Scattered severe thunderstorms developed over Southeast Oklahoma, Southwest Arkansas, and extreme Northwest Louisiana during the late afternoon and evening of the 18th. These storms developed in a very warm, moist, and unstable atmosphere, near a weak inverted surface trough that extended southeast across the area.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS SHV wrote it up.
Scattered severe thunderstorms developed over Southeast Oklahoma, Southwest Arkansas, and extreme Northwest Louisiana during the late afternoon and evening of the 18th. These storms developed in a very warm, moist, and unstable atmosphere, near a weak inverted surface trough that extended southeast across the area. Large hail and isolated instances of damaging winds were reported from these storms initially, before a wider area of severe thunderstorms developed later in the evening across extreme Northeast Texas, ahead of a large trough of low pressure digging south into the Southern Plains. These storms rapidly surged southeast across the remainder of East Texas, Northwest Louisiana, and extreme Southwest Arkansas during the evening, resulting in numerous reports of wind damage. They weakened shortly before midnight on the 19th, due to the much more stable atmospheric environment in place.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Shreveport, LA wrote its last area forecast discussion before the first event at Sep 18, 4:17 AM CST, 6 hours 3 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SHREVEPORT LA 517 AM CDT SUN SEP 18 2011 .DISCUSSION... THE FOUR STATE REGION WILL BE IN FOR A TREAT OVER THE REMAINDER OF THE WEEKEND AND INTO THE FIRST OF THE UPCOMING WORK WEEK. THE COMBINATION OF INCOMING GULF MOISTURE OVER RIDING A SURFACE BOUNDARY OVER EAST TEXAS AND SOUTHEAST OKLAHOMA...ALONG WITH THE ARRIVAL OF SMALL SCALE DISTURBANCES MOVING OVER THE AREA...AND THE APPROACH OF LARGER SCALE DISTURBANCES ASSOCIATED WITH A TROUGH MOVING ACROSS THE PLAINS. SHOWERS AND ISOLATED THUNDERSTORMS SPREADING OVER THE REGION THIS MORNING WILL BE FOLLOWED LATER DURING THE DAY BY ANOTHER ROUND OF ACTIVITY DURING THE AFTERNOON AND OVERNIGHT. ANOTHER SHORTWAVE TROUGH WILL PHASE WITH THE ONE MOVING THROUGH DURING THE NIGHT AND ON MONDAY...THAT WILL ALLOW A COLD FRONT TO MOVE INTO THE FOUR STATE REGION MONDAY...WITH SHOWERS AND THUNDERSTORMS CONTINUING INTO THE DAY BEFORE ENDING FROM NORTHWEST TO SOUTHEAST. THE COLD FRONT WILL BECOME NEARLY STATIONARY ACROSS THE SOUTHEAST SECTIONS OF THE FORECAST AREA AS THE MAIN ENERGY WITH THE UPPER TROUGH MOVES ON TO THE EAST. RAIN CHANCES WILL LINGER OVER THE SOUTHEAST THROUGH MID WEEK UNTIL THE NEXT TROUGH DROPS SOUTH ACROSS THE CENTRAL SECTIONS OF THE COUNTRY SENDING ANOTHER COLD FRONT WITH ADDITIONAL SHOWERS AND THUNDERSTORMS. TEMPERATURES BEHIND THIS FRONT WILL PROVIDE THE AREA WITH MUCH COOLER OVERNIGHT AND DAYTIME TEMPERATURES INTO THE LATE WEEK AND INTO THE WEEKEND...WHICH SHOULD REMAIN DRY UNDER HIGH PRESSURE AND A NORTHWEST FLOW PATTERN ALOFT. /06/ && .AVIATION... UNSETTLED WEATHER EXPECTED FOR MUCH OF THE 12Z TAF PERIOD. ONGOING CONVECTION ACROSS CNTRL OK HAS MOVED INTO PORTIONS OF SE OK/NE TX/SW AR. FARTHER SOUTH...WIDESPREAD SHWRS AND A FEW TSTMS ARE DEVELOPING ALONG AND SOUTH OF I-20 ALONG A STATIONARY FRONT. LLJ AROUND 25-30 KTS IS STREAMING MOISTURE NORTHWARD AND PROVIDING ADDITIONAL LIFT. UPPER LEVEL TROUGH IS JUST EMERGING ONTO THE HIGH PLAINS AND IS MAKING SLOW PROGRESSION EWD. ASSOCIATED COLD FRONT NOT EXPECTED TO REACH THE AREA UNTIL NEAR THE END OF THE 