A heat wave developed as a large upper level high pressure system strengthened over the region producing unseasonably hot weather. High temperatures reached the lower to mid 90s.
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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 HUN wrote it up.
A heat wave developed as a large upper level high pressure system strengthened over the region producing unseasonably hot weather. High temperatures reached the lower to mid 90s. Numerous heat illnesses were reported at a Huntsville 5 and 10K running event on the 30th.
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 Huntsville, AL wrote its last area forecast discussion before the first event at May 30, 5:28 AM CST, 1 hour 32 minutes earlier.
AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE HUNTSVILLE AL 628 AM CDT MON MAY 30 2011 .UPDATE... 12Z AVIATION FORECAST. && .AVIATION... VFR WEATHER SHOULD PREVAIL ACROSS THE TENNESSEE VALLEY THROUGH LATE TONIGHT. THERE IS A SLIGHT CHANCE FOR MVFR FOG/HAZE LATE IN THE PERIOD...SO NOTED IT FOR KMSL AFTER 31/1000Z. && .DISCUSSION... /ISSUED 206 AM CDT MON MAY 30 2011/ SYNOPSIS...A BUILDING RIDGE OVER THE EAST AND SOUTHEAST IS THE MAIN STORY FOR THE FORECAST TODAY THROUGH THE NEXT WEEK. MEANWHILE, A UPPER TROUGH OVER THE ROCKIES AND SIERRAS WILL INDUCE A SFC LOW OVER THE CENTRAL TO NORTHERN PLAINS PROVIDING THE MAIN IMPETUS FOR SEVERE WEATHER OUT THERE. DISCUSSION...MEMORIAL DAY SHOULD BE HOT AND HUMID WITH THE RIDGE CURRENTLY LOCATED OVER THE WESTERN ATLANTIC AND BEGINNING TO BUILD OVER THE REGION. A WARM SOUTHERLY FETCH IN CONJUNCTION WITH THE SUBSIDENCE ACROSS THE REGION WILL ALLOW TEMPS TO RISE INTO THE LOW TO MID 90S WITH OVERNIGHT LOWS IN THE UPPER 60S TO LOW 70S FOR TODAY AND TOMORROW (TUESDAY). MEANWHILE, THE UPPER TROUGH OVER THE SIERRA NEVADA/ROCKIES REGION WILL BEGIN TO LIFT NORTHEAST ATOP THE BUILDING RIDGE. BY TUESDAY THIS WEAKENED TROUGH WILL BE OVER SOUTHWEST ONTARIO AND PROCEEDING EASTWARD. THOUGH THIS MAY NOT SEEM IMPORTANT FOR THE TN VALLEY, A SFC COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL BEGIN TO GRADUALLY MARCH SOUTHEASTWARD TOWARDS THE OHIO RIVER VALLEY BY TUESDAY EVENING. ALL OF THE MODELS OF NOTE APPEAR TO STALL THE FRONT AT THAT LOCATION GIVEN THE STRONG SFC RIDGE OVER THE SOUTHERN STATES. THOUGH THIS FRONT DOES APPEAR TO STALL TO OUR NORTHWEST, TEMPS DO LOOK TO CLIMB INTO THE MID TO UPPER 90S BY WEDNESDAY AND THURSDAY. IN FACT, HEAT INDEX VALUES MAY APPROACH OR RISE JUST ABOVE 100 DEGREES. SO, MAKE SURE TO KEEP PLENTY OF WATER WITH YOU WHEN OUTSIDE THIS WEEK. WITH THESE TEMPERATURES, EXPECTING THAT ISOLATED THUNDERSTORMS WILL BE POSSIBLE, ESPECIALLY OVER NE AL WHERE OROGRAPHIC EFFECTS WOULD COME INTO PLAY. WITH MODERATE INSTABILITY AND AN UNCAPPED ENVIRONMENT, ALONG WITH VERY LITTLE WIND SHEAR, THESE STORMS WILL LIKELY BE PULSE-LIKE. THE STRONG TO SEVERE THREAT WITH THESE STORMS WILL BE QUITE LOCALIZED AND LIMITED TO MICROBURSTS AND MARGINALLY SEVERE HAIL. INTO THE WEEKEND, THE MODELS ARE INDICATING SOME WEAK SHORTWAVES ROUNDING THE BASE OF THE RIDGE ON FRIDAY INTO SATURDAY WHICH MAY CAUSE SCATTERED THUNDERSTORMS TO DEVELOP, BUT NOT CONFIDENT ON THE TIMING. SO, WILL KEEP 20 PERCENT POPS FOR NOW DURING THAT TIME PERIOD. HIGHS WILL LIKELY STILL BE IN THE MID TO UPPER 90S WITH OVERNIGHT LOWS IN THE UPPER 60S TO NEAR 70. SUNDAY AND MONDAY LOOK SIMILAR WITH AN ADDITIONAL WEAK SHORTWAVE ROUNDING THE BASE OF THE RIDGE. SO, WILL KEEP MENTION OF A SLIGHT CHANCE OF THUNDERSTORMS FOR THAT PERIOD AS WELL. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...NONE. TN...NONE. && AVIATION...RSB DISCUSSION...SL.77
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE HUNTSVILLE AL 459 AM CDT MON MAY 30 2011 ALZ001>010-016-TNZ076-096-097-301830- LAUDERDALE-COLBERT-FRANKLIN AL-LAWRENCE-LIMESTONE-MADISON-MORGAN- MARSHALL-JACKSON-DEKALB-CULLMAN-MOORE-LINCOLN-FRANKLIN TN- 459 AM CDT MON MAY 30 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH ALABAMA AND PORTIONS OF SOUTHERN MIDDLE TENNESSEE. .DAY ONE...TODAY AND TONIGHT... NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY... THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. A SLIGHT CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE FROM WEDNESDAY THROUGH SUNDAY. THE MAIN THREAT FROM THE STRONGER STORMS WILL BE GUSTY WINDS. .SPOTTER CALL TO ACTION STATEMENT... ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT PERSONNEL IS NOT ANTICIPATED AT THIS TIME. RSB
The national radar mosaic for the moment the first event began.
1 heat. Local standard time, as filed.
Numerous participants in the Cotton Row Race (5 and 10K) succumbed to heat illness. Up to 5 participants were ambulanced to a local hospital. Dozens of others were treated at a medical area located on site.
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, May 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: 321755.