Alert archive / Minnesota / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 112, NWS Sioux Falls, SD

July 23, 1987Lincoln County, Lyon County, Minnesota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 23, 1987, 9:02 PM CDT for Lincoln County, Lyon County, Minnesota. It was in force for 58 min.

The area

The counties it named.

The facts

Issued
Jul 23, 1987, 9:02 PM CDT (02:02 UTC)
Expired
Jul 23, 1987, 10:00 PM CDT
In force
58 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

Counties Lincoln County, MN, Lyon 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

Aberdeen, SD (KHON), launched 00:00Z, 2.0 hours before the alert went out and 193 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.

Skew-T log-pSkew-T log-p diagram, Aberdeen, SD at 00:00Z on 1987-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3000 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Aberdeen, SD at 00:00Z on 1987-07-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 25 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
3000 J/kg
Mixed-layer CIN
-42 J/kg
Mixed-layer LCL
1575 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
25 m²/s²
0-3 km storm-relative helicity
144 m²/s²
Significant tornado parameter
0.8
Supercell composite
10.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KFSD 240202
SVRFSD
MNC081-083-240300-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
902 PM CDT THU JUL 23 1987
 
THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING
EFFECTIVE UNTIL 1000 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTIES...
 
IN SOUTHWEST MINNESOTA
          ...LINCOLN...LYON
 
SOME CITIES INCLUDED IN THIS WARNING...MARSHALL...TYLER...IVANHOE AND
TRACY.
 
AT 900 PM CDT RADAR INDICATED A SEVERE THUNDERSTORM JUST SOUTH OF
IVANHOE MINNESOTA MOVING EAST AT 20 MPH. THIS STORM WILL PRODUCE
HEAVY RAINS AND LARGE HAIL.
 
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.
 
THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE A TORNADO WITH LITTLE
OR NO ADVANCE WARNING SO BE ON THE LOOKOUT.
JANSEN

What 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 23, 3:36 PM CDT, 5 hours 26 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE HURON SD
335 PM CDT THU JUL 23 1987

...A TORNADO WATCH IS IN EFFECT UNTIL 9 PM CDT
FOR PORTIONS OF EASTERN SOUTH DAKOTA...

AT 325 PM CDT...WIDELY SCATTERED THUNDERSTORMS AND SHOWERS WERE
OCCURRING OVER PARTS OF EXTREME SOUTH CENTRAL SOUTH DAKOTA.

IN SOUTH DAKOTA THE SHOWERS WERE LOCATED OVER SOUTHERN CHARLES MIX AND
GREGORY COUNTIES OR SOUTH OF A BONESTEEL/ARMOUR LINE.

MOVEMENT WAS EAST AT 15 MILES AN HOUR.

MILLER
Special weather statement, Jul 23, 5:20 PM CDT, 3 hours 42 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
515 PM CDT THU JUL 23 1987

...TORNADO WATCH UNTIL 9 PM CDT FOR A LARGE PORTION OF SOUTH DAKOTA
AND SOUTHWEST MINNESOTA...

AT 510 PM CDT RADAR INDICATED ONLY LIGHT RAIN SHOWERS ACROSS DOUGLAS
COUNTY OF SOUTHEAST SOUTH DAKOTA. THESE SHOWERS CONTINUE TO WEAKEN
AS THEY MOVED EAST.
<
HOWEVER...THUNDERSTORMS ARE EXPECTED TO REDEVELOP OVER THE WATCH AREA
TONIGHT AS AN UPPER LEVEL DISTURBANCE MOVES ACROSS SOUTH DAKOTA.
AT 510 PM THUNDERSTORMS HAD BEGUN TO DEVELOP OVER WESTERN SOUTH DAKOTA
WITH THIS DISTURBANCE. PERSONS ACROSS EASTERN SOUTH DAKOTA...SOUTHWEST
MINNESOTA AND NORTHWEST IOWA SHOULD KEEP ABREAST OF THIS WEATHjER
SITUATION BY LISTENING TO NOAA WEATHER RADIO...LOCAL RADIO OR
TELEVISION FOR LATER STATEMENTS OR POSSIBLE WARNINGS.
JANSEN
Special weather statement, Jul 23, 7:42 PM CDT, 1 hour 20 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE HURON SD
740 PM CDT THU JUL 23 1987

...A TORNADO WATCH IS IN EFFECT UNTIL 9 PM CDT
FOR PORTIONS OF EASTERN SOUTH DAKOTA...

