A strong cold front passed through the region during the night. Strong north to northwest winds developed behind the front for several hours.
Every event with a place to put it; 7 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 UNR wrote it up.
A strong cold front passed through the region during the night. Strong north to northwest winds developed behind the front for several hours. The strongest winds occurred in the Rapid City area, where wind gusts to 65 mph were recorded.
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 Rapid City, SD wrote its last area forecast discussion before the first event at Apr 1, 8:13 PM MST, 47 minutes earlier.
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
913 PM MDT SUN APR 1 2012
.UPDATE...
A STRONG COLD FRONT CONTINUES TO PUSH QUICKLY SOUTHEAST ACROSS THE
REGION. STRONG NORTHWEST TO NORTH WINDS WILL CONTINUE OVERNIGHT
WITH SIG PRESSURE RISES ONGOING IN A CAA REGIME...ACCENTUATED BY
FLOW CONSTRICTING AROUND THE EASTERN FLANK OF THE BLACK HILLS.
SPLITTING UPPER TROUGH WILL SUPPORT A PERIOD OF WEAK TO MODERATE
UPLIFT OVER THE AREA...ESP WY AND FAR WESTERN SD. THIS WILL ALLOW
FOR A WINDOW OF RAIN AND SNOW SHOWERS...WITH SOME LIGHT ACCUMS
POSSIBLE IN THE BLACK HILLS. HAVE REMOVED THUNDER MENTION ALL
PLACES SAVE THE FAR SE...GIVEN DISMAL ELEVATED INSTABILITY PER 00Z
RAOBS...IN A MOISTURE STARVED ENVIRONMENT. LL TROUGH/STEEP MID
LEVEL LAPSE RATES/AND WEAK TO MODERATE MOISTURE RETURN OVER SOUTH
CENTRAL SD MAY SUPPORT A CONVECTIVE RESPONSE LATER TONIGHT THERE.
OTHERWISE...ALL ELSE IN GOOD SHAPE.
&&
.PREV DISCUSSION... /ISSUED 559 PM MDT SUN APR 1 2012/
AVIATION.../00Z TAFS/
A COLD FRONT WILL CONTINUE TO PUSH SOUTH THROUGH THE REGION
OVERNIGHT. WINDS WILL VEER NW AND INCREASE...ESP ON THE EASTERN
SLOPE OF THE BLACK HILLS WHERE 40 TO 60 MPH WINDS ARE EXPECTED
OVERNIGHT INTO MONDAY MORNING. RAIN SHOWERS WILL BE POSSIBLE LATER
TONIGHT INTO MONDAY MORNING...POSSIBLY MIXING WITH SNOW IN WY AND
OVER THE BLACK HILLS. VFR CONDITIONS ARE EXPECTED TO PREVAIL
THROUGH EVENING...WITH A TREND TO MVFR AT GCC...WITH LOW END VFR
CONDITIONS EXPECTED ATTM AT RAP.
PREV DISCUSSION... /ISSUED 232 PM MDT SUN APR 1 2012/
DISCUSSION...WATER VAPOR SHOWS STRONG RIDGE OVER THE PLAINS...WITH
UPPER TROF WORKING THROUGH THE WRN CONUS. AT THE SURFACE...COLD
FRONT IS PUSHING THROUGH FAR NWRN SD AND NERN WY. VERY WARM AND DRY
CONDITIONS EXIST SOUTH OF THE FRONT WITH TEMPS IN THE 80S TO LOWER
90S.
TONIGHT...COLD FRONT WILL QUICKLY PUSH SE ACROSS OUR CWFA. STRONG
CAA BEHIND THE FRONT WILL RESULT IN VERY WINDY
CONDITIONS...ESPECIALLY ON THE SD PLAINS WITH ADVISORY WINDS
EXPECTED. THE STRONGEST WINDS WILL FUNNEL ALONG THE EAST SIDE OF THE
BLKHLS...WITH 40-50KT LOWER TROPOSPHERIC AND STEEP LO LVL LAPSE
RATES PUSHING WINDS INTO THE WARNING CATEGORY...SO HAVE ISSUED A
HIGH WIND WARNING THIS AREA. BAND OF STRONG 850-700MB FRONTOGENESIS
WILL PRODUCE LIGHT RAIN SHOWERS...MIXING WITH OR CHANGING TO SNOW
OVER NERN WY AND THE BLKHLS LATE AS PROFILES COOL. COULD EVEN BE
SOME ISOLD -TSRA WITH A TOUCH OF INSTABILITY IN PLACE. ANY SNOW
ACCUMULATIONS LATE TONIGHT SHOULD MAINLY BE CONFINED TO HIGHER
ELEVATIONS.
MONDAY...VERY WINDY CONDITIONS WILL CONTINUE UNDER STEEP LO LEVEL
LAPSE RATES. MORNING RAIN/SNOW SHOWERS WILL CONTINUE IN THE MORNING
AS UPPER TROF AXIS CROSSES THE NRN PLAINS...WITH DRYING EXPECTED IN
THE AFTN. HIGHS TEMPS MAINLY THE 50S...40S IN THE BLKHLS. WIDESPREAD
FREEZING TEMPS THEN EXPECTED MONDAY NIGHT.
TUESDAY...PLEASANT WEATHER EXPECTED WITH HIGH PRESSURE IN PLACE IN
THE MORNING. WINDS COULD GET A BIT BREEZY BY AFTERNOON AS RETURN
FLOW GETS GOING AROUND SURFACE HIGH SHIFTING INTO THE UPPER MIDWEST.
