Alert archive / South Dakota / Severe Thunderstorm Warnings in 1987
Severe Thunderstorm Warning 97, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 20, 1987, 10:06 PM CDT for Moody County, South Dakota; Pipestone County, Minnesota. It was in force for 54 min.
The area
The counties it named.
The facts
- Issued
- Jul 20, 1987, 10:06 PM CDT (03:06 UTC)
- Expired
- Jul 20, 1987, 11:00 PM CDT
- In force
- 54 min
- Issued by
- NWS Sioux Falls, SD
- Area
- Whole counties
Counties Pipestone County, MN, Moody County, SD
The radar
The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.
The nearest sounding before it
Aberdeen, SD (KHON), launched 00:00Z, 3.1 hours before the alert went out and 182 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
- 2744 J/kg
- Mixed-layer CIN
- -6 J/kg
- Mixed-layer LCL
- 1591 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 80 m²/s²
- 0-3 km storm-relative helicity
- 125 m²/s²
- Significant tornado parameter
- 0.4
- Supercell composite
- 5.6
The text
As transmitted, in the capitals the NWS used until 2016.
000
TTAA00 KFSD 210306
SVRFSD
SDC079-101-061-087-MNC117-210400-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1006 PM CDT MON JUL 20 1987
THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING
EFFECTIVE UNTIL 1100 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTIES...
IN EAST CENTRAL SOUTH DAKOTA
...LAKE...SOUTHERN MOODY
IN SOUTHEAST SOUTH DAKOTA
...NORTHERN HANSON...NORTHERN MCCOOK
IN SOUTHWEST MINNESOTA
...PIPESTONE
AT 1005 CDT RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS EXTENDING
FROM 40 MILES WEST NORTHWEST OF MITCHELL SOUTH DAKOTA TO BROOKINGS
SOUTH DAKOTA TO 30 MILES NORTH OF REDWOOD FALLS MINNESOTA.
THIS LINE OF THUNDERSTORMS WAS MOVING SOUTHEAST AT 15 MPH.
IF YOU ARE IN THE PATH OF THIS STORM...YOU SHOULD GET TO A
REINFORCED SHELTER. A SEVERE THUNDERSTORM PRODUCES WINDS IN EXCESS
OF 60 MPH...HAIL 3/4 INCH OR LARGER...DEADLY LIGHTNING...AND HEAVY
RAIN THAT CAN QUICKLY FLOOD A LOW LYING AREA.
ANDERSON/KAPELAWhat forecasters said that day
The local office's own words before this severe thunderstorm 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, Jul 20, 4:44 PM CDT, 5 hours 22 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE HURON SD 435 PM CDT MON JUL 20 1987 AT 430 PM CDT...SCATTERED THUNDERSTORMS...SOME INTENSE...CONTINUED OVER PARTS OF NORTHEAST SOUTH DAKOTA. THESE STORMS WERE MOSTLY NORTH OF A LINE FROM HURON TO MILBANK WITH THE HEAVIEST STORMS LOCATED 10 MILES NORTHWEST OF CLARK...JUST NORTH OF HITCHCOCK AND JUST SOUTH OF DOLAND. A SIGNIFICANT INCREASE IN INTENSITY WAS ALSO NOTED. THESE STORMS ARE CAPABLE OF PRODUCING VERY HEAVY RAIN...HAIL...DANGEROUS LIGHTNING AND STRONG GUSTY WINDS. PERSONS IN SOUTHERN AND EASTERN SPINK AND WESTERN AND NORTHERN CLARK COUNTIES SHOULD BE ALERT FOR THREATENING WEATHER. MOVEMENT WAS qNORTHEAST AT 35 MILES AN HOUR. PFEIFFER
Special weather statement, Jul 20, 5:44 PM CDT, 4 hours 22 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE HURON SD 535 PM CDT MON JUL 20 1987 ...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHERN CLARK COUNTY UNTIL 615 PM CDT... AT 530 PM CDT...AN ISOLATED SEVERE THUNDERSTORM CONTINUED OVER NORTHERN CLARK COUNTY OF NORTHEAST SOUTH DAKOTA. THE HEAVIEST PART OF THIS STORM WAS LOCATED JUST NORTH OF CLARK. LARGE HAIL...DAMAGING THUNDERSTORM WINDS AND VERY HEAVY 1RAINS CAN BE EXPECTED WITH THIS STORM. MOVEMENT WAS NORTHEAST AT 5 MILES AN HOUR. PFEIFFER
