A warm and unstable air mass led to several days of isolated to scattered showers and thunderstorms. Some storms produced damaging winds and heavy rainfall that led to minor flooding.
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 BMX wrote it up.
A warm and unstable air mass led to several days of isolated to scattered showers and thunderstorms. Some storms produced damaging winds and heavy rainfall that led to minor flooding.
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 Birmingham, AL wrote its last area forecast discussion before the first event at Jul 20, 5:45 AM CST, 3 hours 15 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BIRMINGHAM AL 645 AM CDT WED JUL 20 2011 .UPDATE... FOR AVIATION. && .DISCUSSION... CURRENTLY WATCHING SOME SHOWERS ON RADAR...DOWN IN DALLAS COUNTY. NOT SURE WHAT THE FORCING MECHANISM IS DOWN THERE SPECIFICALLY... BUT WILL HAVE TO ACCOUNT FOR THESE SHOWERS IN THE EARLY FIRST PERIOD OF THE FORECAST. OTHERWISE...THE FORECAST REMAINS LARGELY DOMINATED BY THE EBBS... FLOWS...AND MOVEMENTS OF THE UPPER LEVEL RIDGE. LOOKS LIKE THE RIDGE HAS STARTED ITS TRANSITION FROM THE PLAINS/MIDWEST TO THE EASTERN THIRD OF THE COUNTY. THIS WILL CONTINUE TO LEAD TO AFTERNOON TEMPERATURES A BIT ABOVE SEASONAL NORMALS....AT LEAST THROUGH THE REST OF THE WORK WEEK. FOR TODAY...I AGAIN UNDERCUT MAVMOS TEMPS BY A COUPLE DEGREES AS THAT HAS BEEN A WINNING STRATEGY FOR THE PAST FEW DAYS. HOWEVER...AS WE CONTINUE TO RACK UP RAINFREE (OR PREDOMINANTLY RAINFREE) DAYS...AND SURFACE MOISTURE STARTS TO REALLY DRY OUT...THE WARM BIAS IN THE GUIDANCE WILL LIKELY BECOME LESS OF A FACTOR. COUNTER TO THIS...MOTH THE GFS AND ECMWF INDICATE A GENERAL WEAKENING OF THE UPPER RIDGE OVER THE WEEKEND AND EARLY NEXT WEEK...WHICH WOULD SUGGEST A SLIGHT MODERATION OF DAYTIME TEMPERATURES. MOISTURE LEVELS AMONG THE MEDIUM/LONG RANGE MODELS DO NOT SHOW ANY OBVIOUS PERIODS OF ENHANCED OR SUPPRESSED CONVECTION POTENTIAL. THEREFORE...WILL CONTINUE WITH A LARGELY CLIMO-BASED POP FORECAST. && .AVIATION... 12Z TAF DISCUSSION. A VORTICITY MAX DEPICTED ON THE NAM THIS MORNING AND EVIDENT WITH AN INCREASE IN WATER VAPOR VALUES IS CURRENTLY SLIDING SOUTHWEST THROUGH KY/TN TOWARD ALABAMA. AS WELL AS A WEAK SURFACE REFLECTION OF AN INVERTED TROUGH ACROSS GEORGIA IN SOUTHERN ALABAMA. BOTH OF THESE FEATURES ARE HELPING TO ENHANCE LIFT AND TRIGGER SHOWERS AND A FEW ISOLATED THUNDERSTORMS OUT THERE. SO FAR ALL RAINFALL HAS MISSED TAF SITES...BUT LOOKS LIKE MGM MAY SEE THE FIRST ACTIVITY THIS MORNING. WENT AHEAD AND INCLUDE TEMPO TSRA FOR MGM THROUGH 14Z...HOWEVER IT DOES APPEAR THAT THE CURRENT STORM MAY DISSIPATE BEFORE IT WORKS IN. EXPECT OVERALL COVERAGE TO INCREASE AS WE APPROACH THE AFTERNOON...SO WENT WITH VCTS AND CB FOR THE REST OF AFTERNOON AND EVENING THROUGH 3Z. MAY SEE SOME MORE PATCHY MVFR BR AGAIN AFTER 8Z...AND DEPENDING ON WHERE THE RAIN ACTUALLY FALLS TODAY...MAYBE SOME IFR BR THROUGH 12Z. NOTICE...KEET TAF WILL HAVE (AMD LTD TO VIS WIND AND WX) AMENDED TO THE END OF THE FORECAST UNTIL FURTHER NOTICE. THE CEILOMETER DATA WILL BE GOING THROUGH NUMEROUS TESTS AND MONITORED FOR ACCURACY. && .BMX WATCHES/WARNINGS/ADVISORIES... NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BIRMINGHAM AL 605 AM CDT WED JUL 20 2011 ALZ011>015-017>050-211100- MARION-LAMAR-FAYETTE-WINSTON-WALKER-BLOUNT-ETOWAH-CALHOUN- CHEROKEE-CLEBURNE-PICKENS-TUSCALOOSA-JEFFERSON-SHELBY-ST. CLAIR- TALLADEGA-CLAY-RANDOLPH-SUMTER-GREENE-HALE-PERRY-BIBB-CHILTON- COOSA-TALLAPOOSA-CHAMBERS-MARENGO-DALLAS-AUTAUGA-LOWNDES-ELMORE- MONTGOMERY-MACON-BULLOCK-LEE-RUSSELL-PIKE-BARBOUR- 605 AM CDT WED JUL 20 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE COUNTIES SERVED BY THE NATIONAL WEATHER SERVICE OFFICE IN BIRMINGHAM. .DAY ONE...TODAY AND TONIGHT. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY. WARM TEMPERATURES WILL BE IN PLACE ON THURSDAY. AT THIS TIME IT APPEARS THAT HEAT INDICIES WILL BE BETWEEN 103 AND 107 DEGREES AREA WIDE. AS WE APPROACH THURSDAY...A HEAT ADVISORY MAY BE NEEDED IF THESE NUMBERS INCREASE. .SPOTTER INFORMATION STATEMENT... ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT IS NOT EXPECTED AT THIS TIME.
The national radar mosaic for the moment the first event began.
4 flash flood, 1 thunderstorm wind. Local standard time, as filed.
A nursing home had over two feet of water inside, leading to the 63 residents being evacuated by boat. Several other high water rescues were performed in the same area.
A barn had a large portion of its tin roof removed. Several trees were also blown down in Oneonta.
A portion of Sweeney Hollow Road was closed due to flooding.
Water was up over a bridge, leading it to be closed.
Several Roads were closed due to flash flooding.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Alabama in 2011Every state in 2011This day in weather historyWarnings in Alabama, July 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: 336110, 336115, 336111, 336112, 336114.