RUNNING SPRINGS, Calif. — Fresh snow fell in the California mountains on Wednesday, adding to a staggering total that had blocked roads and stranded visitors for days.

The Sierra Nevada range in the north and Southern California mountains were under blizzard warnings for a storm that was expected to add several feet of snow overnight into early Wednesday, dumped more rain in many areas and chilled much of the state.

Record cold temperatures were possible with lows down to 28 degrees Fahrenheit (minus 2.2 degrees Celsius) and the National Weather Service issued freeze and frost warnings into early Wednesday in the San Francisco Bay Area and elsewhere.

The homeless and those without electricity were at special risk from the cold, the weather service said.

California wasn’t the only area battered by fierce weather. The National Weather Service predicted that a powerful weather system would affect most of the lower 48 states into Thursday, with heavy snow across the Southwest and some portions of the High Plains but record high temperatures in the Gulf Coast into the Ohio Valley. Areas in the dividing line between hot and cold, such as the lower Mississippi Valley and Tennessee Valley, could see heavy rain, thunderstorms and some flash flooding.

The high could top 100 degrees F (38 degrees Celsius) across far south Texas and windy, dry conditions would make for a critical risk of wildfire conditions across southeast New Mexico into the Southwest to West Texas for the next few days, according to the weather service.

In Southern California, San Bernardino County declared a state of emergency as crews struggled to plow blocked roads.

Jennifer Cobb and her husband, vacationing in the San Bernardino Mountains, found themselves trapped for a week by a relentless series of storms.

“We hear the phantom sounds of plows, but they never come,” said Cobb, 49. “Being stuck up here in this beautiful place shouldn’t be awful, but it is.”

In the mountain town of Crestline, some people unable to drive trudged on foot to the grocery store.

But Michael Johnstone said his family’s store was running low Tuesday on key inventory.

“We’re completely out of bread. Milk is getting really light. We’re almost completely out of produce,” Johnstone said. Authorities escorted two full grocery trucks up to the mountain community, he said, but just in time for the new storm to add more snow.

The latest storms have bookended the country, with snow closing or delaying the opening for hundreds of schools in the Northeast, which saw the most significant snowfall Tuesday of what has been a mild winter.

And Michigan again fought a battle with an ice after a storm Monday left thousands of customers without power in the central part of the state. To the southeast, around Detroit, some customers still lacked power nearly a week after a prior storm.

The storms have delayed travel, shuttered schools and overwhelmed crews trying to dig out of the snow and repair downed power lines. More than 72,000 customers were without power Tuesday night in Michigan and more than 59,000 in California, according to the website poweroutage.us.

Weather also continued to play a role in the cancellation of hundreds of flights and delays of thousands more around the country.

In California’s Sierra Nevada, the weather service warned that travel could be difficult to impossible because blowing snow could cause whiteout conditions on roadways, while wind chill could drop temperatures to minus 30 F (minus 34.4 C) “could cause frostbite on exposed skin in as little as 10 minutes.”

The Lake Tahoe area that straddles the California and Nevada borders in the Sierra Nevada was expected to have blizzard conditions with winds gusting to 100 mph along the ridgetops, while the lake itself could see waves large enough to capsize small boats, the weather service warned.

“If you risk travel you could become stranded in vehicles for hours,” the weather service warned.

Yosemite National Park, closed since Saturday because of heavy, blinding snow, postponed its planned Thursday reopening indefinitely.

The University of California, Berkeley Central Sierra Snow Laboratory near Donner Pass reported that nearly 41.7 feet (12.7 meters) had fallen since October, more than in any snow year since 1970 and second only to the record of 66.7 feet (20.3 meters) in 1952.

For California’s skiers and snowboarders, the parade of storms was too much of a good thing. Many ski resorts suspended operations on Tuesday, hoping to use the day to dig out so they could reopen Wednesday.

Mammoth Lakes, traditionally one of the snowiest places in California, had nearly 4 feet (1.2 meters) of snow over the past three days. Snow drifts were taller than houses and crews were working around the clock trying to keep roads and sidewalks clear.

The Mammoth Mountain ski resort has received 41.5 feet (12.6 meters) of snow since October and could be on a path to break the all-time snow season record of 55.7 feet (17 meters) set in 2010-2011.

But California also benefited from the back-to-back dumps of heave snow. The Sierra snowpack provides about a third of the state’s water supply and the water content of the snowpack Tuesday — in a state grappling with years of drought — was 186% of normal to date. It was 162% of the average on April 1, when it is historically at its peak, according to the state Department of Water Resources’ online data.

Elsewhere, in a pattern that’s lasted more than a week, much of the West and Northeast battled wintery weather while it simmered in Southern states.

Parts of Connecticut, New York, Massachusetts, New Jersey and Rhode Island had heavy snow forecast through Tuesday afternoon. Some areas of western Massachusetts and northern Connecticut got about 7 inches (18 centimeters). The Albany, New York, area saw less snow than expected — 2 inches (5 centimeters) to 5 inches (13 centimeters) — but it was enough to close schools.

Highs in the 70s and 80s were recorded in Georgia, and a south Alabama man was arrested on reckless murder charges after his 2-year-old child died Monday after being left in a hot car, police said.

The nation’s high Tuesday was 98 F at Zapata, Texas. The low for the day was -21 at 4 miles east-southeast of Estcourt Station, Maine.