By Matt Alto, Meteorologist
October 22, 2012
A front brings winter back to the Sierra.
A storm system pounding into northern California will bring the first significant snowfall of the season to the southern Cascades, Northern Coastal Range and Sierra Nevada, as well as other mountainous areas of the Northwest and northern Rockies early this week.
Aside from the mountainous terrain, a chilly and soaking rain will fall over many of the coastal and valley locations. The rain will be the first significant rain of the season for those of northern California and parts of Oregon.
The storm will bring some wild weather to parts of California as well. An unconfirmed tornado was reported in Sutton County, Ca., about 40 miles north of Sacramento, Monday afternoon. With the exception of downed power lines, damages have not been confirmed.
Snow levels will settle around 5,000 feet.
Gusty winds of 15-25 mph will accompany the snow which will likely reduce visibilities to less than a mile in some locations, especially over the mountain passes. Winds could gust at times to over 50 mph.
People planning to travel through the passes the next couple of days should be prepared for potential delays as well as slow travel.
According to AccuWeather Meteorologist Brian Edwards, the “steady snow will taper to a few snow showers Tuesday morning, but not before dumping 6-12 inches of snow on communities above 5,000 feet, with amounts to 2 feet in some locations above 7,000 feet.” A general 3-6 inches is expected in areas above 4,000 feet.
Edwards added, “snow amounts won’t be quite as much farther south over the central Sierra near Mammoth Lakes and Yosemite National Park. A few inches of snow is possible above 6,000 feet, but amounts won’t be nearly as much as points north.”
The heaviest precipitation will be expected during the midday hours today as the cold front associated with the storm moves through the region. A few rumbles of thunder can’t be ruled out either, especially in coastal locations. This rain will taper to a few showers by the late-afternoon hours.
A general 1-2 inches of rainfall is expected along the coast, and over the coastal mountains with generally lesser amounts expected inland.
A few showers can dampen Game 7 of the NLCS between the St. Louis Cardinals and San Francisco Giants at AT&T Park in San Francisco, but it will not be a washout.
As the storm system continues to track inland across the West, clouds and leftover showers will be leftover over much of northern California and the Pacific Northwest on Tuesday.
The heavy rain and mountain snow will fall on locations in Idaho, Montana, eastern Wyoming and parts of northern Utah beginning this afternoon and evening and lasting through Tuesday.
While snowfall and rain amounts won’t be nearly as impressive throughout the northern Rockies, many locations will pick up between 3-6 inches of snow with locally higher amounts possible well above 5,000 feet. Additionally, healthy rainfall amounts will also be expected in the valleys.
This storm will eventually sweep across the northern tier of the nation, bringing the potential for snow across portions of the Upper Midwest. A cold front will bring drastic changes down through the Denver area with plummeting temperatures and snow.