The National Weather Service in Huntsville has issued a Freezing Fog Advisory for Marshall, Jackson, and DeKalb Counties through 8AM Saturday morning. The rest of the Tennessee Valley is also under a “Significant Weather Advisory” for patchy freezing fog. The difference between the two advisories is simply a matter of coverage and likelihood of impacts. Freezing fog is possible for all of us this morning, but is not expected to be widespread outside of the Jackson, Marshall, or DeKalb Counties.
Freezing fog occurs when regular fog made up of water droplets develops, while the temperature is low enough that the droplets could freeze on contact with surfaces. This would leave elevated surfaces, your windshield, and some patches on the road with a thin layer of ice early this morning.
Visibilities will also be low due to the fog, so you should either be very careful driving this morning or you should wait until the fog has cleared out before driving. The advisory expires at 8AM, and after that the fog and any icy spots will fade away.
The full advisory is listed below from the National Weather Service:
…FREEZING FOG ADVISORY IN EFFECT UNTIL 8 AM CST THIS MORNING…
The National Weather Service in Huntsville has issued a Freezing
Fog Advisory, which is in effect until 8 AM CST this morning.
* TEMPERATURES…In the 28 to 32 degree range.
* VISIBILITIES…Between 0 and 1 mile, especially in valley
* TIMING…Until 8 AM CST this morning.
* IMPACTS…Widespread dense freezing fog will result in hazardous
traveling conditions across the advisory area, where a light,
thin film of ice will be possible on elevated surfaces. Major
thoroughfares such as US Highway 72, Interstate 59, and US
Highway 431 will be impacted.
* LOCATIONS…Marshall, Jackson and De Kalb Counties.
A Freezing Fog Advisory means visibilities will frequently be
reduced to less than one quarter mile. If driving, slow down, use
your headlights, and leave plenty of distance ahead of you. Also,
be alert for ice on bridge decks causing slippery roads.