Thunderstorms developed along a dewpoint boundary extending from central Illinois, through southern Indiana, and into central Kentucky. Some of these storms produced severe weather.
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 ILN wrote it up.
Thunderstorms developed along a dewpoint boundary extending from central Illinois, through southern Indiana, and into central Kentucky. Some of these storms produced severe weather. The main threats from these storms were large hail and damaging thunderstorm winds.
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 Wilmington, OH wrote its last area forecast discussion before the first event at Aug 8, 6:47 PM EST, 18 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 747 PM EDT MON AUG 8 2011 .SYNOPSIS... A SHORT WAVE TROUGH WILL ENHANCE INSTABILITY ALONG A DEW POINT BOUNDARY TONIGHT...RESULTING INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL PUSH THROUGH THE REGION TUESDAY NIGHT...USHERING IN A DRIER AND COOLER AIRMASS FOR MID WEEK. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... THUNDERSTORMS HAVE DEVELOPED ALONG A DEW POINT BOUNDARY EXTENDING FROM CENTRAL ILLINOIS THROUGH SOUTHERN INDIANA TO CENTRAL KENTUCKY. WITH STORMS ENTERING SOUTHWEST COUNTIES...WENT WITH CATEGORICAL POPS THERE FOR THE FIRST COUPLE HOURS OF THE FORECAST. REST OF AREA HAS LIKELY TO HIGH CHANCE POPS SINCE IT APPEARS STORMS WILL CONTINUE AND DEVELOP AND MOVE ACROSS THE AREA THIS EVENING INTO THE OVERNIGHT. THOUGH SURFACE BASED INSTABILITY WILL DECREASE WITH LOSS OF DAYTIME HEATING...A SHORT WAVE ADVANCING FROM THE WEST WILL BRING COOLER AIR ALOFT AND WILL ALLOW CAPE TO REMAIN IN THE POSITIVE RANGE OVERNIGHT. THIS WILL KEEP THE CHANCE FOR THUNDERSTORMS THROUGH TONIGHT. THE THREAT FOR ISOLATED SEVERE THUNDERSTORMS EXISTS DUE RATHER VIGOROUS WIND FIELDS ASSOCIATED WITH THE SHORT WAVE. TEMPERATURES WILL FALL TO AROUND 70 BY 6 AM. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... EXPECT A LULL IN CONVECTION TUESDAY MORNING AS A WEAK RIDGE BUILDS IN BEHIND THE DEPARTING SHORT WAVE. THE CHANCE FOR THUNDERSTORMS WILL INCREASE TUESDAY AFTERNOON WHEN A COLD FRONT WILL PUSH IN FROM THE NORTH. THE CHANCE OF THUNDERSTORMS WILL PERSIST INTO TUESDAY NIGHT AS THE FRONT CONTINUES ACROSS THE AREA. TEMPERATURES WILL RISE TO THE MID AND UPPER 80S...BEFORE FALLING TO THE 60S FOR LOWS TUESDAY NIGHT. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... MODELS SIMILAR WITH FORECAST CHANGE IN UPPER LEVEL PATTERN. ECMWF IS A BIT SLOWER AND DEEPER WITH THE TROUGH EXPECTED TO MOVE THROUGH THE GREAT LAKES REGION THAN THE GFS. THE REGION COMES UNDER THE INFLUENCE OF AN UPPER LEVEL NW FLOW PATTERN STARTING AT MIDWEEK. THIS WILL BRING A MODERATION IN THE TEMPERATURES AND DRY CONDITIONS THROUGH FRIDAY AS AN UPPER LEVEL HIGH PRESSURE RIDGE SETS UP OVER THE SOUTHERN PLAINS. SEVERAL SHORT WAVES WILL MOVE ACROSS THE REGION BEFORE A DEEP TROUGH MOVES THROUGH THE GREAT LAKES SATURDAY INTO SUNDAY. THIS WILL BRING THE CHANCE FOR SHOWERS/THUNDERSTORMS BACK INTO THE FORECAST AREA FOR FRIDAY NIGHT THROUGH SATURDAY NIGHT...LINGERING IN THE EAST ON SUNDAY. THE LONG WAVE TROUGH WHICH WILL EXTEND FROM THE HUDSON BAY WILL PRODUCE COOLER TEMPERATURES THAN WE HAVE SEEN OVER THE LAST 3 WEEKS OR SO. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... SCATTERED CONVECTION WAS STARTING TO INCREASE IN COVERAGE. THESE STORMS WILL AFFECT THE TERMINALS OVER THE FIRST SEVERAL HOURS OF THE FORECAST. CANNOT RULE OUT CONDITIONS BELOW MVFR WITH THESE STORMS BUT IF THAT OCCURS IT SHOULD BE VERY BRIEF. THREAT OF PRECIPITATION WILL DIMINISH CONSIDERABLY IN THE LATTER HALF OF THE NIGHT. ONCE AGAIN THERE IS THE POTENTIAL FOR STRATUS TO DEVELOP ALTHOUGH ITS FORMATION IS UNCERTAIN. APPEARS THAT IF THIS OCCURS THAT IT WILL BE CLOSE TO 12Z. IN ADDITION THERE SHOULD BE SOME VISIBILITY RESTRICTIONS IN MIST. IF LOWER CLOUDS DEVELOP THEN THEY WILL LIFT AND SCATTER DURING THE MORNING. CLOUDS HAVE THE POTENTIAL TO LAST LONGEST AT THE COLUMBUS TERMINALS. OUTLOOK...THUNDERSTORMS WILL BE POSSIBLE TUESDAY NIGHT. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && SYNOPSIS...CONIGLIO NEAR TERM...CONIGLIO SHORT TERM...CONIGLIO LONG TERM...PARKER AVIATION...
