Thunderstorms produced marginally large hail and damaging wind gusts in Plymouth and Cherokee Counties of northwest Iowa during the late afternoon of September 15th.
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 FSD wrote it up.
Thunderstorms produced marginally large hail and damaging wind gusts in Plymouth and Cherokee Counties of northwest Iowa during the late afternoon of September 15th.
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 Sioux Falls, SD wrote its last area forecast discussion before the first event at Sep 15, 2:09 PM CST, 2 hours 26 minutes earlier.
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 309 PM CDT WED SEP 15 2010 .DISCUSSION... COMPACT UPR CIRCULATION MOVING OUT OF CNTRL SD THIS AFTN...WITH ZONE OF INTENSE LIFT ON NOSE OF STRONG PV ADVECTION. CONVECTION DEVELOPING RAPIDLY EARLY AFTN JUST BEHIND INITIAL PREFRONTAL WIND SHIFT AND ALONG MAIN WIND SHIFT. ENVIRONMENTAL PARAMETERS SUGGEST SVR THREAT VALIDATED...WITH 0-6KM DEEP SHEAR OF 40-45 KTS...WITH STRONGEST 0-1KM SHEAR POSITIONED NEAR WARM FRONTAL BNDRY FROM WK SFC LOW ARND KHON...THROUGH AREAS BETWEEN KMWM AND KMJQ. THIS WOULD BE THE PRIMARY TORNADIC THREAT AREA THROUGH THE NEXT SEVERAL HOURS...BUT THE CAPE AND SHEAR ENOUGH TO EXPECT ORGANIZED STORMS FARTHER SWRD TO PRODUCE HAIL AND WINDS AS WELL AS THOSE TO THE NORTH. CONVECTION SHUD BE TIED TO UPR CIRC CORE AND SLINGSHOTTING BNDRY INTO THE EVENING HOURS...THEN REST OF NIGHT DEALS WITH WINDS AND CLOUDS...WHICH LOOK TO BE FAIRLY PERSISTENT. WINDS SHUD DIMINISH LAST PART OF NIGHT...AND MAY BECOME LIGHT IN JAMES VALLEY WHERE CORE OF SFC RIDGE BUILDS IN LATE. TOWARD THE E...CONTINUED OFF SFC CAA WL KEEP NLY WINDS UP AND ALSO HELP KEEP TMPS UNDER CLDS FROM BOTTOMING OUT. THURSDAY LOOKS LIKE A PLEASANT DAY AS A WEAK RIDGE OF HIGH PRESSURE MOVES THROUGH THE CWA. THIS WILL BRING LIGHT WINDS TO THE EAST HALF OF THE CWA MOST OF THE DAY...WHILE AREAS IN THE WEST WILL SEE A SOUTHERLY WIND INCREASE TO ABOUT 10 TO 15 MPH IN THE AFTERNOON. MAY SEE SOME STRATUS AS WELL IN THE EAST...BUT CONFIDENCE NOT REAL HIGH...SO JUST GOING MOSTLY CLOUDY IN THE MORNING...THEN BECOMING MOSTLY SUNNY REMAINDER OF THE DAY. WILL KEEP THE HIGHS ABOUT THE SAME RANGING FROM THE MID 60S IN SW MN TO THE MID 70S IN CENTRAL SD. A WEAK WAVE WILL SCRAPE THE NORTHERN CWA LATE THURSDAY INTO THURSDAY NIGHT...BUT MOISTURE IS NOT TOO IMPRESSIVE...SO WILL ONLY CARRY A SMALL POP FOR THIS THURSDAY NIGHT. WITH THE INCOMING COOL FRONT WILL KEEP LOWS RELATIVELY MILD...AND IN THE LOWER TO MID 50S. FRIDAY INTO SATURDAY LOOKS FAIRLY QUIET WITH AN OUTSIDE CHANCE FOR A FEW SHOWERS IN THE FAR SOUTH ON SATURDAY. OTHERWISE...COOLER AIR WILL SLOWLY FILTER IN WITH HIGHS IN THE 60S BOTH DAYS...A FEW 70S FAR SOUTH ON FRIDAY. IN THE LATTER PERIODS(SUN/WED)...MODELS ARE IN GENERAL AGREEMENT IN SUGGESTING A DECENT SYSTEM EARLY IN THE PERIOD BUT TIMING OF THIS WAVE/FRONT NOT QUITE AS AGREEABLE. WITH THE MODELS TRENDING A LITTLE SLOWER WILL TAKE OUT POPS FOR MOST OF SUNDAY AND ADD SOME POPS IN FOR TUESDAY. WILL HAVE TO WATCH THIS PERIOD AS A