Good morning everyone. I have some bad news this morning regarding the storms this week... Just kidding, all good news still. We are now within 2.5 days of the start of the big storm everyone is hyping up, which gets us into the higher confidence window. But we have a smaller storm to talk about for Sunday night into Monday, and more storms for next weekend. We could see quite a bit of snow over the next 10 days if the forecast holds.

Final Snowfall Reports:

First off, we have to finalize the weak system that moved through Friday night into Saturday. The clouds and snow showers lasted a little longer than expected Saturday, with snow showers into the afternoon on the east side of the lake. The ski areas on the east side of the basin from Northstar down to Heavenly picked up a final 1-2 inches of snow, as well as some areas south of the lake.

That brings the storm totals to 2-7 inches on a forecast of 0-3 inches for the storm. See, not all storms come in under the forecast as some like to think. We've had a few overperformers this season. Looking at the updated forecaster's scorecard almost every ski area came in over the forecast.

The average variance is 1.1 inches so far this season, a combination of over and under forecast. The average snowfall as a percent of average as of this morning around the Tahoe Basin is 46%. Let's see if we can significantly improve that number over the next week to 10 days.

Sunday - Monday System:

We have sunny skies this morning with temperatures in the teens and light winds. We will see increasing clouds and ridgetop winds later today as the next system approaches, with gusts to 40+ mph. Snow showers could move in this afternoon between 1-4 PM. This is another cold and weak system, and you can see the cold air indicated by the popcorn shaped clouds behind the front in the northeast Pacific.

We love cold air and cold storms as that is the best ingredient to getting more snow than the forecast. Cold air can't hold as much moisture, and when you blow that cold moist air up and over mountains it amplifies the orographic lift effect. That cools the air more and raises humidity which basically means a better chance for snow showers to fire up over the mountains and to squeeze out as much snow as possible from weak systems.

It's not guaranteed we get more than forecast, usually just a better chance when we see really cold systems. I love cold air. Most of the moisture should stay on the west slope and along the crest as the front moves through this evening and then dives south into the southern Sierra. But then the flow turns northerly during the early morning hours Monday and we could see a band of snow rotate down from the northeast, similar to Saturday morning but our forecast radar shows possibly a stronger band this time.

Check out the forecast radar and other maps on our site, they are a lot of fun to utilize. The total precip amounts with this system are pretty meager again. The highest amounts along the crest look to be around 0.4 - 0.6 inches of total precip. The best chance to see the higher amounts looks to be south of the lake.

We will have to watch that band moving down from the north early Monday morning to see if the east side of the lake could catch up. Also, the winds are forecast to turn northwest Monday morning with temperatures in the teens. That could develop a lake effect snow band off of Lake Tahoe aimed towards Heavenly. We will watch for that as well to see if Heavenly could get some bonus snow Monday.

Snow levels are low through Monday as scattered snow showers could linger into the evening before completely clearing the region. They could bottom out around 3000 ft. Snow ratios on the mountains running 14-19:1 through Monday bringing us powdery snow, and helping to fluff the totals from the low amounts of precip. In total, we could end up with similar totals as the Friday night system, with 2-7 inches on the mountains.

Bear Valley & Dodge Ridge could see the Crest amounts with higher snowfall possible just south of Kirkwood. We will watch for any heavier snow bands setting up as we saw with the last system that brought one to the NW side of the lake, and we will keep an eye on any lake effect bands. Both of which could bring more than forecast to select mountains.

Tuesday - Thursday Storm:

The main event that everyone is focused on is the storm moving in Tuesday evening and possibly lasting into Friday morning. We start off Tuesday with possibly partly sunny skies, and then increasing clouds later in the day. Then the snow moves in Tuesday evening. 

We could see light-moderate snow to start Tuesday night, but then we are expecting heavier snow during the day Wednesday as an AR (atmospheric river) makes landfall into CA as a trough and low-pressure dig south down the coast. 

Yesterday we discussed the discrepancy among the models with some like the GFS showing the AR shifting to our south and then back towards Tahoe Thursday as the trough digs off the coast, and some like the European model showing the AR shifting and staying south Thursday. This morning most of the models now agree that the AR will shift south Wednesday night and back to the north towards Tahoe Thursday. If that holds it's good news for us. 

This AR is showing up was a moderate strength on the models, but there are some indicators it could be a little stronger than what the models are showing.

