Chicago style cold. It was 15 again this morning in my backyard in Kennesaw, it was 14 in Chicago this morning. I am still not overly impressed with the "snow system" for late Thursday. Might even mix in some sleet or drizzle briefly. I keep seeing and hearing this refereed to as an "Alberta Clipper".  But it is not. A hybrid or Clipper-Like at best but not a true Clipper which almost never get this far south. The upper-level short-wave low-pressure system was spit out of the Aleutian Low in the Northeast Pacific South of Alaska.  Last time I checked my high school geography this was well west and South of Alberta Canada. A minor point but a true Alberta clipper forms up in Canada and heads southeast across either the Great Lakes or upper Midwest to the Mid-Atlantic or New England states. Either way the low is progged well North of Atlanta and it is along and North of the low track you get the best snow production.

Our snow chance comes primarily from the trailing vort max tail and arctic cold front trailing down from the main system up North.  This is not normally a recipe for a lot of snow in Georgia as Atlanta's best snows come from Gulf of Mexico lows (Miller A type).

The models have been on and off on and off on IF there is any Gulf low formed on the arctic front.  We do have to watch the snow ratios however in the polar air it could be greater than the normal 10:1 ratio, more like 12 or 15:1 so that even just a little liquid equivalent equates to more than the usual snow that would be expected to yield. Trying to counter-act that however could be down-slopping from the Mountains and negative motions from cold advection with an unfavorable westly wind component.

Models have done their usual waffling over the past 5 days from impressive amounts of snow (by Southern standards) to NONE at all, so there is no point to reacting to every new computer model run.  I would expect a consensus to emerge from the model madness with the numerical output today and tomorrow.  It could snow flurry in the Florida Pan Handle and there could be more snow South of Atlanta than near the Perimeter and of course more in the Mountains. I am not excited about the amounts for Atlanta now but maybe that will change.

Ignoring the computer model temperature forecasts (their statistical regression algorithms can't handle shallow arctic air or anomalous upper level height fields) I think highs Friday and Saturday struggle to get out of the 20s with lows of 9-16.

Meanwhile, this cold wave ranks up there with others in history. Near-record low temperatures will occur again tonight in the Sunshine State as a cold wave brings frost and freeze into the heart of Florida.

The cold will hold greatest significance for central parts of the sunshine state away from the coast, along a corridor reaching from about Orlando to Lake Okeechobee. Here, any area having important citrus and winter vegetable crops will register low temperatures between 26 and 35 degrees.

Variations in wind as well as proximity to lakes or built-up urban areas will help to make the difference between relatively harmless lower to middle 30s and potentially damaging hard freezes. Most of the region will fall within the former category.

Nevertheless, the coldest spots across the heart of central Florida will dip as low as 25 degrees with readings below freezing for several hours early Wednesday morning.

While freezing temperatures continued to challenge citrus producers today and tomorrow, the next cold wave scheduled to begin this weekend could bring even lower temperatures to agricultural areas in Florida, Texas, Louisiana and much of the Gulf Coast. Temperatures over much of citrus country in Florida could dip between 27 and 34 degrees again tomorrow morning.

The cold will not be enough this time to cause severe damage only slight damage. But there is every indication that the next arctic outbreak will bring lower temperatures to Texas beginning Thursday and in Florida this weekend.

That next cold blast will enter the northern Plains Wednesday and will follow a large swath of light snow or flurries that will visit much of the South later in the week.

Temperatures have the potential to average 3 to 5 degrees lower in Florida during the next blast.

The risk of damaging cold to citrus, strawberries and other fruits and vegetables will stretch from southern Texas to Louisiana to Florida.  Oil refineries may also have to be briefly shut down due to the rare cold wave to boost gasoline prices.