A slow moving cold front aided the development of isolated severe thunderstorms during the afternoon hours over southeast Louisiana.
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 LIX wrote it up.
A slow moving cold front aided the development of isolated severe thunderstorms during the afternoon hours over southeast Louisiana.
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 New Orleans, LA wrote its last area forecast discussion before the first event at Sep 22, 11:23 AM CST, 3 hours 47 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 1223 PM CDT THU SEP 22 2011 .AVIATION... SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO SPREAD ACROSS THE AREA THIS AFTERNOON AHEAD OF AN APPROACHING COLD FRONT. CHANCES OF RAIN ARE BETTER ACROSS THE SOUTHERN PORTION OF THE AREA...AND TEMPO GROUPS FOR THUNDER HAVE BEEN INCLUDED IN THESE AREAS. OTHERWISE...WILL HANDLE ANY ADDITIONAL THREATS WITH SHORT TERM AMENDMENTS. THE FRONT SHOULD COME THROUGH LATE TONIGHT OR DURING THE EARLY MORNING HOURS WITH A WIND SHIFT TO THE NORTH EXPECTED BY 15Z. && .PREV DISCUSSION... /ISSUED 943 AM CDT THU SEP 22 2011/ UPDATE... UPDATED THE GRIDS TO DELAY THE ONSET OF THE MORE NUMEROUS SHOWERS AND THUNDERSTORMS TODAY. ALSO LOWERED THE POP TODAY OVER PORTIONS OF THE CENTRAL AND ESPECIALLY NORTHWESTERN AREAS WHICH ARE FARTHEST FROM THE BEST LOW LEVEL CONVERGENCE AND MORE STABLE. REMAINDER OF THE FORECAST LOOKS ON TRACK FOR NOW. PREV DISCUSSION... /ISSUED 859 AM CDT THU SEP 22 2011/ SOUNDING DISCUSSION... A FAIRLY MOIST AND VERY UNSTABLE SOUNDING THIS MORNING WITH A PW OF 1.74 INCHES AND AN LI OF -6.8. A SHALLOW INVERSION FROM THE SURFACE UP TO AROUND 800 FEET WITH TEMPERATURES RANGING FROM AROUND 70 TO THE MIDDLE 70S THROUGHOUT THAT LEVEL. DEWPOINT DEPRESSIONS AROUND ZERO DEGREES BELOW THE INVERSION CREATING ANOTHER MORNING OF ISOLATED PATCHY DENSE FOG. A LARGE AREA OF DRY AIR REMAINS IN PLACE ABOVE 630 MILLIBARS. A LIGHT EASTERLY FLOW IN PLACE BELOW 850 MB WITH A PREDOMINATE SOUTHWESTERLY FLOW IN PLACE ALOFT. PREV DISCUSSION... /ISSUED 348 AM CDT THU SEP 22 2011/ SHORT TERM... TWO BOUNDARIES TO SPEAK OF WITH RESPONSIBILITY FOR OUR WEATHER. THE FIRST IS OVER THE GULF VERY CLOSE TO US. THIS IS A WEAK INVERTED TROUGH. THE NEXT IS A COLD FRONT CURRENTLY MOVING THROUGH THE PLAINS JUST ENTERING TEXAS AND STRETCHING BACK INTO TENNESSEE. THIS FRONT WILL MOVE INTO THE AREA BY FRIDAY. BOTH OF THESE BOUNDARIES WILL REACT WITH EACH OTHER PRODUCING ENOUGH SUBSIDENCE BETWEEN THEM TO RENDER A MESOHIGH. THE SUBSIDENCE WILL BE STRONG ENOUGH TO PUT A CAP OVER ALMOST ALL SH/TS ACTIVITY FOR FRIDAY. SHOULD STILL SEE A SHOWER OR TWO POP UP. NORTHERLY WINDS WILL NOT LAST LONG AS THE UPPER LOW OVER THE GREAT LAKES GETS CUT OFF AND SINKS SOUTHWARD AS ANOTHER FRONT MOVES AS FAR SOUTH AS CENTRAL MISSISSIPPI BY MONDAY. THIS IS WHERE CONFIDENCE TAKES A NOSE DIVE. A SFC LOW WILL DEVELOP ON THE STALLED FRONT BACK IN TEXAS. THE LOW SHOULD MOVE ALONG THE BOUNDARY TO THE NE UNLESS SFC FRONTOGENESIS OCCURS OVER TEXAS. IF THE RESULT IS A SYSTEM CUT OFF FROM THE MAIN FLOW OVER TEXAS...THEN WE SET UP FOR A WET PERIOD. MARINE... EAST TO SOUTHEAST WINDS WILL PERSIST OVER THE COASTAL WATERS THROUGH THURSDAY. LOOKING AT CURRENT OBS...WINDS WILL BE CLOSE TO THE EXERCISE CAUTION CRITERIA. DUE TO MARGINAL CONDITIONS...WILL