UPDATED 6:52 a.m. 3/25/2021 - Updated with weather information Thursday morning about weather, as Walker County has now been placed at high risk early this morning.
The National Weather Service in Birmingham is forecasting a high risk that severe storms and possibly tornadoes are likely Thursday in an eerie repeat of the line of tornadoes that came through Alabama on March 17. The treat timing in the eastern half of the county also starts at 11 a.m. today.
The county will also be under a wind advisory starting at 11 a.m., with winds possibly gusting up to 40 mph.
The Walker County area was upgraded to a more severe potential threat Thursday morning. The National Weather Service termed it as a significant severe weather event. Most of Walker County except the eastern edge of the county was placed at high risk. That end of the county is at moderate risk, but forecasters had been concerrned about that as well Wednesday when the entire area was placed in that range.
"It’s shaping up to be a very active day, please be weather wise. We will continue to post updates," Walker County E911 posted on Facebook Wednesday morning.
In addition, minor flooding is expected along portions of the Tombigbee and Black Warrior River Basins this weekend and into early next week. The rainfall potential for the top two-thirds of Walker County through Friday at 7 p.m. is projected at between 2 to 3 inches of rain.
Television forecasters in Birmingham were taking the air once again this week to warn residents to be aware of the potential of tornadoes on Thursday afternoon into that evening, urging people to decide now on a shelter location and to secure helmets in case damage comes on top of them.
According to a graphic the National Weather Service posted online Thursday at 5 a.m., Walker County and some of the surrounding area was placed at a high risk. That means the potential of strong tornadoes, damaging winds of up to 80 mph and golf ball size hail. The updated time of the impact for the northwest half of Walker County is expected to be between 11 a.m. and 8 p.m. Thursday, although the other half could see a threat until 11 p.m.
The forecast for Jasper on Thursday, given includes showers and possibly a thunderstorm before 4 p.m., then showers and thunderstorms after 4 p.m. and continuing to about 1 a.m. Some of the storms could be severe. The high will be near 75. The chance of precipitation is 100 percent. New rainfall amounts between 1 and 2 inches are possible.
The low will be 53, while rain chances will be 80 percent that night.
Gerald Satterwhite, a meteorologist with the National Weather Service in Birmingham, said Wednesday afternoon, said for Walker County and surrounding locations, a warm front will move through the state Thursday morning.
"That is going to bring an initial round of showers and some storms, and there may be enough instability and windshear together to produce a couple of strong, maybe marginally severe storms in the Walker County area," he said.
As the warm front moves north, that action will build more unstable air Central and South Alabama and Mississippi to go north. Increasing windshear will move in as well, he said.
"We expect another round of storms to develop in the afternoon and will be moving up toward the northeast, and it is the afternoon to early evening timeframe that we're concerned about, especially over there in Walker County for severe storms with large hail, damaging straight line wind and tornadoes," Satterwhite said. "With the amount of instability and windshear that we are expecting, there could be a couple of strong, long term tornadoes involved as well."
He said, "The windshear and instability is a little bit stronger than the one we had last week. There are other caveats that can interrupt the magnitude of the event. If we have too many storms that develop all at once, they kind of compete with each other. With the parameters we are seeing in place and if that doesn't happen, then we would definitely end up with multiple long-track super cell (events). It would be an event with damaging wind, large hail and potentially strong long-track tornadoes as well."
As for that night, a line of storms is expected to sweep through. "We don't expect it to be a very long duration. It is going to be a pretty progressive system," he said.
He urged the public to take precautions, which would include helmets. He said it could be a motorcycle, football, baseball or even bicycle helmet, although the last one would basically protect the top of the head. A motorcycle helmet would come down the side.
"Anything you can do to protect your head and neck area" is advised, and he said a heavy blanket or a mattress could also help.
He suggested people have a plan in place to shelter when a warning is issued. Anyone living in a vulnerable location like a mobile home, one may one to go to a sturdier building, including a storm shelter or a neighbor's house. They should have multiple ways to receive information, such as by weather radio, regular radio, weather apps and television.
While few changes were in place for Wednesday afternoon, he said there was some potential that some areas of East Mississippi and Northwest Alabama could be upgraded to the highest risk area in an update expected about 1 a.m. Thursday.