Thunderstorms developed northwest of a stationary front that extended across southeast Nebraska. The storms were aided by an upper level disturbance that lifted northeast across South Dakota and a modest low level jet and relatively deep low level moisture over eastern Nebraska.
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 OAX wrote it up.
Thunderstorms developed northwest of a stationary front that extended across southeast Nebraska. The storms were aided by an upper level disturbance that lifted northeast across South Dakota and a modest low level jet and relatively deep low level moisture over eastern Nebraska. One small cluster of storms produced severe weather as they tracked into Harrison county of western Iowa.
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 Omaha, NE wrote its last area forecast discussion before the first event at Aug 9, 2:23 AM CST, 4 hours 24 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 323 AM CDT SUN AUG 9 2009 .DISCUSSION... DIFFICULT FORECAST IN THE THE SHORT TERM...WITH 00Z MODELS NOT IN VERY GOOD AGREEMENT. MAIN CONCERNS ARE THE CHANCE FOR TSTMS AND TEMPS. SURFACE ANALYSIS AT 08Z SHOWED LOW PRESSURE CENTERED OVER WRN WI AND A COLD FRONT TRAILING BACK SWWD ACROSS IA...SERN NE AND THEN INTO ANOTHER LOW ALONG THE CO/KS BORDER. POSITION OF THE FRONT LATER TODAY WILL BE VERY IMPORTANT IN DETERMINING HIGHS. FOR NOW DID ALLOW OUR SOUTHERN ZONES TO WARM INTO THE LOWER 90S BUT KEPT AREA NORTH OF THE FRONT IN THE 80S. SOME STRATUS HAS BEEN TRYING TO DEVELOP NORTH OF THE FRONTAL BOUNDARY. THIS IS NOT AS FAST AS WHAT THE 00Z NAM SHOWED...BUT EXPECT THERE TO BE SOME AROUND. RADAR LOOP INDICATED PCPN WAS INCREASING JUST TO OUR WEST. WATER VAPOR LOOP SHOWED A TROUGH OVER MT AND WY...WITH A RIDGE CENTERED OVER THE SERN U.S. AND OUR AREA STILL IN SOUTHWEST MID LEVEL FLOW. PIECE OF SUB TROPICAL ENERGY/MOISTURE ALSO SEEMED TO BE HEADED TOWARD THE CENTRAL PLAINS FROM NERN TX/SERN OK. NOT TOO SURE THE MODELS ARE HANDLING THAT CORRECTLY. WITH LOW PRESSURE OVER ERN CO/WRN KS GRADUALLY DROPPING DOWN INTO NM...EXPECT A DECENT AMOUNT OF SOUTHERLY FLOW INTO AND UP OVER THE FRONT TODAY. PCPN COULD DEVELOP WITH ENERGY MOVING OUT OF WRN NE OR WITH LIFT ASSOCIATED WITH FRONT. SO GENERALLY KEPT SOME CHANCE POPS ALL AREAS TODAY. FRONTAL BOUNDARY COULD BECOME ACTIVE LATER TODAY AND THIS EVENING WITH HEAVY RAIN POTENTIAL. TRENDED POPS DOWNWARD AFTER 06Z TONIGHT AS FRONT PUSHES SOUTHWARD AND WEAK HIGH PRESSURE TRIES TO BUILD EASTWARD FROM WRN NE. FOR MONDAY...00Z MODELS INDICATED SOME POTENTIAL FOR PCPN...SO HAVE A SLIGHT CHANCE OF TSTMS IN THE SWRN HALF OF OUR AREA. WENT MORE ALONG THE LINES OF WHAT THE NAM WAS SHOWING WITH THAT...SINCE GFS SEEMED OVERDONE WITH QPF MONDAY. BUT THAT NEEDS TO BE WATCHED. KEPT SOME LOW POPS IN THE SOUTH INTO MONDAY NIGHT. THE REST OF THE FORECAST WAS DRY...AND LEFT THINGS THAT WAY THROUGH FRIDAY. SOME PCPN SEEMS POSSIBLE AGAIN BY NEXT WEEKEND AS COLD FRONT APPROACHES FROM THE NW. && .AVIATION... TAF SITES KOFK/KOMA/KLNK 06Z TAF ISSUANCE... QUASI-STATIONARY SURFACE BOUNDARY OVER SOUTHEAST NEBRASKA WILL PROVIDE SOME UNCERTAINTY IN FORECAST CONDITIONS DURING THE PERIOD. NARROW BAND OF LIFR CIGS DEVELOPING BEHIND THE FRONT OVER WESTERN IOWA WITH MVFR CONDITIONS IN SOUTH CENTRAL NEBRASKA SPREADING TO THE NORTHEAST. LATEST RUC DATA SUGGEST A PERIOD OF LIFR CIGS POSSIBLE 09Z-15Z PERIOD AT ALL THREE SITES. CURRENT VFR FORECAST LIKELY TO NEED AMENDMENTS LATER THIS MORNING IF THESE CONDITIONS CONTINUE TO DEVELOP ACROSS THE AREA THIS MORNING. RIGHT NOW APPEARS BEST CHANCE OF STORMS LATER THIS AFTN AND TONIGHT SHOULD BE SOUTH OF THE TAF SITES. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && DISCUSSION...MILLER AVIATION...FOBERT