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE WILMINGTON OH 457 AM EDT MON AUG 8 2011 INZ050-058-059-066-073>075-080-KYZ089>100-OHZ026-034-035-042>046- 051>056-060>065-070>074-077>082-088-090900- WAYNE-FAYETTE IN-UNION IN-FRANKLIN IN-RIPLEY-DEARBORN-OHIO- SWITZERLAND-CARROLL-GALLATIN-BOONE-KENTON-CAMPBELL-OWEN-GRANT- PENDLETON-BRACKEN-ROBERTSON-MASON-LEWIS-HARDIN-MERCER-AUGLAIZE-DARKE- SHELBY-LOGAN-UNION OH-DELAWARE-MIAMI-CHAMPAIGN-CLARK-MADISON- FRANKLIN OH-LICKING-PREBLE-MONTGOMERY-GREENE-FAYETTE OH-PICKAWAY- FAIRFIELD-BUTLER-WARREN-CLINTON-ROSS-HOCKING-HAMILTON-CLERMONT-BROWN- HIGHLAND-ADAMS-PIKE-SCIOTO- 457 AM EDT MON AUG 8 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL INDIANA...SOUTHEAST INDIANA...NORTHEAST KENTUCKY...NORTHERN KENTUCKY...CENTRAL OHIO...MIAMI VALLEY OF OHIO...SOUTH CENTRAL OHIO...SOUTHWEST OHIO AND WEST CENTRAL OHIO. .DAY ONE...TODAY AND TONIGHT. SCATTERED THUNDERSTORMS WILL BE POSSIBLE LATE THIS AFTERNOON INTO TONIGHT. A FEW OF THE STORMS MAY BECOME SEVERE WITH DAMAGING WIND BEING THE PRIMARY THREAT. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WILMINGTON OH
615 PM EDT MON AUG 8 2011
INZ050-058-059-OHZ060-070-082245-
UNION IN-FAYETTE IN-WAYNE IN-BUTLER OH-PREBLE OH-
615 PM EDT MON AUG 8 2011
...A CLUSTER OF STRONG THUNDERSTORMS WILL AFFECT SOUTHWESTERN
PREBLE...NORTHWESTERN BUTLER...SOUTHEASTERN WAYNE...SOUTHEASTERN
FAYETTE AND UNION COUNTIES THROUGH 645 PM EDT...
AT 613 PM EDT...RADAR INDICATED STRONG THUNDERSTORMS FROM
SPRINGERSVILLE TO EVERTON...MOVING EAST AT 25 MPH.
WIND GUSTS TO 40 MPH AND PEA SIZE HAIL ARE POSSIBLE WITH THESE
STORMS.
IN ADDITION...HEAVY RAIN CAN BE EXPECTED WITH THESE STORMS.
SOME LOCATIONS THAT MAY BE AFFECTED INCLUDE...LIBERTY AND WEST
COLLEGE CORNER.
ALSO...PHILOMATH...BROWNSVILLE...DUNLAPSVILLE...ABINGTON...CLIFTON...
WHITEWATER STATE PARK...BILLINGSVILLE AND SALEM ARE NEAR THE PATH OF
THIS LINE OF STRONG THUNDERSTORMS.
WATER WILL POND ON ROADS AND MAY QUICKLY FILL ROADSIDE DITCHES AND
SMALL STREAMS.
