Powder Forecast – Friday March 25th, 2025
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)
Wed 3/26 = 0”
Thu 3/27 = 0”
Fri 3/28 = 0 – 1”
Sat 3/29 = 2 – 3”
Sun 3/30 = 0”
Mon 3/31 = 2 – 4”
Tue 4/1 = 3 – 6”
Wed – Fri 4/2 – 4/4 = 12 – 24”
March Snowfall = 60”
March Forecast = 65 – 70”
Detailed 4-day Snowfall Forecast:
Wed 3/26– No snowfall expected, slight chance for a rain shower during the afternoon.
Thu 3/27– No snowfall expected during the day, chance for light snowfall late at night. Little or no accumulation by Friday AM.
Fri 3/28– Light snowfall is expected at times during the day and overnight. Accumulations 2 – 3” at Main by Saturday AM, 3”+ up top
Sat 3/29– Chance that light snow showers may linger during the early morning, otherwise dry weather returns during the day. Little or no accumulation expected.
Forecast Summary:
Short Term (Days 1 – 4):
The current infrared satellite image (below) this afternoon shows high-pressure centered over Nevada and two separate areas of low pressure moving into the eastern Pacific. The high-pressure ridge will continue to move eastward tomorrow, but spring conditions should continue on the mountain.
Changes in the weather pattern start on Thursday when a deep upper-level low pressure system moves into the West Coast (image below). That system will shift southward on Friday (two images below) with a trailing system moving through central CA on Friday afternoon and night. Most of the snowfall is expected during the day Friday. Snow levels will be around 6000 feet. Dry weather returns Saturday.
The Quantitative Precipitation Forecast (QPF) from the models is generally light with most of the precipitation falling well north of Mammoth. The ECM model (image below) is the wettest at only about 0.25” liquid with the GFS (two images below) only forecasting about a tenth. The Canadian (three images below) is showing slightly more. Forecast follows the ECM model with a couple to a few inches of snowfall on Friday and possibly some low-end powder conditions on parts of the mountain, primarily the upper half.
Long Range (Days 5+):
The longer-range guidance continues to show a better chance for significant snowfall next week. That may be the last hurrah of winter before the weather pattern slowly transitions to more typical spring weather conditions during the second week and through mid-month.
The latest ECM model moves the next trough of low-pressure into the West Coast and CA on later Sunday and Monday next week (image below) that may linger through Tuesday. The system looks to be a bit farther southward upon landfall versus the previous storm and will result in a better chance for powder conditions, although the details remain uncertain. The ECM EPS QPF for the 3-day period (two images below) is around an inch with most of the potential snowfall falling on Tuesday. Thus, there could be low-end powder on Monday followed by deeper powder on Tuesday and/or Wednesday.
The longer-range guidance is not in agreement with how the last part of the storm cycle will play out. The latest ECM model moves a deep closed upper-level trough into CA on Thursday and Friday (image below) and the QPF is over an inch of liquid or a foot plus of snowfall.
That solution matches up only decently with the ECM EPS (image below) that has an open-wave trough for the end of next week. The GFS ensemble (two images below) has a broader trough along the West Coast with a southwest jet into CA as opposed to a westerly jet per the ECM EPS. That would be potentially a wetter solution.
That is evident in the QPF with the ECM EPS showing around 1.5”+ liquid (three images below) while the GFS ensemble has 2.5” liquid or around 20”+ snowfall at Main. Forecast leans toward a middle ground solution and around 2 inches liquid, but hopefully a wetter forecast will verify. Regardless, there should be enough snowfall for powder conditions end of next week.
The trough will probably shift eastward over the following weekend before reforming along the West Coast the next week (image below). Right now, it looks too far northward for significant snowfall in Mammoth. The ECM EPS QPF for the 11-15 day period is showing almost 0.50” liquid, so there is a slight chance for a weaker storm over the second of April.
Beyond that time frame, the guidance is suggesting a shift toward drier weather with the ECM EPS super long range favoring slightly below normal precipitation second week of April (image below). It has a similar forecast for the third week or the Canyon closing week. Get those last powder days in now before it is too late. WG
