S. from the 21st through the 23rd of the month.
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 DMX wrote it up.
A strong weather system moved through the central U.S. from the 21st through the 23rd of the month. Strong convection formed north of a warm frontal boundary lifting north through the state. A cold front dropped southeast, producing severe weather on the 21st before it stalled out to the south of the state. As it lifted northward, deep moisture was transported into the upper Midwest as the remnants of a former eastern Pacific Hurricane was drawn north. The tropical moisture resulted in heavy rainfall over a large part of Iowa again on the 23rd, with some places in southern Minnesota receiving 6 to 10 inches of rain. The rainfall from Minnesota flowed down the Des Moines River and produced flooding as far south as Humboldt. The heavy rain that fell over Iowa during this event caused flooding farther south on the mainstem Des Moines, and on the South Fork Chariton River. The flooding caused some property damage and minor crop damage. Since much of the summer saw very elevated river levels, the flooding caused less damage than would be otherwise expected.
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 Des Moines, IA wrote its last area forecast discussion before the first event at Sep 21, 5:42 PM CST, 1 hour 42 minutes earlier.
AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE DES MOINES IA 642 PM CDT TUE SEP 21 2010 ...UPDATED AVIATION DISCUSSION... .SHORT TERM /TONIGHT/... FRONTAL BOUNDARY WILL SAG THRU THE STATE THIS EVENING BEFORE STALLING NEAR THE IA/MO BORDER. CONVECTION HAS BLOWN SOUTHEAST BUT HAVE SEEN SOME RECENT DEVELOPMENT BEHIND THE LINE BUT AHEAD OF THE TRUE COLD FRONT. ANTICIPATE SOME ADDITIONAL DEVELOPMENT ON THE BACKSIDE PER THE HRRR AND LESSOR EXTENT THE NAM. GIVEN THE HEAVY RAINFALL POTENTIAL...HAVE ISSUED A FLASH FLOOD WATCH IN SOUTHERN IA IN VICINITY OF WHERE HEAVY RAINFALL OCCURRED THIS WEEKEND AND FFG IS AROUND 1.5 TO 2 INCHES. OTHERWISE...DRIER AIR WILL REMAIN IN FAR NORTHERN IA OVERNIGHT WITH SOME CLEARING AND COOL TEMPERATURES. .LONG TERM /WEDNESDAY THROUGH TUESDAY/... ACTIVE PATTERN TO CONTINUE THROUGH AT LEAST THE NEXT FEW DAYS...WITH WHAT SHOULD END UP TO BE QUIETER CONDITIONS TOWARD THE WEEKEND INTO EARLY NEXT WEEK. FRONTAL BOUNDARY MOVING THROUGH THE CWA TONIGHT...WILL MOVE BACK NORTHWARD THROUGH THE CWA AS A WARM FRONT WEDNESDAY. MAIN FORCING WILL BE SITUATED ACROSS THE NORTHERN CWA WITH MAIN PUSH OF THETA-E ADVECTION. REMAINDER OF CWA WILL BE IN THE WARM SECTOR WITH A DECENT CAP EVIDENT ON SOUNDINGS IN PLACE POSSIBLY LIMITING ANY CONVECTION ACROSS THE CENTRAL/SOUTHERN CWA. WARM FRONT TO LIFT NORTH OF THE CWA WEDNESDAY NIGHT...AND MAY STILL SEE SOME ISOLATED CONVECTION...BUT MAIN THOUGHT IS ACTIVITY WILL SPREAD BACK INTO THE AREA AS COLD FRONT/SFC TROUGH APPROACHES THE CWA MAINLY THURSDAY. SFC TROUGH LIFTS NORTHEASTWARD FROM NEAR KSUX EARLY THU MORNING TO NEAR KMSP BY 00Z THURSDAY AND FINALLY INTO THE GREAT LAKES REGION BY 12Z FRIDAY. THIS WILL SPREAD SHOWERS AND THUNDERSTORMS ACROSS THE STATE THURSDAY AND THURSDAY NIGHT. SYSTEM THEN EXITS TO THE EAST WITH DRY CONDITIONS FOLLOWING FOR FRIDAY. FRONTAL TIMING SOMEWHAT SLOWER THAN IN PREVIOUS MODEL RUNS...WITH THE NAM THE FASTEST AND THE GFS/EC SLOWER. HAVE TRENDED THE FORECAST TOWARD THE SLOWER TIMING AS GENERAL TREND WITH A DEEPENING SYSTEM LIKE THIS TO HAVE A SLOWER PROGRESSION WITH TIME. MUCAPE STARTS TO DIMINISH ACROSS THE CWA TOWARD LATE THURSDAY INTO THURSDAY NIGHT...SO DID