Autumn chill, with Siberian express right behind it, to hit U.S. eastern states

NEW YORK (Reuters) - A mid-autumn chill in the northeastern United States on Friday and Saturday is only a mild foreshadow of the winter weather that will break dozens of records across much of the country next week, the National Weather Service said.

The cold front now pushing through the northeast should bring near-record to record low freezing temperatures in the mid-to-upper 20s Fahrenheit from Boston to Washington by Saturday morning, the service said.

Boston will see its record low temperature for the day of 24 degrees Fahrenheit (-4 Celsius) challenged by Saturday morning with an overnight low forecast of 25 degrees.

But that will be overtaken when the Siberian express that is now over Alaska sweeps across the North American continent next week and grips the eastern part of the United States, meteorologist Bryan Jackson said.

“This is the precursor to the stronger cold front that’s coming,” Jackson said by phone from the National Weather Service Weather Prediction Center in College Park, Maryland.

The Arctic air dome should push into the U.S. northern plain states from the Canadian prairies between Sunday and Monday, dropping temperatures to near 0 degrees Fahrenheit (-18 Celsius), before hitting the eastern U.S. with record lows by Wednesday, Jackson said.

While the most frigid temperatures will be in the Upper Midwest and plain states, the record-breaking areas of the country will be in the eastern states that do not normally get polar air masses at this time of year, he said.

“The fact that it makes it all the way to the coast while still being pretty cold is the rarest part,” he added.

Wednesday should see the most records broken as temperatures drop to the low teens to low 20s Fahrenheit when the eastward-moving air mass spans the Gulf coast to New England, he said.

The weather service is forecasting that 30 of its reporting sites will break records for overnight low temperatures with another 30 coming close. It also expects 15 sites to have record low maximum temperatures on Wednesday, with another 78 sites challenging their records for the day.

By Wednesday night, the air mass will move off the coast into the Atlantic Ocean, the weather service said.

Reporting by Peter Szekely in New York; editing by Diane Craft