Very strong northerly winds affected southeast South Dakota during the evening of April 15th. Winds gusted to over 60 mph in parts of the area.
Every event with a place to put it; 11 filed by county or forecast zone are drawn at its center, in a lighter ring. 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.
Very strong northerly winds affected southeast South Dakota during the evening of April 15th. Winds gusted to over 60 mph in parts of the area.
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 Apr 15, 2:10 PM CST, 1 hour 50 minutes earlier.
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
310 PM CDT SUN APR 15 2012
.DISCUSSION.../ISSUED AT 300 PM CDT/
LOW CENTER TRACKING JUST W OF KSUX WITH INVERTED TROUGH/FRONT
EXTENDING NORTHEAST WILL MOVE EAST OUT OF AREA LATER THIS EVENING.
WEST OF SYSTEM NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS WILL
CONTINUE TO AFFECT THE AREA. BRIEF SMALL HAIL POSSIBLE IN STORMS NOT
TOO FAR WEST OF SYSTEM. OTHERWISE SHOWERS WILL CONTINUE TO SPREAD
EAST DURING THE EVENING...MOST NUMEROUS NORTH AND WITH COVERAGE
STARTING TO DECREASE TOWARD MIDNIGHT EVEN AS IT ALSO STARTS TO MOVE
NORTHEAST OF AREA. WILL END ALL SHOWERS LATE TONIGHT. STILL TIME FOR
SEVERE STORMS TO DEVELOP IN NORTHWEST IA AND FAR SOUTHEAST PART OF
SOUTHWEST MN AS VERY STRONG UPPER SYSTEM CATCHES UP WITH DRYLINE
SEEN IN VISUAL SATELLITE AS OVER WESTERN PART OF NORTHWEST IOWA.
THIS WOULD BE FOR LATE THIS AFTERNOON. VERY STRONG SOUTHERLY WINDS
DEVELOPED AS EXPECTED OVER OUR FAR SOUTHEAST CORNER IN NORTHWEST IA
AND WILL CONTINUE WIND ADVISORY THERE UNTIL 01Z/8PM. WIND ADVISORY
FOR THE VERY STRONG NORTHWEST WINDS WILL BE EXPANDED TO COVER THE
EASTERN PART OF AREA. STARTING AND ENDING TIMES WILL BE IN A WEST TO
EAST STEPPINGSTONE FASHION...S WINDS FAR WEST WILL EB DECREASING
TONIGHT AS THE WINDS FAR EAST PICK UP...WILL END THE LAST ADVISORY
IN THE FAR EAST AT 09Z/4 AM CDT. WITH SYSTEM MOVING EAST AND
PRESSURES RISING SO QUICKLY LATER ON THOSE WINDS SHOULD HAVE LITTLE
TROUBLE PICKING UP TO ADVISORY LEVELS. TEMPERATURES WILL COOL TO A
LITTLE BELOW MET GUIDANCE LEVELS THOUGH AM RAISING LOWS A TAD OVER
WHAT WE HAD BEFORE FOR WIND FACTOR. FOR SKIES...CLOUDS WILL START TO
DECREASE FROM THE WETS LATE TONIGHT AS SHOWERS ABATE...BECOMING
PARTLY CLOUDY WEST LATE AS APPROACHING SECONDARY AREA OF MID LEVEL
MOISTURE KEEPS SKIES FROM GOING CLEAR. / WILLIAMS
THE UPPER LOW SHOULD EXIT THE AREA BY 12Z MONDAY...WITH CLOUD COVER
GRADUALLY BREAKING UP DURING THE LATE MORNING AND AFTERNOON. STRONG
NORTHWEST WINDS AND RESULTANT COLD AIR ADVECTION WILL ALSO GRADUALLY
DECREASE...ALLOWING FOR A LITTLE MORE HEATING THAN SOME OF THE MODEL
GUIDANCES SUGGEST. NUDGED TEMPERATURES A TOUCH ABOVE THE BLENDED
GUIDANCES...AND TRENDED MORE TOWARDS THE RAW ECMWF TEMPERATURES.
