Tahoe Daily Snow
By Bryan Allegretto, Forecaster Posted 15 days ago February 11, 2024
Partly-mostly sunny skies through Wednesday. Snow is possible Wednesday night into Thursday. More storms are possible for President's Weekend into the week of the 19th. That pattern backs off later next week, but a colder and semi-active pattern is possible for the last week of February.
Short Term Forecast
After the gusty northeast winds Saturday morning, we continue our nicer weather Sunday through Tuesday. Partly-mostly sunny skies are expected each day. Highs in the 40s for the lower elevations and 30s for the upper elevations.
Wednesday - Thursday Storm:
Wednesday could see partly sunny skies but with increasing southwest winds ahead of the next system. Ridgetop winds could be gusting up to 50-60+ mph, which could affect some exposed upper mountain lifts. Highs are still in the 40s for the lower elevations and 30s for the higher elevations.
We've been watching a weak system the models have been showing moving through around Thursday, but for most of the week, most of the models were keeping this storm just to our north with us only getting brushed by a few showers.
The GFS model continues to keep the system to our north and keeps us mostly dry through Thursday.
However, most of the other models have been trending this system wetter and farther south.
They have snow moving in by later Wednesday evening through the day on Thursday, and clearing out Thursday night. Some models, like the Canadian, show up to 2 inches of precipitation falling near the crest by Thursday evening!
Always fun for forecasters, especially snowfall forecasters, when models 3-4 days out show zero - 2 inches of precipitation falling, ugh. Unfortunately, the GFS model has a lot of influence on snowfall forecasts, and it is in the minority with its dry forecast. Its ensemble mean model shows a wetter solution.
The GFS being dry and the Canadian with 2 inches are the outliers, with the other models showing between 0.9 - 1.3 inches falling near the crest and up to 0.8 inches to the east side of the basin. This is a big change to the forecast from two days ago for Thursday. The model average is now getting close to 0.9 inches near the crest.
Snow levels will need to be fine-tuned as the drier GFS model is likely a little too high, but the other models may be a bit cold. Overall this morning they are showing snow levels starting around 6000-6500 ft. Wednesday evening and falling to around 5300-5800 ft. early Thursday morning, and then rising to around 6300-6800 ft. by Thursday evening.
If that holds it could be cold enough at lake level for a few inches of snow before turning to rain by the end. Here is my initial snowfall forecast for this storm, for totals by Thursday night.
We will have to fine-tune this over the next few days, most importantly to make sure the GFS model all alone being dry isn't still a possibility.
The weather could still be unsettled on Friday. But we could see some sun with scattered showers around. Highs back near 40 degrees at lake level and 30s on the mountains.
By President's Weekend, the long-range models continue to show a strong and extended Pacific jet stream aimed at southern CA...
...with a large low-pressure trough to the north and storms spinning up in the trough and moving toward CA. We've seen this pattern several times this winter, including last week. We usually see storms that are on the warmer side as they tap subtropical moisture and they can split with the heaviest precipitation to our north and drop south toward the jet stream into southern CA.
The next storm is still on track to try and move in on Saturday. This storm looks to tap into moisture from back by Hawaii. The phrase "Pineapple Connection" is over-used and not accurate for a lot of storms. The moisture feed has to actually come from near Hawaii like this one is forecast to do.
Saturday looks like a windy and unsettled day with ridgetop winds likely up to 60+ mph, with some lifts being affected. How much precipitation we see is still in question. The GFS model is showing more southerly flow and has very little precipitation reaching the Sierra and Tahoe basin. But it is once again becoming the outlier with the other models showing heavier precipitation.
Snow levels will likely be above 7000 ft. for the storm with rain at lake level and wet snow for the upper mountains. It doesn't look like a nice day for skiing. We'll be fine-tuning the precipitation forecasts all week and looking at potential snowfall amounts once the storms are within the 5-day storm window.
Sunday could be unsettled but still looks to be a bit of a break before the next storm moves in for Monday the 19th into Tuesday the 20th. This storm looks to be longer, wetter, and colder. The GFS model is trying to split this storm, but the other models are showing a fairly wet storm with some heavy snow possible down to lake level.
The European ensemble mean model shows up to 4+ inches of liquid reaching the crest over the 4-day period from Saturday through Tuesday the 20th.
We'll be tracking these storms all week. Friday looks like the best travel day. Saturday looks like a windy and wet day, Sunday could be ok for skiing and travel, and then Monday - Tuesday look snowy and not good for travel. It's a bad weekend for this pattern. No one wants to drive up Friday to get wet Saturday, and then drive home Sunday before a possibly bigger snowstorm Monday...
The long-range models continue to show the jet stream weakening and retracting beyond the 20th with the active pattern diminishing later next week.
The pattern is starting to look a little more interesting for the last week of February as the models are showing a negative PNA pattern developing.
That is a colder West Coast trough pattern, which could open the door to colder storms dropping into the trough from the northwest.
That would be the first time we've seen this type of pattern since the first half of January. That is also the only period this winter that we saw a series of colder storms with lighter-density snow.
We'll continue to watch the trends closely as we get later into the month. This is a pattern I always favor for good snow and powder days versus the extended jet stream patterns that usually bring warmer and sometimes splitting storms.