Clearing skies Saturday. Highs in the 30s. Ridgetop winds to 50+ mph and falling. Sunday the next storm moves in with rain and snow becoming all snow down to lake level. Several inches of snow expected into Sunday night. After a break Monday - Wednesday we may see another storm bring more snow on Thursday, and possibly another storm next weekend.
Short Term Forecast
The bad news: The system that moved through Friday night hit the Sierra and moved south quickly without much forcing. That led to snowfall amounts just under the low end of the forecast. The good news: We have a 2nd storm for Sunday that is trending colder and wetter on the models this morning, and may make up for what we didn't get on the 1st storm.
I knew right away watching the radar Friday evening we were screwed. The moisture streaming in off of the Pacific was aimed just south of the lake and wasn't pushing over the crest.
Then overnight the bulk of the precipitation continued to be aimed to the south and was not spilling over very well, and was sliding south fairly quickly.
Just enough showers pushed north towards the Tahoe Basin for 2-3 inches of snow along the crest, and a coating up to 2 inches to the east side of the lake on the mountains. Even to the south with the lack of forcing the heavier precip stayed west of the ski areas with similar snowfall amounts.
The forecast was for 1-5 inches on the east side above 7k and 3-7 inches on the west side of the lake. So the totals are coming in around 1-2 inches under the low end of my forecast. I'll have the variance report tomorrow morning because we could still see a little snow Saturday morning. Season to date we are sitting at around 42% of average snowfall.
Looking at the radar this morning a small band of snow associated with teh front moving down from the north is near Reno, and may bring some light snow to the mountains on the east side of the lake. Not sure if it holds together enough to get an inch of additional snowfall.
For the rest of the day today, we will have clearing skies with sun by late morning/afternoon. Ridgetop winds were gusting to 90+ mph Friday night and have dropped to around 60 mph this morning. They should come down a little more through the day and turn more northerly. Highs in the 30s.
The next storm is approaching the West Coast, and this is more of a classic West Coast storm that will sweep through a cold front. That means we won't have to worry about the system missing to the north or south and we will have better forcing for precipitation into the Tahoe Basin.
This system has been trending wetter on the models over the last few days, and that continues this morning. The latest model runs show precipitation pushing into the area around 7-10 a.m. on Sunday, with snow levels starting out around 7000 ft. Then heavier precipitation pushes in into the afternoon with snow levels falling below lake level as the front moves through.
Ridgetop winds increase Sunday to 70-80+ mph so expect upper mountain lifts to be affected. Highs in the 30s dropping into the 20s on the upper mountains in the afternoon. Snow showers are expected to fire up behind the cold front Sunday night as snow levels fall to 4000 ft. and we finish off the storm with a few inches of powdery snow on the mountains.
Total precipitation amounts on the models this morning mostly range from 1.0 - 1.1 inches of total precipitation near the crest with up to 0.9 inches to the east side of the lake. The outliers are the Canadian model with only 0.7 inches on the high end near the crest, and the GFS on the other end with over 1.6 inches of total precip. Here is a look at the NAM forecast showing up to 1 inch which is also the total model average.
Average snow ratios at 8k around 10:1 on Sunday increase to around 15:1 Sunday night. The average for the storm around 13 inches so the model average has that as the high-end forecast. But looking at just the deterministic model runs the wetter GFS run this morning is skewing the high end up 1 additional inch. The GFS on its own has 21 inches, but we are not paying attention to that.
Rain turns to snow at lake level Sunday afternoon so we are expecting accumulating snow for all elevations by early Monday morning when the storm clears out. Here is a look at the updated snowfall forecast. Add this to the totals from this morning and we end up with more snow in total than the forecast for both storms yesterday. We have one more morning to fine-tune the forecast and hopefully the wetter trend holds.
Monday - Wednesday:
We should see mostly to partly sunny skies all 3 days. A few clouds Tue-Wed from a system passing to the north. The winds look to be lighter but could still be gusting to around 30+ mph over the ridges Monday. Highs in the 30s for Monday and then 40s at lake level Tue-Wed.
Another bit of good news is that the rest of the forecast models are trending towards the GFS model on a farther south track with the Thursday storm.
It is starting to look more likely that we will be coming out with an initial snowfall tomorrow for this system. We will have to fine-tune the forecast over the next several days. Right now most of the models are showing a storm similar to the Sunday storm.
A final bit of good news is that the models are coming into better agreement that a storm next weekend could also track farther south into northern CA. I thought you would like 3 pieces of good news this morning after we were let down by the Friday night storm. Hopefully the trend of systems tracking farther south this week holds.
The long-range models are trying to hold off the ridge building in over the West Coast until around the 23rd instead of the 21st. That could allow one more storm to sneak in early that week before the ridge builds over CA likely bringing a drier pattern into Christmas week.
We are still watching the last few days of the month for a shift in the pattern that could allow storms to track farther south into northern CA into the beginning of January. We are still expecting a much better month for storms in January looking at the teleconnection pattern forecasts, but don't expect it starts right on 1/1. It may take a few days into the month before we see a real change.
Be sure to listen to us discuss the snowfall forecasts for ski regions around the U.S. on our weekly episodes of The Flakes Podcast on your favorite podcast platforms.