Powder Forecast – Friday February 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 2/21= 0”
Sun 2/22 = 0”
Mon 2/23 = 0”
Tue 2/24 = 0 – 1”
Wed 2/25 = 0 – 1”
Thu 2/26 = 0”
Fri 2/27 = 0”
Sat– Mon 2/28 – 3/2 = 0 – 3”
February Snowfall = 87”
February Forecast = 87 – 90”
Detailed 4-day Snowfall Forecast:
Sat 2/21 through Mon 2/23– No snowfall expected all days.
Tue 2/24 – Chance for light snow during the early morning, then any snowfall changes over to rain at Main with snowfall from about McCoy to the top. Accumulations 0 – 1” at Main and 3 – 6” up top by Wednesday AM
Forecast Summary:
Short Term (Days 1 – 4):
The current infrared satellite image (below) this afternoon shows weak high pressure over the state, but lots of clouds streaming into California from a low-pressure system in the eastern Pacific. Clouds will continue to stream over Mammoth at times through tomorrow.
A deep trough in the forecast is expected to become established in the eastern Pacific (image below) by Sunday, with the first short-wave moving into NorCal and Oregon. Any precipitation will stay well north of Mammoth with just passing clouds and a bit more breeze. The longwave trough will also strengthen the subtropical ridge off Baja through early next week, resulting in warmer temperatures in Mammoth on Sunday and Monday.
A short wave will then eject from the parent low on Tuesday (image below) and drag a large precipitable water plume, or a weak atmospheric river, into Central CA. With the subtropical ridge holding firm, there will be very little cold air (purple arrow at the Oregon border) associated with the passing moisture plume, and snow levels will be unseasonably high and likely McCoy to the Top for the majority of the event, although snow levels may start around 9000 feet briefly Tuesday early morning.
The latest ECM model (image below) shows almost an inch of liquid for the event, which is slightly less than the GFS ensemble (two images below). The ECM EPS shows about 2/3 of an inch (image below), which is the best-case scenario to limit rainfall. The ECM model shows a few inches of snowfall (image below), but that is a better estimate for the Top, as it is usually about 1000 feet too low with the snow level forecast. Overall, it looks like rain on the mountain on Tuesday and Tuesday night, with maybe 3-6 inches of slushy snow up Top and generally deteriorating snowfall conditions early next week.
Long Range (Days 5+):
The longer-range guidance favors dry weather for the last part of the month and into early March, although there is a chance of something small at the start of the month. The fantasy range guidance shows a chance for a weak storm over the first full weekend of March; otherwise, the super-longer range guidance is saying nothing meaningful until around mid-month or later.
High pressure builds northward at the end of next week (image below) and will hold into the following weekend, with the parent upper low remaining quasi-stationary off the coast. It will eventually move inland in a weakened state late over the weekend (see two images below) and may produce some light snowfall at relatively high elevations. Current ECM EPS is showing about a third of an inch of liquid (three images below), thus, if snow levels stay low enough, there could be a couple or three inches of snowfall.
Dry weather is then favored for the first part of March, with the longer-range guidance saying that the next slight chance for snowfall will be around the first full weekend, with the GFS ensemble moving a weak trough into the state (image below). The ECM EPS (two images below) is weaker with this feature and farther northward, and the ensembles are only showing very light amounts.
Both super-duper long-range forecasts are now aligned, showing dry weather through the second week of March (images below). They are also both showing not quite as dry conditions just after mid-month (images below), and that may be when the next chance for meaningful snowfall may occur.
Looking briefly at the tropics, the ECM model, which did well forecasting the MJO moving into phase 2 and 3 a few weeks ago, is showing the MJO (image below) moving into the dry phases 4 and 5 in the short term. It then moves the signal inside the unit circle by day 10, where the ensemble mean keeps it. However, many members show the MJO strengthening in phase 6/7 in the 15-20 day timeframe, and that could induce a favorable pattern change thereafter, or sometimes heading into mid-March. The GEFS has it moving into phase 7 third week of March. WG
