Thunderstorms produced damaging winds at several locations along a long path from Gregory to Brookings Counties in southeast South Dakota during the evening of August 19th. There was also one report of marginally large hail.
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 at several locations along a long path from Gregory to Brookings Counties in southeast South Dakota during the evening of August 19th. There was also one report of marginally large hail.
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 19, 2:18 PM CST, 4 hours 52 minutes earlier.
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 318 PM CDT THU AUG 19 2010 .DISCUSSION... MID AFTN SFC ANLYS INDICATES THAT SFC WAVE HAS MOVED INTO SCNTRL SD BTWN KPIR AND K9V9...WITH DIFFUSE WMFNT N OF INTERSTATE 90 INTO SRN MN. DRYLINE OUT IN SCNTRL SD AND NCNTRL NEBRASKA. DESTABILIZATION HAS BEEN SOMEWHAT HURT BY THICKER MID TO HIGH LVL CLDS WHICH HAVE BEEN STREAMING IN FROM THE SW THRU THE AFTN. BEEN ATTEMPTING TO FOLLOW THE WEAKENING OF THE CAP THROUGH THE DAY...AND HAS NOT BEEN TOO EASY GIVEN SPC POWER OUTAGE...AND FACT THAT RUC IS FAR ENOUGH OFF ON SFC T/TD FIELDS THAT IS PRACTICALLY USELESS. REALLY IS NO REASON TO EXPECT CAP TO BREAK VIA DIURNAL HEATING...AND EVEN STRONG ENOUGH CAP THAT LOW LVL CONVERGENCE FIELD IS LKLY UNIMPOSING TOWARD CONVECTIVE INITIATION. THEREFORE...HAVE TRIED TO TIME THE CONVECTIVE DEVELOPMENT TOWARD APPROACH OF UPR WAVE AND ASSOCIATED COOLING OF MID LVLS. MAY YET SEE A LITTLE ELEVATED TS DEVELOP LATE AFTN AND EARLY EVNG AS FIRST OF WAVES APPROACHES FROM SW...NOTED IN WV IMAGE LIFTING NWRD THRU NEBRASKA. SECONDARY WAVE MOVING THRU NEBRASKA PANHANDLE AND IN 03Z-06Z PD LOOK TO GET BETTER INFLUENCE FROM WAVE AND SHUD ALLOW WNKG CAP TO BREAK CLOSER TO LOCATION OF TRIPLE PT OF WRN DRYLINE/WMFNT. EXPECT THAT MODE WL INITIALLY BE ISOLD...BUT EXPAND IN COVERAGE FEEDING OFF LLJ AHEAD OF WAVE. SVR THREAT IN ORDER...BUT PRIMARILY EXPECT WIND OVER OTHER MODES AFTER INITIAL DEVELOPMENT...AND GREATER FROM SERN SD INTO SW MN...LESSER HEADING SE THRU NW IA. MID LVL WNDS APPEAR STRONG ENOUGH TO DRIVE A HIGHER ORGANIZATIONAL LEVEL TO STORMS...EXHIBITING BOWING STRUCTURES. BEST CHC FOR CONVECTION WL BE NORTH OF I90...BUT MOST ALL LOCATIONS WL SEE RAINFALL GIVE THE STRENGTH OF FORCING THRU THE NIGHT. MAIN PV APPROACHES LATE IN NIGHT...AND SHUD HELP KEEP THREAT LINGERING IN SE...DESPITE AN ATTEMPT FOR SYSTEM TO BECOME FORWARD PROPAGATING. /CHAPMAN ON FRIDAY...THE MAIN CHALLENGE REMAINS HOW FAR BACK TO HANG THE CHCS FOR CONVECTION. AS IN PREV RUNS...THERE IS A FAIR AMOUNT OF UPPER QG FORCING PRESENT ACROSS THE ERN HALF OF OUR FA IN THE MORNING... COUPLED WITH ABUNDANT MID LEVEL PV AND LOW LEVEL THTE ADVECTION. DUE TO THE STUBBORN PRESENCE OF THESE FEATURES...DECIDED TO EXTEND OUR SLGT CHC POPS WWD EARLY IN THE MORNING TO A LINE ALONG AND E OF TYNDALL SD TO BROOKINGS SD. THEN IN THE AFTN...WE WILL BE