That is the question that has been posted frequently by weather pundits at NOAA and in the weather forums this week. We have the first significant AR event of the season still taking shape for the Northern California area Wednesday into Thursday. Currently that system is dropping copious amounts of rain and a lot of wind in the state of Washington. With the storm now just three days out, we can be fairly certain that it’s going to happen. But there’s been enough variability from model run to model run to make a weather prognosticator crazy.
Yesterday it was looking like a bust, with the atmospheric river just glancing the state of California. Today the model runs bring it closer to Tahoe, but not quite as far south as we might like. The GIF below shows the last dozen model runs of just how much snow we could see by Friday morning. The first thing to note is the variability between models runs, ranging from just a few inches of snow possible to as much as 12-15 inches at higher elevations.
The second thing to note is how skinny that band of snow looks on the snowfall map. I offer this simple lesson several times a season. Seeing just a narrow band like that on a snowfall map indicates that snow levels will be high, with snow only at the crest. When we get those really cold storms with snow to the foothills, that band of snow looks much wider. As of today, the snow levels look to be around 8000 feet: above Donner Pass, somewhere around the bottom of Alpine Bowl, but lower than the base at Mount Rose. This time of year, the Mount Rose tagline of “Where The Snow Is” entirely accurate.
I would love to see Rose get a sloppy foot of wet natural snow, then temperatures dropping to allow for consistent snowmaking on top of that starter base. My fingers are crossed! Yeah, this time of year you can just call us Unofficial Mount Rose, as my former buddy is no longer doing that site.
Looking at the models today, most of Tahoe will be just south of the jet stream, which is the warm side. We like it when that jet stream sags farther south, where we get the influence of the colder air on the north side. Mammoth Mountain, another early season favorite, has the elevation for snow from this system, but not much moisture will make it that far south.
One thing we see time and time again is that that first system that breaks down an extended period of high pressure ridging is often the sacrificial lamb, losing a lot of energy as it runs into a big dome of stagnant air. Theoretically, these first storms serve to “open the storm door”. The models are supporting that idea right now. Only the first week of November looks dry and warm. After that we get stronger and colder systems every few days. We hope that is a patten that holds. The GIF below shows potential rainfall over 24 hour periods over the next 16 days. You can see that are several waves of storms after the first, and it gets better as we near mid month.
I am leaving you with this positive image here. It’s one model run of one model and that is absolutely NOT a forecast. But seeing the GFS showing 7 inches of precipitation near Alpine Meadows by November 18th is better than facing a long extended fire season. Hopefully we get the colder temperatures to accompany this so its a nice and wet base builder than can set us up for a good season that requires minimal P-Tex interventions.
Ooooooohhhh!