TRANSITION TO MORE OF AN ISOLATED THUNDER TO MAINLY SHOWER MENTION DURING THAT TIMEFRAME. HIGH PRESSURE THEN TO BUILD INTO THE CWA FOR FRIDAY NIGHT INTO EARLY SATURDAY...WITH ANOTHER WEAK UPPER LEVEL TROUGH TO DROP SOUTHEAST THROUGH THE MN/WI/NE IA REGION. AT THIS TIME MODELS COMING INTO MORE OF A CONSENSUS KEEPING THIS AN OPEN WAVE VERSUS THE TREND TO STRENGTHEN THE SYSTEM AS IT DROPS SOUTH AS SEEN IN SOME OF THE PREVIOUS MODEL RUNS. WITH THAT BEING SAID...MODELS KEEP MUCH OF THE MOISTURE ASSOCIATED WITH THIS SYSTEM JUST TO THE NORTH AND EAST SO HAVE CONTINUED A DRY FORECAST INTO THE WEEKEND. UPPER RIDGING THEN BUILDING INTO THE REGION FOR SUNDAY INTO EARLY MONDAY...WITH ANOTHER WEAK WAVE DROPPING SOUTHEASTWARD THROUGH THE REGION MONDAY INTO TUESDAY. MAIN TRACK OF THIS SYSTEM IS MORE TOWARD NRN MN/GREAT LAKES REGION SO SHOULD KEEP ANY PRECIP ASSOCIATED WITH THIS SYSTEM NORTH AND EAST OF THE STATE AS WELL. AS FOR TEMPERATURES...CONTINUE TO SEE A MILD AIRMASS OVER THE REGION THROUGH THURSDAY WITH WAA KICKING BACK IN WEDNESDAY. AIRMASS MUCH COOLER BEHIND COLD FRONT TO MOVE THROUGH THURSDAY INTO THURSDAY NIGHT...WITH H85 TEMPS INTO THE SINGLE DIGITS ABOVE FREEZING TO AROUND +10C FRIDAY. THIS WILL ALLOW TEMPERATURES TO FALL INTO THE 60S TO AROUND 70 FOR FRIDAY ACROSS THE CWA. TEMPERATURES ARE THEN EXPECTED TO GRADUALLY WARM THROUGH THE WEEKEND INTO EARLY NEXT WEEK. && .AVIATION... 22/00Z...THUNDERSTORM ACTIVITY WILL CONTINUE ACROSS THE SOUTHEAST THROUGH THE EVENING AND LOOKS TO MAINLY AFFECT THE DSM AND OTM AREAS. STRATUS DECK BEGINNING TO ERODE AND SLOWLY SHIFT EAST BUT STILL ANTICIPATING IFR CIGS AT TIMES ACROSS ALO/DSM BEFORE CIGS LIFT TO MVFR LATE TONIGHT. FOG LOOKS TO SETTLE IN OVERNIGHT WITH THE RECENT RAINFALL AND TEMPS CLOSE TO SATURATION. WITH BOUNDARY STILL LAID UP ACROSS THE STATE...WINDS REMAIN LIGHT AND VARIABLE THROUGH TOMORROW AFTERNOON. EXPECTING MVFR TO IFR VIS PAST 09Z. WINDS BEGIN TO MIX BY 18Z WED TO AOA 12KTS. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR APPANOOSE- CLARKE-DAVIS-DECATUR-LUCAS-MONROE-RINGGOLD-TAYLOR- WAPELLO-WAYNE. && SHORT TERM...COGIL LONG TERM...BEERENDS AVIATION...PODRAZIK
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 742 PM CDT TUE SEP 21 2010 IAZ083>086-092>097-230045- CLARKE-LUCAS-MONROE-WAPELLO-TAYLOR-RINGGOLD-DECATUR-WAYNE-APPANOOSE- DAVIS- 742 PM CDT TUE SEP 21 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA. .DAY ONE...TONIGHT SCATTERED NON SEVERE THUNDERSTORMS WILL CONTINUE THROUGH THE REMAINDER OF THE EVENING. THE MAIN THREAT WILL BE LOCALLY BRIEF HEAVY RAIN AND POSSIBLY SMALL HAIL. A FLASH FLOOD WATCH IS IN EFFECT FOR THE AREA. PLEASE REFER TO THE NATIONAL WEATHER SERVICE WEBSITE AT WEATHER.GOV/DESMOINES FOR FURTHER DETAILS. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY THUNDERSTORM CHANCES WILL PERSIST THROUGH FRIDAY MORNING FROM TIME TO TIME. A FEW SEVERE THUNDERSTORMS AND LOCALLY HEAVY RAINFALL WILL BE POSSIBLE AT TIMES. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS POSSIBLE FROM TIME TO TIME THROUGH EARLY FRIDAY MORNING. IAZ061-062-074-075-230045- JASPER-POWESHIEK-MARION-MAHASKA- 742 PM CDT TUE SEP 21 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA. .DAY ONE...TONIGHT LINGERING THUNDERSTORMS ARE EXPECTED ACROSS THE AREA THROUGH MIDNIGHT. NO SEVERE THUNDERSTORMS ARE EXPECTED BUT LOCALLY BRIEF HEAVY RAIN IS POSSIBLE. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY THUNDERSTORM CHANCES WILL PERSIST THROUGH FRIDAY MORNING FROM TIME TO TIME. A FEW SEVERE THUNDERSTORMS AND LOCALLY HEAVY RAINFALL WILL BE POSSIBLE AT TIMES. