Flash freeze likely after big rainfall

A rarely used weather term is coming up this week: flash freeze.

That’s because the conditions are ripe for a lot of rain followed by a cold front, and not just any cold front, but an arctic air mass.

The AccuWeather hourly forecast for Delaware County is showing rain tonight into early Friday with the temperature climbing into the low 50s until about daybreak.

For a couple hours Friday expect a slight drop-off in temperature, but then the polar express rolls in and the temperature is forecast to pass freezing on the way down rapidly by 4 p.m.

The plunge is likely to go all the way to the midteens by early Saturday.

With more than an inch of rain expected during 24 hours of precipitation, there’s bound to be plenty of spots were water pools and will freeze over. Some of the pooling will be reduced as the wind picks up Friday afternoon, however.

But the wind brings its own danger.

According to the National Weather Service office in Mount Holly, N.J.: “Right along the cold front as it moves through on Friday, a narrow squall line could develop bringing localized wind gusts up to 60 mph. These winds could lead to downed trees and power outages.”

There could be snow showers as well with the squall line, which could be timed with the afternoon rush hour.

Frigid and windy conditions are expected Saturday as the frozen tundra comes to the region. Expect the temperature to struggle to make it to 20 degrees during the day Christmas Eve.

Then, a sunny and cold Sunday on Christmas with a high in the mid-20s is expected and the same conditions on Monday and a couple degrees warmer, according to AccuWeather.