After one of the warmer starts to an October in the period of record, something resembling autumn is about to visit the Philadelphia region, and it might make a dramatic entrance.

The government’s Storm Prediction Center has the region under a “slight risk” for severe storms Saturday afternoon, those with winds up to 60 mph or more, with an outside chance of a tornado, as a potent cold front crosses the region.

“You’ll definitely notice when it comes through,” said Jonathan O’Brien, a meteorologist with the National Weather Service in Mount Holly.

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While the atmosphere’s instability isn’t all that impressive, he said, “We’ll probably get a line of showers and embedded thunder.”

In addition, the storm center said that conditions could favor “storm-scale rotation” and lists a a 2% chance of tornadoes in the region. “We can’t rule it out,” said O’Brien.

Behind the front, expect “a much different feel tomorrow,” he said.

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Overnight lows are expected to drop to near 50 early Sunday, and into the 40s Monday and Tuesday, with daytime highs in the mid-60s.

Those highs aren’t too much above the average overnight lows for the first half of the month. Save for Oct. 1, every day has had above-average temperatures, which are running 7 degrees above normal for the month.

All thermal comfort being relative, Sunday is likely to feel quite chilly, although temperatures will feel quite close to normal.