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS POSSIBLE FROM TIME TO TIME THROUGH EARLY FRIDAY MORNING. IAZ004>007-015>017-023>028-033>039-044>050-057>060-070>073-081-082- 230045- EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO- POCAHONTAS-HUMBOLDT-WRIGHT-FRANKLIN-BUTLER-BREMER-SAC-CALHOUN- WEBSTER-HAMILTON-HARDIN-GRUNDY-BLACK HAWK-CRAWFORD-CARROLL-GREENE- BOONE-STORY-MARSHALL-TAMA-AUDUBON-GUTHRIE-DALLAS-POLK-CASS-ADAIR- MADISON-WARREN-ADAMS-UNION- 742 PM CDT TUE SEP 21 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL IOWA. .DAY ONE...TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY THUNDERSTORM CHANCES WILL PERSIST THROUGH FRIDAY MORNING FROM TIME TO TIME. A FEW SEVERE THUNDERSTORMS AND LOCALLY HEAVY RAINFALL WILL BE POSSIBLE AT TIMES. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS POSSIBLE FROM TIME TO TIME THROUGH EARLY FRIDAY MORNING.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
227 PM CDT TUE SEP 21 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1255 PM TSTM WND DMG SULLY 41.58N 92.85W
09/21/2010 JASPER IA BROADCAST MEDIA
AIR EXCHANGER ON ROOF RIPPED OFF TOP OF GYM BUILDING.
AROUND ONE QUARTER OF THE ROOF OF THE GYM WAS PEELED BACK
WITH A SECTION OF THIS ROOF THROWN 50 TO 100 FEET TO THE
EAST OF THE BUILDING CAUSING SOME TREE DAMAGE. ONE WINDOW
WAS ALSO BLOWN OUT. NO INJURIES REPORTED. INFORMATION
RELAYED FROM WOI-TV
&&
CCOGILSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DES MOINES IA 433 PM CDT TUE SEP 21 2010 IAZ096-097-212230- APPANOOSE-DAVIS- 433 PM CDT TUE SEP 21 2010 ...STRONG THUNDERSTORMS CONTINUE OVER SOUTHEAST IOWA... AT 428 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM OVER SOUTHEASTERN APPANOOSE COUNTY...MOVING EAST AT 30 MPH. ONE HALF INCH DIAMETER HAIL...WINDS GREATER THAN 40 MPH...FREQUENT CLOUD TO GROUND LIGHTNING AND FREQUENT DOWNPOURS ARE POSSIBLE WITH THIS STORM. * THE THUNDERSTORM WILL BE NEAR... BLOOMFIELD BY 500 PM CDT... PULASKI BY 520 PM CDT... GUSTY WINDS MAY CAUSE SMALL OBJECTS SUCH AS TRASH BINS TO BLOW AROUND. STAY AWAY FROM HIGH OBJECTS OUTDOORS SUCH AS TREES. SEEK SHELTER IN A STURDY STRUCTURE UNTIL THIS STORM HAS PASSED. TORRENTIAL RAINS MAY PRODUCE LOW VISIBILITIES AND PONDING WATER ON ROADS. SMALL
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
514 PM CDT TUE SEP 21 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0502 PM HEAVY RAIN 1 W SEYMOUR 40.68N 93.15W
09/21/2010 M2.00 INCH WAYNE IA TRAINED SPOTTER
2 INCHES OF RAIN SINCE 330 PM CDT. 3-4 INCHES OF WATER
FLOWING PRETTY QUICK ACROSS COUNTY ROAD 230TH JUST
NORTHWEST OF SEYMOUR.
&&
PODRAZIKPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
515 PM CDT TUE SEP 21 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0452 PM HEAVY RAIN 5 ENE DAVIS CITY 40.66N 93.72W
09/21/2010 M3.20 INCH DECATUR IA TRAINED SPOTTER
SPOTTER MEASURED 3.2 INCHES
&&
JBPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
529 PM CDT TUE SEP 21 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0452 PM FLASH FLOOD 3 NNE PLEASANTON 40.62N 93.71W
09/21/2010 DECATUR IA TRAINED SPOTTER
SPOTTER REPORTED WATER RUSHING OVER QUARRY RD NEAR R46 TO
DEEP TO CROSS...ALSO LITTLE RIVER OUT OF ITS BANKS IN A
FEW AREAS.
&&
JBThe national radar mosaic for the moment the first event began.
5 flood. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2010Every state in 2010This day in weather historyWarnings in Iowa, September 2010
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: 254792, 254795, 254793, 254794, 254796.