It's been more than three decades since there has been a snowfall in downtown San Francisco, and there is a possibility that this long streak will be broken tonight.
Lower elevations around Los Angeles, as well as other parts of California and the Southwest where it rarely snows, could also have snowflakes flying this weekend. People in areas around Las Vegas could even see snowflakes.
In some places, the snow will be heavy enough to significantly disrupt or even shut down travel.
Snow already made an appearance in some of the higher elevations around San Francisco with a storm last weekend, and a storm moving in through early this weekend will bring snow to even lower elevations.
This is the same storm brought several inches of snow to Seattle and Portland.
The cold air coming in with this storm has Clark very impressed.
"There indeed could be snow in the San Francisco Bay area and the Central Valley of California Friday afternoon or night," Clark stated, "and a few rain and snow showers Saturday. Snow levels could go down to 1,000 feet in the L.A. Basin Saturday."
In downtown San Francisco, he adds that it is very possible that in a heavy rain shower there could at least be wet snowflakes. It's not a guarantee but it's certainly possible.
There is growing concern that major passes around the San Francisco Bay area will be affected by snow.
In addition to the San Francisco Bay area and some valleys of Southern California, snow could also fall in the Upper Deserts and the heavily-traveled passes of Southern California, including the Grapevine and Cajon Pass.
"Precipitation will end up being all snow above 3,000 feet, or certainly below pass level," Clark said, "so the Grapevine could pick up 6 to 10 inches of snow."
Clark adds that other passes, such as the 14 Freeway from L.A. to the Antelope Valley, will also be affected. He says that even the Antelope Valley itself could have snow.
Snow along Interstate 40 into Arizona could become a major problem as well.
The last time it snowed in downtown San Francisco was on Feb. 5, 1976, when 1 inch of snow was measured.
For more details on the storm and what to expect at different elevations across California, refer to Clark's blog.
Photo courtesy of Photos.com
Heavy rain will soak the Gulf Coast and expand into the Southeast early this week, perhaps bringing isolated flooding but also helping to battle the drought.
As arctic air is held at bay next week, warmth will build from the West to the Central states, while the temperatures rebound to seasonable levels in the Northeast.
Interstate 64 was closed between Reidland and Cadiz, Kentucky, due to heavy snowfall. Kentucky Gov. Steve Beshear activated the Kentucky National Guard to assist stranded motorists.
An upcoming thaw will raise concerns for flooding and ice jams in parts of the Midwest and East through the middle of March.
The explosion was one of five such incidents in the borough late Wednesday into Thursday according to the New York City Fire Department.
This week, rounds of snow, rain and ice pummeled areas from Oklahoma City to Boston, creating treacherous travel conditions and causing widespread power outages in the tens of thousands across the country.
Pensacola, FL (1954)
2.1" of snow, greatest 24 hour snowfall in city's history, also greatest single storm total.
East Coast (1962)
Great Atlantic Coast Storm caused over $200 million damage from New England to Florida. Major shoreline erosion from Long Island to North Carolina from 40 foot waves, 70 mph winds. Deep snow piled up in Virginia Mountains. Big Meadows/Blue Ridge Mts. (6th-7th) had 42.0" of snow, greatest 24 hour snowfall.
Winnipeg, Manitoba (1983)
Severe ice storm in the city and over southern Manitoba. Winnipeg International Airport closed until the 8th and several TV towers collapsed.