Powder Forecast –Friday November 26th, 2021
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 11/27 = 0”
Sun 11/28 = 0”
Mon 11/29 = 0”
Tue 11/30 = 0”
Wed 12/1 = 0”
Thu 12/2 = 0”
Fri 12/3 = 0”
Sat – Mon 12/4 – 6 = 0”
November Snowfall = 8”
November Forecast = 8”
Detailed 4-day Snowfall Forecast:
Sat 11/27 through Tue 11/30 – No snowfall expected all days.
Short Term (Days 1 – 4):
The current infrared satellite image (below) shows high pressure off the CA coast ready to build into the state tomorrow and for the rest of the weekend.
Models peak the ridge in strength on Sunday (image below) before weakening it slightly early next week. Nonetheless, fair and mild weather will continue for the next four days with limited snowmaking opportunities under the mild temperatures.
Long Range (Days 5+):
The longer-range guidance keeps shifting that “carrot” further out in time and dangling hope in the 11-15 day range, while continuing to keep the 10-day forecast period dry.
The latest ECM model keeps the ridge in place through next week (images below) and the GFS mean keeps in over CA through the following weekend (three images below).
So it looks like the fair and generally mild weather will continue for the foreseeable future and through the 6-10 forecast time horizon. GFS ensemble mean has zero precipitation in the 10 day period (image below).
The GFS ensemble mean does flatten the ridge early over the following week (image below), but any storms will probably stay north of Mammoth.
That model does develop a trough along the West Coast in the fantasy period (image below) and keeps it in place heading into mid-month (two images below). That would lead to the opportunity for some storminess into CA and Mammoth starting over the second week of December.
The other models are also showing a long-wave trough develops along the West Coast with uncertainty with how far southward the jet stream will move. Overall, the GFS mean is showing well over an inch of liquid in the 11-15 day period for at least some snowfall (image below).
As mentioned in previous posts, the forecast may hinge upon the teleconnection forcing from the MJO. Historically, models are generally too fast with moving the signal eastward and that is likely the case again and is tied to the wet forecast continuing to shift farther out in time as the MJO might not make it into the wetter phase 7 by the second week of December as forecast.
The ECM model is still trying to move into phase 7 by that time frame (image below), albeit a weaker signal versus the previous forecast. But the Canadian model stalls the MJO in phase 6 into mid-December (two images below) and that phase is a dry phase for CA first half of the month before turning wetter mid-December.
And looking at the latest PNA teleconnection forecast (image below), models are now trending to shift the PNA back to positive toward the end of the first week of December, although there is a huge spread with the ensembles. That is not a good trend for storms moving into the West Coast and CA.
Overall, I would not be surprised if the slower trend back to a wet pattern continues and that the transition doesn’t actually take place until closer to mid-December. The good news is that the climate models keep the storm chances going for the rest of December and into January. What comes around, goes around. So hopefully this extended dry pattern will turn into an extended wet pattern during the climatologically wettest period of the winter season. WG