Powder Forecast – Friday March 21st, 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)
Sat 3/22 = 0”
Sun 3/23 = 0”
Mon 3/24 = 0”
Tue 3/25 = 0”
Wed 3/26 = 0”
Thu 3/27 = 1 – 3”
Fri 3/28 = 2 – 4”
Sat – Mon 3/29 – 4/1 = 6 – 12”
March Snowfall = 60”
March Forecast = 70 – 80”
Detailed 4-day Snowfall Forecast:
Sat 3/22 through Tue 3/25– No snowfall expected all days.
Forecast Summary:
Short Term (Days 1 – 4):
The current infrared satellite image (below) this afternoon shows a weather system moving into the PacNW and clouds streaming into central CA. That system will slide to the north of Mammoth with no snowfall expected other than flurries this evening.
High pressure will build into the state on Sunday and peak on Monday (image below) resulting in fair and warmer weather. The recent wind buff machine will turn off on Sunday and most of the mountain except possibility the very top will transition into spring conditions, especially by Monday and Tuesday.
Long Range (Days 5+):
The longer-range guidance continues to show a better scenario for the last part of the month with the dry period ending by the end of next week. The models are suggesting one last hurrah of winter that should continue through early April before more typical spring weather returns by the second week.
The latest ECM model run ends the dry spell when a trough of low pressure moves into CA around the middle part of next week (image below). The first round of potential snowfall looks light and may not be enough for powder conditions with the ECM model (image below) only showing very light amounts around 0.10”,
That model and others then develop a deep longwave trough over the following weekend (image below) along the West Coast, downstream of a building high pressure ridge over the Aleutians. It has a fairly strong westerly jet stream into CA for the end of March that would allow strong storms to move into the state. That model run is showing around 4” liquid (two images below) for the event that would last trough early April.
This pattern is fairly well supported by the ECM EPS (image below) that also depicts a deep trough along the West Coast and jet stream into CA. That model keeps this longwave trough in place similar to the ECM deterministic run through most of the first week of April with the main trough passage around Wed/Thu April 2nd or 3rd.
QPF from the ECM EPS shows about an inch through the weekend (image below) with the better chance for more significant snowfall over the next week (two images below). It is showing around 2” inches liquid or more for that period that could be two feet of snowfall at Main. Thus, powder conditions could start over the weekend with the best chance over the next week.
The super long range guidance is suggesting more typical spring weather will return by the second week of April. The ECM EPS is showing slightly below normal precipitation (image below) that week which is basically nothing that time of year. While there could always be a late season surprise, if you need more powder days, then plan for the end of the month and through early April. WG