LAT...LON 3975 8508 3976 8466 3951 8471 3952 8482
3952 8493 3953 8512PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE WILMINGTON OH
620 PM EDT MON AUG 08 2011
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0610 PM HAIL CONNERSVILLE 39.66N 85.14W
08/08/2011 M0.75 INCH FAYETTE IN NWS EMPLOYEE
&&
BCSPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WILMINGTON OH
644 PM EDT MON AUG 8 2011
INZ059-066-OHZ060-070-082315-
UNION IN-FRANKLIN IN-BUTLER OH-PREBLE OH-
644 PM EDT MON AUG 8 2011
...A CLUSTER OF STRONG THUNDERSTORMS WILL AFFECT SOUTHERN PREBLE...
NORTHWESTERN BUTLER...NORTHEASTERN FRANKLIN AND SOUTHEASTERN UNION
COUNTIES THROUGH 715 PM EDT...
AT 642 PM EDT...RADAR INDICATED STRONG THUNDERSTORMS EXTENDING FROM
COTTAGE GROVE TO MIXERVILLE...MOVING EAST AT 20 MPH.
WIND GUSTS TO 40 MPH AND PEA SIZE HAIL ARE POSSIBLE WITH THESE
STORMS.
IN ADDITION...HEAVY RAIN CAN BE EXPECTED WITH THESE STORMS.
SOME LOCATIONS THAT MAY BE AFFECTED INCLUDE...OXFORD...CAMDEN...SEVEN
MILE AND GRATIS.
ALSO...FAIRHAVEN...MORNING SUN...REILY...HUESTON WOODS STATE PARK...
MUTTONVILLE...MCGONIGLE...SOMERVILLE AND COLLINSVILLE ARE NEAR THE
PATH OF THIS LINE OF STRONG THUNDERSTORMS.
WATER WILL POND ON ROADS AND MAY QUICKLY FILL ROADSIDE DITCHES AND
SMALL STREAMS.
LAT...LON 3966 8487 3968 8448 3966 8448 3939 8452
3943 8491PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE WILMINGTON OH
703 PM EDT MON AUG 08 2011
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0555 PM TSTM WND DMG CONNERSVILLE 39.66N 85.14W
08/08/2011 FAYETTE IN NWS EMPLOYEE
LARGE TREE LIMBS DOWN
&&
BCSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE WILMINGTON OH 730 PM EDT MON AUG 8 2011 OHZ061-062-070>072-090030- BUTLER OH-CLINTON OH-GREENE OH-MONTGOMERY OH-WARREN OH- 730 PM EDT MON AUG 8 2011 ...A STRONG THUNDERSTORM WILL AFFECT WARREN...SOUTHEASTERN MONTGOMERY...SOUTHWESTERN GREENE...NORTHWESTERN CLINTON AND EASTERN BUTLER COUNTIES THROUGH 830 PM EDT... AT 729 PM EDT...RADAR INDICATED A STRONG THUNDERSTORM NEAR SOUTH MIDDLETOWN...MOVING EAST AT 20 MPH. WIND GUSTS TO 40 MPH AND PEA SIZE HAIL ARE POSSIBLE WITH THIS STORM. IN ADDITION...FREQUENT CLOUD TO GROUND LIGHTNING AND HEAVY RAIN CAN BE EXPECTED WITH THIS STORM. SOME LOCATIONS THAT MAY BE AFFECTED INCLUDE...MONROE...CARLISLE... FRANKLIN...LEBANON...SPRINGBORO...WAYNESVILLE...BELLBROOK...XENIA AND WILMINGTON. ALSO...HAGEMAN...SOUTH LEBANON...PEKIN...GENNTOWN...LYTLE... OREGONIA...CORWIN AND CAESAR CREEK STATE PARK ARE NEAR THE PATH OF THIS STRONG THUNDERSTORM. DO NOT STAY IN THE OPEN NOR SEEK SHELTER UNDER TREES WHEN LIGHTNING THREATENS. MOVE INDOORS WHEN A THUNDERSTORM APPROACHES. WATER WILL POND ON ROADS AND MAY QUICKLY FILL ROADSIDE DITCHES AND SMALL STREAMS. LAT...LON 3971 8387 3940 8378 3935 8445 3953 8451
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE WILMINGTON OH
757 PM EDT MON AUG 08 2011
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0755 PM HEAVY RAIN 1 NNE OXFORD 39.51N 84.74W
08/08/2011 E2.00 INCH BUTLER OH TRAINED SPOTTER
&&The Cincinnati radar (KILN), 24 km away, was scanning. The volume nearest the first event began at 00:03 UTC.
3 thunderstorm wind, 3 hail. Local standard time, as filed.
A tree was reported down due to damaging thunderstorm winds.
A tree was reported down due to damaging thunderstorm winds.
Trees were uprooted and there was structural damage to a roof due to damaging thunderstorm winds.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Ohio in 2011Every state in 2011This day in weather historyWarnings in Ohio, August 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: 335610, 335611, 335608, 335609, 335604, 335605.