AT 730 PM CDT...AN ISOLATED INTENSE THUNDERSTORM WITH VERY HEAVY
RAIN WAS LOCATED OVER SOUTHEAST CENTRAL SOUTH DAKOTA.

THE THUNDERSTORM WAS OVER CENTRAL AURORA COUNTY...NEAR PLANKINTON
OR ABOUT 30 MILES WEST OF MITCHELL.

HAIL AND STRONG WINDS ARE POSSI)BLE WITH THIS STORM.

MOVEMENT COULD NOT BE DETERMINED AT THIS TIME.

MILLER
Special weather statement, Jul 23, 7:44 PM CDT, 1 hour 18 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE HURON SD
740 PM CDT THU JUL 23 1987

...A TORNADO WATCH IS IN EFFECT UNTIL 9 PM CDT FOR A
LARGE PART OF WESTERN..CENTRTAL AND EASTERN SOUTH DAKOTA...

AT 730 PM CDT...AN ISOLATED INTENSE THUNDERSTORM WITH VERY HEAVY
RAIN WAS LOCATED OVER SOUTHEAST CENTRAL SOUTH DAKOTA.

THE THUNDERSTORM WAS OVER CENTRAL AURORA COUNTY...NEAR PLANKINTON
OR ABOUT 30 MILES WEST OF MITCHELL.

H+AIL AND STRONG WINDS ARE POSSIBLE WITH THIS STORM.

MOVEMENT COULD NOT BE DETERMINED AT THIS TIME.

MILLER
Special weather statement, Jul 23, 8:02 PM CDT, 1 hour before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
800 PM CDT THU JUL 23 1987

...TORNADO WATCH UNTIL 9 PM CDT FOR A LARGE PORTION OF SOUTH DAKOTA
AND SOUTHWEST MINNESOTA...

AT 800 PM CDT...THUNDERSTORMS...SOME OF THEM INTENSE WITH HEAVY RAIN
WERE SCATTERED OVER SOUTHEAST SOUTH DAKOTA AND SOUTHWEST MINNESOTA.
THUNDERSTORMS EXTENDED IN A NARROW BAND FROM ABOUT 50 MILES NORTH OF
SIOUX FALLS...JUST NORTH OF BROOKINGS SOUTH DAKOTA...NORTHEAST TO
ABOUT 100 MILES NORTHEAST OF SIOUX FALLS...NEAR REDWOOD FALLS MIN/
NESOTA.  THUNDERSTORMS WERE ALSO OCCURRING OVER A SMALL AREA ABOUT 70
MILES WEST OF SIOUX FALLS...NEAR MITCHELL SOUTH DAKOTA.  SOME OF THE
HEAVIEST RAIN WAS FALLING ABOUT 55 MILES NORTH OF SIOUX FALLS...JUST
NORTH OF BROOKINGS SOUTH DAKOTA.

THESE THUNDERSTORMS WERE MOVING EAST AT ABOUT 30 MILES AN HOUR.

THESE THUNDERSTORMS MAY PRODUCE SOME HEAVY RAIN...SMALL HAIL AND
DANGEROUS LIGHTNING.  PLEASE LISTEN FORI LATER STATEMENTS AND
POSSIBLE WARNINGS.
GOLDEN
Special weather statement, Jul 23, 8:45 PM CDT, 17 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE HURON SD
840 PM CDT THU JUL 23 1987

...A TORNADO WATCH IS IN EFFECT UNTIL 9 PM CDT FOR
MOST OF SOUTH DAKOTA...

AT 830 PM CDT...AN ISOLATED INTENSE THUNDERSTORMS WITH VERY HEAVY
RAIN WERE LOCATED OVER EXTREME EASTERN SOUTH DAKOTA AND ALSO
OVER SOUTHEAST CENTRAL SOUTH DAKOTA.

THE THUNDERSTORMS WERE OVER SOUTHEAST DUEL AND NORTHEAST BROOKINGS
COUNTIES OR ABOUT 15 MILES NORTHEAST OF BROOKINGS AND ALSO OVER
CENTRAL DAVISON COUNTY NEAR MITCHELL.

HAIL AND STRONG WINDS ARE POSSIBLE WITH THESE STORMS.

MOVEMENT WAS EAST 25 MILES AN HOUR.
MILLER

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 23, 7:46 PM CDTSevere Thunderstorm WarningFSDLincoln, Lyon59 min

Nearby

Severe 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.