Special weather statement, Jul 20, 6:47 PM CDT, 3 hours 19 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE HURON SD 635 PM CDT MON JUL 20 1987 AT 630 PM CDT...SCATTERED INTENSE THUNDERSTORMS CONTINUED OVER PARTS OF NORTHEAST...EAST CENTRAL AND SOUTH CENTRAL SOUTH DAKOTA. THESE STORMS WERE MOSTLY WITHIN A 50 MILE WIDE BAND BETWEEN WILMOT AND THE NEBRASKA BORDER...SOUTHWEST OF MISSION. THE HEAVIEST STORMS WERE LOCATED 10 MILES NORTHWEST OF WATERTOWN...JUST NORTH OF BRISTOL ...5 MILES SOUTHEAST OF CONDE...JUST WEST OF DOLAND...10 MILES NORTHEAST OF FORT THOMPSON AND 10 MILES SOUTHEAST OF PRESHO. THESE STORMS ARE CAPABLE OF PRODUCING VERY HEAVY RAIN...HAIL AND DANGEROUS LIGHTNING. PERSONS IN THE NORTHEAST...EAST CENTRyAL AND SOUTH CENTRAL PARTS OF SOUTH DAKOTA SHOULD BE ON THE ALERT FOR THREATENING WEATHER. MOVEMENT WAS NORTHEAST AT 15 MILES AN HOUR. PFEIFFER
Special weather statement, Jul 20, 9:05 PM CDT, 1 hour 1 minute before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 905 PM CDT MON JULY 20 1987 AT 9PM CDT...THUNDERSTORMS...SOME OF THEM INTENSE WITH HEAVY RAIN WERE OCCURRING OVER PARTS OF SOUTHEAST SOUTH DAKOTA AND SOUTHWEST MINNESOTA. THE THUNDERSTORMS EXTENDED NORTH OF A LINE FROM ABOUT 90 MILES WEST/NORTHWEST OF SIOUX FALLS...NEAR WOONSOCKET SOUTH DAKOTA...NORTHEAST TO ABOUT 100 MILES NORTHEAST OF SIOUX FALLS... NEAR GRANITE FALLS MINNESOTA. SOME OF THE MOST INTENSE THUNDERSTORMS WERE OCCURRING ABOUT 90 MILES WEST/NORTHWEST OF SIOUX FALLS...JUST NORTH OF WOONSOCKET AND ABOUT 85 MILES NORTH OF SIOUX FALLS...NEAR BRANDT SOUTH DAKOTA. THESE THUNDERSTORMS ARE CAPABLE OF PRODUC;ING VERY HEAVY RAIN...HAIL AND DANGEROUS LIGHTNING. THEY ARE MOVING NORTHEAST AT ABOUT 15 MILES AN HOUR. GOLDEN
Special weather statement, Jul 20, 9:27 PM CDT, 39 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 925 PM CDT MON JULY 20 1987 AT 925 PM CDT A THUNDERSTORM WITH STRONG GUSTY WINDS AND VERY HEAVY RAIN WAS LOCATED 10 MILES WEST OF BROOKINGS SOUTH DAKOTA. THIS THUNDER/ STORM WAS PRODUCING WIND GUSTS TO 45 MPH ACCORDING TO THE BROOKINGS FIRE DEPARTMENT. SMALL HAIL WAS ALSO POSSIBLE WITH THIS THUNDERSTORM AS IT MOVED EAST/SOUTHEAST AT 15 MPH. THIS THUNDERSTORM WAS PART OF A LINE OF THUNDERSTORMS WHICH EXTENDED FROM 35 MILE NORTH OF REDWOOD FALLS MINNESOTA TO JUST NORTH OF CHAMBERLAIN SOUTH DAKOTA. THIS LINE OF THUNDERSTORMS WAS SAGGING SLOWLY SOUTH AT 10 MPH. EVENTUALLY THE CITIES OF MITCHELL AND SIOUX FALLS WILL EXPERIENCE BEFORE MIDNIGHT CDT IF THESE STORM HOLD TOGETHER. ANY OF THE THUNDERSTORMS CAN PRODUCE GUSTY WINDS TO AROUND 45 MPH... SMALL HAIL...AND VERY HEAVY RAINS. SMALL STREAM AND URBAN FLOODING IS ALSO POSSIBLE DUE TO REPEAT THUNDERSTORMS PASSINhG THROUGH THE SAME AREAS. KAPELA
Special weather statement, Jul 20, 10:05 PM CDT, 1 minute before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 1005 PM CDT MON JULY 20 1987 AT 1000 PM CDT...THUNDERSTORMS...SOME OF THEM INTENSE WITH HEAVY RAIN ...CONTINUED OVER PARTS OF EASTERN SOUTH DAKOTA AND NORTHWEST MIN/ NESOTA. THESE THUNDERSTORMS EXTENDED NORTH OF A LINE FROM ABOUT 90 MILES WEST OF SIOUX FALLS...NEAR PLANKINTON SOUTH DAKOTA...NORTHEAST TO ABOUT 100 MILES NORTHEAST OF SIOUX FALLS...NEAR REDWOOD FALLS MINNESOTA. SOME OF THE MOST INTENSE THUNDERSTORMS WERE OCCURRING ABOUT 45 MILES NORTHWEST AND NORTH OF SIOUX FALLS...NEAR HOWARD AND BROOKINGS SOUTH DAKOTA. THESE THUNDERSTORMS CAN PRODUCE HEAVY RAIN...HAIL AND DEADLY LIGHT/ NING AS THEY MOVE EAST AT ABOUT 10 MILES AN HOUR. GOLDEN
The office that day
Everything else NWS Sioux Falls, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 20, 9:40 PM CDT | Severe Thunderstorm Warning | FSD | Brookings, Lake, Moody | 65 min |
| Jul 20, 10:06 PM CDT | Severe Thunderstorm Warning | FSD | Lake, McCook | 54 min |
| Jul 20, 10:06 PM CDT | Severe Thunderstorm Warning | FSD | Hanson | 54 min |
| Jul 20, 10:52 PM CDT | Severe Thunderstorm Warning | FSD | McCook, Minnehaha | 68 min |
| Jul 20, 10:52 PM CDT | Severe Thunderstorm Warning | FSD | Murray | 68 min |
| Jul 20, 11:33 PM CDT | Severe Thunderstorm Warning | FSD | Nobles, Rock | 57 min |
Nearby
Severe Thunderstorm Warnings in South Dakota, 1987Severe Thunderstorm Warnings in Minnesota, 1987Every severe thunderstorm warning in 1987
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.