It was a rough night in Moulton last night as a severe thunderstorm caused some major damage in the downtown area. The National Weather Service sent a crew out there and found evidence of wind gusts up to 115 mph. No, that is not a typo! It’s another one of these “downbursts” which are sometimes referred to as “microbursts.” This one covered slightly more area that a typical microburst, so they called it a “macroburst.”

Regardless of what it’s called, the process is the same. A storm dies down, it shoots a bomb of cold, dry air to the ground. When it hits the warm/moist air at the surface, it expands in all directions very quickly, often moving fast enough to cause significant wind damage. The way I like to think of it is like dropping a cube of ice into warm water.. what does it do? it expands in all directions.. a downburst is the same idea except it’s on a much bigger scale.

Downbursts aren’t a rare occurrence in summertime storms due to the fast forming/collapsing nature of them. Already today we’ve had multiple reports of wind damage around the Shoals as a round of early afternoon storms went through. There’s usually a ton of lightning in these guys as well so when they pop up, make sure to take them seriously and get inside. We will

Here is the NWS statement on the Moulton storm:

…PRELIMINARY STORM SURVEY INFORMATION FROM LAWRENCE COUNTY…

A PRELIMINARY STORM SURVEY OF THE DAMAGE INCURRED ACROSS LAWRENCE
COUNTY HAS BEEN COMPLETED BY NATIONAL WEATHER SERVICE AND LOCAL
EMERGENCY MANAGEMENT PERSONNEL. INITIAL FINDINGS ARE AS FOLLOWS:

* EVENT TYPE: MACROBURST
* EVENT DATE: 07/05/12
* EVENT TIME: 932 PM CDT TO 945 PM CDT

* ESTIMATED PEAK WIND: 115.0 MPH (SEE BASIS AT END OF SUMMARY)

* SUMMARY: A SEVERE THUNDERSTORM PRODUCE A SWATH OF WIND DAMAGE
ACROSS MOULTON ON THURSDAY EVENING IN THE FORM OF A MACROBURST OR
LARGE SCALE MICROBURST. THE OVERALL DAMAGE AREA STRETCHED
APPROXIMATELY 4 MILES FROM WEST TO EAST AND 3.3 MILES FROM NORTH TO
SOUTH COVERING THE CITY PROPER. THE MAJORITY OF DAMAGE WAS
IDENTIFIED AS SNAPPED SOFTWOOD AND HARDWOOD TREES ALONG WITH DAMAGE
TO POWER LINES. MANY TREES WERE NOTED DOWN ON HOMES AND BUSINESSES
ACROSS THE CITY. SEVERAL BUSINESSES HAD WINDOWS PARTIALLY BROKEN
OUT. MUCH OF THIS DAMAGE WAS DEEMED TO BE DUE TO WINDS BETWEEN 70
AND 80 MPH.

HOWEVER…AN AERIAL SURVEY OF THE DAMAGE AND SUBSEQUENT FOLLOWUP
GROUND SURVEY FOUND POCKETS OF MORE INTENSE DAMAGE. SPECIFICALLY AN
AREA ALONG HIGHWAY 157 JUST NORTH OF HIGHWAY 24 RECEIVED HEAVY
DAMAGE. THE LAWRENCE COUNTY EXCHANGE BUILDING RECEIVED SIGNIFICANT
ROOF DAMAGE AND THE SURROUNDING GROUNDS HAD DAMAGE TO FENCING AND
LARGE ITEMS PICKED UP AND THROWN SOME DISTANCE. THE ADJACENT
BUILDING AND FARM EQUIPMENT WERE COMPLETELY FLATTENED. ACROSS THE
STREET…THE LAWRENCE FUNERAL HOME HAD ITS ROOF PARTIALLY RIPPED
OFF WITH SIGNIFICANT INTERIOR DAMAGE.

IN TOWN…THE SHIRT FACTORY BUILDING (A FREE STANDING CONCRETE
BUILDING) ALONG COURT STREET HAD THE ROOF COMPLETELY RIPPED OFF
ALONG WITH PARTIAL WALL COLLAPSE. SEVERAL POWER POLES WERE SNAPPED
NEAR THE BASE IN THIS AREA. THE STOREFRONT ACROSS THE STREET HAD
ITS WINDOWS COMPLETELY BLOWN OUT. FURTHER WEST ALONG COURT
STREET…A GAS STATION SUSTAINED ROOF DAMAGE AND ANOTHER BUILDING
HAD ITS GARAGE DESTROYED.

THE HIGH SCHOOL ALSO SUSTAINED SIGNIFICANT DAMAGE WITH THE
GYMNASIUM ROOF COVERING BEING COMPLETELY REMOVED AND OTHER PORTIONS
OF THE SCHOOL HAVING THE WINDOWS BLOWN OUT. SIGNIFICANT WATER
DAMAGE WAS NOTED INSIDE OF THE MAIN CLASSROOMS OF THE SCHOOL.

NOTE: THE FINAL MAXIMUM WIND RATING WAS BASED ON A COMBINATION OF
THE DAMAGE TO POWER POLES AND DAMAGE TO FREE STANDING STRUCTURES IN
THREE SEPARATE LOCATIONS ACROSS THE CITY.

THESE FINDINGS ARE PRELIMINARY AND ARE SUBJECT TO ADJUSTMENT.
PICTURES AND SUMMARY MATERIALS WILL BE MADE AVAILABLE ON OUR WEB PAGE
AT WEATHER.GOV/HUNTSVILLE /ALL LOWER CASE/.

SURVEYED BY: DARDEN

We keep the chance for some strong storms popping up for the next few days, especially during the afternoons.

- Ari Sarsalari