Confidence is growing. Alabama could be hit by a winter storm starting late Friday and lasting through Saturday.

The National Weather Service has issued winter storm warnings for northern and part of central Alabama, effective at midnight Friday. The weather service warned that snow amounts of up to 6 inches were possible, with up to 8 inches possible in some areas of northern Alabama. Central Alabama could see up to 5 inches of snow and sleet.

You can find out more about the current forecast here.

Winter Storm Warning, Monitoring and Advisory

Local national weather service offices issue individual winter weather advisories, and local criteria for a storm play a role. For example, according to the NWS, the amount of snow that triggers a winter storm warning in the Northeast Plains is typically much higher than the amount needed to trigger a winter storm warning in the Southeast.

A winter storm warning means snow, sleet or ice is possible and people should take precautions now.

“The likelihood that a winter storm could produce heavy snow, sleet, or freezing rain and have significant impacts is moderate,” the NWS description says. A winter storm warning means that snow, sleet or ice is expected and people should prepare for the storm. When a winter storm warning is issued, “confidence is high” that a storm “could produce heavy snow, sleet or freezing rain and have significant impacts.”

A winter weather advisory is the lowest level of warnings issued. This means that wintry weather is to be expected and people should exercise caution. A winter weather advisory means “small amounts of winter precipitation or isolated blowing snow could result in slippery conditions and impact travel if precautions are not taken,” NWS said.

Important terms to understand from NWS:

• Freezing rain: Rain that freezes when it hits the ground; This creates a layer of ice on roads, sidewalks, trees and power lines.
• Sleet: Rain turning into ice pellets before reaching the ground. Sleet also causes moisture on roads to freeze and become slippery.
• Wind chill: A measure of how cold people feel due to the combined effects of wind and cold temperatures; The Wind Chill Index is based on the rate of heat loss from exposed skin. Both cold and wind remove heat from the body; The higher the wind speed in cold weather, the faster the body loses heat. Over time, the internal body temperature also drops and hypothermia can occur. Animals also feel the effects of wind chill; However, this is not the case with inanimate objects such as vehicles and buildings. They only cool down to the actual air temperature, but much faster in windy conditions.