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Saturday, November 19, 2011

Frustrating Pattern Makes Forecasts Very Difficult

 Yucksville
We have been in a frustrating pattern that has baffled the weather models and made weather forecasters look like babbling idiots, including yours truly. Having said all that, I have not been far off. I also search for storms that are way out and try to will them in. Not exactly scientific but many skiers and riders like that about this column ... something to possibly look forward to.

Storm 1
I am looking at a couple of storms. The first is knocking on the door. The models are generally in agreement. The storm, born in the Gulf of Ak, will travel down the west coast and cut inland somewhere between Central California and the Mexican border. However, GFS has this storm going right by us while EC has the storm coming down the coast more to the east and at least giving us a glancing blow. The first image is the GFS forecast, the 2nd is the EC forecast. This is for tonight and tomorrow. If the models are not in agreement 12-24 hours out ... then it is anybody's guess. But, I am siding with GFS, mostly because this is what the trend has been lately. Also, this is what I forecast on Wednesday and I am sticking with that forecast ... I hope I am wrong.



Storm 2
The next storm we have to talk about still looks poised for Thanksgiving. However it looks like it will hold off until the evening of the 24th or later. The models are backing off on the size of this storm and consequently the amount of precip that could potentially be coming our way. Again, GFS has this storm impacting south of us much more so, while EC has it directly hitting Tahoe.

Storm 2 Timing
The timing of the Thanksgiving storm is important for all those faithful readers of the TWB that are traveling for the holiday. Right now, here is my best estimation:

The storm should stay clear of the Sierra until at least Thursday afternoon. Therefore if you get out Thursday morning, you should be ok. My best guess is late Thursday afternoon into Friday morning the storm will begin to impact the Sierra. Once out of the Sierra, this will be all rain. I will show you two forecasts and you can interpret for yourself, but again, I think you are fine on Thursday morning or before, and probably ok in the early afternoon, but things will turn nasty on Thursday evening.

GFS Forecast for 4:00am Friday 11-25-2011

EC Forecast for 4:00pm Thursday 11-24-2011

As I started out this post saying, the models are in general agreement. However, pinpointing what is going to happen is very difficult. My forecasts are much more accurate when I can get a consensus from 2 or more models.

The last image here is for the diehard skiers and riders. This is the EC forecast for total liquid precipitation. Snow levels for the Thusday/Friday storm should be starting around 7,500 feet and falling through the event.


As you can see we are in the 1.75 - 2.00 inch area. So we are talking somewhere in the 1-3 foot range insofar as snowfall. Obviously we would like more, but will take what we can get, especially if it falls in the upper range.

Looking forward, both models have this pattern continuing with storms every 4 or 5 days, none of which are the big one we are looking for. However, that can change in a hurry and when it does, I will let you know.

I will fine tune the timing of the Thanksgiving storm in the coming days.

Stay Tuned ...

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