Four to 6 inches of fresh snow and roughly half an inch of rain fell over the Central Sierra Monday morning, and weather experts say more is on the way.National Weather Service forecasters issued a Winter Storm Warning for the region this morning, saying rain and snow as low as 2,600 feet are all but certain late tonight.More of the same is forecast for Wednesday - with a 100 percent chance of precipitation and snow down to 1,600 feet. While flakes may fall, little or no snow accumulation is forecast in the foothills.Holly Osborne, National Weather Service meteorologist, said the storm system that passed south of Interstate 80 on Monday was relatively weak, but the system expected to hit the region over the next 24 hours will pack more of a punch."This storm is stronger than the ones we've seen lately," Osborne said. "We haven't seen much this winter."The system could drop nearly 2 feet of snow in the high elevations of the Sierra Nevada by Wednesday morning.Temperatures will drop to the low to upper 30s on Wednesday, before another warming trend begins on Friday. Highs on Saturday will likely be in the upper 50s or lower 60s, Osborne said.The rain and snow couldn't come a moment too soon for area water resource managers and ski resort operators, who for months have been grappling with precipitation levels well below normal for this time of year.Dodge Ridge spokeswoman Amber Jenquin said the Pinecrest-area ski resort got a healthy dose of snow on Monday and was looking forward to even more favorable ski conditions over the weekend. She said various ski runs received 3 to 6 inches of powder."It could be perfect skiing conditions for Saturday," she said.She said the recent snowfall will greatly improve prospects for a winter recreation season that has seen fewer skiers and snow boarders hitting the slopes than years past."We will be open through April as long as the snow keeps coming," she said.The story was similar at Bear Valley off Highway 4. The resort has seen 4 inches of fresh powder, according to Mattly Trent, assistant ski patrol director."We're hoping for crowds of people to get psyched about the snow and then come up," he said.He said the snowfall for the season is below normal, at 90 inches. It would typically be above 200 inches for this time of year."I think these storms are going to help us out for the rest of the season," said Trent, who added that the slopes will be open through April.The rain did little to help storage levels at Lyons and Pinecrest reservoirs, the source of much of Tuolumne County's drinking water, but officials at the Tuolumne Utilities District were hopeful Wednesday's storm will bring yet more water."We'll take what we can get, but it was a pretty weak rainfall and snowfall," said TUD General Manager Pete Kampa. "We certainly need a lot more (rain) or we are looking at substantial water conservation to get us through the rest of the year."The light storm had a negligible impact on traffic in the region.Sonora, Ebbetts and Tioga passes all remain closed for the winter season. The Grapevine Pass on Interstate 5 was closed briefly on Monday as crews tried to clear snow from the vital Central and Southern California artery.For more information on highway conditions, call the Caltrans automated number for road conditions at 800-427-7623.