(Adds details about Consumers Energy ending natgas conservation appeal)
By Scott DiSavino
Jan 31 (Reuters) - Several utilities on Thursday urged U.S. customers to cut back on power and gas consumption during a brutal freeze blanketing the eastern half of the country after homes and businesses used record amounts of natural gas for heating on Wednesday.
Harsh arctic winds brought record-low temperatures across much of the Midwest, causing at least a dozen deaths and forcing residents who pride themselves on their winter hardiness to huddle indoors.
As consumers cranked up heaters to escape the bitter cold, gas demand in the lower 48 U.S. states jumped to a preliminary record high of 145.1 billion cubic feet per day (bcfd) on Wednesday, according to financial data provider Refinitiv.
That topped the current all-time high of 144.6 bcfd set on Jan. 1, 2018. One billion cubic feet is enough gas to supply about five million U.S. homes for a day.
In Michigan, automakers agreed to interrupt production schedules through Friday after local utility Consumers Energy made an emergency appeal to curtail gas use so it could manage supplies following a fire at a gas compressor station on Wednesday.
Fiat Chrysler said on Thursday it canceled two additional shifts at its Warren Truck and Sterling Heights Assembly plants and General Motors said it was suspending operations at 13 Michigan plants and a tech center.
Consumers, a unit of Michigan energy company CMS Energy Corp , said that its appeal to consumers to conserve natural gas is ending at midnight on Thursday night.
Ford said it had also taken steps to reduce energy use at its four Michigan plants supplied by CMS.
Consumers had earlier urged all of its 1.8 million Michigan customers to extend their conservation efforts through Friday.
"Repairs at the Ray Compressor Station are ongoing, and one of the station’s three compressors is partially in service," the utility added.
Elsewhere in Michigan, DTE Energy Inc asked its 2.2 million power customers to reduce electric use voluntarily to help safeguard the reliability of the regional grid.
PJM Interconnection LLC, the electric grid operator for all or parts of 13 states from New Jersey to Illinois, said there were no reliability issues and noted that power demand on Thursday had already peaked below 140,000 megawatts.
That is well below the region's all-time winter peak of 143,338 MW set on Feb. 20, 2015. One megawatt of electricity can power about 1,000 homes.
While the brutal cold boosts gas use for heating, it can also reduce production by freezing pipes in producing regions' gathering systems, an effect known as freeze-offs.
Gas production in the lower 48 was projected to fall to a four-month low of 84.9 bcfd on Thursday due primarily to freeze-offs in the Marcellus and Utica, the nation's biggest shale gas-producing region in Pennsylvania, Ohio and West Virginia, according to Refinitiv.
Reporting by Scott DiSavino in New York and Harshith Aranya in Bengaluru; editing by David Gregorio, Dan Grebler and G Crosse