The Climate Prediction Center released their forecast for the winter today. While it’s not forecasting the super deep snow year everyone wanted, it’s not forecasting a return of the Ridiculously Resilient Ridge that kept us exceptionally dry for more than a year. While the other local bloggers jumped at the CPC forecast in an effort to be first, we waited patiently for the Reno office of the NOAA to release their analysis of the forecast. Yes, real experts, that are a bit more familiar with exactly what it will mean for the greater Reno-Tahoe area.
Without any further ado, here’s Part One of the forecast, which gives a “state of the drought” report and summarizes today’s CPC forecast:
In a nutshell, there’s a 65% chance that we will see an El Niño this year in our region. It is expected to be weak, at best, and not strong like the 1997 event. What does it mean? CPC says the following:
• Expect warmer than normal temperatures for the entire western US during the winter months. That would translate into some higher snow levels, which is a plus for Alpine Meadows, and more of a plus for Mount Rose and Mammoth.
• The Pacific Northwest may see a drier than normal year, while the southern third of the country can expect to see a wetter than normal winter.
None of those conclusions are surprising as they are typical “El Nino” results. Lake Tahoe happens to land right in the middle of the wet and dry zones, leading the CPC to stamp a big “EC” over the Tahoe region. The Reno guys are quick to point out that EC does not equal normal or average, it simply means there are equal chances of the wetter solution and the drier solution…or the average solution.
The guys over at WeatherWest.com have noted in recent weeks that the El Niño event continues to become more neutral, but a positive PDO (Pacific Decadal Oscillation) signal could lead to a better chance for a wetter solution than the last several years, which were negative PDO years. We’ll take any chance we can at getting even close to a normal year, which would seem pretty sensational.
Part Two of the Reno NOAA seasonal forecast focuses on the difficulties of assessing the long term forecast in the Sierra and Reno-Tahoe area. It also does an analysis on the 8 climate models that make up the North American Multi-Model Ensemble. This new ensemble model is only a couple of seasons old.
• Unfortunately 7 of the 8 models that make the Ensemble are suggesting a drier winter in the west. That said, the same ensemble suggested at this time last year that it would be a very wet year, and we know how that prediction turned out. So the accuracy of these climate models in seasonal predictions is still a very young science. Do not panic yet!
• Discussion over at WeatherWest.com suggests that the models are concerned about the warm blob of water that still exists near Alaska that may be related to the occurrence of the RRR. The effect of a positive PDO with that blob is unknown.
For now, we just have to rejoice in the idea that this year could very well turn out “normal”, not that there is such a thing in the Sierra. No matter what happens, eventually there will be some snow and many of us will choose to ski it, whether it is a powder day or a WROD day. Closing with a great weather quote for the day:
“Weather and cats do what they please, and men and dogs may as well accustom themselves to it.”
The KSL curse?