Thursday Storm:
Precipitation is pushing into the Sierra and will continue to do so for much of the day with varying intensity, and snow showers for Thursday night. Highs in the 30s for the lower elevations and 20s for the higher elevations. The winds this morning are gusting up to 50-60+ mph over the ridges, and are now expected to gust up to 40-50+ mph during the afternoon as well.
Snow levels are already below the base Thursday morning. That will help to boost snowfall over the mountain from the higher snow:liquid ratios with the colder air. The latest model runs are slightly wetter with the storm, so the snowfall forecast has increased a bit. By Friday morning we could see around 4-9 inches near the base, 5-10 inches near mid-mountain, and 6-11 inches up top.
Friday – Saturday Storm:
The latest model runs are trending toward showers reaching the mountain earlier in the day on Friday as compared to previous forecasts, with show showers from the next system moving in as early as Friday morning. They do disagree on how far south the steadiest precipitation will reach as the moisture plume is stalled to our northwest until Saturday when we expect the heaviest snow.
The weather for Friday will be snow showers with highs in the 30s. Ridgetop winds from the west increase to 60-70+ mph by afternoon, which could close some upper mountain lifts. Snow levels rise up to around 7000-7500 ft. Friday night before dropping back below the base Saturday morning.
The heaviest precipitation aimed at northern CA Friday into Friday night finally pushes south Saturday with the front before waning into Saturday night and as the front moves south towards the southern Sierra. Highs in the 30s with ridgetop winds from the southwest gusting up to 100+ mph. So I am expecting quite a few upper mountain ski lifts to be closed on Saturday.
By Sunday morning we could see storm totals of around 5-10 inches near the base, 10-15 inches near mid-mountain, and 13-18 inches up top. The amounts for the lower mountain depend on how long the snow levels stay higher Friday – Friday night before falling on Saturday.
Sunday Weather:
We will see a break between storms Sunday into Monday morning. Partly – mostly sunny skies for Sunday with highs in the 30s. Ridgetop winds drop off for a day so this should be the best day of skiing of the period!
Monday Storm:
The final storm in the series is forecast to push rain & snow back into the northern Sierra Monday afternoon into Monday night. The latest model runs now show ridgetop winds increasing up to 80-90+ mph over the exposed ridges on Monday, so we will likely see another round of lift closures for upper mountain lifts. Highs in the 30s.
This system is weaker and is expected to bring light precipitation amounts. The snow levels could be close to the base around 6000-6800 ft. Monday afternoon, and then falling below the base by the end early Tuesday morning. By Tuesday morning we could see an additional 1-4 inches of snow near the base, 2-5 inches near mid-mountain, and 3-6 inches up top.
Tuesday – Wednesday Weather:
Some models show a final very weak system bringing a few scattered snow showers on Tuesday with highs still in the 30s. If not, it would be mostly sunny and cool behind the storms. By Wednesday high pressure is building over the region as we go into a drier pattern. Mostly sunny skies are expected for Wednesday. Highs warming into the 40s for the lower elevations.
Long-Range Forecast:
The dry pattern is expected to last through at least the 20th. Some of the ensemble mean models push the eastern Pacific trough close to the West Coast but the strong ridge over the West looks to block any storms from reaching the northern Sierra. We will continue to watch the period around the 21st – 22nd.
The trough is forecast to pull away from the West Coast beyond the 22nd through the Christmas holiday. That would bring back or keep us in a dry pattern through the last week of the month. It looks like it will get pretty warm over much of the country by Christmas.
There are some signs of the ridge weakening a bit near the end of the month, maybe enough for a weakened storm to reach CA, we’ll see…
BA
