We are going to have quiet weather for a while which I talked about below in yesterday's post. I also talked about what is going on in the pattern and what we need to re-open the storm door. The weather is going to be beautiful though for skiing and riding with temps in the 30's and sun for the next 2 weeks. The good news is that we are only 1/3 of the way into the season but have already received 80% of our annual snowfall. The snowpack will not be going anywhere over this extended quiet period.
We can take advantage of this lull in activity to go over the final numbers for December. December was the third month in row now of well above average precip for the Tahoe Basin. We saw 183% of average precipitation in December which brings our average for the water year which started in October to 206% of average. We have now picked up 71% of our total precipitation average for the entire water year just 3 months in. We have also picked up about the same percentage of snowfall 1/3 of the way into the snowfall season. Northstar has now picked up 289 inches of snow with the seasonal average being 350 inches.
Going off the Truckee airport reporting station we were 0.8 degrees above average for the month thanks to the mild and rainy week we had the second week of the month. It was the overnight lows that were above average for the most part because of the cloud cover not allowing for any radiational cooling at night. This was the first month with an above average average temp since last February, and only the 5th in the last 3 years. I believe some of that may be caused by the fact that we have been headed into the next 20-30 year cold cycle of the Pacific. I was thinking about La Nina's and the 2 strong ones that gave the state above average precip were in the last cold cycle of the PDO. If this one ends up above average, which we are track for, that may be a strong trend of above average snowfall for us when we have a strong La Nina during a cold PDO.
Joe Bastardi was saying that he thought the jetstream may be so strong this year due to the warmer than average water in the far Western Pacific where the jetstream originates that helps to juice it. Then it comes across the rest of the Pacific that is colder than average which causes condensation and it picks up lots of moisture before slamming the coast. Either way we have a strong than average jetstream this year. We also have a ton of cold air being forced South over the continent thanks ot the very negative Arctic Oscillation. This is a pattern of lots of blocking and it is a fragile pattern for us. It is basically an all or nothing pattern and we have been lucky to get the "all" the past 2 months. We are getting the "nothing" to start this month.
The blocking is setup too far West over Canada and too far North near alaska so the ridge is going makes its home off our coast for a while. The NAO is forecasted to move towards positive and weaken the block over the next 2 weeks. Hopefully this continues and we can see the pattern become a little more progressive and troughing come into the West Coast. Can't keep the strong jetstream away forever and we still have 2/3rds of our snowfall season to go so it's not over yet. Stay tuned because I will let you know when the storm door will open again at least 2 weeks out. BA