High pressure is building in over the West and it may anchor there for about 2 weeks. That is bringing us a quiet weather pattern this week and most likely next week as well. It has been cold the last few nights with lows into the teens and highs only in the 20's. That has allowed for snowmaking around the clock at most of the ski resorts. For the rest of this week daytime highs will be in the 40's and overnight lows in the 20's. We may warm a little next week with highs reaching 50 degrees at lake level, with lots of sunshine. There is some hope looking at the forecast models. Several runs suggest that we could begin to see a pattern change around the 20th. Hopefully that pattern change will lead to snowstorms.
16 iconic destinations. 32 days. No blackout dates.
The snow is already piling up. Hurry and lay claim to it. The Mountain Collective pass is available for a limited time at just $519. 32 days of skiing at 16 iconic destinations with half-off additional days and no blackout dates. Join the Mountain Collective now: http://opsw.co/2htgMXG
Short Term Forecast
I'm getting the post out a little late this morning. I had to drop my truck off for repairs early this morning and Lyft back to the house. It is another cold morning, brrr....
The cold air has been great for snowmaking with the ski resorts blasting all day yesterday. Here is pic from Squaw.
That has allowed for expanding coverage of the lower terrain that has not benefited from the higher elevation snowfall we have been seeing so far this season. Sugar Bowl has been able to make enough snow that they are now opening tomorrow!
The forecast for the short-term is pretty easy. With high pressure dominating the West this week we will see dry weather and highs in the 40's with lows in the 20's.
The forecast for next week is pretty easy as well. Continued dry pattern with the ridge anchored over the West. Temperatures should warm slightly breaking into the 50's next week at the lower elevations.
Once we get beyond 10 days we get beyond any forecast accuracy on the models (if we assume they lose 10% accuracy each day). So two weeks out we are looking for a pattern change that could bring a change in the weather and hopefully storms. Grasping at straws basically as I am only going to cherry pick the models today to look for hope in a pattern change.
The ensemble models use an average of several different model members of the same forecast model, each with a small change to initial data input. Taking the average is supposed to create a more accurate forecast as it cuts off the outliers. Thats what I use for the height forecast maps above. Looking at the GFS ensemble mean two weeks out today we see this.
It is showing the ridge of high pressure over the West shifting West off the coast by the 19th, and a ridge beginning to build over the Southeast.
The control run is run off initial conditions without any adjustments. Looking at the ensemble control run we also see a pattern change.
The control run is similar in the ridge shifting west and building over the southeast. If this happens we could see a shift of the trough further West with cold air moving down from the North further West over the Western U.S., and we could see storms cut under the ridge in the North Pacific into CA.
The storms breaking under the ridge would most likely have warmer air. We could see one or the other happen, or both. Or we could see neither with the ridge remaining over the West as the European ensemble mean forecast shows.
But the European control run is also showing the stronger ridge centered up near Alaska and storms able to break underneath.
The forecast for the PNA(pacific north american) pattern is forecast to begin to become less positive dropping towards negative two weeks from now.
Meanwhile the EPO(eastern pacific oscillation) is forecast to remain in negative phase. This is similar on both the GFS and European models. That would argue for the shifting of the ridge NW towards Alaska and away from the Western U.S. like we are seeing on some of the ensemble model runs.
Looking at the GFS ensemble runs for the next 2 weeks for snowfall, we see that about 1/3 of the members show snow on the Sierra by the 21st.
Taking the mean we get this...
So while we are seeing the pattern potentially starting to shift two weeks from now there is not much snow showing up yet. So we have low confidence in a pattern change that could bring little snow.
The models only go out 2 weeks. Looking at the European weeklies yesterday that go out 46 days we have an ensemble mean snowfall forecast that is similar to the GFS in showing light snows possible by the 21st, and the control run that shows we could get a decent storm around Christmas Eve.
Looking at the CFSv2, a climate model that goes out several months, we see that it shows precip showing back up in Northern CA between the 20th-25th.
To recap: we have low confidence in a pattern change around the 20th that could allow for colder air, warm storms, or a mix of both. Enough of the ensemble runs show it to make us want to keep an eye on it. The precip and snowfall maps are only to confirm that the potential pattern change could bring some storms right before or on Christmas.
I think we could start to see a change in the pattern week 3 but also I see enough model runs and potential conditions that could keep the ridge over the West. This post was just to give some hope that beyond the 2 weeks of dry weather we could possibly see a storm before Christmas.
(I keep that on my desk;)
I did a pole yesterday on the TahoeWeather instagram story and the results were: 73% of you voted YES we will see a storm before Christmas, and 27% voted NO. So the majority of you are hopeful!
Stay tuned, stay hopeful...BA
Set Powder Alerts! Sign Up for an Account, there's a free option as well!
Don't Forget to Download the OpenSnow Mobile App to access powder info on the go!
Did you know that you can get more from OpenSnow?
If you’re looking for a way to support OpenSnow and get access to more data, consider signing up for the All-Access Pass.
- 10-day forecasts
- Custom alerts to know about upcoming powder days
- Time-lapse webcams for tracking exactly when fresh snow has fallen
- Email delivery of the Tahoe Daily Snow as soon as it’s published
All of this costs just $19 for one full year (365 days) and helps to support OpenSnow so that we can spend money and time to further improve our website and mobile apps.
I’d love to count you as an All-Access member!