LITTLE SEVERE WEATHER AND ESPECIALLY HEAVY RAIN WILL BE A THREAT. COOLER AND DRIER AIR WILL WORK IN BEHIND THIS SYSTEM LATE TUESDAY INTO WEDNESDAY SO GOING A LITTLE COOLER ON WEDNESDAY. KEPT TEMPERATURES RELATIVELY COOL ON SUNDAY WITH HIGHS MAINLY IN THE 60S. COOL HIGH PRESSURE WILL BE WORKING SLOWLY EAST AND WILL NEED TO WATCH A FEW AREAS...ESPECIALLY SW MN...FOR SOME FROST POTENTIAL. BY MONDAY THE WAVE WILL BE MOVING INTO THE ROCKIES AND SOUTHERLY FLOW WILL DEVELOP AHEAD...LIFTING MORE MOIST AIR NORTHWARD. AT THIS TIME MONDAY AFTERNOON INTO TUESDAY MORNING LOOKS LIKE THE BEST CHANCE FOR RAIN AND THUNDERSTORMS. /08 && .AVIATION... CONVECTION IN THE SHORT RANGE THE LARGEST THREAT. SHUD BE NARROW WINDOW FOR CONVECTION AT ALL TAF SITES...ONE TO TWO HOURS...TIED TO FROPA FOR KFSD AND KSUX...WHILE FOR KHON...THE THUNDER THREAT SHUD END BY 21Z FOR THE MOST PART. CIGS/VSBYS LKLY BRIEFLY IN THE IFR RANGE WITH STRONGEST CORES TO STORMS. REFER TO TOR WATCH FOR SVR THREAT WITH HAIL/WINDS. REMAINDER OF AVIATION CONCERN FOR THE NIGHT WL BE DEALIG WITH LOWER CIGS. LOCAL STUDY ON MOISTURE AND INVERSION STRENGTH CASTS A BIT OF DOUBT ON PERSISTENCE OR EVEN EXISTANCE OF LOW CIGS PAST THE INITIAL POST PRECIP PUSH THIS EVENING. IF CLOUDS DO HAPPEN TO BREAK...WHICH IS A STRONGER THREAT FOR KHON UNDER LOW LVL RIDGE LATE...WL BE VERY OPEN TO FOG DEVELOPING AND EVEN LOWER CIGS. /CHAPMAN && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SIOUX FALLS SD 1153 AM CDT WED SEP 15 2010 SDZ038>040-050-052>071-MNZ071-072-080-081-089-090-097-098- IAZ001>003-012>014-020>022-031-032-NEZ013-014-161200- AURORA-BEADLE-BON HOMME-BROOKINGS-BRULE-BUENA VISTA IA- CHARLES MIX-CHEROKEE IA-CLAY-CLAY IA-COTTONWOOD MN-DAKOTA NE- DAVISON-DICKINSON IA-DIXON NE-DOUGLAS-GREGORY-HANSON-HUTCHINSON- IDA IA-JACKSON MN-JERAULD-KINGSBURY-LAKE-LINCOLN-LINCOLN MN- LYON IA-LYON MN-MCCOOK-MINER-MINNEHAHA-MOODY-MURRAY MN-NOBLES MN- OBRIEN IA-OSCEOLA IA-PIPESTONE MN-PLYMOUTH IA-ROCK MN-SANBORN- SIOUX IA-TURNER-UNION-WOODBURY IA-YANKTON- 1153 AM CDT WED SEP 15 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST SOUTH DAKOTA... SOUTHWEST MINNESOTA...NORTHWEST IOWA...AND NORTHEAST NEBRASKA. .DAY ONE...TODAY AND TONIGHT THUNDERSTORMS... AFTER A FAIRLY QUIET PERIOD LATE MORNING...SCATTERED THUNDERSTORMS ARE EXPECTED TO REDEVELOP MIDDAY INTO EARLY AFTERNOON IN THE JAMES VALLEY. THESE STORMS WILL BUILD EASTWARD THROUGH THE AFTERNOON...GAINING STRENGTH HEADING TOWARD THE INTERSTATE 29 CORRIDOR BY MID TO LATE AFTERNOON. THE BEST FOCUS FOR STORMS LOOKS TO OCCUR FOR AREAS MAINLY ALONG AND NORTH OF INTERSTATE 90 IN SOUTH DAKOTA...THEN SOUTHEAST THROUGH THE SPENCER AREA OF NORTHWEST IOWA. WHILE THE PRIMARY THREAT FROM STORMS WILL BE HAIL UP TO HALF DOLLAR SIZE AND WINDS TO 65 MPH...A SMALL THREAT FOR TORNADIC STORMS SHOULD EXIST FROM PARTS OF EAST CENTRAL SOUTH DAKOTA EARLY TO MID AFTERNOON...THEN SOUTHEAST TOWARD THE IOWA GREAT LAKES AND SPENCER AREAS BY VERY LATE AFTERNOON AND EARLY EVENING. FLOODING... LOWLAND FLOODING WILL CONTINUE ALONG PORTIONS OF THE MISSOURI RIVER BETWEEN FORT RANDALL DAM AND LEWIS AND CLARK LAKE FOR THE NEXT FEW WEEKS. MINOR FLOODING WILL CONTINUE ALONG THE JAMES RIVER AROUND HURON FOR AROUND A WEEK...AND PERHAPS AS LONG AS TWO WEEKS FOR AREAS NEAR FORESTBURG AND MITCHELL. