Alert archive / Minnesota / Severe Thunderstorm Warnings in 1991

Severe Thunderstorm Warning 103, NWS Twin Cities, MN

July 17, 1991Chippewa County, Yellow Medicine County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Jul 17, 1991, 8:10 PM CDT for Chippewa County, Yellow Medicine County, Minnesota. It was in force for 35 min. 3 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Jul 17, 1991, 8:10 PM CDT (01:10 UTC)
Expired
Jul 17, 1991, 8:45 PM CDT
In force
35 min
Issued by
NWS Twin Cities, MN
Area
Whole counties

Counties Chippewa County, MN, Yellow Medicine County, MN

What was reported inside it

TimeReportWhereRemark
Jul 17, 8:15 PM CDTThunderstorm Wind 52Chippewa, MN
Jul 17, 8:33 PM CDTThunderstorm Wind 0Chippewa, MN
Jul 17, 8:35 PM CDTThunderstorm Wind 0Chippewa, MN

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Minneapolis, MN (KSTC), launched 00:00Z, 1.2 hours before the alert went out and 167 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, Minneapolis, MN at 00:00Z on 1991-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1083 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, Minneapolis, MN at 00:00Z on 1991-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 9 square meters per square second.193958Sfc1 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
1083 J/kg
Mixed-layer CIN
-159 J/kg
Mixed-layer LCL
1349 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
9 m²/s²
0-3 km storm-relative helicity
61 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KSTC 180110
SVRSTC
MNC023-173-180145-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST CLOUD MINNESOTA
810 PM CDT WED JUL 17 1991
 
THE NATIONAL WEATHER SERVICE IN ST CLOUD MINNESOTA   HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  845 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN WEST CENTRAL MINNESOTA
 
   ...WESTERN CHIPPEWA COUNTY...EASTERN YELLOW MEDICINE COUNTY
 
INCLUDING THE CITIES OF MONTEVIDEO AND GRANITE FALLS.
 
AT 805 PM RADAR INDICATED A SEVERE THUNDERSTORM 10 MILES NORTHWEST
OF MONTEVIDEO MOVING SOUTHEAST AT 25 MPH. THIS STORM WILL MOVE
THROUGH MONTEVIDEO BY 830 PM AND INTO GRANITE FALLS BY 845 PM.
 
 
THIS IS A DANGEROUS STORM.  IF YOU ARE IN ITS PATH YOU SHOULD
PREPARE FOR DAMAGING WIND IN EXCESS OF 55 MPH...LARGE HAIL...AND
DEADLY LIGHTNING.  PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT STAY AWAY FROM WINDOWS.
 
NNNN

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 17, 6:44 PM CDT, 1 hour 26 minutes before
MNZ014-013-011-180045-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST CLOUD MINNESOTA
644 PM CDT WED JUL 17 1991

...SEVERE THUNDERSTORM WATCH UNTIL MIDNIGHT...

A NEW SEVERE THUNDERSTORM WATCH EFFECTIVE UNTIL MIDNIGHT COVERS MUCH
OF CENTRAL MINNESOTA INCLUDING THE ST CLOUD AREA.

AT 630 PM CDT THUNDERSTORMS CONTINUED TO DEVELOP OVER CENTRAL
MINNESOTA. THE STRONGEST STORM WAS LOCATED 20 MILES NORTHWEST OF
ALEXANDRIA AND WAS MOVING SOUTHEAST AT 25 MPH. OTHER STRONG STORMS
WERE LOCATED IN WEST CENTRAL MINNESOTA AND NORTH OF THE TWIN CITIES.

ALTHOUGH NO SEVERE WEATHER HAS BEEN REPORTED SINCE 500 PM THE
POTENTIAL FOR STRONG WINDS...LARGE HAIL...HEAVY RAINS AND FREQUENT
LIGHTNING STRIKES DOES EXIST WITH THESE STORMS AS THEY MOVE THROUGH
CENTRAL MINNESOTA.

NNNN

The office that day

Everything else NWS Twin Cities, MN issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 17, 7:29 PM CDTSevere Thunderstorm WarningMPXPope, Stearns53 min
Jul 17, 8:27 PM CDTSevere Thunderstorm WarningMPXRedwood, Renville48 min
Jul 17, 9:07 PM CDTSevere Thunderstorm WarningMPXRenville53 min
Jul 17, 9:54 PM CDTSevere Thunderstorm WarningMPXRenville24 min
Jul 17, 9:54 PM CDTSevere Thunderstorm WarningMPXMcLeod, Sibley36 min
Jul 17, 10:29 PM CDTSevere Thunderstorm WarningMPXSibley31 min
Jul 17, 10:34 PM CDTSevere Thunderstorm WarningMPXNicollet41 min
Jul 18, 4:48 PM CDTSevere Thunderstorm WarningMPXTodd42 min
Jul 18, 5:16 PM CDTSevere Thunderstorm WarningMPXPope44 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 1991Every severe thunderstorm warning 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.