Wednesday, January 02, 2008

Coldest air of the season

This morning's low at your fearless author's home was 17.4 degrees. It will be colder tonight!

J.B. Elliott has the full scoop here. My 17 degree reading was the second coldest temp J.B. could find this morning. It was 15 at the Mt. Cheaha 33/40 SkyCam, and Hamilton (NWS coop observer). It was 17 at Vinemont and Springville/Simmons Mountain.

Notice that last night's lowest readings were at higher elevations. Tonight I expect the coldest air to settle in the valleys. This happens quite often. Cold air is heavy and sinks. But on the first night after a cold front, conditions are usually more windy, preventing the coldest air from sinking. Then, elevation takes over as the main factor.

Our elevation range isn't that great, though, like it is in other parts of the country. Despite that, areas that are 500-1000 feet higher can have temperatures a few degrees colder on those windy nights after a front first enters. Last night I took the boys to see Alvin and the Chipmunks. When we left the theater at 7:10, the wind was strong out of the north, probably at least 20 miles per hour.

The core of the cold air is moving across Alabama today. Much of the state will fail to make it above freezing. Tonight, with calm air in place and the core of the air moving east, I expect the coldest temperatures tomorrow to be in the valleys of Northeast Alabama.

Fellow ABC 33/40 Skywatcher Vic Bell from Scrougeout, AL may flirt with single digits.

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