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY SHOWERS AND THUNDERSTORMS ARE EXPECTED FROM SUNDAY NIGHT THROUGH MONDAY NIGHT ACROSS THE AREA. AREAS OF HEAVY RAINFALL WILL BE POSSIBLE...AND IT APPEARS THERE COULD BE A SLIGHTLY BETTER THREAT FOR THIS HEAVY RAIN TO OCCUR IN AREAS NORTH OF INTERSTATE 90 AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL BE POSSIBLE AFTER 2 PM IN EAST CENTRAL SOUTH DAKOTA...AND AFTER 4 PM ALONG AND EAST OF A LINE FROM BROOKINGS TO SIOUX CITY. && FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE AT WWW.WEATHER.GOV/SIOUXFALLS. THIS INCLUDES THE GRAPHICAL HAZARDOUS WEATHER OUTLOOK.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
338 PM CDT WED SEP 15 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0320 PM HAIL 5 NE TYNDALL 43.04N 97.80W
09/15/2010 E1.00 INCH BON HOMME SD PUBLIC
DIME TO QUARTER SIZE HAIL ALMOST COVERED THE GROUND. ALSO
ESTIMATED 40MPH WIND GUSTS.
&&
WILLIAMSPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
404 PM CDT WED SEP 15 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0347 PM HAIL 4 NNW WINFRED 44.05N 97.38W
09/15/2010 E1.00 INCH MINER SD PUBLIC
PEA TO QUARTER SIZE HAIL.
&&
WILLIAMSPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
412 PM CDT WED SEP 15 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0400 PM HAIL 3 NE UTICA 43.01N 97.44W
09/15/2010 E1.00 INCH YANKTON SD TRAINED SPOTTER
PEA TO QUARTER SIZE HAIL.
&&
WILLIAMSPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
423 PM CDT WED SEP 15 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0330 PM HAIL LESTERVILLE 43.04N 97.59W
09/15/2010 E1.00 INCH YANKTON SD EMERGENCY MNGR
&&
LAFLINPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
434 PM CDT WED SEP 15 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0405 PM HAIL 5 SW MAYFIELD 43.04N 97.40W
09/15/2010 E1.00 INCH YANKTON SD PUBLIC
&&
WILLIAMSPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
530 PM CDT WED SEP 15 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0519 PM HAIL 3 WNW ELK POINT 42.69N 96.74W
09/15/2010 E1.00 INCH UNION SD PUBLIC
MARBLE TO QUARTER SIZE HAIL COVERED THE GROUND.
&&
WILLIAMSThe Sioux Falls radar (KFSD), 94 km away, was scanning. The volume nearest the first event began at 22:33 UTC.
4 thunderstorm wind, 2 hail. Local standard time, as filed.
Thunderstorm winds caused tree damage, including a few branches blown down.
Thunderstorm winds caused tree damage, including several branches blown down. The winds were accompanied by small hail.
Thunderstorm winds caused tree damage, including a few branches blown down. The winds were accompanied by small hail.
Thunderstorm winds caused tree damage, including several branches blown down. the winds were accompanied by small hail.
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: 261066, 261067, 261068, 261069, 261070, 261071.