BIRMINGHAM, Ala. (AP) - Earlier this week, thousands of people were stranded in schools, cars and offices for a day because they relied on a weather forecast that turned into a spectacular bust. The first official winter storm warning didn’t go out until after snow and freezing rain were falling in the state’s largest metropolitan area.
How could meteorologists get it so wrong?
Predicting the weather is an intricate science, and experts say it’s even more complicated when forecasters are making quick judgments during a rare event that’s developing quickly thousands of feet in the air.
“I have a lot of sympathy for people who were forecasting this in Alabama,” said Jeff Masters, meteorology director with Weather Underground Inc., a commercial forecasting company. “I think the rarity of it plays into it.”
Meteorologists at the National Weather Service office that covers central Alabama couldn’t simply look out the window, see snow and issue a warning. They had to rely on an evaluation of computer models, radar, ground reports and data from weather balloons to realize that what was supposed to be a trace of snow actually was a mix of snow and ice that would cripple an area of more than 1 million people for days.
“There are about six or seven things that have to come together just right in the forecast models,” said state climatologist John Christy of the University of Alabama in Huntsville. “If that doesn’t happen you can’t do it.”
And, in this case, they didn’t. The weather service said it will try to do better next time.
“We are assessing our models and forecasts related to this storm to determine where improvements could be made,” the agency said in a statement.
The weather service predicted snow in Atlanta, and it was right. The city was crippled as motorists jammed on to crowded freeways trying to get home when things began getting bad.
In Birmingham, the weather service didn’t predict much snow and the same kind of traffic nightmare happened.
Forecasters had been saying for days that all the snow accumulation and travel problems would be more than 75 miles south of Birmingham. Only a trace of snow was expected in the metro area, certainly not enough to be anything other than a pretty picture.
So, commuters drove to work from the suburbs to downtown Birmingham as normal, and most schools opened just like every other day. The state sent winter weather equipment south, where the snowfall was supposed to be heaviest and the problems worse.
A statement from the National Weather Service said forecasters realized conditions were changing in central Alabama and issued a public advisory around 9 a.m. CST. Snow began falling around 10 a.m., the weather service said, and a winter storm warning was issued one hour later.
It was too late.
Schools already were releasing students by the time the warning was out, and commuters were flooding back on to roads including Interstate 65, Interstate 20/59 and U.S. 280, where they’d be stuck for up to a day because bridges and overpasses froze within minutes. On side roads and in neighborhoods, conditions deteriorated so quickly that some buses returned to schools with students almost immediately.
With buses unable to run and parents stuck in traffic or at their workplaces, more than 11,000 children spent Tuesday night in schools with thousands of teachers and staff members.
In Hoover, authorities used convoys of fire trucks and police cars following sand-spreading trucks to rescue motorists stranded on Interstate 65.
“They made, basically, a continual sweep on the interstates. We picked up about 200 people and took them to shelters,” said Capt. Jim Coker, a police spokesman.
Forecasters say they missed the forecast because air was colder aloft than anticipated, and a layer of warmer air hovered above the ground, which was already frozen with temperatures in the 20s. Snow and freezing rain turned roads into a sheet of ice almost instantly, leading to the shutdown.
John Knox, a meteorologist at the University of Georgia, said Birmingham received the snow and ice that computer models said would happen around Montgomery.
“That’s why everybody missed it,” he said. “This happens because meteorology is not an exact.”
On Friday, thousands of Alabama school kids were still out of class because school systems throughout central Alabama took the day off because of lingering icy spots on roads. Temperatures rose into the 50s, and Saturday should be nice enough for a trip to the park with sunny skies and temperatures near 60 degrees.
Masters, the Weather Underground expert, said it was “fairly unusual” for the weather service to issue a winter storm warning after snow was already falling, as happened in central Alabama. But overall, he said, the forecast wasn’t off that much - the snow just fell about 70 miles north of where it was expected.
“Seventy miles is nothing in a storm that spans 1,000 miles of atmosphere,” he said.
Copyright © 2021 The Washington Times, LLC.