For much of the year, precipitation was above normal across the southeast and below normal over the northwest. Very heavy rain fell from the 25 to 27th over southeastern Iowa, resulting in widespread 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 DMX wrote it up.
For much of the year, precipitation was above normal across the southeast and below normal over the northwest. Very heavy rain fell from the 25 to 27th over southeastern Iowa, resulting in widespread flooding. Monthly precipitation totals varied from only 1.40 inches at Spencer to 14.44 inches at the Cedar Rapids Airport. The Cedar Rapids total broke their previous August record of 13.09 inches set in 1993. While southeastern Iowa is saturated, parts of northwest and north central Iowa are on the verge of drought conditions. Streamflows are below normal over some parts of the northwest but this summer’s cool weather has prevented significant crop impacts in that area. The most significant flooding was in the Promise City area in Wayne County. The South Fork of the Chariton River rose to nearly 6 feet over flood stage. For the most part, rises were just over flood stage across south central into southeast Iowa, limiting the damage to agricultural lands. Flooding on the South Fork of the Chariton River resulted in some minor flooding, but again, mostly agricultural.
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 Aug 26, 10:25 PM CST, 2 hours 26 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 1125 PM CDT WED AUG 26 2009 .AVIATION DISCUSSION 27/06Z. .DISCUSSION... MID LEVEL WAVE TO MOVING OUT OF CENTRAL NEBRASKA TO MOVE THROUGH THE STATE TONIGHT. AREA OF SHOWERS ASSOCIATED WITH THIS WAVE ALREADY MOVING INTO THE WESTERN CWA...AND EXPECT THIS AREA TO CONTINUE TO TRANSITION EASTWARD WITH TIME AS THE MID LEVEL WAVE PUSHES EAST NORTHEAST ACROSS THE AREA. LITTLE INSTABILITY ALOFT NOTED...AND LITTLE LIGHTNING HAS BEEN OBSERVED WITH THE AREA OF SHOWERS AS OF THE PAST FEW HOURS...SO WENT WITH AN ISOLATED MENTION OF THUNDER. HOWEVER WOULD NOT BE SURPRISED IF JUST THE SHOWER TREND CONTINUED. COOLER AIR CONTINUES TO PUSH IN ALOFT...WITH H85 TEMPS DROPPING INTO THE +10 TO 15C RANGE...SO HAVE PUSHED TEMPS A LITTLE COOLER THAN LAST NIGHT. WENT WITH THE COOLEST TEMPERATURES WHERE SKIES HAVE A BETTER CHANCE OF CLEARING SOME ACROSS THE NORTHWESTERN CWA. FNTL SYS WILL BE SLOW TO MOVE OUT OF THE AREA WITH BLOCKING TAKING PLACE FROM DANNY. WILL HOLD ON TO SOME SHRA OVR THE SERN ZNS THRU FRI. WITH THE PASSAGE OF NEXT CDFNT...COULD SEE ISOLD TSRA FRO AFTN OVR THE NRN AND ERN SXNS OF THE CWA AS WELL. MSTR WILL BE LMTD FOR THIS SYS THOUGH AS MUCH OF IT WILL BE TAKEN SEWD WITH THE CURRENT SYS. NEXT WX STORY WILL BE THE SHOT OF COOLER AIR FOR THE WKND. NO REAL CHNG IN THE THINKING FROM YDA AND WILL CONT WITH THE THINKING OF A COUPLE NGTS OF WDSPRD MINS IN THE 40S. WOULD NOT BE TOO SURPRISED TO SEE AN ISOLD UPR 30S MON MRNG IF THE TIMING OF THE SFC HI PRES OVR IA IS JUST RIGHT. SLOW WRMG AS THE HI SLIPS