Alert archive / South Dakota / Tornado Warnings in 1991
Tornado Warning 4, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this tornado warning at Jun 4, 1991, 3:46 PM CDT for Gregory County, South Dakota. It was in force for 29 min.
The area
The counties it named.
The facts
- Issued
- Jun 4, 1991, 3:46 PM CDT (20:46 UTC)
- Expired
- Jun 4, 1991, 4:15 PM CDT
- In force
- 29 min
- Issued by
- NWS Sioux Falls, SD
- Area
- Whole counties
County Gregory County, SD
The nearest sounding before it
Aberdeen, SD (KHON), launched 12:00Z, 8.8 hours before the alert went out and 200 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 234 J/kg
- Mixed-layer CIN
- -83 J/kg
- Mixed-layer LCL
- 729 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- 138 m²/s²
- 0-3 km storm-relative helicity
- 104 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KFSD 042047 TORFSD SDC053-042115- BULLETIN - EBS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE SIOUX FALLS SD 346 PM CDT TUE JUN 4 1991 THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A TORNADO WARNING EFFECTIVE UNTIL 415 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTIES... IN SOUTH CENTRAL SOUTH DAKOTA ...EASTERN GREGORY COUNTY AT 340 PM CDT A TORNADO WAS REPORTED 21/2 MILES WEST OF BONESTEEL. SIGNIFICANT DAMAGE TO A BUILDING AND NUMEROUS CARS THROWN AROUND WERE REPORTED. THE STORM WAS MOVING NORTH AT 15 MPH WITH NO TOWNS IN ITS PATH. THIS WARNING INCLUDES THE ADJACENT WATERS OF THE MISSOURI RIVER. IF YOU ARE IN THE PATH OF A TORNADO...THE SAFEST PLACE IS A BASEMENT. GET UNDER A WORKBENCH OR PIECE OF STURDY FURNITURE. IF NO BASEMENT IS AVAILABLE...SEEK SHELTER IN AN INTERIOR ROOM SUCH AS A CLOSET ON THE LOWEST FLOOR. USE BLANKETS...PILLOWS... OR CUSHIONS TO COVER YOUR BODY. AVOID WINDOWS. RYRHOLM
What forecasters said that day
The local office's own words before this tornado warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
In the hours before
Special weather statement, Jun 4, 1:45 PM CDT, 2 hours 1 minute before
SDZ010-015-016-019-050000- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 145 PM CDT TUE JUN 4 1991 ...COLD AIR FUNNELS SIGHTED... COLD AIR FUNNEL CLOUDS HAVE BEEN OBSERVED NORTHWEST OF WINNER THIS AFTERNOON AROUND 1 30 PM CDT. STUDIES OF FUNNEL CLOUDS DURING THE PAST DEVERAL YEARS INDICATE THAT A KIND OF FUNNEL CLOUD FORMS WITH WEATHER CONDITIONS SIMILAR TO THOSE THAT PREVAIL TODAY. THESE ARE SO CALLED COLD AIR FUNNEL CLOUDS AND ARE NOT AS VIOLENT AS THOSE ASSOCIATED WITH SEVERE THUNDERSTORMS. STUDIES OF COLD AIR FUNNEL CLOUDS SHOW THAT THEY RARELY TOUCH THE GROUND AND AS SUCH RARELY DO ANY DAMAGE. ATMOSPHERIC CONDITIONS OVER SOUTHEAST SOUTH DAKOTA WILL CONTINUE FAVORABLE FOR THE FORMATION OF COLD AIR FUNNEL CLOUDS FOR THE REST OF THE AFTERNOON. PEOPLE IN SOUTHEAST OR SOUTH CENTRAL SOUTH DAKOTA SHOULD NOT BECOME UNDUELY ALARMED BUT SHOULD REMAIN ALERT AND MOVE TO A PLACE OF SAFETY IF A COLD AIR FUNNEL CLOUD APPROACHES THE GROUND. ADDITIONAL STATEMENTS WILL BE ISSUED AS NECESSARY. BIER
