Alert archive / Iowa / Severe Thunderstorm Warnings in 1987
Severe Thunderstorm Warning 94, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 11, 1987, 10:54 PM CDT for Osceola County, Iowa; Jackson County, Minnesota. It was in force for 66 min.
The area
The counties it named.
The facts
- Issued
- Jul 11, 1987, 10:54 PM CDT (03:54 UTC)
- Expired
- Jul 12, 1987, 12:00 AM CDT
- In force
- 66 min
- Issued by
- NWS Sioux Falls, SD
- Area
- Whole counties
Counties Osceola County, IA, Jackson County, MN
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
Minneapolis, MN (KSTC), launched 00:00Z, 3.9 hours before the alert went out and 205 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
- 2069 J/kg
- Mixed-layer CIN
- -19 J/kg
- Mixed-layer LCL
- 1014 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- 4 m²/s²
- 0-3 km storm-relative helicity
- 71 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted, in the capitals the NWS used until 2016.
000
TTAA00 KFSD 120354
SVRFSD
IAC143-MNC063-120500-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1054 PM CDT SAT JUL 11 1987
THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING
EFFECTIVE UNTIL MIDNIGHT CDT FOR PEOPLE IN THE FOLLOWING COUNTIES...
IN NORTHWEST IOWA
...OSCEOLA
IN SOUTHWEST MINNESOTA
...JACKSON
CITIES EFFECTED ARE...HERON LAKE AND LAKEFIELD IN JACKSON COUNTY
MINNESOTA AND SIBLEY IN OSCEOLA COUNTY IOWA.
GOLF BALL SIZE HAIL HAS BEEN REPORTED WITH SOME OF THESE
STORMS...WITH EXTREMELY HEAVY RAIN.
IF YOU ARE IN THE PATH OF THIS STORM...YOU SHOULD GET TO A
REINFORCED SHELTER. A SEVeERE 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.
KOSCIELSKIWhat 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 11, 9:20 PM CDT, 1 hour 34 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 915 PM CDT SAT JUL 11 1987 ...INTENSE THUNDERSORMS WERE INCREASING ACROSS SOUTHEAST SOUTH DAKOTA... AT 9 PM CDT A LINE OF INTENSE THUNDERSTORMS WITH VERY HEAVY RAIN CONTINUED TO INCREASE ACROSS SOUTHEAST SOUTH DAKOTA. THE LINE EXTENDED FROM 70 MILES SOUTHWEST OF SIOUX FALLS...NEAR SPRING/ FIELD TO 60 MILES NORTH OF SIOUX FALLS...NEAR BROOKINGS. THESE STORMS WERE PRODUCING VERY HEAVY RAIN AND ARE CAPABLE OF PRODUCING HAIL... STRONG GUSTY WINDS AND DANGEROUS LIGHTNING AS THEY MOVE TO THE EAST AT 25 MILES AN HOUR. PERSONS IN THE SOUTH DAKOTA COUNTIES OF MOODY...MINNEHAHA...MCCOOK... TURNER AND LINCOLN INCLUDING THE COMMUNITIES OF FLANDREAU...SIOUX FALLS ...DELL RAPIDS AND MARION SHOULD BE ON THE LOOKOUT FOR THESE STORMS THROUGH 10 PM CDT. STAY TUNED TO YOUR LOCAL TV OR RADIO STATION FOR FURTHER STATEMENTS OR POSSIBLE WARNINGS. BUSS
Special weather statement, Jul 11, 9:38 PM CDT, 1 hour 16 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE HURON SD 935 PM CDT SAT JUL 11 1987 ...TORNADO WATCH FOR PORTIONS OF CENTRAL AND EASTERN SOUTH DAKOTA UNTIL MIDNIGHT CDT THIS SATURDAY NIGHT... AT 930 PM CDT...A LINE OF INTENSE THUNDERSTORMS CONTINUED TO MOVE OVER SOUTHEAST SOUTH DAKOTA AND WESTERN MINNESOTA. THE LINE OF THUNDERSTORMS WAS ALONG AND 10 MILES EITHER SIDE OF A LINE FROM YANKTON TO SIOUX FALLS TO BROOKINGS. THE STRONGEST THUNDERSTORMS WERE JUST WEST OF YANKTON AND 10 MILES NORTH OF YANKTON. THE LINE OF THUNDERSTORMS WAS MOVING EAST AT 30 MILES AN HOUR. THESE STORMS ARE CAPABLE OF PRODUCING STRONG GUSTY WINDS...FREQUENT LIGHTNING AND HAIL. IF YOU ARE IN THE PATH OF THESE STORMS YOU SHOULD SEEK SHELTER. OTHERWISE...SCATTERED SHOWERS AND THUNDERSTORMS CONTINUED OVER MOST OF CENTRAL AND EASTERN SOUTH DAKOTA. THESE SHOWERS AND THUNDERSTORMS WERE EAST OF A LINE FROM MOBRIDGE TO PIERRE (TO MITCHELL AND WERE MOVING EAST AT 30 MILES AN HOUR. EDDY
