"F" word in forecast, but no reason to panic

This has certainly been a strange winter so far. We can't buy a snowflake here, but balmy locations like Brownsville, Texas, and Tallahassee, Florida, have seen accumulating snows.

Despite the ridiculously cold airmass in place since Christmas, the next storm system is expected to raise the temperature just enough to prevent snow. It will be just rain. The only question is whether any of this rain will fall as the F-word variety (freezing).

The computer models struggle with these kinds of storms where the temperature is hovering around 32 degrees at the surface. Some of the models suggest that the current Arctic airmass will be slow to budge, keeping the mercury just low enough to allow freezing rain Sunday afternoon.

There's three scenarios that could play out:

1. It ends up being warmer than expected and we just get POUR (Plain Ol' Liquid Rain).

2. The cold air lingers long enough for the precip to begin as freezing rain, but the warm air finally wins out, and everything changes to liquid rain overnight Sunday.

3. The cold air is stronger than expected and we end up with a major ice storm.

Thankfully I haven't seen any computer models that depict the last scenario. The GFS suite of models is leaning toward the first scenario (all liquid rain) while the NAM model suite is leaning toward the second scenario (freezing-rain-changing-to-liquid-rain).

The College of DuPage weather lab offers an excellent website for analyzing the computer models. For example, this map shows the simulated precipitation (purple = freezing rain, green = liquid rain) for one of the NAM model runs. Notice that Cape Girardeau is right on the knife edge:

The national Weather Prediction Center offers graphics showing the probability of freezing rain based on a blend of various computer models. Right now the odds of receiving a tenth-of-an-inch of ice is very low at Cape Girardeau, but is much higher toward the Ozarks.

Although anything can happen, it appears that any freezing rain that does fall Sunday will be short-lived. By Monday morning the temperature should be high enough to prevent travel troubles. But it will be close.