Thunderstorms produced damaging winds in Ida Grove in Ida County, and flash flooding at Hornick in Woodbury County, on the morning of July 28th.
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 damaging winds in Ida Grove in Ida County, and flash flooding at Hornick in Woodbury County, on the morning of July 28th.
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 Jul 28, 2:51 AM CST, 1 hour 54 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SIOUX FALLS SD 351 AM CDT TUE JUL 28 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 351 AM CDT TUE JUL 28 2015 UNSEASONABLY STRONG WAVE MOVING ALONG THE INTERNATIONAL BORDER EARLY THIS MORNING...WITH STRONG WARM LAYER ALOFT AND LOW LEVEL JET ACROSS THE CWA. MCS WITH ORIGINS IN WESTERN HIGH PLAINS CONTINUES TO WORK EASTWARD ACROSS THE AREA EARLY THIS MORNING...FEATURING MAINLY SUB SEVERE WINDS AND HEAVY RAINFALL TO THIS POINT. SUSTAINING UPPER FORCING IS LIFTING NORTHWARD AWAY FROM THE AREA... AND SQUALL LINE PUSHING TOWARD A BIT MORE STABLE CONDITIONS OVERALL. SEE NO REASON THAT CONVECTIVE LINE WILL NOT CONTINUE TO MAINTAIN IN A GRADUALLY WEAKENING STATE AS IT PUSHES EAST AT 40 MPH THROUGH THE EARLY MORNING HOURS. LOW LEVEL SHEAR VECTORS SUGGEST MAY HAVE TO WATCH FOR BREAKDOWN TO A FEW VORTICES...BUT HAVE BEEN UNABLE TO ESTABLISH PERSISTENT ENOUGH UPDRAFTS ALONG THE LEADING EDGE TO THIS POINT... AND PROSPECT FOR KEEPING FOCUSED UPDRAFTS WILL NOT GET ANY BETTER WITH THE STATE OF THE AIRMASS. BOUNDARY WILL START TO LAY OUT A BIT MORE THROUGH THE SOUTHERN CWA WITH TIME EARLY MORNING...AND HAVE LINGERED SOME CHANCE LEVEL POPS INTO MID TO LATE MORNING ALONG THE LOWER MISSOURI VALLEY. MAIN SURFACE BOUNDARY AND SHARPER DRYING BACK WEST OF THE CWA AT 09Z...AND THIS MOISTURE DISCONTINUITY WILL PROVIDE THE NEXT CHANCE FOR PRECIPITATION DURING THE AFTERNOON HOURS. HOWEVER...WARM TEMPS ALOFT AND MODIFICATION OF THE AIRMASS BY SQUALL LINE WILL PROVE DIFFICULT TO DESTABILIZATION. ALTHOUGH SURFACE BOUNDARY HAS TRENDED JUST A TOUCH SLOWER THAN EARLIER RUN... QUESTION WHETHER WILL BE ABLE TO REACH A RENEWED CONVECTIVE POINT NEAR THE BOUNDARY AS IT WORKS TO CLEAR THE CWA DURING THE AFTERNOON. ENOUGH OF A CAP INDICATED ON FAIRLY WARM RAP TO REALLY LIMIT ANY POP MENTION TO LOWER CHANCE...AND SHOULD BE LARGELY CLEAR OF THE FAR SOUTHEAST CWA BY 00-01Z. ANY STORMS THAT DO FORM WOULD HAVE A CONDITIONAL SEVERE HAIL OR WIND THREAT ACROSS THE SOUTHEAST CWA AFTER 19-20Z. LIKELY GOING TO BE BIT SLOWER RELAXING HUMIDITY IN THE SOUTHERN AND EASTERN AREAS WITH BOUNDARY STILL WELL BACK IN NW IA AND SW MN BY 18Z...BUT EVENTUAL PASSAGE OF FRONT WILL BRING NOTICEABLY LOWER DEWPOINTS. STRONGER PUSH OF COOLING ALOFT WILL SETTLE IN TONIGHT AS UPPER LOW MOVES NORTH OF THE AREA...WITH WESTERN WINDS DECOUPLING SOME ACROSS THE SOUTH COMPARED TO NORTH. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 351 AM CDT TUE JUL 28 2015 WEDNESDAY AND THURSDAY BOTH LOOKING DRY AND WARM. WEDNESDAY ALSO LOOKING A BIT WINDY...ESPECIALLY NORTH OF INTERSTATE 90 WHERE A FEW GUSTS OF 30 TO 35 MPH ARE LIKELY. BY THURSDAY THE GRADIENT WILL WEAKEN BUT THE LOW LEVEL AIR MASS LOOKS A BIT WARMER. HIGHS WEDNESDAY IN THE LOWER TO MID 80S AND THURSDAY THE MID 80S TO LOWER 90S. IN THE OUTER PERIODS(FRIDAY THROUGH MONDAY)...NORTHWEST FLOW ALOFT IN PLACE THROUGH THE PERIOD WITH HIGHS MAINLY IN THE 80S AND LOWS MAINLY IN THE 60S. SATURDAY STILL LOOKING LIKE THE DAY WHEN IT COULD GET HOTTEST SO WILL KEEP SOME 90S ACROSS THE AREA. HUMIDITY WILL ALSO BE PRETTY NORMAL FOR THIS TIME OF YEAR...MAYBE JUST A TOUCH BELOW NORMAL...WITH DEW POINTS IN THE 60S. WILL MAINTAIN SOME SMALL CHANCES FOR THUNDERSTORMS SATURDAY THROUGH MONDAY BUT AT THIS TIME NOT CONFIDENT ENOUGH TO ADD ANYTHING OTHER THAN THAT. