Powder Forecast – Saturday January 18th, 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)
Sun 1/19 = 0”
Mon 1/20 = 0”
Tue 1/21 = 0”
Wed 1/22 = 0”
Thu 1/23 = 0”
Fri 1/24 = 0”
Sat – Mon 1/25 – 1/27 = 2 – 6”
January Snowfall = 1”
January Forecast = 10 – 20”
Detailed 4-day Snowfall Forecast:
Sun 1/19 through Wednesday 1/22– No snowfall expected all days except for a chance for flurries overnight Sunday and into Monday AM.
Forecast Summary:
Short Term (Days 1 – 4):
The current infrared satellite image (below) this morning shows high pressure still dominating the eastern Pacific and West Coast and a weak cut-off low positioned well off the Central CA coast. A dry cold front is moving southward through the interior West and its only affect on Mammoth will be slightly colder temperatures on Sunday, but still seasonable.
Another stronger short-wave will move southward through the Great Basin on Monday (image below) and that will result in much colder temperatures on Monday in addition to breezy to gusty easterly winds (and another Santa Ana wind event for SoCal). There is also a chance for flurries on Sunday overnight/early Monday, but a better chance of the very top of the mountain getting stripped of snow again from the east winds for hard/fast conditions. High pressure will then build into mid-week for continued fair and warmer temperatures.
Long Range (Days 5+):
The longer-range guidance is still favoring mostly dry weather to continue through the end of January and possibly into early February now. There is a chance for light/moderate snowfall next weekend, otherwise, the models are not showing any good chances for snowfall in the foreseeable future.
High pressure will peak in strength around Thursday next week (image below) and if it builds directly over the state then temperatures will get unseasonably mild. The ECM is more bullish on that scenario and temperatures could hit upper 30s up top and low/mid 50s at Canyon including late morning spring conditions on the Ch 25/Ch 9 side of the mountain.
The ECM model is then the most bullish about moving a deepening short-wave trough into the state over the following weekend (image below). The Canadian model has that solution too, but the 12z GFS deterministic run is not showing that short-wave and has the ridge remaining in place.
Since it is a high-latitude type storm with limited moisture, the models are not showing big amounts. The ECM model is showing about 0.50” liquid precipitation (image below) as the outlier wetter solution with the Canadian (two images below) showing a couple tenths. The GFS model is obviously dry.
However, the GFS ensemble is showing a low-pressure trough over CA (image below) that would support the Canadian or ECM solution. The GFS mean has similar amounts as the Canadian and that also lines up with the ECM EPS (two images below). Thus, there is a decent chance for light snowfall, but question marks remain to whether it will be more than dust on crust, especially after the warmer weather prior to any snowfall.
The longer range guidance is then showing more of the same through the end of the month with the ridge holding firm along West Coast and a trough in the center of the country. That would mean more inside sliders (and Santa Ana winds for SoCal) and dry/seasonable temperatures for Mammoth. The fantasy range guidance is still saying it will get much stormier over the first part of February with above average precipitation (image below), we will just have to wait and see if it pans out. WG
