FRESNO, Calif. (KFSN) -- Travelers have set out on the road to visit family for the Thanksgiving holiday, but an incoming storm headed toward the Central Valley could lead to risky conditions and road closures.
Hour-by-hour Grapevine forecast:
According to the California Highway Patrol, all southbound lanes of Highway 99 are now open after it was shut down due to roadway flooding.
CHP officials say snow and even some fog made for limited visibility on the Grapevine. Officers paced traffic, slowly bringing cars through in groups.
By mid-morning, the snow had stopped falling, temperatures warmed and the CHP determine it was safe to let traffic flow freely again.
It was good news for travelers, including the Lewis family from Hanford, who are making their annual trip to Disneyland. They came prepared.
"Well, we have chains, we have blankets, we have flashlights, we have a tarp in ther in case I have to lay down and put chains on," said Jarred Lewis.
Chains are not allowed on the Grapevine because the topography doesn't allow for a safe place to put them on tires. If it snows, all you can do is drive slowly and carefully. CHP is warning drivers to be prepared for changing weather conditions.
The timing and gusto-like predictions have prompted many to get a move on their travel.
"We were originally going to come tomorrow, we got looking at the weather and said it's easier to drive when it's not raining than when it is," said Bill Daniel of San Fernando Valley.
Bill and Janet Daniel woke up early Tuesday to make the trip from the San Fernando Valley to visit their children in the Central Valley. They prefer to sit back and enjoy the weather, instead of being stuck in it.
Watch the latest Accuweather Forecast from the StormWarn 30 center
"Our daughter lives in the foothills in Clovis, and so we'll have a beautiful view of the snow-covered mountains," Janet said.
"The timing is unfortunate for holiday travel because it's going to have a lot of wintry impacts," said Kevin Durphee, a meteorologist with the National Weather Service.
A Winter Storm Warning is in effect from Tuesday until Friday.
"Snow levels can be as low as 1,500 feet by late Thursday night into Friday morning," Durphee said. "Any elevation that gets snow, even in the foothills where it's rare, is going to have road delays, road closures. It's going to be a wintry mess."
Along with the snow, Durphee says parts of the San Joaquin Valley and the foothills could also see some thunderstorms.
RELATED: CHP expects heavy traffic, hazardous driving conditions on Grapevine Wednesday
Commuters are reminded of necessities needed during storms: good windshield wipers, a full tank of gas, and enough tire tread.
The roads are slick, all that oil that has built up through the year ends up coming up to the surface and it causes less friction for tires," said Gregorio Rodriguez, public information officer for Madera County California Highway Patrol.
But the most important thing drivers should remember is to take their patience.
"There's going to be a lot of extra vehicles on the roadway. Give yourself plenty of time when you are heading out the door and if you have a normal four hour travel time, make sure that you give yourself six hours," said Shasta Tollefson with the California Highway Patrol.
The weather could impact travel on the Grapevine, some detours include Highway 101 or Highway 14. For up to date traffic conditions head to our Traffic Map.
The storm has also cut power to thousands of Pacific Gas and Electric (PG&E) customers throughout the Valley and into the foothills. At one point nearly 2,000 customers were without power in Fresno's Tower District.
RELATED: Thousands of PG&E customers without power as major storm moves through the Valley
In Northern California, this same storm was being dubbed a "bomb cyclone" by several meteorologists.
"Bomb cyclone, or bombogenesis, is a rapidly developing area of low pressure. In fact, it's been at least 15 years or more since we have experienced a bomb cyclone in the Bay Area," according to ABC7 News Meteorologist Mike Nicco.
A "bomb cyclone" is a mixture of blizzard-like conditions in mountains with near hurricane-force winds.
For the latest on the storm click here.
For the latest on the storm click here.