People in the path of the deadly tornado that ripped through Lee County, Alabama, had eight to nine minutes of warning before touchdown, said Holly Allen, a senior forecaster with the National Weather Service in Birmingham.
That is below the national average: Typically, the tornado warning lead time – the time between when a warning is issued and when the tornado hits ground – is about 14 minutes, the weather service has said.
On average in Alabama, there’s about a 15 minute lead time for warnings, according to National Weather Service data.
That's a vast improvement since 1990, when the national lead time was 5 five minutes.
The National Weather Service’s Storm Prediction Center in Norman, Oklahoma, had posted forecasts for higher possible tornado activity in the region on Thursday, three days before the killer twister struck.
Also that day, the weather service in Birmingham issued its first forecast about possible tornadoes on Sunday.
On Saturday afternoon, one day before the twister hit, both the weather service and the prediction center upgraded the risk for severe weather.
Finally, Sunday morning at 11:04 a.m. CST, about three hours before the tornado hit, the weather service issued a tornado watch for south-central Alabama, Allen said. A
watch means conditions are ripe for tornadoes to form.
The specific warning for the deadly tornado was issued at 1:58 p.m. CST. At about 2:06 to 2:07 pm CST, the tornado roared between Marvyn and Beauregard, Alabama, producing EF4 damage and killing dozens of people. EF4 tornadoes have estimated wind speeds of 166 to 200 mph.
University of Georgia meteorology professor Marshall Shepherd praised the warnings from the weather service and its prediction center, saying they “were all over it in the days and hours before the storms.”
As for tornado sirens in Lee County, reports were conflicting on whether they sounded. More information about the sirens were expected in the days ahead.
Contributing: Marty Roney, Montgomery Advertiser; The Associated Press
This article originally appeared on USA TODAY: People in path of deadly, 170 mph Alabama tornado had about 9 minutes warning