DEALING WITH A CDFNT PASSAGE...REALLY LITTLE MORE THAN A WIND SHIFT LINE AS THE THERMAL GRADIENT IS ACTUALLY WARMER BEHIND THE FRONT THAN AHEAD OF IT IN OUR FA. SO DECIDED TO KEEP OUR LOW POPS GOING ALONG AND E OF I 29 DURING THE AFTN ALONG THE WIND SHIFT. WILL BE INTERESTING TO SEE IF ANY STORM DEVELOPMENT WHICH MAY OCCUR IN THE AFTN MAY BE MARGINALLY SEVERE. SO AS FAR AS TEMPERATURES...NEARLY DID A FULL MIXOUT OF H85 TEMPS WHICH WL GIVE OUR FA A LOT OF MID 80S TO LOWER 90S...AND ALSO ACCOUNTING FOR WHAT MAY BE A FAIR AMOUNT OF RESIDUAL CLOUD COVER IN OUR EAST DURING THE AFTN. THEN FROM FRI NIGHT THRU THE WEEKEND...THINGS ARE PRETTY BASIC. OUR WELL ADVERTISED BUILDING HEIGHTS ALOFT ARE CREATING QUITE A STOUT RIDGE IN THE MIDDLE CONUS. ATTM...SEE NO THREAT FOR ANY ELEVATED TSRA SAT NIGHT AS THE WINDS SHIFT BACK AROUND TO THE S AND SE DUE TO A HORRIFIC LACK OF MOISTURE. THEREFORE BELIEVE WE ARE JUST LOOKING AT VERY WARM TEMPERATURES WHICH ARE WELL ABV NORMAL...AND INCREASING HUMIDITY AGAIN. IN THE EXTENDED SUN NIGHT THROUGH THURSDAY...MODELS CONT TO BE IN GENERAL AGREEMENT WITH THE LARGE SCALE. THEY ARE STILL SHOWING AN UPPER WAVE/SFC CDFNT PASSAGE MON AFTERNOON AND MON NIGHT. THE LATEST SERIES OF MODELS AND LAST COUPLE OF RUNS HAVE ALL SPED UP THE FROPA TIMING ABOUT 6 TO 12 HRS. NOT SURE IF THAT IS TO BE TRUSTED YET OR NOT. AT ANY RATE...ONLY CHC POPS ARE STILL WARRANTED AS IT LOOKS TO BE JUST A BASIC CDFNT PASSAGE...QUICK MOVG AND LIKELY PRODUCING ONLY SCT TO BKN CONVECTION. ONE PROBLEM IS THE VARIOUS MODELS ARE SHOWING A LARGE CUTOFF LOW MEANDERING UP THE EAST COAST EARLY NEXT WEEK WHICH IS HAVING SOME AFFECT ON OUR DEEPER LOW LEVEL MOISTURE. WE DO HAVE SOME MOISTURE TO WORK WITH MON NIGHT...BUT IT COULD BE BETTER. AFTER THE FROPA...WE ARE LOOKING AT MUCH COOLER TEMPERATURES AND DRIER AIR TUE THRU THURSDAY. /MJF && .AVIATION... VFR CONDITIONS WILL PREVAIL OTHERWISE WITH LID OF WARM TMPS ALFT LIMITING CONVECTIVE THREAT THRU THE REMAINDER OF THE AFTN AND INTO EARLY EVNG...WITH ONLY SUB MENTIONABLE THREAT FOR AREAS IN JAMES VLY AND TOWARD BKX/MML AREAS BY EARLY EVNG. STRONG UPPER WAVE MOVING OVER THE CENTRAL ROCKIES AND INTO THE WRN PLAINS THIS EVENING SHUD IGNITE THREAT FOR TSRA ACROSS THE FORECAST AREA TONIGHT...MAINLY 02Z TO 10Z. BRIEF PDS MVFR-IFR VSBYS AND MVFR CIGS LKLY WITH THE TSRA STARTING EARLY TO MID EVNG FOR KHON AREA...BUT LKLY WAITING UNTIL LATE EVENING FOR KFSD AND AFT MIDNIGHT FOR KSUX. /CHAPMAN && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SIOUX FALLS SD 1145 AM CDT THU AUG 19 2010 SDZ038>040-050-052>071-MNZ071-072-080-081-089-090-097-098- IAZ001>003-012>014-020>022-031-032-NEZ013-014-201200- 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- 1145 AM CDT THU AUG 19 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST SOUTH DAKOTA... SOUTHWEST MINNESOTA...NORTHWEST IOWA...AND NORTHEAST NEBRASKA. .DAY ONE...TODAY AND TONIGHT THUNDERSTORMS... ISOLATED