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 500 AM CDT SUN AUG 9 2009 IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034- 042>045-050>053-065>068-078-088>093-092000- ANTELOPE-BOONE-BURT-BUTLER-CASS-CEDAR-COLFAX-CUMING-DODGE-DOUGLAS- FREMONT IA-GAGE-HARRISON IA-JEFFERSON-JOHNSON-KNOX-LANCASTER-MADISON- MILLS IA-MONONA IA-MONTGOMERY IA-NEMAHA-OTOE-PAGE IA-PAWNEE-PIERCE- PLATTE-POTTAWATTAMIE IA-RICHARDSON-SALINE-SARPY-SAUNDERS-SEWARD- SHELBY IA-STANTON-THURSTON-WASHINGTON-WAYNE- 500 AM CDT SUN AUG 9 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR MOST OF EASTERN NEBRASKA AND PARTS OF SOUTHWEST IOWA. .DAY ONE...TODAY AND TONIGHT THUNDERSTORMS ARE POSSIBLE ACROSS THE AREA TODAY AND TONIGHT. SOME STRONG TO SEVERE STORMS ARE POSSIBLE...MAINLY ALONG AND SOUTH OF A LINE FROM ABOUT ALBION TO ONAWA. DAMAGING WINDS AND HAIL WOULD BE THE MAIN HAZARDS...BUT LOCALLY HEAVY RAIN MAY ALSO OCCUR OVER PORTIONS OF SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. THE STORMS WILL BE POSSIBLE MAINLY ALONG AND NORTH OF A NEARLY STATIONARY FRONT THAT EXTENDS FROM NORTHEAST IOWA INTO WESTERN KANSAS. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY THERE IS A SLIGHT CHANCE OF THUNDERSTORMS ACROSS PARTS OF SOUTHEAST NEBRASKA AND SOUTHWEST IOWA FROM MONDAY AFTERNOON INTO MONDAY NIGHT. AT THIS TIME...THE CHANCE FOR SEVERE STORMS SEEMS LOW. .SPOTTER INFORMATION STATEMENT... STORM SPOTTER ACTIVATION IS NOT LIKELY TODAY OR TONIGHT...BUT PLEASE PASS ALONG ANY REPORTS OF HAIL...WIND DAMAGE OR RAINFALL AMOUNTS OVER ONE INCH. MILLER
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
610 AM CDT SUN AUG 09 2009
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0608 AM HAIL COLUMBUS 41.43N 97.36W
08/09/2009 E1.75 INCH PLATTE NE LAW ENFORCEMENT
HAIL UP TO GOLFBALL SIZE WEST SIDE OF COLUMBUS
&&
MILLERPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
632 AM CDT SUN AUG 09 2009
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0605 AM HAIL COLUMBUS 41.43N 97.36W
08/09/2009 E2.00 INCH PLATTE NE TRAINED SPOTTER
HAIL UP TO TWO INCHES IN DIAMETER
&&
MILLERPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
655 AM CDT SUN AUG 09 2009
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0641 AM HAIL 4 N ROGERS 41.52N 96.92W
08/09/2009 E1.75 INCH COLFAX NE PUBLIC
&&
DFOBERTPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
702 AM CDT SUN AUG 09 2009
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0652 AM HAIL 4 NW NORTH BEND 41.51N 96.84W
08/09/2009 E1.75 INCH DODGE NE AMATEUR RADIO
&&
DFOBERTPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE OMAHA/VALLEY NEBRASKA
740 AM CDT SUN AUG 09 2009
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0730 AM TSTM WND DMG 3 NW BLAIR 41.57N 96.18W
08/09/2009 WASHINGTON NE TRAINED SPOTTER
SMALL TREE DOWN WIND EST 60 MPH
&&
DFOBERTThe Omaha radar (KOAX), 44 km away, was scanning. The volume nearest the first event began at 12:45 UTC.
2 hail, 1 thunderstorm wind. Local standard time, as filed.
A few hailstones a bit larger than golf ball-size fell in the Modale area. The larger hailstones were relatively few and far between.
Thunderstorm wind gusts estimated at 60 mph downed several large tree limbs in the Logan area and also caused some sporadic crop damage.
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: 178814, 178815, 178816.