The Rock Hill area is going to get rain. Then it’s going to get really cold this week

A surge of arctic air is expected to sweep across the Rock Hill area and the rest of the eastern United States this week, bringing what forecasters say will be the coldest temperatures since last February.

Afternoon highs will struggle to reach the lower 40s Wednesday, meteorologists say. That is well below even mid-January averages.

The arctic-based air will arrive on the heels of a cold front that is forecast to cross the Rock Hill area sometime Tuesday morning. Showers or a steadier rain will precede the front, with the precipitation changing to snow in the North Carolina mountains.

Some accumulations are expected in the higher elevations.

National Weather Service meteorologist Justin Lane said temperatures Tuesday will reach their peak — around 50 degrees — in the morning. As the colder air surges in behind the front, Lane says, “temperatures will be steady or slowly falling after the initial cold air surge.”

By daybreak Wednesday, Rock Hill-area residents will be dealing with temperatures in the lower 20s.

And despite full sunshine Wednesday, Lane says temperatures will remain about 20 degrees below seasonal averages, with highs in the lower 40s.

Morning lows Thursday again will be in the low to mid 20s.

Temperatures will moderate slowly later in the week.

“Temperatures are not forecast to return to normal anytime (through Friday),” he says.

Computer guidance indicates a low pressure system will form in the Gulf of Mexico later this week, but that system is expected to remain south of the Rock Hill area.