SHOWERS AND THUNDERSTORMS WILL CONTINUE MIDDAY NORTH OF HIGHWAY 14. THESE STORMS WILL NOT BE SEVERE. BY VERY LATE AFTERNOON OR EARLY EVENING...HOWEVER...THERE WILL BE A SLIGHT CHANCE FOR STORMS TO REDEVELOP THROUGH THE HIGHWAY 14 CORRIDOR...WITH A SLIGHTLY BETTER CHANCE FOR AN ISOLATED STORM IN LOWER BRULE AREAS OF SOUTH CENTRAL SOUTH DAKOTA. IF A STORM CAN DEVELOP PRIOR TO 8 PM...IT WOULD RAPIDLY BECOME SEVERE...WITH A THREAT FOR LARGE HAIL TO TEA CUP SIZE ALONG WITH DAMAGING WIND GUSTS OVER 65 MPH. THERE WOULD ALSO BE A SMALL WINDOW FOR TORNADIC DEVELOPMENT NORTH OF A WESSINGTON SPRINGS TO WINDOM LINE. THUNDERSTORM COVERAGE SHOULD INCREASE CONSIDERABLY THROUGH THE EVENING THROUGH THE JAMES VALLEY...WITH STORMS PUSHING EASTWARD BY MID TO LATE EVENING INTO SOUTHWEST MINNESOTA AND THE INTERSTATE 29 CORRIDOR. AS STORMS BECOME MORE WIDESPREAD...THEY WILL LIKELY ORGANIZE INTO BOWING SEGMENTS WHICH COULD PRODUCE DAMAGING WIND GUSTS TO AROUND 80 MPH...EVEN INTO FAR NORTHWEST IOWA AFTER MIDNIGHT. FLOODING... MINOR RIVER FLOODING ALONG PORTIONS OF THE LOWER JAMES RIVER IS FORECAST TO DROP BELOW FLOOD STAGE LATE NEXT WEEK. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY THUNDERSTORMS MAY OCCUR ON FRIDAY IN AREAS FROM THE INTERSTATE 29 CORRIDOR AND EAST. THESE STORMS ARE NOT EXPECTED TO BE SEVERE. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL BE LIKELY AFTER 6 PM CDT...STARTING IN AREAS FROM THE JAMES VALLEY WEST AND ALSO EASTWARD ALONG AND JUST SOUTH OF HIGHWAY 14... THEN AFTER 9 PM CDT IN SOUTHEAST SOUTH DAKOTA...FAR NORTHWEST IOWA...NORTHEAST NEBRASKA...AND THE REMAINDER OF SOUTHWEST MINNESOTA. && FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE AT WWW.WEATHER.GOV/SIOUXFALLS. THIS INCLUDES THE GRAPHICAL HAZARDOUS WEATHER OUTLOOK.
The North Platte radar (KLNX), 183 km away, was scanning. The volume nearest the first event began at 01:10 UTC.
12 thunderstorm wind, 1 hail. Local standard time, as filed.
Thunderstorm winds caused tree damage, including branches blown down.
Thunderstorm winds blew down power poles and lines.
Thunderstorm winds caused tree damage, including branches blown down.
Thunderstorm winds blew down branches from several trees.
Thunderstorm winds caused scattered tree damage. The winds were accompanied by very heavy rain.
Thunderstorm winds blew the roof off a hog barn.
Thunderstorm winds caused tree damage, including several small branches blown down.
Thunderstorm winds caused tree damage, including several trees snapped off.
Thunderstorm winds caused widespread tree damage, including some trees over 3 feet in diameter blown down.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in South Dakota in 2010Every state in 2010This day in weather historyWarnings in South Dakota, August 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: 257175, 257177, 257181, 257281, 257284, 257285, 257287, 257288, 257289, 257290, 257291, 257292, 257293.