EXTENDED...AN UPPER LEVEL RIDGE WILL BRING WARM AND DRY WEATHER TO
THE AREA FOR WEDNESDAY AND THURSDAY. AN UPPER LEVEL TROUGH WILL MOVE
ACROSS THE ROCKIES INTO THE PLAINS BEFORE STARTING TO CLOSE OFF
THURSDAY NIGHT INTO FRIDAY...BRINGING CHANCES OF PRECIPITATION.
THERE IS SOME DISAGREEMENT WITH STRENGTH AND POSITION OF THIS
SYSTEM...SO WILL HOLD OFF ON HIGHER POPS UNTIL BETTER AGREEMENT IS
REACHED.
FIRE WEATHER...CRITICAL FIRE WEATHER CONDITIONS WILL CONTINUE ACROSS
THE AREA THIS AFTERNOON INTO TONIGHT AS TEMPERATURES CLIMB INTO THE
MID 70S TO LOWER 90S...WITH RELATIVE HUMIDITY VALUES DROPPING INTO
THE SINGLE DIGITS AND TEENS. A STRONG COLD FRONT HAS JUST PUSHED
INTO FAR NORTHWESTERN SOUTH DAKOTA AND NORTHEASTERN WYOMING...AND
WILL CONTINUE SLIDING ACROSS THE AREA THROUGH THIS AFTERNOON INTO
TONIGHT. GUSTY WEST TO SOUTHWESTERLY WINDS WILL BECOME NORTHWEST AND
INCREASE AS THE FRONT PASSES THROUGH. BEHIND THE FRONT...ISOLATED
THUNDERSTORMS WITH DRY LIGHTING WILL BE POSSIBLE INTO THE EARLY
EVENING...PARTICULARLY OVER NORTHEAST WYOMING INTO FAR WESTERN SOUTH
DAKOTA. SHOWERS WILL THEN DEVELOP AND INCREASE IN COVERAGE...
SPREADING ACROSS THE AREA OVERNIGHT. SHOWERS WILL TAPER ON MONDAY AS
TEMPERATURES COOL BACK TO NEAR AVERAGE. NORTHWEST WINDS WILL REMAIN
GUSTY WHILE RELATIVE HUMIDITY VALUES IN THE UPPER TEENS TO UPPER 20S
ARE EXPECTED IN THE AFTERNOON. TEMPERATURES WILL SLOWLY CLIMB
THROUGH MID-WEEK WHILE CONDITIONS REMAIN DRY. THE NEXT CHANCES FOR
WETTING RAINS WILL COME THURSDAY NIGHT INTO FRIDAY.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 6 PM MDT /7 PM CDT/ MONDAY FOR BENNETT-
JACKSON-MELLETTE-TODD-TRIPP.
WIND ADVISORY UNTIL NOON MDT MONDAY FOR BUTTE-FALL RIVER-HAAKON-
HARDING-HERMOSA FOOT HILLS-NORTHERN FOOT HILLS-NORTHERN
MEADE CO PLAINS-PERKINS-SHANNON-SOUTHERN FOOT HILLS-ZIEBACH.
HIGH WIND WARNING UNTIL NOON MDT MONDAY FOR CUSTER CO PLAINS-
PENNINGTON CO PLAINS-RAPID CITY-SOUTHERN MEADE CO PLAINS-
STURGIS/PIEDMONT FOOT HILLS.
WY...NONE.
&&
SHORT TERM...JOHNSON
LONG TERM...77
AVIATION...JC
UPDATE...JCHAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE RAPID CITY SD 905 PM MDT SUN APR 1 2012 SDZ001-002-012>014-024>032-041>044-046-047-049-072>074-WYZ054>058- 071-030315- HARDING-PERKINS-BUTTE-NORTHERN MEADE CO PLAINS-ZIEBACH- NORTHERN BLACK HILLS-NORTHERN FOOT HILLS-RAPID CITY- SOUTHERN FOOT HILLS-CENTRAL BLACK HILLS-SOUTHERN BLACK HILLS- CUSTER CO PLAINS-PENNINGTON CO PLAINS-HAAKON-FALL RIVER-SHANNON- JACKSON-BENNETT-MELLETTE-TODD-TRIPP-STURGIS/PIEDMONT FOOT HILLS- SOUTHERN MEADE CO PLAINS-HERMOSA FOOT HILLS-NORTHERN CAMPBELL- SOUTHERN CAMPBELL-WESTERN CROOK-WYOMING BLACK HILLS-WESTON- NORTHEASTERN CROOK- 905 PM MDT SUN APR 1 2012 /1005 PM CDT SUN APR 1 2012/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN SOUTH DAKOTA AND NORTHEASTERN WYOMING. .DAY ONE...TONIGHT STRONG GUSTY NORTHWEST TO NORTH WINDS WILL CONTINUE THROUGH THE NIGHT OVER THE SOUTH DAKOTA PLAINS...ESPECIALLY ADJACENT TO THE BLACK HILLS. A HIGH WIND WARNING AND WIND ADVISORY ARE IN EFFECT. AN ISOLATED THUNDERSTORM IS POSSIBLE OVERNIGHT ACROSS SOUTH CENTRAL SOUTH DAKOTA...MAINLY IN MELLETTE...TODD AND TRIPP COUNTIES. SEVERE THUNDERSTORMS ARE NOT EXPECTED. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY STRONG NORTHERLY WINDS WILL CONTINUE ACROSS THE SOUTH DAKOTA PLAINS THROUGH MONDAY AFTERNOON. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY. JC
The national radar mosaic for the moment the first event began.
7 high wind. Local standard time, as filed.
A semi trailer was blown over on Interstate 90 six miles east of New Underwood.
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: 370453, 370456, 370452, 370458, 370455, 370457, 370454.