KEPT A LOW CHANCE OF SHOWERS ACROSS THE SOUTHWEST ON MONDAY
AFTERNOON WITH AN UPPER WAVE MOVING THROUGH EASTERN SOUTH DAKOTA...
BUT LEFT PRECIPITATION AMOUNTS LOW AS ANY SHOWERS SHOULD BE LIGHT
AND WIDELY SCATTERED.
ON TUESDAY...SOUTHERLY FLOW WILL RETURN TO THE REGION WITH DECENT
MIXING TO AROUND 850 MB AND TEMPERATURES AT THAT LEVEL RANGING FROM
6 TO 12 DEGREES CELSIUS. WARM AIR ADVECTION AND SOME SUBTLE ELEVATED
CONVERGENCE ALONG THE NEBRASKA/IOWA BORDER COULD BE A FOCUS FOR
SCATTERED THUNDERSTORM DEVELOPMENT ON TUESDAY EVENING...WHICH WILL
INCREASE IN COVERAGE AND SPREAD NORTHWARD WITH A STRENGTHENING LOW
LEVEL JET ACROSS WESTERN IOWA AND INTO SOUTHWEST MINNESOTA. AN UPPER
WAVE WILL DIP INTO EASTERN SOUTH DAKOTA AND WESTERN MINNESOTA AFTER
06Z MONDAY...WHICH COULD PROLONG THE POTENTIAL FOR THUNDERSTORMS
THROUGH THE NIGHT. A BROAD AREA OF PRECIPITATION WILL ALSO SPREAD
ALONG THE WARM FRONT...BUT SHOULD STAY PRIMARILY NORTH OF THE
FORECAST AREA. STORMS WILL PUSH EAST DURING THE MORNING... ENDING
SOMETIME AROUND NOON ON WEDNESDAY. /LAFLIN
FOR THE EXTENDED...ANOTHER WAVE WILL BRING A THREAT OF SHOWERS
THURSDAY INTO FRIDAY ALONG WITH THE COOLER TEMPERATURES BEHIND
WEDNESDAY SYSTEM. WARMING NEXT WEEKEND MAY BE ACCOMPANIED BY A FEW
THUNDERSTORMS SATURDAY BUT WX SHOULD BE DRY BY SUNDAY WITH DRY WX
LIKELY CONTINUING BEYOND PERIOD INTO EARLY THE FOLLOWING WEEK.
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
CEILINGS 1 TO 3K FEET WILL BE GENERAL OVER SOUTHEAST SD AND
SOUTHWEST MN THROUGH 06Z WITH AREAS OF CEILINGS BELOW 1K FEET AND
VISIBILITIES 3-5SM IN NUMEROUS SHOWERS. ISOLATED THUNDERSTORMS THESE
AREAS MAINLY THROUGH 02Z. FROM 06Z TO 12Z SHOWERS WILL END FROM THE
WEST. FROM 08Z TO 18Z CEILINGS WILL SLOWLY IMPROVE TO VFR OR
UNLIMITED WITH THIS IMPROVEMENT A FEW HOURS BEHIND ENDING OF
SHOWERS. OVER NORTHWEST IA HIGHLY VARIABLE CONDITIONS THROUGH 03Z
WITH VFR VARIABLE TO LOCAL IFR IN POTENTIALLY STRONG CONVECTION.
AFTER 03Z CEILINGS 1-3K FEET WILL BECOME GENERAL OVER NORTHWEST IA
WITH LOCAL VISIBILITIES 3-5SM IN SHOWERS. IMPROVEMENT TO VFR OVER
NORTHWEST IA 12Z-18Z. / WILLIAMS
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...WIND ADVISORY FROM 10 PM THIS EVENING TO 4 AM CDT MONDAY FOR
IAZ001>003-012>014-020>022-031-032.
WIND ADVISORY UNTIL 8 PM CDT THIS EVENING FOR IAZ003-013-014-
021-022-031-032.
MN...WIND ADVISORY FROM 10 PM THIS EVENING TO 4 AM CDT MONDAY
FOR MNZ072-080-081-089-090.
WIND ADVISORY FROM 7 PM THIS EVENING TO 1 AM CDT MONDAY FOR
MNZ097-098.
WIND ADVISORY UNTIL 1 AM CDT MONDAY FOR MNZ071.
NE...WIND ADVISORY FROM 10 PM THIS EVENING TO 4 AM CDT MONDAY FOR
NEZ014.
WIND ADVISORY FROM 7 PM THIS EVENING TO 1 AM CDT MONDAY FOR
NEZ013.
SD... WIND ADVISORY FROM 10 PM THIS EVENING TO 4 AM CDT MONDAY
FOR SDZ071.
WIND ADVISORY FROM 7 PM THIS EVENING TO 1 AM CDT MONDAY FOR
SDZ062-066-067-069-070.
WIND ADVISORY UNTIL 11 PM CDT THIS EVENING FOR SDZ038-050-052-
053-057>059-063-064.
WIND ADVISORY UNTIL 1 AM CDT MONDAY FOR SDZ039-040-054>056-060-
061-065-068.
&&HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SIOUX FALLS SD 429 PM CDT SUN APR 15 2012 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- 429 PM CDT SUN APR 15 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST SOUTH DAKOTA... SOUTHWEST MINNESOTA...NORTHWEST IOWA...AND NORTHEAST NEBRASKA. .DAY ONE...TODAY AND TONIGHT THUNDERSTORMS... SCATTERED THUNDERSTORMS OVER NORTHWEST IOWA AND SOUTHWEST MINNESOTA MAY BE SEVERE INTO EARLY THIS EVENING...WITH A RISK OF TORNADOES AND LARGE HAIL. MORE SPOTTY THUNDERSTORMS OVER SOUTHEAST SOUTH DAKOTA ARE NOT EXPECTED TO BE SEVERE...AND SHOULD DECREASE TO SHOWERS DURING THE EVENING. WIND AND FOG... VERY STRONG SOUTHERLY WINDS WILL CONTINUE IN PART OF NORTHWEST IOWA UNTIL SUNSET. VERY STRONG NORTHWEST WINDS SPREADING ACROSS SOUTHEAST SOUTH DAKOTA THROUGH EARLY EVENING WILL ALSO SPREAD INTO SOUTHWEST MINNESOTA AND NORTHWEST IOWA LATER IN THE EVENING. THIS MEANS THAT ALL OF THE AREA WILL EXPERIENCE VERY STRONG WINDS TONIGHT. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY SCATTERED THUNDERSTORMS WILL BE POSSIBLE LATE TUESDAY AND TUESDAY NIGHT BUT ARE NOT EXPECTED TO BECOME SEVERE. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL BE POSSIBLE THROUGH EARLY THIS EVENING IN SOUTHWEST MINNESOTA AND NORTHWEST IOWA. && FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE AT WWW.WEATHER.GOV/SIOUXFALLS. THIS INCLUDES THE GRAPHICAL HAZARDOUS WEATHER OUTLOOK. WILLIAMS
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1217 PM CDT SUN APR 15 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1150 AM HAIL 2 N ARTESIAN 44.04N 97.92W
04/15/2012 E1.00 INCH SANBORN SD PUBLIC
MOSTLY DIME SIZE BUT A FEW AS BIG AS QUARTERS
&&
LAFLINSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 329 PM CDT SUN APR 15 2012 SDZ053-059-060-064-065-068-152130- SANBORN-DAVISON-HANSON-DOUGLAS-HUTCHINSON-BON HOMME- INCLUDING THE CITIES OF...WOONSOCKET...MITCHELL...ALEXANDRIA... EMERY...ARMOUR...CORSICA...DELMONT...PARKSTON...FREEMAN...MENNO... TRIPP...TYNDALL...SCOTLAND...SPRINGFIELD...AVON...TABOR 329 PM CDT SUN APR 15 2012 ...SPECIAL WEATHER STATEMENT... DURING THE LATE AFTERNOON HOURS...THUNDERSTORMS CONTINUE TO MOVE NORTHWARD THAT ARE PRODUCING FUNNEL CLOUDS. IT IS QUITE POSSIBLE THAT SOME FUNNELS MAY TOUCH THE GROUND BRIEFLY PRODUCING BRIEF TORNADIC TOUCHDOWNS. BE ALERT FOR CHANGING WEATHER CONDITIONS AS SHORT LIVED...NON SUPERCELL TORNADOES ARE EXTREMELY DIFFICULT TO DETECT WITH ADVANCED NOTICE.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
414 PM CDT SUN APR 15 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0410 PM HAIL 2 N GHENT 44.54N 95.89W
04/15/2012 M1.00 INCH LYON MN TRAINED SPOTTER
&&
KHANKOPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
417 PM CDT SUN APR 15 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0411 PM TORNADO 5 N GHENT 44.59N 95.89W
04/15/2012 LYON MN TRAINED SPOTTER
TORNADO ON GROUND. SPOTTER 3 MILES NORTH OF GHENT LOOKING
NORTH.
