event arrives. Showers currently last through Thursday of this week. As we discussed yesterday, this storm has changed its track enough to be bringing in more mild air from the south, which means high snow levels. When the heaviest precipitation arrives Wednesday, the snow levels will be around 9,000 to 9,500 feet on Wednesday, gradually lowering to around 8,000 feet on Thursday.

The snow line will be right at town at the end of the storm, with 1 to 5 inches of very wet and heavy snow possible at Main Lodge, very marginal snow lines, and then 5 to 10 inches possible at higher places including the summit of Mammoth Mountain. My friends, El Niños have a real warm tilt for our storms, as they typically bring in a lot of moisture. There’s nothing harder than forecasting snowfall amounts with marginal or shifting snow elevations… Wish me luck this winter!

After this, another potential storm window is appearing on models for the last two days of October, but it’s too far out to discuss at the moment.

And now for the weather forecast this week:

In Mammoth Lakes and the surrounding areas.

Tuesday. Increasing clouds with a high near 57 and an overnight low of 35. Light south winds gusting up to 20mph in the afternoon. Low chance for isolated showers ahead of the storm.

Wednesday will be mostly cloudy with an 80 percent chance of precipitation. A slight chance of rain in the morning, then showers and possibly a thunderstorm in the afternoon, mixing with snow overnight. A high near 52 and a low of 34. Snow levels start high, around 9,000 to 10,000 feet, then drop to around 8,000 feet after midnight, so we could see some wet snow at Main Lodge overnight, while town stays marginal.

Thursday. Snow showers likely in the morning, then rain later in the day. A 70 percent chance of precipitation and a high near 46. Snow levels rise to around 8,400 feet in the afternoon. Then clear weather for Friday and the weekend, with a warming trend.

And now, down to our friends in the Owens Valley.

Tuesday. Mostly sunny with a high near 74, and strong south-southeast winds gusting up to 39mph, with patchy blowing dust in the afternoon. A 30 percent chance of showers overnight with a low of 46.

Wednesday. Showers and thunderstorms, with an 80 percent chance of precipitation. Breezy southeast winds gusting up to 37mph and a high near 68. Showers overnight with a 90 percent chance of precipitation and a low of 41.

Thursday. Showers and possibly a thunderstorm, with a high near 61. Then clear weather for Friday and the weekend, with a warming trend.