HOLD OFF ON HEADLINE FOR NOT. THE NEXT COLD FRONT SHOULD MOVE INTO THE COASTAL WATERS BY FRIDAY...BRINGING NORTH WINDS ALONG WITH SOMEWHAT DRIER AIR. SOUTHERLY WINDS BRING BACK THE MOISTURE BY SUNDAY THROUGH MONDAY. A REINFORCING SURGE BEHIND ANOTHER COLD FRONT WILL MOVE IN TUESDAY BRINGING MUCH DRIER AIR WITH IT AND STRONGER WIND SPEEDS. && .PRELIMINARY POINT TEMPS/POPS... MCB 87 66 85 58 / 30 20 20 10 BTR 89 69 87 62 / 30 20 20 10 ASD 88 69 87 63 / 50 30 20 10 MSY 88 73 87 70 / 50 30 30 10 GPT 87 70 87 65 / 60 40 30 10 PQL 88 69 87 65 / 70 50 30 10 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && AVIATION...95/DM UPDATE...22/TD SOUNDING...GP MARINE...MEFFER REST OF DISCUSSION...17
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE NEW ORLEANS LA 1103 AM CDT THU SEP 22 2011 GMZ530-532-534-536-538-550-552-555-557-570-572-575-577-LAZ034>037- 039-040-046>050-056>072-MSZ068>071-077-080>082-231615- LAKE PONTCHARTRAIN AND LAKE MAUREPAS-MISSISSIPPI SOUND- LAKE BORGNE-CHANDELEUR SOUND-BRETON SOUND- COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER OUT 20 NM- COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM- COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM- COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM- COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA RIVER FROM 20 TO 60 NM- COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO 60 NM- COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM- COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM-POINTE COUPEE-WEST FELICIANA-EAST FELICIANA-ST. HELENA- WASHINGTON-ST. TAMMANY-IBERVILLE-WEST BATON ROUGE- EAST BATON ROUGE-ASCENSION-LIVINGSTON-ASSUMPTION-ST. JAMES- ST. JOHN THE BAPTIST-UPPER LAFOURCHE-ST. CHARLES-UPPER JEFFERSON- ORLEANS-UPPER PLAQUEMINES-UPPER ST. BERNARD-UPPER TERREBONNE- LOWER TERREBONNE-LOWER LAFOURCHE-LOWER JEFFERSON- LOWER PLAQUEMINES-LOWER ST. BERNARD-NORTHERN TANGIPAHOA- SOUTHERN TANGIPAHOA-WILKINSON-AMITE-PIKE-WALTHALL-PEARL RIVER- HANCOCK-HARRISON-JACKSON- 1103 AM CDT THU SEP 22 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS SOUTHEAST LOUISIANA...SOUTH MISSISSIPPI AND THE ADJACENT COASTAL WATERS. .DAY ONE...THIS AFTERNOON AND TONIGHT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS AFTERNOON. SOME OF THE THUNDERSTORMS MAY BECOME STRONG WITH GUSTY WINDS AND FREQUENT LIGHTNING. BRIEF PERIODS OF HEAVY RAINFALL MAY ALSO LEAD TO NUISANCE FLOODING IN ISOLATED LOW LYING AND URBAN AREAS. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY NO HAZARDOUS WEATHER IS EXPECTED. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED. 22/TD
LAZ060-061-063-221845- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE NEW ORLEANS LA 111 PM CDT THU SEP 22 2011 ...FUNNEL CLOUDS POSSIBLE WITH THUNDERSTORM MOVING NORTHWEST AFFECTING ST. CHARLES PARISH...UPPER JEFFERSON PARISH...UPPER PLAQUEMINES PARISH... AT 105 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A THUNDERSTORM CAPABLE OF PRODUCING SHORT LIVED FUNNEL CLOUDS 9 MILES SOUTH OF MARRERO...OR NEAR JEAN LAFITTE... MOVING NORTHWEST AT 5 MPH. THE THUNDERSTORM WILL AFFECT AREAS IN AND AROUND...WESTWEGO... MARRERO...HARVEY AND AVONDALE. THIS THUNDERSTORM HAS ALREADY PRODUCED ONE FUNNEL CLOUD AND IS CAPABLE OF PRODUCING MORE. THESE FUNNEL CLOUDS ARE NOT EXPECTED TO REACH THE GROUND...BUT NATIONAL WEATHER SERVICE METEOROLOGISTS WILL BE MONITORING THE STORM CLOSELY FOR STRENGTHENING. IF YOU SEE A FUNNEL CLOUD...PLEASE REPORT IT TO THE NATIONAL WEATHER SERVICE OR YOUR LOCAL LAW ENFORCEMENT AGENCY. BE PREPARED TO TAKE QUICK ACTION IF A WARNING IS ISSUED. STAY TUNED TO NOAA WEATHER RADIO OR YOUR FAVORITE LOCAL MEDIA OUTLETS FOR FURTHER DETAILS OR UPDATES FROM THE NATIONAL WEATHER SERVICE. 95/DM