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 616 PM CDT MON JUL 27 2015 THUNDERSTORMS MAY DEVELOP ACROSS THE AREA OVERNIGHT...AFFECTING KHON AROUND 05Z...THEN KFSD AND KSUX LATER AS THE SYSTEM PUSHES TO THE EAST. WINDS WILL TRANSITION TO NORTHWESTERLY ON TUESDAY MORNING BEHIND THE SYSTEM. SOME GUIDANCE SUGGESTING THAT THERE COULD BE MVFR/IRF STRATUS DEVELOPMENT TOWARD TUESDAY MORNING. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && SHORT TERM...CHAPMAN LONG TERM...08 AVIATION...JM
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SIOUX FALLS SD 508 AM CDT TUE JUL 28 2015 IAZ001-002-MNZ071-072-080-081-089-090-097-098-SDZ038>040-050- 052>069-291015- LYON IA-OSCEOLA-LINCOLN MN-LYON MN-MURRAY-COTTONWOOD-NOBLES- JACKSON-PIPESTONE-ROCK-BEADLE-KINGSBURY-BROOKINGS-GREGORY-JERAULD- SANBORN-MINER-LAKE-MOODY-BRULE-AURORA-DAVISON-HANSON-MCCOOK- MINNEHAHA-CHARLES MIX-DOUGLAS-HUTCHINSON-TURNER-LINCOLN SD- BON HOMME-YANKTON- 508 AM CDT TUE JUL 28 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST IOWA...SOUTHWEST MINNESOTA...EAST CENTRAL SOUTH DAKOTA...SOUTH CENTRAL SOUTH DAKOTA AND SOUTHEAST SOUTH DAKOTA. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL BE POSSIBLE THIS EVENING AND OVERNIGHT. IAZ003-012>014-020>022-031-032-NEZ013-014-SDZ070-071-291015- DICKINSON-SIOUX-O'BRIEN-CLAY IA-PLYMOUTH-CHEROKEE-BUENA VISTA- WOODBURY-IDA-DIXON-DAKOTA-CLAY SD-UNION- 508 AM CDT TUE JUL 28 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST IOWA...NORTHEAST NEBRASKA AND SOUTHEAST SOUTH DAKOTA. .DAY ONE...TODAY AND TONIGHT SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS NORTHEAST NEBRASKA AND NORTHWEST IOWA EARLY THIS MORNING. HEAVY RAIN MAY CAUSE SOME TRAVEL PROBLEMS WITH 1 TO 2 INCHES POSSIBLE IN AN HOUR OR TWO. A FEW OF THE STORMS MAY ALSO PRODUCE WIND GUSTS TO 50 MPH AND SMALL HAIL THROUGH SUNRISE. AN ISOLATED THUNDERSTORM THIS AFTERNOON COULD PRODUCE 60 MPH WINDS AND HALF DOLLAR SIZED HAIL IF THUNDERSTORMS CAN REDEVELOP. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL GENERALLY NOT BE NEEDED TONIGHT.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1243 AM CDT TUE JUL 28 2015
...TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
...DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1215 AM TSTM WND GST CHAMBERLAIN 43.81N 99.32W
07/28/2015 M46 MPH BRULE SD AWOS
&&
NWS SIOUX FALLS SD
IRIS SYSTEMPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
140 AM CDT TUE JUL 28 2015
...TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
...DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0130 AM TSTM WND GST HURON 44.36N 98.22W
07/28/2015 M62 MPH BEADLE SD ASOS
&&
NWS SIOUX FALLS SD
IRIS SYSTEMPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
217 AM CDT TUE JUL 28 2015
...TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
...DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0215 AM TSTM WND GST 2 N MITCHELL 43.76N 98.03W
07/28/2015 M48 MPH DAVISON SD ASOS
&&
NWS SIOUX FALLS SD
IRIS SYSTEMThe Omaha radar (KOAX), 136 km away, was scanning. The volume nearest the first event began at 10:45 UTC.
1 thunderstorm wind, 1 flash flood. Local standard time, as filed.
Thunderstorm winds caused tree damage, including large limbs blown down. The winds also blew down at least two power lines.
Heavy rain caused flash flooding of several roads, including the area near the intersection of Highway 141 and road K64.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2015Every state in 2015This day in weather historyWarnings in Iowa, July 2015
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: 594498, 594500.