Special weather statement, Jun 4, 1:45 PM CDT, 2 hours 1 minute before
SDZ010-011-012-041935 RADAR SUMMARY AND SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE HURON SD 144 PM CDT TUE JUN 4 1991 AT 130 PM CDT...SCATTERED THUNDERSTORMS WITH VERY HEAVY RAIN CONTINUED TO DEVELOP OVER CENTRAL AND EAST CENTRAL SOUTH DAKOTA. THE THUNDERSTORMS WERE MOSTLY WEST OF A LINE FROM MOBRIDGE...TO HURON...TO MITCHELL. THE STRONGEST THUNDERSTORMS WERE OVER SULLY...HUGHES...SOUTHERN LYMAN... AND AURORA COUNTIES. DUE TO PREVIOUS HEAVY RAINS THE LAST SEVERAL DAYS ADDTIONAL HEAVY RAINS MAY CAUSE URBAN...AND LOWLAND FLOODING AND RAPID RISES IN STREAMS. SHOWERS AND THUNDERSTORMS WERE MOVING NORTH AT 20 MILES AN HOUR. FREDERICK
Special weather statement, Jun 4, 2:47 PM CDT, 59 minutes before
SDZ010-011-012-042035 SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE HURON SD 244 PM CDT TUE JUN 4 1991 AT 230 PM CDT...SCATTERED THUNDERSTORMS WITH VERY HEAVY RAIN CONTINUED IN CENTRAL AND EAST CENTRAL SOUTH DAKOTA. THUNDERSTORMS WERE WEST OF A LINE FROM 20 MILES NORTHWEST OF YANKTON TO 20 SOUTHWEST OF ABERDEEN TO 30 MILES NORTH OF MOBRIDGE. THE STRONGEST WITH VERY HEAVY RAIN WERE 20 MILES SOUTHWEST OF HURON NEAR WESSINGTON SPRINGS AND 30 MILES NORTHWEST OF HURON NEAR MILLER... OLSO JUST NORTH OF PIERRE SOUTH DAKOTA. DUE TO PREVIOUS HEAVY RAINS THE LAST SEVERAL DAYS ADDITIONAL HEAVY RAINS MAY CAUSE URBAN...AND LOWLAND FLOODING AND RAPID RISES ON STREAMS. SHOWERS AjND THUNDERSTORMS WERE MOVING NORTH AT 20 MILES AN HOUR. PRESTON
Special weather statement, Jun 4, 3:42 PM CDT, 4 minutes before
SDZ010-011-012-042135 SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE HURON SD 345 PM CDT TUE JUN 4 1991 ...FLASH FLOOD WARNING IN EFFECT FOR WESTERN AND NORTHERN LYMAN AND WESTERN HUGHES AND WESTERN SULLY AND EASTERN STANLEY UNTIL 515 PM CDT... AT 325 PM CDT...NUMEROUS THUNDERSTORMS WITH VERY HEAVY RAIN CONTINUED IN CENTRAL AND EAST CENTRAL SOUTH DAKOTA. THUNDERSTORMS WERE WEST OF A LINE FROM YANKTON TO HURON TO ABERDEEN TO MOBRIDGE. THE STRONGEST THUNDERSTORM WITH VERY HEAVY RAIN WAS 20 MILES SOUTHWEST OF HURON NEAR WESSINGTON SPRINGS. ALSO THERE WAS A LINE OF THUNDERSTORMS WITH VERY HEAVY RAIN FROM NORTHERN SULLY COUNTY SOUTH TO NEAR PIERRE AND SOUTHEAST TO NEAR IONA. THE THUNDERSTORMS WERE MOVING NORTH AT 20 MILES AN HOUR. MILLER
Nearby
Tornado Warnings in South Dakota, 1991Every tornado warning in 1991Tornadoes in 1991
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive.