Wondering whether winter will welcome white weather
After the extremely dry year we are about to complete, rumors are flying around the Tahoe basin that we’re in for a heavy winter because Australia and Argentina have just experienced heavy winters in their mountainous regions.
While that is true, there is no correlation between the weather in those regions and what we will experience in the 2007-2008 winter season. Here is the official outlook for our region and my thoughts on what may happen this upcoming winter:
The Climate Prediction Center (CPC) is calling for the eastern Sierra to have possibly warmer-than-average temperatures.
The CPC is also calling for possibly a slightly wetter-than-average winter season. These findings are based primarily on the development of a moderate La Nina weather pattern that has been occurring for the past two months or so. The forecast is for the La Nina to grow stronger.
Typically, La Nina winters produce abundant precipitation in the Pacific Northwest and dry conditions in the Pacific Southwest. For our region, there is really no correlation in either direction. Temperatures also tend to be colder than average across the Pacific Northwest.
From my own research, I believe the upcoming eastern Sierra and Tahoe winter will be colder than average with average to slightly-below-average precipitation.
I expect we will see several storm systems drop into our region from western Canada and with them rather cold temperatures. To date, the year 1988-1989 most closely resembles the numbers for this year.
That winter featured some very cold temperatures in the Tahoe basin along with near-average precipitation and slightly above-average snowfall. If all ingredients come together, then a repeat of that winter is likely.
I do not believe, though, we will see a heavy winter: The conditions are not favorable for that type of a winter pattern, but as we all know, weather has a habit of pulling some surprises.
With colder temperatures, more snowfall and lower snow levels, the threat of mudslides and excessive runoff exacerbated by the Angora fire is diminished. The exception is the possibility of the Pineapple Express – a Pacific Ocean subtropical jet stream that brings warm moist air from Hawaii to the U.S. West Coast – which is rather common during La Nina episodes.
As always, the outlook is subject to change, but this is the best guess for now. Look for colder weather to typically begin arriving as early as October. In the meantime, enjoy the remaining warm days before we maneuver through another eastern Sierra winter.
— Simon Smith is the South Lake Tahoe co-op observer for the National Weather Service in Reno.