A thunderstorm produced damaging winds at Hull in Sioux County of northwest Iowa before daybreak on the morning of August 11th.
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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.
A thunderstorm produced damaging winds at Hull in Sioux County of northwest Iowa before daybreak on the morning of August 11th.
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 Aug 11, 12:27 AM CST, 1 hour 59 minutes earlier.
Area Forecast Discussion National Weather Service Sioux Falls SD 127 AM CDT THU AUG 11 2016 .SHORT TERM...(This evening through Thursday) Issued at 315 PM CDT Wed Aug 10 2016 As we move towards mid-afternoon, a moderately unstable environment has grown across the Tri-State area. However, forcing itself is on the minimal side. Still keeping a close eye on a few areas this afternoon, first being the old outflow boundary from overnight convection in Minnesota. As a more cooler and stable environment begins to heat up, starting to see this boundary jump northward rather quickly. Nevertheless, wherever this boundary falls will be a focal point or tracking point for overnight convection that forms in ND/SD. A secondary area we're monitoring is across northwest Iowa and adjacent areas of MN/NE where a large area of congested CU have developed as convective temperatures are met. A rather highly unstable (MLCAPE 3000+ J/KG) but weakly forced environment will persist into the early evening hours. It's possible to see a few stronger storms form on the far eastern fringes of the CWA, with a diurnal downtrend this evening. The main focus tonight will be on a frontal boundary stalled across west central and northeastern SD this afternoon. A highly unstable environment has developed, with elevated convection already ongoing across portions of North Dakota and extreme northern South Dakota. This initial convection across ND/SD should remain elevated into the late afternoon hours, but as the warm sector lifts northward, an upscale growth will likely begin late this afternoon and early evening. Dominating east to northeasterly flow should keep this potential MCS tracking eastward tonight, but would not rule out a bit of a southeastern track. Focus then turns to an area west of the CWA along a stationary boundary from just east of Rapid City northeast towards Aberdeen. This boundary has retrograded slightly further west than earlier models where suggesting. With a very warm and humid environment ahead of the boundary, expecting to see a bit more CU begin to develop as we move through the afternoon and convective temperatures are met. However, upscale growth along the boundary may lag until the very late afternoon or early evening hours until the nose of a more impressive upper jet edges into the region. As low-lvl convergence begins to increase along the front, several CAMs are indicating high based convection will begin to build along a Okaton to Pierre to Aberdeen line towards 00z. Given a very unstable environment and increasing shear aloft, initial storms should display supercellular characteristics. As we move through the evening and into the overnight hours, we should gradually see more cold pool development and mergers into larger clusters as the front tries to slide eastward. The eastward timing should be quite late, which may mitigate the severe weather risk to a degree. However, areas west of the I-29 corridor should see an increased risk through midnight, with storms moving eastward well after midnight. With the LLJ veering, may also see elevated convection develop ahead of the front prior to the pre-dawn hours. Initial risks will be very large hail (2"+) combined with 70 mph winds. Eventually should bowing segments form, threat would transition to wind. The biggest question tonight is just how much coverage in storms there will be. As we move into Thursday the aforementioned front may likely bisect the CWA by mid-day. Another muggy day is anticipated, and soundings are suggesting limited capping by mid-day. While temperatures with increased cloud cover, may only reach into the lower 80s, a fairly large reservoir of elevated instability will persist through the day. Expectations are that we'll have several clusters of storms develop by mid-day with continued upscale growth by mid-afternoon. Shear is rather limited through the day, but given elevated instability would not be surprised to have a few severe storms into the early afternoon. Of bigger concern may be the potential for localized heavy rainfall.PWAT values by Tuesday afternoon will be pushing 200% of normal for early August. With the flow running near parallel to the boundary, could see the potential for flash flooding, especially over areas along and south of I-90. While we have been dry recently, any flooding could be the result of rainfall and run-off rates. In coordination with other offices, will not issue any type of watch, but one may need to be considered after trends of overnight convection are shown. .LONG TERM...