Isolated strong to severe thunderstorms developed in an unstable atmosphere.
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.
Isolated strong to severe thunderstorms developed in an unstable atmosphere.
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 Jul 9, 7:14 AM CST, 1 hour 20 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 814 AM CDT THU JUL 9 2009 .UPDATE... ...SOUNDING DISCUSSION... NO PROBLEMS WITH THE FLIGHT THIS MORNING. A VERY STRONG INVERSION IS PRESENT FROM THE SURFACE UP TO 300 FEET. MOISTURE IS CONTINUING TO DECREASE...HOWEVER WITH A PW STILL AT 1.52 INCHES AND A VERY UNSTABLE ATMOSPHERE...HAVING AN LI OF -8.5...THERE WILL LIKELY BE MORE SHOWERS AND THUNDERSTORMS POP UP TODAY AS DAYTIME HEATING OCCURS. && .PREV DISCUSSION... /ISSUED 327 AM CDT THU JUL 9 2009/ SYNOPSIS... SIGNIFICANTLY LESS CONVECTION TONIGHT COMPARED TO LAST NIGHT. ONLY A FEW ISOLATED SHOWERS AND THUNDERSTORMS ARE EVIDENT ON THE RADAR SCOPE...AND THEY/RE LIMITED TO THE OFFSHORE WATERS OF THE GULF OF MEXICO. TEMPS ARE SLIGHTLY WARMER THAN LAST NIGHT WITH MOST PLACES CURRENTLY STILL SITTING IN THE UPPER 70S. MAIN EXCEPTION IS THE FAR NORTHERN ZONES WHERE TEMPS ARE CURRENTLY IN THE MID 70S. DEWPOITNS ARE STILL IN THE LOW TO MID 70S ACROSS THE REGION. DISCUSSION... LITTLE HAS CHANGED IN THE FORECAST THINKING. THE MID LEVEL HIGH IS FORECAST TO CONTINUE NUDGING EASTWARD TODAY...BUT SHOULD STILL SEE SCATTERED SHOWERS AND THUNDERSTORMS ACROSS AREAS SOUTH OF I-10. ELSEWHERE...WILL CARRY SLIGHT CHANCE POPS. LESS CONVECTIVE COVERAGE WILL LEAD TO SLIGHTLY HIGHER TEMPERATURES TODAY COMPARED TO YESTERDAY. GENERALLY EXPECT AFTERNOON HIGHS TO TOP OUT IN THE MID 90S ACROSS INLAND AREAS AND LOWER 90S FOR AREAS CLOSER TO THE COAST. ALL MODELS FORECAST THE THE HIGH TO CONTINUE BUILDING EASTWARD FRIDAY THROUGH THE WEEKEND. LUCKILY...IT DOESN/T LOOK LIKE THE RIDGE WILL HAVE QUITE AS STRONG A HOLD OF THE AREA AS IT DID IN JUNE. THE MAIN DIFFERENCES IN THE MODEL FORECASTS CONCERN THE AMOUNT OF CONVECTION THAT IS FORECAST TO DEVELOP DESPITE THE CAPPING. THE GFS IS THE DRIEST OF THE MODELS WITH ONLY ABOUT A 10 PERCENT CHANCE OF RAIN EACH DAY. THE NAM IS THE WETTEST WITH UP TO 50 PERCENT POPS FRIDAY AND SATURDAY. PERSONALLY FEEL THAT THE GFS IS PROBABLY A TAD TOO DRY AND THE NAM IS TOO WET. WITH THAT SAID...WILL CONTINUE TO CARRY SLIGHT CHANCE POPS ACROSS MOST OF THE AREA FIGURING THAT ISOLATED SHOWERS AND THUNDERSTORMS WILL BE ABLE TO BREAK THROUGH THE CAP EACH AFTERNOON. GENERALLY EXPECTING TEMPERATURES TO TOP OUT IN THE MID TO UPPER 90S THROUGH THE REMAINDER OF THE FORECAST PERIOD. IT/S A LITTLE BEYOND MY FORECAST PERIOD...BUT TOWARD THE END OF NEXT WEEK IT LOOKS LIKE ANOTHER TROUGH WILL DIG SOUTHWARD ALONG THE EAST COAST AND PUSH THE RIDGE TOWARD THE SOUTHWEST CONUS PUTTING THE NORTHERN GULF COAST UNDER NORTH TO NORTHWEST FLOW ALOFT. THIS WOULD RESULT IN HIGHER CHANCES OF RAIN SIMILAR TO WHAT WE/VE BEEN EXPERIENCING OVER THE LAST FEW DAYS. AVIATION... SHORT-TERM MVFR VSBY IN BR THIS MORNING AT KMCB AND KGPT...OTHERWISE VFR AT MOST LOCATIONS. SCATTERED TSRA EARLY THIS AFTERNOON MAINLY ALONG SEA BREEZE BUT RELATIVELY DRIER AIR OVER REGION TO KEEP COVERAGE LOWER THAN CLIMATOLOGY. BEST CHANCE FOR TSRA WOULD BE AT KMSY AND KHUM. VFR CONDITIONS EXPECTED AFTER 00Z. MARINE... WINDS AND SEAS TO REMAIN RATHER LOW NEXT SEVERAL DAYS AS HIGH PRESSURE RIDGE BUILDS OVER THE GULF STATES AND PRESENTS A FLAT GRADIENT IN THE COASTAL WATERS. THUNDERSTORM COVERAGE MAINLY BEYOND 20 NM IN RESPONSE TO LINGERING FRONTAL ZONE TO MAINTAIN LOCALLY HIGHER WIND GUSTS...CHOPPY SEAS AND POSSIBILITIES FOR WATERSPOUTS THIS MORNING. && .PRELIMINARY POINT TEMPS/POPS... MCB 94 70 94 71 / 20 10 10 0 BTR 95 75 95 75 / 20 10 20 10 MSY 92 76 93 76 / 30 10 20 10 GPT 91 74 92 74 / 20 10 20 10 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE NEW ORLEANS LA 626 AM CDT THU JUL 9 2009 GMZ530-550-555-570-575-LAZ034>040-046>050-056>070-MSZ068>071-077- 080>082-101130- LAKE PONTCHARTRAIN AND LAKE MAUREPAS- COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO LOWER ATCHAFALAYA RIVER LA OUT 20 NM- COASTAL WATERS FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER OUT 20 NM- COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO LOWER ATCHAFALAYA RIVER LA FROM 20 TO 60 NM- COASTAL WATERS FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM-POINTE COUPEE-WEST FELICIANA- EAST FELICIANA-ST. HELENA-TANGIPAHOA-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-WILKINSON-AMITE-PIKE-WALTHALL-PEARL RIVER- HANCOCK-HARRISON-JACKSON- 626 AM CDT THU JUL 9 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF COASTAL WATERS OF SOUTHEAST LOUISIANA AND SOUTH MISSISSIPPI...SOUTHEAST LOUISIANA AND SOUTHERN MISSISSIPPI. .DAY ONE...TODAY AND TONIGHT ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON. MOST OF THESE STORMS WILL REMAIN WEAK...BUT A FEW COULD BECOME STRONG WITH WIND GUSTS OF UP TO 40 MPH. SEVERE WEATHER IS NOT EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY ISOLATED THUNDERSTORMS WILL BE POSSIBLE EACH AFTERNOON THROUGH WEDNESDAY...BUT SEVERE WEATHER IS NOT EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED. 95/DM
The national radar mosaic for the moment the first event began.
1 lightning, 1 thunderstorm wind. Local standard time, as filed.
A man in an aluminum boat was struck by lightning near the Louisiana Universities Marine Consortium. The man was hospitalized.
Thunderstorm winds damaged several trailers. Most of the wind damage was minor; however, one of the trailers had a portion of the roof removed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Louisiana in 2009Every state in 2009This day in weather historyWarnings in Louisiana, July 2009
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: 190619, 190618.