Alert archive / Minnesota / Severe Thunderstorm Warnings in 1991

Severe Thunderstorm Warning 97, NWS Twin Cities, MN

July 7, 1991Fillmore County, Freeborn County, Mower County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Jul 7, 1991, 12:09 PM CDT for Fillmore County, Freeborn County, Mower County, Minnesota. It was in force for 51 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 7, 1991, 12:09 PM CDT (17:09 UTC)
Expired
Jul 7, 1991, 1:00 PM CDT
In force
51 min
Issued by
NWS Twin Cities, MN
Area
Whole counties

Counties Fillmore County, MN, Freeborn County, MN, Mower County, MN

What was reported inside it

TimeReportWhereRemark
Jul 7, 12:10 PM CDTTornado F1Mower, MN
Jul 7, 12:20 PM CDTTornado F0Mower, MN
Jul 7, 12:45 PM CDTThunderstorm Wind 61Fillmore, 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 12:00Z, 5.2 hours before the alert went out and 148 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 12:00Z on 1991-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 1991-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 99 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1724 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
99 m²/s²
0-3 km storm-relative helicity
166 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KRST 071710
SVRRST
MNC047-045-099-071800-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ROCHESTER MN
1209 PM CDT SUN JUL 7 1991
 
THE NATIONAL WEATHER SERVICE IN ROCHESTER MN HAS ISSUED A
SEVERE THUNDERSTORM WARNING     EFFECTIVE UNTIL  100 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN SOUTH CENTRAL MINNESOTA
 
   ...SOUTHEASTERN FREEBORN COUNTY
 
IN SOUTHEAST MINNESOTA
 
   ...SOUTHWESTERN FILMORE COUNTY...SOUTHERN MOWER COUNTY
 
 
THIS WARNING INCLUDES THE TOWNS OF AUSTIN...HAYWARD...OSTRANDER
...AND SPRING VALLEY.
 
AT 12 NOON RADAR INDICATED SEVERE THUNDERSTORMS NEAR INTERSTATE
BETWEEN ALBERT LEA AND AUSTIN MINNESOTA.  THE STORMS WERE MOVING
RAPIDLY EAST AT 45 MPH.
 
 
WINDS IN EXCESS OF 60 MPH..MAKE THIS A DANGEROUS STORM. YOU SHOULD
PREPARE FOR STRONG WINDS..LARGE HAIL..DEADLY LIGHTNING AND HEAVY RAIN
BY MOVING TO SHELTER IN A STRONG BUILDING. REMEMBER SEVERE
THUNDERSTORMS CAN AND DO PRODUCE TORNADOES WITH LITTLE OR NO WARNING.

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 7, 10:50 AM CDT, 1 hour 19 minutes before
MNZ017-018-071630-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MINNEAPOLIS ST PAUL MN
1045 AM CDT SUN JUL 7 1991

...SEVERE WEATHER WATCH CANCELLED FOR SOUTHWEST MINNESOTA...

THE NATIONAL WEATHER SERVICE HAS CANCELLED THE SEVERE THUNDERSTORM
WATCH WHICH HAD BEEN IN EFFECT FOR A PORTION OF SOUTHWEST MINNESOTA
UNTIL 1 PM.

SEVERE WEATHER IS EXPECTED TO REMAIN IN NORTHERN IOWA BUT SHOWERS AND
THUNDERSTORMS ARE STILL LIKELY OVER MUCH OF SOUTHERN MINNESOTA INTO THE
AFTERNOON HOURS.
JPR

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 7, 12:12 PM CDTTornado WarningMPXFillmore33 min
Jul 7, 12:46 PM CDTSevere Thunderstorm WarningMPXFillmore, Olmsted, Winona44 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.