A powerful storm system expected to bring severe weather to areas in south Alabama on Thursday is also going to leave some snow behind in north and central Alabama on Friday.

But who gets snow and how much will fall was not a sure thing as of Thursday afternoon.

Winter weather advisories, in purple, have been issued for north and north-central Alabama that will go into effect on Friday. Areas under an advisory could get an inch or more of snow starting Friday afternoon. (National Weather Service)

Snow in Alabama is notoriously challenging to forecast, and the National Weather Service said that snowfall amounts will depend on two things: the exact track of the storm system and how quickly temperatures fall below freezing.

But snow -- at least a little -- is looking more likely than not.

The National Weather Service office in Huntsville issued a winter weather advisory Thursday afternoon for north Alabama, and the weather service office in Birmingham also issued an advisory for part of north-central Alabama.

The north Alabama advisory will be in effect from noon Friday until 3 a.m. Saturday.

The advisory for central Alabama will be in effect from noon Friday until 6 a.m. Saturday.

Computer models as of Thursday were offering differing scenarios of what would unfold -- so the timing and details could change -- but here's what forecasters were thinking as of Thursday afternoon.

What the weather service described as a "potent" storm system is expected to move through Alabama later today and overnight. The storm could generate severe weather in the warm sector over south Alabama and bring up to an inch of rain to the rest of the state on Thursday.

Rain and storms were already moving into the state as of Thursday afternoon, and tornado watches were in effect to the west in Mississippi.

Another dose of cold air is expected to rush in behind the system -- with many in Alabama seeing their high temperatures at midnight Friday and the thermometer falling during the rest of the day.

Computer models predict that there will be enough moisture wrapping around the back side of the low pressure area to generate snow across north and parts of central Alabama starting Friday afternoon.

North Alabama will have the best shot at accumulating snow. The National Weather Service in Huntsville said Thursday that rain could begin to change over to snow by Friday afternoon.

Forecasters said greatest chance for accumulating snow will be from 6 p.m. through midnight on Friday.

Between 1 and 1.5 inches is likely in northwest Alabama and the higher terrain of northeast Alabama, the weather service said. Up to 1 inch will be more likely for the rest of north Alabama.

Light snow or flurries are expected to keep falling through Saturday morning.

The weather service cautioned that the combination of snow and freezing water on roadways could make travel hazardous through Saturday morning.

That will also be the case across much of north-central Alabama, according to the weather service in Birmingham.

The transition from rain to snow could begin in west-central Alabama by early Friday afternoon, and accumulations are expected to be 1 inch or less.

The weather service said that the snow could accumulate roughly along and north of a line from Carrollton to Calera to Heflin.

Forecasters cautioned that snow will not fall uniformly across the area: Some areas may get more than an inch -- and some may not get measurable snow at all.

A rain-snow mix will be possible all the way to the Intestate 85 corridor, the weather service said.

The main window for accumulating snow in central Alabama will be from 3 p.m. Friday until midnight, the weather service said. Flurries could hang around through Saturday morning.

Don't think this is the last shot at winter precipitation for a while -- the weather service will be watching for the potential of another storm system to track toward the state around mid-week that could bring another chance for snow.

Here's more from the National Weather Service in Birmingham: