Jeff Berardelli is WFLA's Chief Meteorologist and Climate Specialist
TAMPA, Fla. (WFLA) — Parts of the Gulf Coast measured a foot of snow on Tuesday. For many cities, the totals obliterated long-standing snowfall records. Milton, Florida recorded 9 inches of snow, which more than doubles the all-time statewide Florida record of 4 inches.
The heaviest snow fell in Louisiana, where the city of New Orleans piled up 10 inches of snow with isolated reports of over a foot. And Mobile, Alabama also shattered their record, picking up around 8 inches.
Heavy snow was still falling in northern Florida Tuesday night where Tallahassee had a chance to break their all-time record snowfall of 2.8 inches. Snow and ice will fall across the I-10 corridor into Lake City and Jacksonville, with perhaps a few ice pellets as far south as Ocala. All precipitation will end by daybreak.
Temperatures will fall below freezing from Citrus County northward. Patches of ice on roads will become more prevalent the further north you go from there.
So what is causing this bizarre weather system? It's due to a very unique set up where very cold air is being forced south into the Gulf, while warm-moist air is being propelled above it by a stalled front and weak low pressure over the Gulf.
This is all happening because the polar jet stream is stuck over the Gulf Coast, being forced thousands of miles south of its normal location by a displaced Polar Vortex. That Polar Vortex, normally far north in Canada, is positioned in the northern U.S. — forced south by very warm air over the Arctic Ocean. It's all connected.
The position of the jet stream over the Gulf is activating a stalled front, initiating development of low pressure (and moisture) while all the cold air is being forced south.
The result is what we call "overrunning," where the warm air is forced north by low pressure, and because it is lighter (and cold air is heavier/denser), the warm air "overruns" the cold air at the surface. That lifting of the warm-moist air creates clouds and precipitation. Since it is cold enough for snow, that is what is falling.
The snow is made heavier by very warm water in the western-central Gulf. In some cases, about 5 degrees above normal.
You may hear some people mentioning climate change — either that this event proves it exists or does not exist. I'm here to tell you that this event proves neither. There's no way of knowing whether this event would have occurred or not without climate change.
What we can say is that the warmer air in the Arctic influences the further south displacement of the Polar Vortex. And we can also say that the warmer Gulf produced heavier snowfall rates than it otherwise would have.
Here in Tampa Bay, no snow will fall, but it will feel like snow Wednesday morning with wind chills in the 20s for many and whipping winds gusting over 25 mph. That's brutal for Tampa Bay!
Looking ahead this week into the weekend, many cold mornings and chilly days are ahead. Tampa's lows will bottom out Friday and Saturday morning in the mid 30s with upper 20s on the Nature Coast.
Daytime temperatures will be in the 50s through Saturday, finally popping above the 70-degree mark on Sunday, with nice weekend sunshine.