Either way, we should see heavy snow Wednesday with strong ridgetop winds gusting to 70+ mph over the ridges. Then we may taper to light-moderate snow Wednesday night. If the AR does shift back north Thursday as the models are showing, we would see heavy snow again Thursday. Then light-moderate snow Thursday night into Friday morning as the AR shifts south again, and then the low moves inland, and eventually, the system clears to the east on Friday.

The range in total precip amounts on the models this morning has narrowed, with the low and high-end amounts dropping off. The range is now between 4 - 6 inches of total precip along the crest and 3 - 5 inches to the east side of the lake. Not a bad range 2.5 - 5 days out. The average this morning is close to 5 inches along the crest. Here is the WPC's blended model forecast for total precip through Thursday night.

The positive thing with this storm that we don't see very often is not the AR but the cold air and lower snow levels during an AR event. The combination of both is what's driving the high snowfall forecasts. There is still the chance that the AR does not shift back far enough Thursday as the trough digs off the coast, which would lower the forecast.

Snow levels may start around 3000-3500 ft. Tuesday night. Then rising slowly through Wednesday but topping out around 4500-5000 ft. (1000 ft. below lake level). Then we could peak out Thursday as the AR shifts back north, but the models still show a high end of 5500 ft. snow levels. So we should see all snow over the 2.5 days down at lake level. Snow ratios on the mountains could be running around 12-15:1 through the storm, with an average around 15:1 at 8k.

That is pretty high for snow ratios when we see storms that could bring 3-4+ inches of liquid. That is still giving us high snowfall forecasts. The range on the models yesterday for high-end snowfall along the crest was 37 - 99 inches. This morning it has narrowed to 58 - 89 inches. So taking the average of the models that has nudged up the snowfall forecast slightly with most models now showing the AR shifting back north on Thursday.

Disclaimer: We will have to continue to watch the trend with the AR forecasts over the next 2 days. If we don't' see the shift back to the north then we could be looking at 2-4 feet on the mountains instead of 3-6 feet. 3-6 feet is also the amount the NWS Reno came out with in the Winter Storm Watch they posted yesterday. So lots of alignment on the models and with forecasters with this storm right now.

I'm already getting a lot of messages about travel and resort operations during a big storm like this one. It's been since 2019 that we've had the potential for a storm like this, so I haven't had to make this disclaimer in a while. I can't tell you if a ski resort will have the upper mountain closed for wind or avalanche danger, it does happen with storms like this. I also don't know if roads will close, but that also happens. I give my travel forecasts on the I-80 Daily Snow, so check that out.

Also, if you want to know right away when I post new updates, the best way to have the app and set up the Tahoe Daily Snow as your favorite so it is their first thing that pops up. Or you can sign-up for All-Access and have it emailed directly to you.

The snowfall forecast above is only through Thursday night. The snow showers could linger into Friday morning. We may not see much of a break Friday afternoon before the next system moves in, and possibly no break along the crest. The long-range models still agree that a weaker system moves in by Friday night into Saturday.

Then we may not see much of a break Saturday night before another stronger storm could move in next Sunday into the following Monday.

The latest long-range model runs even suggest a final wave moving through Tuesday, February 2nd. So if the forecast were to hold, we could see a week straight of snow. That's why I gave the suggestion of a "10 Day Blitz" in the title today. It could be quite the snow 10-day period starting tonight.

Fantasy Range:

The long-range models still show the trough shifting east starting around the 3rd, with a drier pattern setting up for CA.

The GFS model above suggests the ridge stays off the coast which would keep us in a colder pattern with weak systems possibly dropping down from the north. The Canadian model has the ridge closer to the coast with a slightly warmer and drier pattern. The European model is in the middle between the two. So we will keep an eye on that.

We are keeping an eye on the active phase of the MJO strengthening in the Western Pacific and forecast to move east over the next few weeks. We will see if that has any effect on the long-range pattern. Until then, we have plenty to focus on storm wise over the next week.

Stay tuned...BA

P.S. Check out our new Southern California Daily Snow blog at the link below!

https://opensnow.com/dailysnow/southerncalifornia

I put the Tahoe Weather Nerd store back up for this storm series. Check it out if you want a "Model Riders", "Hype Train", "I'll Believe It When I See It", or "Where's the Crest?" shirt.

Don't miss this week's show! We talk to Jay Cordeira from the Atmospheric River Recon Team about the Big storm coming to CA & Climatologist Daniel Swain from Weather West! We also review the snowfall reports & forecasts for each ski region.

Listen below via Spotify or wherever you get your podcasts. (Apple, Google, Amazon, etc.)