Heavy rainfall caused flash flooding and flooding in Brown County Ohio during the night of September 21st and into the early morning hours of the 22nd.
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.
Heavy rainfall caused flash flooding and flooding in Brown County Ohio during the night of September 21st and into the early morning hours of the 22nd.
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 Sep 21, 6:51 PM EST, 1 hour 31 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 751 PM EDT MON SEP 21 2009 .SYNOPSIS... A SOUTHERLY FLOW WILL CONTINUE TO DRAW MOISTURE UP FROM THE GULF OF MEXICO AND INTO THE GREAT LAKES AND OHIO VALLEY REGION. THIS WILL ALLOW UNSETTLED WEATHER TO PERSIST FOR MUCH OF THE WEEK. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... SHOWERS AND THUNDERSTORMS ARE OCCURRING OVER SOUTHEASTERN COUNTIES IN A BAND OF CONVERGENCE EMBEDDED IN THE BROAD SOUTHERLY FLOW. WENT WITH POPS AS HIGH AS CATEGORICAL FOR THIS EVENING...DIMINISHING WITH LOSS OF DAYTIME HEATING. OTHER LOCATIONS WILL HAVE SCATTERED TO ISOLATED SHOWERS AND THUNDERSTORMS. HUMID AIRMASS WILL KEEP LOW TEMPERATURES UP IN THE MID 60S...AROUND 10 DEGREES ABOVE CLIMATOLOGICAL NORMALS. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... BANDS OF CONVERGENCE ALIGNED ALONG THE SOUTHERLY FLOW...ENHANCED BY DAYTIME HEATING-INDUCED INSTABILITY...WILL LEAD TO ADDITIONAL SCATTERED SHOWER AND THUNDERSTORM DEVELOPMENT. NAM MODEL GUIDANCE SEEMS TO HAVE THE BEST HANDLE ON THE SITUATION...POSSIBLY DUE TO THE NARROW MESOSCALE NATURE OF THE CONVERGENCE BANDS. WENT CLOSE TO GUIDANCE FOR TUESDAY WITH HIGHS FORECAST TO BE IN THE UPPER 70S. STAYED BELOW WARMER MAV GUIDANCE FOR WEDNESDAY AND WENT WITH HIGHS IN THE LOWER 80S. && .LONG TERM /THURSDAY THROUGH MONDAY/... OPERATIONAL MODELS START OUT IN AGREEMENT AT MIDWEEK WITH CUTOFF UPPER LEVEL LOW WOBBLING AROUND OVER THE CENTRAL PLAINS FROM MID WEEK THRU THE END OF THE WEEK. OPERATIONAL GFS SOLUTION IS STILL FARTHEST WEST WITH THIS FEATURE BUT IS CATCHING UP. THIS UPPER LOW LIFTS NORTHEAST...OPENS UP AND COMES THRU THE GREAT LAKES/OHIO VALLEY NEXT WEEKEND. THERE ARE SOME TIMING DIFFERENCES WITH OPERATIONAL GFS BEING SLOWER AND ECMWF QUICKEST. LOOKING AT ENSEMBLE SOLNS AND TRENDS...HAVE TRENDED FCST TOWARD A COMPROMISE. WITH THESE DIFFERENCES IN TIMING CONFIDENCE IN EXACT TIMING ON INDIVIDUAL FEATURES IS LOW. HAVE CHC POPS ACRS THE SOUTH EARLY THURSDAY AND THEN HAVE SHOWN A DRYING TREND LATER ON THURSDAY FROM NORTH TO SOUTH. WITH UPR LEVEL RIDGING OVER THE REGION HAVE CONTD DRY PERIOD THURSDAY NIGHT INTO FRIDAY. WITH UPR LOW SHIFTING EAST...HAVE SPREAD CHC POPS BACK IN FROM THE SW FRI NIGHT INTO SATURDAY. HAVE CONTD A MENTION OF PRECIP ON SUNDAY WITH UPR TROF EXPECTED TO BE OVER THE GREAT LAKES. NORTHWEST FLOW ALOFT TO DOMINATE ON MONDAY. CAN NOT RULE OUT A SHOWER FROM EMBEDDED S/W ENERGY. LATEST ECMWF SUGGESTS A WETTER SOLN MON BUT GFS IS DRY. AT THIS TIME HAVE OPTED FOR A SILENT 20 POP ON MONDAY. TEMP WISE...HAVE GENERALLY TREND HIGHS COOLER THAN MEX GUID. FOR LOWS HAVE GENERALLY STAYED CLOSE TO OR SLIGHTLY COOLER THAN GUID THRU THE PERIOD. