HUNTSVILLE, Ala. (WHNT) - Many are still cleaning up following severe storms that swept through the Tennessee Valley on Tuesday, July 14. Six tornadoes have since been confirmed, but not a single tornado warning was issued while the storms were happening.
Chris Darden, Meteorologist-in-Charge at the National Weather Service in Huntsville, says the day's events were "unprecedented." That's because tornadoes rarely happen in Alabama in July.
Since record keeping began more than 100 years ago, fewer than two dozen tornadoes have been reported in north Alabama during July. To have six occur in one day is extremely rare. Before this year, the most tornadoes to occur in a single July day was four on July 14, 2004.
When damage surveys confirming tornadoes began coming in following last Tuesday's storms, many people began to feel they either weren't warned adequately -- or at all, if you live in Colbert and Lauderdale counties.
It's important to understand the types of tornadoes that typically happen in July are nowhere near the same kind we deal with in the fall and spring. We've never had a tornado stronger than an EF-1, and the tornadoes that have formed have been short lived. In many cases, the tornadoes only last a few minutes or have damage paths less than a mile long.
It has long been a point of discussion amongst the National Weather Service as to how best handle these types of situations. Do you issue a tornado warning in the same manner you would a violent, long-track tornado? Or do you issue severe thunderstorm warnings and include stronger wording about the possible impacts of the storm? The NWS's warning strategy Tuesday seemed to be the latter.
"These types of really fast-developing, quick-evolving spin-up tornadoes are very difficult to see on radar. I have looked at this radar data six ways of Sunday and I still wouldn't have issued tornado warnings," Darden offered.
Darden explained how many of the tornadoes seemed to develop in an ascending fashion, rather than descending, which is more common. By the time the radar beam finds the circulation off the ground, the tornado may have been on the ground for up to several minutes or already dissipated. Issuing a tornado warning then becomes useless.
The process of getting a warning out to a weather radio, television crawl system or smartphone app only takes about 60 seconds. In the context of a tornado that may only last two minutes, however, that is a considerable amount of time, and if the tornado has already dissipated, why create a false alarm?
In Tuesday's case, issuing severe thunderstorm warnings was absolutely the right call. "Expect considerable tree damage. Damage is likely to mobile homes, roofs and outbuildings," the warning text stated. Darden said the average lead time on severe thunderstorm warnings Tuesday was around 20 minutes, and a severe thunderstorm watch had been issued by the Storm Prediction Center more than two hours before storms formed.
The message here: Pay attention to severe thunderstorm warnings.
Candidly, Darden called the situation in Colbert County "without a doubt, a miss." Neither a severe thunderstorm nor a tornado warning was issued for this particular storm which caused damage in Sheffield and Tuscumbia and went on to produce another tornado in the southeastern part of Colbert County. "Even using our best judgement, we sometimes get it wrong," Darden said.
Most of the damage that occurred during the storms on July 14 was exactly what was called for by each severe thunderstorm warning. So why not leave it at that? Is it really that important to distinguish between 75 mile per hour straight-lined winds and low-end tornado damage? Darden says yes.
WHNT News 19 asked Darden if he thought it sent a mixed message to the public to have such an aggressive strategy to go out after the fact to identify even the smallest, weakest tornadoes, but an overly-cautious approach about issuing warnings.
Darden explained about the importance of having as accurate of a database as possible. Knowing exactly what occurred will allow us go back and study events closely in hopes of gaining more knowledge before the next severe weather episode.
"We're going to be as transparent in an event like this as possible. Whether we get everything right, or whether there were some things that we could've done better; we're not going to sweep it under the rug," Darden said. That means going out and finding tornado damage knowing not a single warning was issued.
Statistics aside, it's about making the warning process better. It's about keeping you as safe as possible. "I got a call last Tuesday night from the senior forecaster that we had lost [someone] in Cullman County [during the storms] and he was almost in tears. When we lose someone, we take it personally," Darden remarked.
And that's true for all of us in this business.