Shot of Cold, then Milder

Today is the first day of Meteorological winter, and the good news is that temperatures dropped just enough overnight that it is near to below freezing from top to bottom. The snowmaking team is blasting away, trying to make as much snow as possible in the colder temperatures.

Week 1:

We will continue to see marginal snowmaking temps at night, Monday and Tuesday, with highs in the 40s during the day. On Wednesday, we see a shot of colder air from a trough backing just far enough west to touch the Sierra. That will drop highs into the 30s for a day and bring better snowmaking conditions at night for a night or two.

Thursday through the weekend, temperatures start to warm again. Highs into the 40s. Partly-mostly sunny skies are expected each day throughout the week. With high pressure stuck in the NE Pacific and along the West Coast over the next 7 days, the storm track will stay to our north.

Week 2:

We will see a pattern change starting this upcoming weekend, but not the full pattern change we need. We will see a flip in the EPO (Eastern Pacific Oscillation) pattern from negative (NE Pacific/Gulf of Alaska ridge) to positive (NE Pacific/Gulf of Alaska trough).

But sometimes in the northern Sierra, we flip from one dry pattern to another. We need the +EPO to combine with a negative PNA (Pacific North American) teleconnection pattern (deeper West Coast trough). We look to be just going into a neutral pattern next week.

The ridge in the NE and Gulf of Alaska is replaced by a trough, but high pressure is still to the south into the southwestern U.S. and CA. No deep trough down the West Coast that we need to really open the storm door farther south.

In this pattern, we typically need a big storm to try and smash down the high pressure over CA to push the precipitation farther south. As of this morning, just about every forecast model is dry through at least Friday the 12th.

Long-Range Outlook:

Beyond the 12th, the models are hinting at storms closer to mid-month, but beyond 10 days from now is the fantasy range (the models historically lose a lot of accuracy). For now, we’ll continue to watch the trends as we wait out what is looking like at least a 3-week dry spell starting back on 11/22.

Snowmaking will be our best option for new snow. We have marginal conditions to start the week, more favorable briefly midweek, and then less favorable by the weekend. Milder air from Pacific storms to our north into next week looks to bring milder temperatures even at night.

I will continue to look for colder air and a return of storms. Hopefully, by midweek, we can make enough snow to open by the weekend.

BA