Powder Forecast – Friday March 20th, 2026
Ted Schlaepfer CCM —- Mammoth Mountain WeatherGuy
Snowfall forecasts are valid at the Sesame snow course (Main Lodge) for the prior 24 hours as reported in the 6-7 AM morning snow report.
**Snowfall forecast confidence ranges from very low (1) to very high (5)
Sat 3/21 = 0”
Sun 3/22 = 0”
Mon 3/23 = 0”
Tue 3/24 = 0”
Wed 3/25 = 0”
Thu 3/26 = 0”
Fri 3/27 = 0”
Sat – Mon 3/28 – 3/30 = 0 – 1””
March Snowfall = 1”
March Forecast = 1 – 6”
Detailed 4-day Snowfall Forecast:
Sat 3/21 through Tue 3/24 – No snowfall expected all days.
Forecast Summary:
Short Term (Days 1 – 4):
The current infrared satellite image (below) this afternoon shows strong high pressure is over the state and West Coast resulting in very warm/summer-like temperatures today. Current temperature at 2 PM this afternoon is 58°F at McCoy and almost 71°F at Eagle.
The high-pressure ridge will weaken only slightly this weekend (image below) from a passing weak weather system that is currently well off the coast. Slightly cooler temperatures by about 5-6 degrees are expected over the weekend but with continued spring across the mountain. Fair and slightly warmer weather returns early next week as the high pressure ridge rebuilds.
Long Range (Days 5+):
The longer-range guidance has not changed much and still favors dry weather for almost the rest of the month. A pattern change is now expected at the end of March and early April that will produce more seasonable temperatures and also a chance for spring storms.
What seems like a never-ending high-pressure ridge will hold firm through the middle of next week (image below) before slowly weakening end of the week and over the following weekend. That means continued dry weather and spring conditions into the last weekend of March, although the snowpack may start firming up by Sunday if the longer-range guidance is correct.
Both the ECMWF (image below) and the GFS (two images below) models move a deep upper-level low-pressure system into CA at the end of the month and into early April. That would bring the weather back to winter conditions across the Sierra.
The latest 12z run of the ECMWF is the wetter model (image below), with around 2” of liquid or almost 2 feet of snowfall. The GFS is not showing nearly as much (two images below), at around 0.75” of liquid, but enough for powder conditions.
Unfortunately, those solutions are not currently well-supported by the respective ensemble means of both model suites. The ECM EPS (image below) is showing a much weaker long-wave trough, and the GFS ensemble (two images below) is also much weaker in its representation of any potential storm pattern.
That is reflected in the QPF from the ensembles with the ECMWF EPS (image below) showing only about half an inch of liquid and the GFS ensemble (two images below) even less at about a quarter/third inch. While significant precipitation is still very uncertain, cooler temperatures are more certain, which should at least slow down the melt.
The longer range fantasy guidance from the ECMWF EPS 45-day forecast shows about 1.5” liquid falling at Mammoth up until the currently announced Canyon/Eagle lodge closing dates. While adding onto the snowpack to extend the season is not looking likely currently, there is still a decent chance for a late season powder day. WG
