Alabama severe weather: What is a PDS tornado watch?
All of Alabama faces the risk of seeing severe weather today, according to the National Weather Service.
NOAA’s Storm Prediction Center has placed a Level 5 out of 5 risk for severe weather across a large part of the state, which means numerous severe storms are expected.
Here is the latest severe weather outlook for Alabama:
Alabama has a rare Level 5 out of 5 risk for severe weather today. Severe storms moved through north Alabama this morning. A more significant round of storms is expected starting this afternoon. Tornadoes, some of them strong ones, damaging winds and large hail will all be possible through early Sunday morning. Areas in pink have a Level 5 out of 5 severe weather risk this afternoon. The rest of the state has a Level 4 risk. The latest forecast update has stayed relatively the same.Storm Prediction Center
Severe storms are expected to track across Alabama this afternoon and tonight, according to forecasters.
NOAA’s Storm Prediction Center has issued a tornado watch for part of the state, and more parts of Alabama will likely be put under tornado watches before the night is over.
The current watch is what’s called a PDS tornado watch. PDS stands for “particularly dangerous situation.”
It will be in effect until 8 p.m. Saturday.
The Storm Prediction Center said “the severe threat will increase through the afternoon, including the potential for multiple intense, destructive tornadoes.”
The Alabama counties in the watch are: Autauga, Bibb, Blount, Butler, Calhoun, Chilton, Choctaw, Clarke, Colbert, Conecuh, Coosa, Cullman, Dallas, DeKalb, Elmore, Etowah, Fayette, Franklin, Greene, Hale, Jackson, Jefferson, Lamar, Lauderdale, Lawrence, Limestone, Lowndes, Madison, Marengo, Marion, Marshall, Monroe, Montgomery, Morgan, Perry, Pickens, Shelby, St. Clair, Sumter, Talladega, Tuscaloosa, Walker, Washington, Wilcox and Winston.
A PDS watch isn’t used often and makes weather watchers take notice because it signifies a greater risk for strong or violent tornadoes.
In today’s watch it’s written in red across the top of the watch:
“THIS IS A PARTICULARLY DANGEROUS SITUATION”
All tornado and severe thunderstorm watches are issued by the Storm Prediction Center, which is in Norman, Okla.
Your local National Weather Service office issues tornado warnings, however.
According to the Storm Prediction Center a PDS watch is issued when “the forecaster has high confidence that multiple strong (EF-2 or EF-3 on the Enhanced Fujita Scale) or violent tornadoes (EF-4 and EF-5) will occur in the watch area.”
See also:
According to a study from the SPC most deaths and damage from tornadoes are caused by EF-2 to EF-5 tornadoes, even though they make up less than 10 percent of all tornadoes reported.
That was the motivation for creating a PDS watch, to highlight the “unusually high threat,” according to the SPC.
PDS watches are rarely issued. According to the SPC of the 3,058 tornado watches issued from 1996-2005, only 7 percent were PDS watches.
Alabama’s PDS tornado watch is the second PDS watch of the day. Parts of Mississippi and Louisiana were put under a PDS watch earlier on Saturday.