LAZ061-062-221945- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE NEW ORLEANS LA 157 PM CDT THU SEP 22 2011 ...CLUSTER OF STRONG THUNDERSTORMS MOVING NORTHWEST AFFECTING UPPER JEFFERSON PARISH...ORLEANS PARISH... AT 156 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A CLUSTER OF STRONG THUNDERSTORMS NEAR AVONDALE AND BRIDGE CITY...MOVING NORTHWEST AT 5 MPH. THE CLUSTER OF STRONG THUNDERSTORMS WILL AFFECT AREAS IN AND AROUND...HARAHAN...WAGGAMAN...METAIRIE...KENNER AND NEW ORLEANS ARMSTRONG AIRPORT THE PRIMARY THREATS FROM THESE STORMS ARE FREQUENT LIGHTNING AND WIND GUSTS 30 TO 40 MPH...WHICH COULD DOWN TREE LIMBS AND BLOW AROUND UNSECURED SMALL OBJECTS. SEEK SHELTER IN A SAFE HOME OR BUILDING UNTIL THESE STORMS HAVE PASSED. THESE STORMS COULD PRODUCE RAINFALL AMOUNTS OF ONE TO TWO INCHES IN A SHORT PERIOD OF TIME...RESULTING IN PONDING OF WATER AROUND LOW LYING ROADWAYS. REMEMBER...DO NOT DRIVE YOUR VEHICLE INTO WATER COVERED ROADWAYS. THE DEPTH MAY BE TOO GREAT TO ALLOW A SAFE CROSSING. 22/TD
LAZ060-222030- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE NEW ORLEANS LA 232 PM CDT THU SEP 22 2011 ...STRONG THUNDERSTORM MOVING NORTHWEST AFFECTING ST. CHARLES PARISH... AT 228 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A STRONG THUNDERSTORM NEAR KENNER...OR ABOUT 5 MILES EAST OF DESTREHAN...MOVING NORTHWEST AT 5 MPH. THE STRONG THUNDERSTORM WILL AFFECT AREAS IN AND AROUND...NORCO...NEW SARPY...HAHNVILLE...DESTREHAN AND BOUTTE THE PRIMARY THREATS FROM THIS STORM ARE FREQUENT LIGHTNING AND WIND GUSTS 35 TO 45 MPH...WHICH COULD DOWN TREE LIMBS AND BLOW AROUND UNSECURED SMALL OBJECTS. SEEK SHELTER IN A SAFE HOME OR BUILDING UNTIL THIS STORM HAS PASSED. THIS STORM COULD PRODUCE RAINFALL AMOUNTS OF ONE TO TWO INCHES IN A SHORT PERIOD OF TIME...RESULTING IN PONDING OF WATER AROUND LOW LYING ROADWAYS. REMEMBER...DO NOT DRIVE YOUR VEHICLE INTO WATER COVERED ROADWAYS. THE DEPTH MAY BE TOO GREAT TO ALLOW A SAFE CROSSING. FREQUENT LIGHTNING IS OCCURRING WITH THIS STORM. IF OUTDOORS...STAY AWAY FROM ISOLATED HIGH OBJECTS SUCH AS TREES. MOVE INDOORS IF POSSIBLE. WHEN INDOORS...STAY AWAY FROM WINDOWS AND DOORS AND AVOID USING TELEPHONES UNLESS IT IS AN EMERGENCY. 95/DM
LAZ056-057-222045- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE NEW ORLEANS LA 302 PM CDT THU SEP 22 2011 ...THUNDERSTORMS PRODUCING HEAVY RAIN NEARLY STATIONARY AFFECTING ST. JAMES PARISH...ASSUMPTION PARISH... AT 256 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A CLUSTER OF THUNDERSTORMS OVER ST. JAMES AND ASSUMPTION PARISHES. THESE THUNDERSTORMS ARE NEARLY STATIONARY. THE PRIMARY THREATS FROM THESE STORMS ARE FREQUENT LIGHTNING...AND LOCALLY HEAVY RAINFALL. THESE STORMS COULD PRODUCE RAINFALL AMOUNTS OF ONE TO TWO INCHES IN A SHORT PERIOD OF TIME...RESULTING IN PONDING OF WATER AROUND LOW LYING ROADWAYS. REMEMBER...DO NOT DRIVE YOUR VEHICLE INTO WATER COVERED ROADWAYS. THE DEPTH MAY BE TOO GREAT TO ALLOW A SAFE CROSSING. FREQUENT LIGHTNING IS ALSO OCCURRING WITH THESE STORMS. IF OUTDOORS...STAY AWAY FROM ISOLATED HIGH OBJECTS SUCH AS TREES. MOVE INDOORS IF POSSIBLE. WHEN INDOORS...STAY AWAY FROM WINDOWS AND DOORS AND AVOID USING TELEPHONES UNLESS IT IS AN EMERGENCY. 95/DM
