12/22 – Rob Knight’s “ARCTIC AIR MASS AHEAD” Thursday Morning Forecast

The coldest air of the season is approaching, with a very uncomfortable few days ahead. Current expectation is that cold front will reach the extreme western portions of our area northwest of Baton Rouge and McComb around sunset, moving rapidly across the area to the Mississippi-Alabama border before midnight. Only real question for the daytime hours today is whether we get any significant breaks in the cloud cover. That’ll determine how warm we get. Temperatures and dew points in the 60s aren’t very far offshore, and with onshore winds expected for a few hours today, any significant breaks in the cloud cover will allow temperatures to get well into the 60s. If we don’t get any breaks, temperatures may struggle to get out of the 50s. Can’t rule out an isolated shower in advance of the front this afternoon and evening, but precipitation would be very light, and will dry quickly behind the front.

By midnight, today’s highs will be a distant memory as cold air plunges into the area. As the cold air arrives, temperature drops of 20-30 degrees in a few hours are likely. Temperature fall Tonight…and by 3 AM Friday, most of the area should be near or below freezing, with pretty much the entire area meeting hard freeze criteria by sunrise. With 20-25 mph winds (at least) behind the front, wind chill values are likely to be in the single digits Friday morning. While it may look nice from indoors, with sunny skies for most of the area, it`ll be dangerously cold outside if people aren’t dressed for the weather on Friday. Little recovery in temperatures is anticipated during the day Friday and most of the area may remain below freezing all day. Overnight lows Friday night are likely to be in the teens for pretty much the entire area. Some question as to whether we’ll see high cloud cover overnight with a minor disturbance moving through the area.

Regarding headlines, I’ve continued with the Wind Advisory and Hard Freeze Warnings as previously constructed. An extended Wind Chill Advisory until 10 am Saturday, per wind chill/apparent temperature grids. May be a few hours during that period where criteria are not strictly met, but overall threat deems the advisory necessary.

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