Slowly but surely, confidence in a wintry weather threat in the Sunday/Monday timeframe increases. It’s still a little too close to call for most of North Alabama, but we are seeing a trend toward a greater chance of some ice to the west of Huntsville and a much lower risk to the east.

Why can’t you just ‘know’ what will happen?

It’s the future. No one has been there yet to tell us what happened, so we make a prediction based on the best-available information. That prediction also includes a statement of certainty: in this case, it’s not a very high statement of certainty.

So what are we looking at here?

It’s complicated. That won’t stop us from giving you some scenarios that could play out in a complex environment.

First of all, we’re very close to the boundary between air that’s ‘way too warm’ and air that is ‘definitely cold enough’ for sleet and/or freezing rain. It does NOT look like snow.

Those two scenarios in the middle of the above picture look most plausible west of Huntsville; east of Huntsville, it’s more like the far left: primarily rain.

What’s this mean for Monday?

Ice ‘storms’ like this are not always a result of what’s happening now so much as how it’s been in the time leading up to now.

Ground warm? Then it has to get very cold to cause icy roads: usually 29ºF or lower. Bridges may freeze before getting that cold, though. Ice can accumulate in trees and on power lines at 32ºF while roads and sidewalks are mostly wet. Sometimes it’s the county highways and side streets that get icy patches while main roads stay clear.

In other words, there are parts of the impact that go beyond the weather forecast itself and deal with things we have no way of knowing like precise pavement temperatures.

Over a matter of 10-15 miles we could go from significant freezing rain to just a cold, soaking rain.

What do you do with this?

Be ready for some short-term ice problems with sleet and freezing rain Sunday night into Monday: especially in Northwest Alabama and Southern Middle Tennessee. That could mean some icy travel and potentially some power outages, too. We’ll outline who gets it and who doesn’t with a greater degree of certainty in coming days, so expect some changes to the forecast!