Miserable winter weather is still hitting Texas and it's spreading to the East Coast

(CNN)As Texans continue to cope with the effects of deadly cold weather, much of the eastern half of the country was dealing with snow, ice or rain.

The storm system that took shape this week in the South will "continue to bring significant impacts from the Mid-Atlantic to Northeast US (Thursday)," according to the National Weather Service. "Significant ice accumulations and heavy snowfall are expected."

About 78 million Americans are under a winter weather alert and more than 27 million are going to bed under a hard-freeze warning.

At least 38 people have died nationwide from winter storms or frigid conditions since last week, a time in which more than 2,500 records for the lowest maximum temperature for the date have been set. Eight other deaths are suspected to be weather-related but authorities are waiting on autopsy results.

Woman fears for her daughter's health. A man searched 8 hours for food. These are the stories of the Texas storm

In Texas, communities are desperately seeking warmth and other necessities without electricity in freezing or near-freezing temperatures.

Gov. Greg Abbott was reassuring citizens he will get to the bottom of why so many people lost power this week as grid operators struggle to provide electricity.

"Texans deserve answers about why the shortfalls occurred, and how they're going to be corrected and Texans will get those answers," Abbott said.

In San Antonio, Claudia Lemus said power returned to her home Wednesday night -- but many stores' shelves were empty.

"We're able to get enough to get by ... but the grocery stores, most of them shut down," Lemus told CNN's Jim Sciutto on Thursday morning. "And when we tried the few that are open, you have to stand in line for 20-30 minutes at a time, and then you just go in and get whatever is available, because stores are (largely) empty."

Texans face yet another day of misery as families struggle with unheated homes and water problems

She said that during the times power has been off she and her husband have tried to keep their children's minds off the cold by keeping them busy and bundled up. To add a little warmth, the family ran the burners on the stove.

"We have lived all over the States, being a military family. We heard of the snow coming. We never thought it was going to be like this," she said. "We never anticipated to have ... the challenges."

Almost 300,000 Texas homes and businesses still were without power Thursday, down from around 4.5 million earlier in the week, according to utility tracker PowerOutage.us.

Bad weather has helped knock out power to a further 480,000 customers in many other states, including Oregon, Louisiana, Mississippi, Illinois, Kentucky, Ohio, West Virginia, Virginia and North Carolina, according to PowerOutage.us.

Why water is a huge issue for Texans right now

Texas officials say a deep freeze starting Sunday crippled utilities' power generation, causing rolling blackouts or continuous outages. The issues affect a Texas-only grid that covers 90% of the state and is isolated from the rest of the country, so the grid cannot import power from elsewhere to make up for the shortage.

Days without power in freezing conditions have sent Texans scrambling for alternative heating, through generators, fireplaces, living in running cars, or sheltering in powered warming centers or businesses.

About 13 million people are facing water disruptions, with boil-water notices, broken pipes and failing systems, state officials said. Austin and San Antonio issued boil-water notices to their residents on Wednesday evening.

Firefighters at a large apartment blaze in San Antonio were having supply issues Thursday night. Hydrants were frozen and crews were having to go down the street to where they could get water for their trucks.

"That's our problem. Once we make a little bit of advance on the fire, we run out of water," Bexar-Bulverde Volunteer Fire Department Chief Jerry Bialick said.

Difficult weather conditions across the country, meanwhile, have had serious implications for the coronavirus pandemic: Some shipments of Covid-19 vaccines have been delayed, and some clinics have had to cancel vaccine appointments.

The Houston Health Department said it will resume vaccinations this weekend with about 4,800 appointments.