OFF THE FIRST PART OF THE WK. NEXT CHC FOR PCPN LOOKS TO BE ABOUT THU OR THU NGT. SOME TIMING DIF BTWN THE MDLS...BUT ONLY ABT 12 HRS DIF WITH THE EC RUNNING A LITTLE SLOWER. && .AVIATION...27/06Z CURRENT MCV MOVING ACROSS THE AREA WITH MOD TO HEAVY RAIN AND LOW CIGS ACROSS THE SOUTHEAST WHERE KOTM WILL BE MOST AFFECTED. CIGS EXPECTED TO BOUNCE UP AND DOWN AS THE SYSTEM TRACKS EAST THIS EVENING. CURRENTLY HAVE VFR/MVFR NORTH AND IFR/MVFR CIGS IN THE SOUTH WITH SOME BR AS WELL OVERNIGHT WITH THE RAIN AND THE PARTIAL CLEARING NORTH TOWARD MORNING. PRESENTLY LOOKS LIKE THE MCV WILL BE WITH THE FORECAST AREA THROUGH 8 OR 10Z...EXITING EAST AROUND 09Z. THUS...NOT MUCH CHANGE EXPECTED FROM CURRENT OBS FOR THE FIRST HALF OF THE FORECAST...THEN GENERALLY BETTER CONDITIONS FROM 12Z ON...EXCEPT IN THE SOUTH AT KOTM WHERE CIGS MAY TAKE A WHILE TO RECOVER FROM MVFR CAT. SOUNDINGS THERE SUGGEST LITTLE CHANGE INTO THE AFTERNOON HOURS. /REV && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && SHORT TERM...MJA LONG TERM...MS AUG 09 AVIATION...REV
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DES MOINES IA 509 PM CDT WED AUG 26 2009 IAZ036>039-044>050-057>062-070>075-081>086-092>097-271130- HAMILTON-HARDIN-GRUNDY-BLACK HAWK-CRAWFORD-CARROLL-GREENE-BOONE- STORY-MARSHALL-TAMA-AUDUBON-GUTHRIE-DALLAS-POLK-JASPER-POWESHIEK- CASS-ADAIR-MADISON-WARREN-MARION-MAHASKA-ADAMS-UNION-CLARKE-LUCAS- MONROE-WAPELLO-TAYLOR-RINGGOLD-DECATUR-WAYNE-APPANOOSE-DAVIS- 509 PM CDT WED AUG 26 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL AND SOUTHERN IOWA. .DAY ONE...TONIGHT SCATTERED SHOWERS AND ISOLATED NON SEVERE THUNDERSTORMS WILL CONTINUE TO AFFECT CENTRAL IOWA THROUGH TONIGHT WITH MORE WIDESPREAD COVERAGE POSSIBLE SOUTH. A THREAT FOR LOCALLY HEAVY RAINS AND POTENTIALLY MINOR FLOODING WILL CONTINUE THIS EVENING. PONDING WATER ON ROADS AND RAPID RISES IN SMALL STREAMS AND CREEKS ARE POSSIBLE. RAINFALL AMOUNTS MAY REACH ONE TO TWO INCHES IN SOME AREAS...IN ADDITION TO WHAT HAS ALREADY FALLEN EARLIER TODAY. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY CHANCES FOR SHOWERS AND A FEW NON SEVERE THUNDERSTORMS REMAIN IN THE FORECAST TO THE SOUTH AND EAST OF DES MOINES THURSDAY AND THURSDAY NIGHT. LOCALLY HEAVY RAINS AND THE POTENTIAL FOR MINOR FLOODING WILL STILL EXIST. .SPOTTER INFORMATION STATEMENT... REPORTS OF HEAVY RAINS OR FLOODING ARE ALWAYS APPRECIATED. IAZ004>007-015>017-023>028-033>035-271130- EMMET-KOSSUTH-WINNEBAGO-WORTH-PALO ALTO-HANCOCK-CERRO GORDO- POCAHONTAS-HUMBOLDT-WRIGHT-FRANKLIN-BUTLER-BREMER-SAC-CALHOUN- WEBSTER- 509 PM CDT WED AUG 26 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHERN IOWA. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED. SMALL/REV
The national radar mosaic for the moment the first event began.
4 flood. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2009Every state in 2009This day in weather historyWarnings in Iowa, August 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: 188987, 188984, 188988, 188986.