Powder Forecast –Friday April 11th, 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 4/12 = 0”
Sun 4/13 = 0”
Mon 4/14 = 0”
Tue 4/15 = 0”
Wed 4/16 = 0”
Thu 4/17 = 0”
Fri 4/18 = 0 – 2”
Sat – Mon 4/19 – 4/21 = 0”
April Snowfall = 17”
April Forecast = 20 – 25”
Detailed 4-day Snowfall Forecast:
Sat 4/12 through Tue 4/15– No snowfall expected all days.
Forecast Summary:
Short Term (Days 1 – 4):
The current infrared satellite image (below) this afternoon a dissipating weather system moving into NorCal with some passing clouds for Mammoth. Clouds should continue to move through Mammoth overnight as the weak trough passage tomorrow (two images below) and into Sunday. The end result will be slightly cooler temperatures over the weekend.
Weak high pressure builds north of Mammoth on Monday with a weak cut-off low positioned off the CA coast (image below). That weak cut-off will meander toward the coast into mid-week and could produce some late afternoon showers and isolated thunderstorms, otherwise, fair weather should continue with seasonable temperatures.
Long Range (Days 5+):
The longer-range guidance is generally dry through the Canyon/Eagle closing with just a chance for light snowfall end of next week that probably won’t be enough for powder conditions, if it happens. Typical spring weather is still favored for the last part of April, although there is always a chance for a surprise storm, with models hinting at something for the end of the month.
The ECM model is the most bullish about the cut-off low moving ashore end of next week farther northward and slightly deeper versus the other models (image below). It also combines it with another short-wave dropping southward from western Canada. The Canadian model is the most similar, but take the low into Baja and doesn’t merge it with the other low from Canada. The GFS doesn’t have the short-wave moving out of Canada and the ensemble mean (two images below) keeps the cut-off off the coast through Friday. So there is uncertainty.
As expected, the ECM model has the highest QPF (image below) at just under half an inch liquid with snow levels around 7000-7500 feet. That would be enough for low-end powder conditions; however, the ECM EPS (two images below) is showing about 0.15” liquid that would be mostly dust on crust. Forecast follows a blend of the dry models to possibly an inch or two per the ECM EPS. If it does snow, it would be Thursday and into Thursday night.
Dry weather should return over the Canyon closing weekend, then the models (image below) are then favoring a longwave trough to set up just east of CA across the interior West for the rest of the following week. If a low moves southward into CA far enough westward, then there could be some light snowfall. The ECM EPS is showing normal/slightly below average precipitation for that period, which this time of year, is about a quarter to third inch of water. So not much, maybe a few inches of snowfall at best.
The rest of April is favored to see typical spring weather. While most days will be sunny and warm/mild, typical spring weather also means a chance for a surprise storm. The control run from the latest run of super long range ECM EPS 45-day forecast (image below) is saying that there is a chance for a storm around the end of the month or early May. Spring surprises almost always happen. WG
