Forecasters: Dry weather in Sierra to continue
November 27, 2013
The reign of dry weather continues to hold sway over Northern California, which is fast approaching records for aridity during the calendar year.
"This might be the driest calendar year on record," said Holly Osborne, National Weather Service forecaster. "A lot depends on rainfall during December."
Last week, forecasters were warning rain could hit the Sierra foothills on Thanksgiving Day, but have since backed off the predictions, saying while the sky may be overcast, little rain is expected.
A low-pressure system carrying modest amounts of moisture will skirt the coast of California, heading due south, although the Tahoe/Truckee region may get slight snow accumulations with the snow level pegged at 6,000 feet, Osborne said.
The overcast weather should hang around through Friday before a high-pressure system ushers in clear skies and dry weather.
Another low-pressure system might enter the region Sunday into Monday, but the system will be cold and dry as it will originate in the north, Osborne said.
The true gully-washers occur when storm systems from the south, which typically carry heavy concentrations of moisture, meet up with the cold storm systems from the north and form an atmospheric river over Northern California.
Such an occurrence happened last December and created widespread flooding and damage throughout western Nevada County.
Weather forecasters are riding the fence when it comes to the long-term outlook for the region, as there are no distinctive macro-weather events such as an "El Nino" to indicate whether the season will be dry or wet.
For now, forecasters are predicting a normal year, Osborne said.
While the calendar year aridity is dominating the conversation, the water year, which begins Oct. 1 in California, also is well below normal.
Currently, 2.5 inches of rain has fallen on the region, most of which occurred in the early part of last week.
Last year, about 11 inches of rain had fallen on the Northern Sierra by late November, with about 25 inches of rain accumulating by Dec. 5.
The average for Nov. 25 is about 8 inches, according to the Department of Water Resources.