(Thursday night through Wednesday) Issued at 315 PM CDT Wed Aug 10 2016 Ongoing shower and thunderstorm chances extend into the overnight hours on Thursday night. Frontal boundary will exit the region to the southeast, with showers and storms gradually diminishing from northwest to southeast overnight. The best chance for storms will be across the southeast half of the region, particularly in far southeast SD into northwest Iowa and portions of southwest MN. Marginal severe threat will wane fairly quickly in the evening, but seasonally very high precipitable water values nearing 2 inches, along with potential for precipitation to move parallel with the front will keep heavy rainfall as the main threat. In particular, will need to watch the area east of a Yankton to Windom line for heavy rainfall and possible flooding concerns. Precipitation exits the bulk of the region by daybreak on Friday, perhaps with some isolated showers potentially lingering near the Iowa Great Lakes into the morning hours. Slightly cooler airmass begins working into the region on Friday with northern stream trough sliding across the northern Plains. High temperatures will reach the 80s with much lower dewpoints returning. Troughing this weekend transitions into a flat ridge early next week. Overall pattern remains dry with temperatures warming back into the mid 80s to lower 90s next week, but dewpoints stay in relatively low. Models are beginning to hint at a shortwave tracking through the northern Plains Monday night or Tuesday, but will leave precipitation chances less than 25 percent for now given the inconsistencies in timing and track. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) Issued at 127 AM CDT Thu Aug 11 2016 Convective trends provide the greatest challenge to aviation elements through the next 24 hours. Current line of convection pushing through southeast South Dakota with wind gusts 40 to 55 mph as it approaches KFSD after 07z. Ceilings also briefly will lower into the MVFR range, along with heavy rain reducing visibility to IFR or lower MVFR for a brief time. After line moves through during the predawn hours, a lingering threat for more isolated shower and thunder activity will persist south of I-90 through early morning. Storms are expected to redevelop by afternoon near boundary working through the area, and could be severe in parts of northwest Iowa through early evening. Conditions in storms will most likely briefly visit the MVFR or IFR levels on both ceiling and visibility fronts. && .FSD Watches/Warnings/Advisories... SD...None. MN...None. IA...None. NE...None. && SHORT TERM...Dux LONG TERM... AVIATION...Chapman
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SIOUX FALLS SD 650 PM CDT WED AUG 10 2016 MNZ071-072-080-081-089-090-097-098-SDZ039-040-054>056-061-062- 120000- LINCOLN MN-LYON MN-MURRAY-COTTONWOOD-NOBLES-JACKSON-PIPESTONE- ROCK-KINGSBURY-BROOKINGS-MINER-LAKE-MOODY-MCCOOK-MINNEHAHA- 650 PM CDT WED AUG 10 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST MINNESOTA...EAST CENTRAL SOUTH DAKOTA AND SOUTHEAST SOUTH DAKOTA. .DAY ONE...TONIGHT SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP MAINLY AFTER MIDNIGHT. AN ISOLATED STORM COULD PRODUCE HAIL TO THE SIZE OF HALF DOLLARS AND WIND GUSTS TO 70 MPH. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY SHOWERS AND THUNDERSTORMS WILL BECOME INCREASINGLY LIKELY THROUGH THE DAY THURSDAY...WITH THE BEST CHANCE THURSDAY AFTERNOON AND EVENING. SEVERE WEATHER IS NOT LIKELY BUT HEAVY RAIN WILL BE POSSIBLE WITH SOME OF THE STORMS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL BE POSSIBLE AFTER MIDNIGHT. IAZ001>003-012>014-020>022-031-032-NEZ013-014-SDZ066-067-069>071- 120000- LYON IA-OSCEOLA-DICKINSON-SIOUX-O'BRIEN-CLAY IA-PLYMOUTH-CHEROKEE- BUENA VISTA-WOODBURY-IDA-DIXON-DAKOTA-TURNER-LINCOLN SD-YANKTON- CLAY SD-UNION- 650 PM CDT WED AUG 10 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST IOWA...WEST CENTRAL IOWA...NORTHEAST NEBRASKA AND SOUTHEAST SOUTH DAKOTA. .DAY ONE...TONIGHT ISOLATED THUNDERSTORMS WILL BE POSSIBLE AFTER ABOUT 3 AM TONIGHT. THESE STORMS ARE NOT EXPECTED TO BE SEVERE. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY THE CHANCE FOR THUNDERSTORMS WILL INCREASE LATE THURSDAY AFTERNOON AND CONTINUE INTO THURSDAY NIGHT. AN ISOLATED STORM COULD PRODUCE HAIL TO THE SIZE OF QUARTERS AND WIND GUSTS TO 60 MPH. HOWEVER THE BIGGER THREAT SHOULD BE LOCALLY HEAVY RAIN. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED. SDZ038-050-052-053-057>060-063>065-068-120000- BEADLE-GREGORY-JERAULD-SANBORN-BRULE-AURORA-DAVISON-HANSON- CHARLES MIX-DOUGLAS-HUTCHINSON-BON HOMME- 650 PM CDT WED AUG 10 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL SOUTH DAKOTA...EAST CENTRAL SOUTH DAKOTA...SOUTH CENTRAL SOUTH DAKOTA AND SOUTHEAST SOUTH DAKOTA. .DAY ONE...TONIGHT SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED AFTER 900 PM CDT...A FEW OF WHICH COULD PRODUCE HAIL TO THE SIZE OF HALF DOLLARS AND WIND GUSTS TO 70 MPH. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY SCATTERED THUNDERSTORMS WILL REMAIN POSSIBLE INTO THURSDAY AFTERNOON BUT THESE STORMS ARE NOT EXPECTED TO BECOME SEVERE. ISOLATED STORMS COULD HOWEVER PRODUCE LOCALIZED HEAVY RAINFALL. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS POSSIBLE AFTER 9 PM CDT.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1215 AM CDT THU AUG 11 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1200 AM TSTM WND DMG 2 S HURON 44.33N 98.22W
08/11/2016 BEADLE SD STORM CHASER
HIGH WINDS ESTIMATED AT 80 MPH. GROCERY CART
STANDS KNOCKED OVER. TREES SNAPPED.
&&
NWS SIOUX FALLS SD
IRIS SYSTEMPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1216 AM CDT THU AUG 11 2016
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1149 PM TSTM WND GST HURON 44.36N 98.22W
08/10/2016 U72 MPH BEADLE SD ASOS
.
&&
NWS SIOUX FALLS SD
IRIS SYSTEMThe Sioux Falls radar (KFSD), 66 km away, was scanning. The volume nearest the first event began at 08:24 UTC.
1 thunderstorm wind. Local standard time, as filed.
Thunderstorm winds caused tree damage, including several trees blown down. Some of the fallen trees blocked a road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2016Every state in 2016This day in weather historyWarnings in Iowa, August 2016
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: 656475.