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... A MOIST SOUTHERLY FLOW WILL CONTINUE OUT OF THE GULF OF MEXICO THROUGH THE TAF PERIOD. MAIN CONCERN THIS FORECAST PACKAGE IS WHETHER LOW STRATUS WILL FORM AT TAF SITES AND WHEN. HAVE PRETTY MUCH LEFT PREVIOUS FORECAST IN TACT WHICH IS TO BRING STRATUS TO THE TAF SITES BETWEEN 04Z AND 08Z. DAYTIME HEATING WILL ALLOW IFR/LOCAL LIFR CIGS TO RISE TO VFR BETWEEN 18Z AND 20Z TUESDAY. ATTM...MAINLY MVFR VSBYS ARE EXPECTED OVERNIGHT...EXCEPT AT KLUK WHICH MAY EXPERIENCE SOME IFR VSBYS. WEAK DISTURBANCES ALOFT...COMBINED WITH DAYTIME HEATING AND WEAK LOW LEVEL CONVERGENT BOUNDARIES...WILL KEPT A 30 TO 40 PERCENT THREAT FOR SHOWERS AND THUNDERSTORMS...MAINLY DURING THE AFTERNOON AND EARLY EVENING HOURS. IT IS TOO EARLY AT THIS TIME TO PINPOINT MESOSCALE BOUNDARIES SO HAVE PLACED A VCSH AND CB CLOUD DESCRIPTOR AT ALL TAF SITES DURING THE AFTN AND EARLY EVENING HOURS. OUTLOOK...IFR CIGS AND MVFR VSBYS POSSIBLE TUESDAY NIGHT AND WEDNESDAY MORNING. THUNDERSTORMS POSSIBLE WEDNESDAY AFTERNOON/EVENING. MVFR CEILINGS POSSIBLE SATURDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && SYNOPSIS...CONIGLIO NEAR TERM...CONIGLIO SHORT TERM...CONIGLIO LONG TERM...AR AVIATION...HICKMAN
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE WILMINGTON OH 516 AM EDT MON SEP 21 2009 INZ050-058-059-066-073>075-080-KYZ089>100-OHZ026-034-035-042>046- 051>056-060>065-070>074-077>082-088-220915- 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- 516 AM EDT MON SEP 21 2009 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. THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY. THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE WILMINGTON OH
456 PM EDT MON SEP 21 2009
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0432 PM FLOOD MAYSVILLE 38.63N 83.78W
09/21/2009 MASON KY PUBLIC
HIGH WATER REPORTED OVER ROADWAYS.
&&
SFHPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE WILMINGTON OH
842 PM EDT MON SEP 21 2009
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0700 PM FLASH FLOOD MAYSVILLE 38.63N 83.78W
09/21/2009 MASON KY EMERGENCY MNGR
ONE CAR WASHED AWAY AT U.S. 68 AND BANK ST. 4 CARS WASHED
OUT OF A PARKING LOT NEARBY. PEOPLE WERE TRAPPED FOR
SOMETIME ON THE SECOND FLOOR OF AN APARTMENT BUILDING.
&&
SFHThe Cincinnati radar (KILN), 65 km away, was scanning. The volume nearest the first event began at 01:20 UTC.
1 flash flood, 1 flood. Local standard time, as filed.
A report indicated that high water was rushing over the road near the intersection of Straight Creek Road and Myers Hollow Road. A tree was also uprooted from the flowing water.
Water remained on several low-lying roads across southern portions of the county.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Ohio in 2009Every state in 2009This day in weather historyWarnings in Ohio, September 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: 193691, 193695.