Major Storm to hit the south...

While we had a short reprieve from the cold temperatures today, an arctic front has passed by, causing temperatures to plummet. Lows by tomorrow morning will be around 5 degrees and highs tomorrow will only be in the teens. The cold front will advance towards the gulf coast, interacting with subtropical energy. This will result in a massive winter storm for the south while we freeze, with the snow shield just to the south. The storm will exit the area on wednesday.

New Orleans winter wx forecast

Winter storm and ice storm warnings are in effect for most of the gulf coast and carolina coasts. Areas along the gulf coast will mainly deal with a nasty mix of freezing rain and sleet transitioning to snow with between .25 and .5 inches of ice expected. The farther south, the less snow and he more ice there is because although the cold air will make it far south, it will bu overrun by warm air, which will mean that any precip that falls will be liquid. Farther north, the cold air is deeper so the precip has time to refreeze into sleet or remain as snow all the way down.

In the eastern Carolinas with the exceptions of areas close to the shore and farther south, the precipitation will mostly be in the form of snow. Coastal south carolina is under a ice storm warning for .25-.75 inches of ice accretion, meaning that there will be a shell of ice on trees, power lines, roads, and everything else. This is dangerous even to New Englanders that are used to the snow. This amount of ice will break trees and weigh down power lines, not to mention that the infrastructure to deal with winter weather is non-existent across the deep south.

Farther north, .25-.5 inches of ice will give way to sleet and snow and areas to the north and west will receive mainly snow, with up to a foot expected. Areas far to the north and west from Western NC through Southern MD can expect less snow. As with all the storms this season, there will be a extremely tight gradient in the precipitation shield so a small shift of a few tens of miles can result in the a difference between a foot and only a couple of inches.

Watches, Warnings and Advisories 

Forecast snow totals:

3 day 50 percentile snow accumulation- snowfall has a 50/50 chance of being either greater or less than this.

This is the most likely scenario, with 1-3 inches across GA and SC, 4-6 across central NC and northern SC, and a swath of 6-8 inches across eastern NC through the Virginia beach area. The snow totals are likely overdone toward the west due to the extremely tight precip gradient with this storm.

These are the 90 percentile snow accumulations, meaning that there is a 90% chance of the snowfall being less than this.

This is what can be considered the reasonable "worst case scenario" for any given area. Not all the area will reach this threshold but some small areas where the most intense snow bands up may reach this. It forecasts 1-3 across central Mississippi and Alabama. GA is increased to 4-6 around the center and 1-3 to the north and south. The 6" contour extends from GA to the Delmarva peninsula. central and eastern NC is hammered with 8-15 inches of snow although the coasts get considerably less due to warm air intrusion in the mid to lower levels off the ocean.

This is a very serious event for the south as they are not accustomed to this weather. Even by northern standards, an half an inch of ice accretion and a foot of snow is a major event. They have no way of dealing with this in the south. In addition, temperatures will remain in the low 40s with lows in the 20s, which will promote slow melting, keeping the region encased in ice or buried by snow for a long time.