1 thunderstorm wind, as filed by the National Weather Service.
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 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 21, 2:57 PM CST, 2 hours 3 minutes earlier.
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 357 PM CDT WED JUL 21 2004 .DISCUSSION... IN THE SHORT TERM...CONCERN CENTERS ON CONVECTIVE CHANCES IN THE EVENING AND THEN PRECIP CHANCES WITH COLD CORE TROUGH MOVING IN THROUGH THE WEEKEND. FOR THIS EVENING...SFC BOUNDAR EXTENDS INTO THE WRN CWA. THUNDERSTORMS HAVE DEVELOPED FROM KABR INTO K9V9 AREA. SHEAR IS LIMITED SO STORMS WILL HAVE LITTLE STRUCTURE THROUGH THE EVENING. THE BIGGEST CONCERN WILL BE MIDLEVEL DRY AIR MOVING IN WHICH WILL ALLOW FOR SOME LOWERING OF WET BULB ZEROS AND INCREASING THE THETA-E DIFFERENCE. SO THERE COULD BE ISOL LARGE HAIL AND MICORBURSTS THROUGH THE EARLY EVENING. STORMS SHOULD DIE RAPIDLY WITH LOSS OF SOLAR HEATING AT SUNSET. HOWEVER...STRONGER 850 MB GRADIENT SINKS TO I90 CORRIDOR LATER TONIGHT AS ANOTHER WAVE MOVES OUT OF THE ROCKIES AND INTO THE PLAINS. EXPECT CONVECTION TO DEVELOP ALONG THIS BOUNDARY IN WRN SD. PRECIPITATION COULD REACH THE FAR WRN ZONES AFTER MIDNIGHT AND HAVE CONTINUED A CHANCE THEN. STRONG FRONTOGENESIS WILL HELP PROVIDE LIFT WITH UPPER WAVE THU MORNING ACROSS TEH SWRN CWA. THIS FRONT WILL RAPIDLY MOVE SOUTHWARD DURING THE DAY. WILL KEEP CHC POPS FROM 9V9 TO SUX THROUGH THE DAY WITH CHC TAPERING OFF BY 00Z. THE BEST CHC FOR PCPN WILL BE WEST OF YKN SINCE AS THE WAVE MOVES EAST THE LOW LEVEL FRONT WILL DROP INTO NEBRASKA FOCUSING PCPN ALONG I80 BY LATE AFTERNOON. AS TEMPS...BKN-OVC SKIES...ESP IN THE SRN CWA...WILL PUT A BREAK ON TEMPS. HAVE LOWERED TEMPS IN THE 70S IN ENTIRE CWA WITH WARMEST READINGS LIKELY IN SW MN WHERE THERE WILL BE THE MOST SUN. SKIES SHOULD CLEAR THU NIGHT AND WITH DEW POINTS FALLING INTO THE LOWER TO MID 50S...LOWS WILL DO LIKEWISE UNDER LIGHT WINDS. ON FRIDAY...HIGH PRESSURE SETTLES OVER. RESIDUAL BL MOISTURE AND EVAPOTRANSPIRATION WILL MEAN RAPIDLY CU DEVELOPMENT DURING THE MORNING. 700 MB TEMPS STILL ABOVE ZERO AND NO UPPER WAVE IN THE AREA SO HAVE KEPT IT DRY. TEMPS WILL BE COOL WITH MOST AREAS REMAINING IN THE 70S. ANOTHER CLEAR AND COOL NIGHT ON FRIDAY NIGHT. THEN ON SATURDAY A STRONGER WAVE MOVES AROUND THE LONG WAVE TROUGH. AT THE SAME TIME...COLD ADVECTION AT 700 MB WILL PRODUCE 850-700 MB OF 9C/KM. THE INSTABILITY COMBINED WITH UNSEASONABLY COLD MID-LEVEL TEMPS SHOULD RESULT IN NOT ONLY RAPID CU DEVELOPMENT BUT ALSO DEVELOPMENT OF INSTABILITY SHOWERS DURING THE AFTERNOON. SO HAVE ADDED POPS TO SE SD AND SW MN WITH BEST CHANCE NORTH OF I90 WHERE 700 MB TEMPS ARE COLDEST AND UPPER FOCING IS STRONGEST. TEMPS WILL AGAIN BE COOL IN THE MID TO UPPER 70S. LOSS OF HEATING WILL END RAIN THREAT ON SATURDAY EVENING. IN THE EXTENDED...HAVE TRENDED TOWARD THE ECMWF FOR TEMPS AND OVERALL EVOLUTION OF WINDS AND PCPN THROUGH THE PERIOD. ONLY EXCEPTION IS ON WEDNESDAY WHEN ECMWF WOULD IMPLY A STRONG WAVE AND FRONT MOVING ACROSS. COMPARISONS TO THE CANADIAN, 00Z AND 06Z GFS SHOW THERE IS QUITE A BIT OF UNCERTAINTY WITH THE MOVEMENT FOR THIS WAVE WITH THE 06Z GFS SLOWER AND CANADIAN SHOWING A MUCH WEAKER WAVE MOVING ACROSS. SO HAVE OPTED TO KEEP PRECIPITATION OUT ON WEDNESDAY AT THIS TIME. OTHERWISE...FOR SUNDAY ECMWF AND GFS AGREE AN UPPER LOW WITH 700 MB TEMPS AOB 0C OVER THE CWA. RESIDUAL BL MOISTURE AND STEEP 850-700 MB LAPSE RATES EXPECTED TO RESULT IN INSTABILTY SHOWERS. THESE SHOWERS SHOULD BE FAVORED MORE IN THE ERN CWA WHERE MIDLEVELS ARE COLDER. THIS WILL ALSO MEAN THAT TEMPS WILL HOLD IN THE 70S AS RAPID DEVELOPMENT OF AFTERNOON CU PREVENTS JULY SUN FROM WARMING AREA INTO THE 80S. ON MONDAY AND TUESDAY...ECMWF AND 06Z GFS HAVE UPPER LOW MOVING EAST. SFC RIDGE ALSO