MSZ081-082-222130- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE NEW ORLEANS LA 341 PM CDT THU SEP 22 2011 ...CLUSTER OF STRONG THUNDERSTORMS MOVING NORTHWEST AFFECTING JACKSON COUNTY...HARRISON COUNTY... AT 337 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A CLUSTER OF STRONG THUNDERSTORMS 7 MILES NORTH OF ST. MARTIN...MOVING NORTHWEST AT 10 MPH. THE CLUSTER OF STRONG THUNDERSTORMS WILL AFFECT AREAS IN AND AROUND...BILOXI...D IBERVILLE...AND ST. MARTIN. THE PRIMARY THREATS FROM THESE STORMS ARE FREQUENT LIGHTNING AND WIND GUSTS 35 TO 45 MPH...WHICH COULD DOWN TREE LIMBS AND BLOW AROUND UNSECURED SMALL OBJECTS. SEEK SHELTER IN A SAFE HOME OR BUILDING UNTIL THESE STORMS HAVE PASSED. THESE STORMS COULD PRODUCE RAINFALL AMOUNTS OF ONE TO TWO INCHES IN A SHORT PERIOD OF TIME...RESULTING IN PONDING OF WATER AROUND LOW LYING ROADWAYS. REMEMBER...DO NOT DRIVE YOUR VEHICLE INTO WATER COVERED ROADWAYS. THE DEPTH MAY BE TOO GREAT TO ALLOW A SAFE CROSSING. SHORT LIVED FUNNEL CLOUDS MAY ALSO ACCOMPANY THESE STORMS. THESE FUNNEL CLOUDS ARE NOT EXPECTED TO REACH THE GROUND. NATIONAL WEATHER SERVICE METEOROLOGISTS ARE MONITORING THE STORM CLOSELY FOR ANY INCREASED THREAT. BE PREPARED TO TAKE ACTION IF A WARNING IS ISSUED FOR YOUR AREA. 95/DM
LAZ046-049-056-057-222145- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE NEW ORLEANS LA 352 PM CDT THU SEP 22 2011 ...CLUSTER OF STRONG THUNDERSTORMS MOVING NORTH AFFECTING ST. JAMES PARISH...ASCENSION PARISH...ASSUMPTION PARISH...IBERVILLE PARISH... AT 351 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A CLUSTER OF STRONG THUNDERSTORMS NEAR GONZALES...OR ABOUT 5 MILES SOUTHWEST OF SORRENTO...MOVING NORTH AT 15 MPH. THE CLUSTER OF STRONG THUNDERSTORMS WILL AFFECT AREAS IN AND AROUND...SORRENTO...GONZALES...WHITE CASTLE...GEISMER...CARVILLE AND PRAIRIEVILLE THE PRIMARY THREATS FROM THESE STORMS ARE FREQUENT LIGHTNING AND WIND GUSTS 35 TO 45 MPH...WHICH COULD DOWN TREE LIMBS AND BLOW AROUND UNSECURED SMALL OBJECTS. SEEK SHELTER IN A SAFE HOME OR BUILDING UNTIL THESE STORMS HAVE PASSED. THESE STORMS COULD PRODUCE RAINFALL AMOUNTS OF ONE TO TWO INCHES IN A SHORT PERIOD OF TIME...RESULTING IN PONDING OF WATER AROUND LOW LYING ROADWAYS. REMEMBER...DO NOT DRIVE YOUR VEHICLE INTO WATER COVERED ROADWAYS. THE DEPTH MAY BE TOO GREAT TO ALLOW A SAFE CROSSING. 95/DM
The national radar mosaic for the moment the first event began.
3 thunderstorm wind, 2 hail, 1 lightning. Local standard time, as filed.
Lightning sparked a fire that caused an estimated $1 milliion in damage to the Gator Stop Super Truck Stop and Casino.
Golfball size hail was reported south of Denham Springs.
A tree was blown down across U.S. Highway 190 between Juban Road and Eden Church Road.
A tree was blown down on a house on Dabney Drive.
Quarter size hail was reported in Walker.
A tree was blown down on a house on Burgess Avenue.
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: 335783, 335785, 335789, 335792, 335786, 335793.