Special weather statement, Jul 11, 10:20 PM CDT, 34 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 1020 PM CDT SAT JUL 12 1987 ...THUNDERSTORMS WITH HEAVY RAIN CONTINUED ACROSS SOUTHEAST SOUTH DAKOTA AND SOUTHWEST MINNESOTA... AT 1015 PM CDT A LINE OF SCATTERED THUNDERSORMS WITH HEAVY RAIN CONTINUED ACROSS SOUTHEAST SOUTH DAKOTA AND INTO SOUTHWEST MINNESOTA. THE LINE EXTENDED FROM 35 MILES SOUTH OF SIOUX FALLS...NEAR CENTERVILLE SOUTH DAKOTA TO 70 MILE NORTHEAST OF SI"OUX FALLS...NEAR MARSHALL MINNESOTA. THESE STORMS ARE CAPABLE OF PRODUCING HEAVY RAIN...SMALL HAIL... GUSTY SURFACE WINDS AND DANGEROUD LIGHTNING AS THEY MOVE TO THE EAST AT 25 MILES AN HOUR. BUSS
Special weather statement, Jul 11, 10:24 PM CDT, 30 minutes before
^DSMSPSSUX SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX CITY IA 1022 PM CDT SAT JUL 11 1987 ...TORNADO WATCH FOR UNION COUNTY IN SOUTH DAKOTA UNTIL MIDNIGHT CDT... AT 1018 PM CDT STRONG THUNDERSTORMS HAD DEVELOPED JUST WEST OF SIOUX CITY IOWA. THESE THUNDERSTORM WERE MOVING TO THE EAST AT 30 MILES AN HOUR AND WILL BE MOVING INTO SIOUX CITY BY 1030 PM CDT. PEOPLE IN EASTERN DAKOTA COUNTY IN NEBRASKA AND WESTERN WOODBURY COUNTY IN IOW*A SHOULD BE ALERT AND BE PREPARED TO TAKE COVER IF SEVERE WEATHER IS OBERVED. THESE THUNDERSTORMS ARE CAPABLE OF PRODUCING SMALL HAIL... STRONG GUSTY WIND...DANGEROUS LIGHTNING AND VERY HEAVY RAIN. ROSNER
Special weather statement, Jul 11, 10:34 PM CDT, 20 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE HURON SD 1030 PM CDT SAT JUL 11 1987 ...TORNADO WATCH FOR PORTIONS OF CENTRAL AND EASTERN SOUTH DAKOTA UNTIL MIDNIGHT CDT THIS SATURDAY NIGHT... AT 1030 PM CDT...A LINE OF INTENSE THUNDERSTORMS CONTINUED TO MOVE OUT OF SOUTHEAST SOUTH DAKOTA AND INTO WESTERN MINNESOTA AND EXTREME NORTHWESTERN IOWA. THE LINE OF THUNDERSTORMS WAS ALONG AND 30 MILES WEST OF A LINE FROM SIOUX CITY IOWA TO REDWOOD FALLS MINNESOTA. THE LINE OF THUNDERSTORMS WAS MOVING EAST AT 30 MILES AN HOUR. THESE STORMS ARE CAPABLE OF PRODUCING STRONG GUSTY WINDS...FREQUENT LIGHTNING AND HAIL. IF YOU ARE IN THE PATH OF THESE STORMS YOU SHOULD SEEK SHELTER. OTHERWISE...SCATTERED SHOWERS AND THUNDERSTORMS CONTINUED OVER NORTH CENTRAL AND NORTHEAST SOUTH DAKOTA. THESE SHOWERS AND THUNDERSTORMS WERE NORTH AND EAST OF A LINE FROM MOBRIDGE TO HURON TO BROOKINGS AND WERE MOVING EAST AT 30A MILES AN HOUR. EDDY
Local storm report, Jul 11, 10:51 PM CDT, 3 minutes before
STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1050 PM CDT SAT JUL 11 1987
420 PM CDT PEA/MARBLE SIZE HAIL AND .54 PRECIP AT SIOUX CENTER IOWA
430 PM CDT TORNADO REPORTED FEW MILES WEST OF WHITE RIVER IN
MELLETTE COUNTY SOUTH CENTRAL SD
900 PM CDT TORNADO TOUCHDOWN AT MENNO IN HUTCHINSON COUNTY SD
901 PM CDT GOLF BALL SIZE HAIL NORTH OF MONTROSE IN MCCOOK COUNTY SD
901 PM CDT 40 MPH WINDS AND HEAVY RAIN AT COLTON IN MINNEHAHA COUNTY
IN SD
908 PM CDT ESTIMATED 50 MPH WINDS AND VERY HEAVY RAIN AT PARKER IN
TURNER COUNTY SD
920 PM CDT FUNNEL CLOUD 6 MILES WEST OF YANKTON SD
925 PM CDT 60 MPH PLUS WINDS AT IRENE SD CAUSING DAMAGE
925 PM CDT FUNNEL CLOUD 3 MILES SOUTH OF VIBORG IN TURNER COUNTY SD
950 PM CDT GOLF BALL SIZE HAIL TYLER LINCOLN COUNTY MINNESOTA
1002 PM CDT FUNNEL 3 MILES SOUTH OF LENNOX REPORTED BY LINCOLN SD
COUNTY XSHERIFF
RYRHOLMThe office that day
Everything else NWS Sioux Falls, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 11, 10:22 PM CDT | Severe Thunderstorm Warning | FSD | Lyon, Sioux | 68 min |
| Jul 11, 10:00 PM CDT | Severe Thunderstorm Warning | FSD | Lyon | 60 min |
| Jul 11, 10:22 PM CDT | Severe Thunderstorm Warning | FSD | Cottonwood, Murray, Nobles | 68 min |
Nearby
Severe Thunderstorm Warnings in Iowa, 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.