BEGINS TO SLIDE SOUTHEAST SO RETURN FLOW BEGINS TO SET UP IN THE WRN CWA ON MONDAY. THIS WILL BEGIN A SLOW WARMING TREND. MODELS SUGGEST THAT THE SE CWA WILL BE SLOWEST TO WARM UP AND THAT SW FLOW WILL SET UP ACROSS THE NORTH. THIS WOULD MEAN COOLER TEMPS IN SE QUARTER OF CWA WITH POTENTIAL FOR MORE RAPIDLY WARMING IN FAR NRN CWA...ESP MML AREA WHICH TENDS TO WARM MORE RAPIDLY WITH WEST COMPONENT. EXPECT TEMPS TO REACH SEASONAL NORMS BY WEDNESDAY WITH DEW POINTS BACK INTO THE MID 60S. && .FSD...WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && SCHUMACHER
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SIOUX FALLS SD 201 PM CDT WED JUL 21 2004 SDZ038>040-050-052>071-MNZ071-072-080-081-089-090-097-098- IAZ001>003-012>014-020>022-031-032-NEZ013-014-221200- 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- 201 PM CDT WED JUL 21 2004 THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST SOUTH DAKOTA... SOUTHWEST MINNESOTA...NORTHWEST IOWA...AND NORTHEAST NEBRASKA. .DAY ONE...TODAY AND TONIGHT THUNDERSTORMS... A WEAK COLD FRONT WILL SLIDE ACROSS EASTERN SOUTH DAKOTA AND INTO SOUTHWESTERN MINNESOTA AND NORTHWEST IOWA. SCATTERED STORMS WILL DEVELOP AHEAD OF THIS FEATURE. SOME OF THESE STORMS MAY BECOME SEVERE WITH HAIL UP TO GOLF BALL SIZE AND WIND GUSTS TO 70 MPH THE PRIMARY THREAT. THESE STORMS WILL BE STRONGLY DRIVEN BY DAYTIME HEATING AND STORMS SHOULD DIMINISH AFTER 9 PM. EXCESSIVE TEMPERATURES... HEAT INDICES WILL REACH THE 100 TO 105 DEGREE RANGE THIS AFTERNOON... AS HIGH TEMPERATURES WILL BE IN THE LOWER TO MID 90S WITH DEWPOINT TEMPERATURES IN THE LOWER TO MID 70S. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY THERE IS A SLIGHT CHANCE OF THUNDERSTORMS THURSDAY ALONG AND SOUTH OF INTERSTATE 90. THESE STORMS ARE NOT EXPECTED TO BE SEVERE. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL BE POSSIBLE AFTER 3 PM. && FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE AT WWW.CRH.NOAA.GOV/FSD. THIS INCLUDES THE GRAPHICAL HAZARDOUS WEATHER OUTLOOK.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
452 PM CDT WED JUL 21 2004
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION...ST.. ...SOURCE....
..REMARKS..
0409 PM HAIL 6 N PLANKINTON 43.80N 98.48W
07/21/2004 0.88 INCH AURORA SD TRAINED SPOTTER
0440 PM TSTM WND GST 2 SW MITCHELL 43.71N 98.06W
07/21/2004 60 MPH DAVISON SD BROADCAST MEDIA
ALSO RECIEVED DIME SIZE HAIL AT THAT LOCATION.
&&
JBPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
456 PM CDT WED JUL 21 2004
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION...ST.. ...SOURCE....
..REMARKS..
0435 PM TSTM WND DMG 3 SSW MITCHELL 43.69N 98.06W
07/21/2004 DAVISON SD BROADCAST MEDIA
NUMEROUS TREE LIMBS DOWN UP TO 6 INCHES IN DIAMETER.
&&
JBPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
515 PM CDT WED JUL 21 2004
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION...ST.. ...SOURCE....
..REMARKS..
0508 PM TSTM WND GST 10 SW ALEXANDRIA 43.55N 97.92W
07/21/2004 60 MPH HANSON SD PUBLIC
&&
JBPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
548 PM CDT WED JUL 21 2004
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION...ST.. ...SOURCE....
..REMARKS..
0538 PM HAIL 7 S ARTESIAN 43.91N 97.92W
07/21/2004 0.88 INCH SANBORN SD TRAINED SPOTTER
&&
JBThe Sioux Falls radar (KFSD), 110 km away, was scanning. The volume nearest the first event began at 23:01 UTC.
1 thunderstorm wind. Local standard time, as filed.
Thunderstorm winds caused tree damage, including 6 to 8 inch diameter limbs blown down.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in South Dakota in 2004Every state in 2004This day in weather historyWarnings in South Dakota, July 2004
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 2026-10-01. Each event’s entry at NCEI: 5416499.