Tuesday March 7th, 2017
Ted Schlaepfer CCM —- Mammoth Mountain WeatherGuy
Dry weather is expected for the rest of the week and through the weekend with seasonable temperatures except for a chance for flurries Saturday night/early Sunday. A weak storm system is then possible around Tuesday or Wednesday next week with another chance around the 20th. The longer range forecast is calling for just a chance for a few storms over the second half of the month and no major storm cycles.
Next update Saturday 3/11
Snowfall forecast are for the Sesame snow course (Main Lodge)
**Snowfall forecast confidence ranges from very low (1) to very high (5)
Wed 3/8 = 0”
Thu 3/9 = 0”
Fri 3/10 = 0”
Sat 3/11 = 0”
Sun 3/12 = 0”
Mon 3/13 = 0”
Tue 3/14 = 0”
Wed – Fri 3/15 – 17 = 0 – 6”
March Snowfall = 10”
March Forecast = 40 – 50”
Seasonal Snowfall = 520”
Seasonal Forecast = 575 – 600”
Detailed 5-day Snowfall Forecast:
Wed 3/8 through Sat 3/11 — No snowfall expected all days.
A high pressure ridge has built into the central part of CA today (image below) and will hold for the rest of the week. It will be a dirty ridge with middle and high clouds moving into CA as storm systems move into the Pacific Northwest that could result in flat light at times, primarily Friday and Saturday with more sun on Thursday. Freezing levels will rise to near 10K tomorrow or Thursday and then hold there through Saturday.
The high pressure ridge will weaken slightly Sunday when a low moves to the North. That will lower temps slightly and also kick up some westerly winds. Could be some wind buff on the top half of the mountain Sunday. Dry weather is expected to last into next Monday and probably Tuesday too.
In the last update, we discussed the potential forecast position of a blocking high pressure ridge near the Aleutians and Bering Sea. It was proposed that if the ridge build more southeastward to CA then the downstream storm track would be farther south in latitude and Mammoth would get more snow. And if the ridge built more toward Siberia, then the storm track would be in the PacNW with a ridge building northward from Baja.
The longer range models are now settling on a solution that puts the blocking ridge in a mean position closer to Siberia (image below) that would cause the subtropical ridge over Baja to build northward and push the storm track into the PacNW through mid-month or longer. The ECM model (image below) does move a strong low pressure system into the PacNW early next week and the tail end of front could move into the Sierra for light snow.
That model quickly rebuilds the ridge (image below) behind that trough then for the rest of next week for more fair and dry weather. The GFS and Canadian models are similar with the dry scenario.
The ECM ensemble mean is mostly dry for the entire 15 day period while the GFS operational model is still trying to be active in the fantasy period (image below) by moving the mean trough and jet stream southward enough for snow to return to Mammoth.
The differences probably lie in each model’s interpretation of the MJO signal in the tropics. The GFS (image below) keeps trying to rebuild the MJO into phases 1 and 2 in the extended range which supports troughing along the West Coast and cold storms.
The ECM (image below) shows a much weaker MJO influence and doesn’t have a strong presence in any phase in the fantasy range with supports the climatological pattern of the jet into the PacNW.
Nonetheless, the month of March looks drier now and the monthly forecast was greatly reduced. Hopefully the GFS is right about the MJO signal and we could see cold storms over the last part of the month for a return of powder days before the season winds down for good. WG