&&
JMSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 436 PM CDT SUN APR 15 2012 SDZ053-054-059-060-152245- SANBORN-MINER-DAVISON-HANSON- INCLUDING THE CITIES OF...WOONSOCKET...HOWARD...MITCHELL... ALEXANDRIA...EMERY 436 PM CDT SUN APR 15 2012 ...SPECIAL WEATHER STATEMENT... DURING THE LATE AFTERNOON HOURS...THUNDERSTORMS CONTINUE TO MOVE NORTHWARD THAT ARE PRODUCING FUNNEL CLOUDS ACROSS PARTS OF SOUTHEAST AND EAST CENTRAL SOUTH DAKOTA. CURRENTLY...FUNNELS ARE BEING REPORTED ALONG THE I 90 CORRIDOR BETWEEN SPENCER SOUTH DAKOTA AND MITCHELL...AND THIS ACTIVITY WILL LIKELY MOVE NORTHWARD. IT IS QUITE POSSIBLE THAT SOME FUNNELS MAY TOUCH THE GROUND BRIEFLY PRODUCING BRIEF TORNADIC TOUCHDOWNS. BE ALERT FOR CHANGING WEATHER CONDITIONS AS SHORT LIVED...NON SUPERCELL TORNADOES ARE EXTREMELY DIFFICULT TO DETECT WITH ADVANCED NOTICE.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
456 PM CDT SUN APR 15 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0240 PM TORNADO 2 N SANTEE 42.87N 97.85W
04/15/2012 BON HOMME SD TRAINED SPOTTER
ROPE TORNADO CROSSING THE RIVER
&&
LAFLINThe national radar mosaic for the moment the first event began.
11 high wind. Local standard time, as filed.
Strong north winds affected the area during the late afternoon and early evening. A large outbuilding was destroyed near the western edge of Hitchcock, and a power pole in standing water was snapped off 4 1/2 miles east of Hitchcock.
Strong north winds affected the area during the late afternoon and early evening. A gust of 63 mph was measured at Chamberlain.
Strong north winds affected the area during the late afternoon and early evening. A gust of 66 mph was measured 2 miles southeast of Wessington Springs.
Strong north winds affected the area during the late afternoon and early evening. A gust of 58 mph was measured 1 mile east southeast of Gregory.
Strong north winds affected the area during the late afternoon and early evening. Gusts were estimated at 60 mph.
Strong north winds affected the area during the late afternoon and early evening. A gust to 61 mph was measured 14 miles west of Platte.
Strong north winds affected the area during the evening. A gust to 61 mph was measured at Mitchell airport.
Strong north winds affected the area during the evening. Gusts were estimated at 60 mph.
Strong north winds affected the area during the evening. Gusts were estimated at 60 mph.
Strong north winds affected the area during the evening. Gusts were estimated at 60 mph.
Strong north winds affected the area during the evening. Gusts were estimated at 60 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in South Dakota in 2012Every state in 2012This day in weather historyWarnings in South Dakota, April 2012
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: 378236, 378242, 378241, 378243, 378244, 378245, 378246, 378247, 378248, 378249, 378250.