12Z TAF PERIOD WHICH SHOULD BRING ANOTHER ROUND OF PRECIP DURING THE OVERNIGHT AND EARLY MORNING HOURS OF MONDAY. S/SW WINDS AROUND 12 KTS OR LESS ARE EXPECTED TO PREVAIL. VFR CONDITIONS ARE ALSO EXPECTED WITH PERIODIC REDUCTIONS TO MVFR OR LOWER CIGS/VSBYS DUE TO CONVECTION. /09/ && .PRELIMINARY POINT TEMPS/POPS... SHV 88 69 86 65 87 / 70 70 50 20 10 MLU 87 68 87 66 87 / 60 70 60 40 30 DEQ 84 66 84 57 86 / 70 70 40 10 0 TXK 85 67 86 61 84 / 70 70 40 10 0 ELD 87 67 86 64 84 / 70 70 60 30 20 TYR 88 69 87 66 86 / 60 70 40 10 0 GGG 88 69 86 65 86 / 60 70 40 10 0 LFK 89 70 87 67 88 / 60 70 50 30 20 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...NONE. LA...NONE. OK...NONE. TX...NONE. && 06/09
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SHREVEPORT LA 600 AM CDT SUN SEP 18 2011 ARZ050-051-059>061-070>073-LAZ001>006-010>014-017>022-OKZ077-TXZ096- 097-108>112-124>126-136>138-149>153-165>167-181700- ANGELINA-BIENVILLE-BOSSIER-BOWIE-CADDO-CALDWELL-CAMP-CASS-CHEROKEE- CLAIBORNE-COLUMBIA-DE SOTO-FRANKLIN-GRANT-GREGG-HARRISON-HEMPSTEAD- HOWARD-JACKSON-LA SALLE-LAFAYETTE-LINCOLN-LITTLE RIVER-MARION- MCCURTAIN-MILLER-MORRIS-NACOGDOCHES-NATCHITOCHES-NEVADA-OUACHITA- PANOLA-RED RIVER LA-RED RIVER TX-RUSK-SABINE LA-SABINE TX- SAN AUGUSTINE-SEVIER-SHELBY-SMITH-TITUS-UNION AR-UNION LA-UPSHUR- WEBSTER-WINN-WOOD- 600 AM CDT SUN SEP 18 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST AND SOUTH CENTRAL ARKANSAS...NORTHWEST AND NORTH CENTRAL LOUISIANA... SOUTHEAST OKLAHOMA...AND EAST AND NORTHEAST TEXAS. .DAY ONE...TODAY AND TONIGHT... SHOWERS AND ISOLATED THUNDERSTORMS WILL OCCUR ACROSS THE AREA TODAY AND OVERNIGHT DUE TO AN INCREASE IN GULF MOISTURE ALONG WITH THE COMBINATION OF UPPER DISTURBANCES SPREADING OVERHEAD... AND ACROSS A NEARLY STATIONARY FRONT...THAT WILL LIFT NORTHEAST... AND THE APPROACH OF AN UPPER TROUGH LATE TONIGHT. LIGHTNING AND GUSTY WINDS WITH STORMS WILL BE MAIN CONCERNS TODAY...WITH INCREASING AMOUNTS OF RAINFALL OVERNIGHT. RAINFALL AMOUNTS OF UP TO ONE INCH CAN OCCUR TONIGHT. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY... SHOWERS AND THUNDERSTORMS WILL CONTINUE OVER THE AREA ON MONDAY AND START TO TAPER OFF FROM WEST TO EAST THROUGH MONDAY NIGHT INTO TUESDAY. BY WEDNESDAY THE RAIN CHANCES INCREASE...ESPECIALLY WEDNESDAY NIGHT INTO THURSDAY...AS ANOTHER UPPER TROUGH APPROACHES FROM THE NORTHWEST AND SENDS A STRONGER COLD FRONT ACROSS THE REGION. MUCH COOLER TEMPERATURES ARRIVE IN WAKE OF THE LATE WEEK FRONT WITH DRY WEATHER EXPECTED INTO THE WEEKEND. LIGHTNING ALONG WITH GUSTY WINDS AND BRIEF HEAVY RAINFALL POSSIBLE. RAINFALL AMOUNTS OF ONE HALF TO ONE INCH CAN OCCUR. .SPOTTER INFORMATION STATEMENT... THE ACTIVATION OF HAM RADIO OPERATORS...STORM SPOTTERS...OR EMERGENCY MANAGEMENT PERSONNEL WILL NOT BE NEEDED TODAY OR TONIGHT. 06
The Shreveport radar (KSHV), 32 km away, was scanning. The volume nearest the first event began at 16:19 UTC.
5 thunderstorm wind. Local standard time, as filed.
A large tree was blown down on Bellview Road at Autumn Wood Circle.
Two trees were downed on Old Mooringsport Road and Eds Blvd.
A tree was downed on Hwy. 2 near Millers Bluff in Plain Dealing, Louisiana.
A large tree was downed on Bellview Road at Autumn Wood Circle.
A tree was downed on Sandage Road and Pine Cove Street.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Louisiana in 2011Every state in 2011This day in weather historyWarnings in Louisiana, September 2011
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 338984, 338985, 339033, 339036, 339035.