Alert archive / Minnesota / Severe Thunderstorm Warnings in 1989

Severe Thunderstorm Warning 76, NWS Twin Cities, MN

August 21, 1989Swift County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Aug 21, 1989, 4:58 PM CDT for Swift County, Minnesota. It was in force for 47 min.

The area

The counties it named.

The facts

Issued
Aug 21, 1989, 4:58 PM CDT (21:58 UTC)
Expired
Aug 21, 1989, 5:45 PM CDT
In force
47 min
Issued by
NWS Twin Cities, MN
Area
Whole counties

County Swift 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 12:00Z, 10.0 hours before the alert went out and 170 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 1989-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 12:00Z on 1989-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 103 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
2 J/kg
Mixed-layer CIN
-374 J/kg
Mixed-layer LCL
1007 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
103 m²/s²
0-3 km storm-relative helicity
152 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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, Aug 21, 4:36 PM CDT, 22 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST CLOUD MN
430 PM CDT MON AUG 21 1989

...THUNDERSTORMS MOVING INTO BIG STONE COUNTY...

...SEVERE THUNDERSTORM WATCH FOR WEST CENTRAL MINNESOTA TILL 10PM...

AT 425 PM CDT RADAR SHOWED THUNDERSTORM MOVING INTO BIG STONE
COUNTY OF WEST CENTRAL MINNESOTA.  THE BIG STONE COUNTY SHERIFF
REPORTS HEAVY RAIN AND SMALL HAIL NORTH OF ORTONVILLE...65 MILES
SOUTHWEST OF ALEXANDRIA.

THIS THUNDERSTORM WAS MOVING EASTNORTHEAST AT 35 MPH.

NO SEVERE WEATHER HAS BEEN REPORTED AT THIS TIME...HOWEVER...
WESTCENTRAL MINNESOTA REMAINS IN A SEVERE THUNDERSTORM WATCH
AREA SO PEOPLE SHOULD REMAIN ALERT TO CHANGING CONDITIONS AND
BE PREPARED TO ACT IMMEDIATELY.

NISTLER
Special weather statement, Aug 21, 4:58 PM CDT, 0 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MINNEAPOLIS/ST PAUL MN
850 PM CDT SUN AUG 13 1989

...DANGEROUS SEVERE WEATHER SITUATION SETTING UP FOR SOUTH AND
   CENTRAL MINNESOTA THIS EVENING...
AFTER SEVERAL YEARS OF LOW SEVERE WEATHER FREQUENCY FOR MUCH OF
SOUTH MINNESOTA..A VERY ACTIVE EVENING APPEARS TO BE SHAPING UP
FOR MUCH OF THE AREA THIS MONDAY.

THE WEATHER SITUATION THIS EVENING IS FAVORABLE FOR BOTH SEVERE
THUNDERSTORM AND TORNADO FORMATION DUE TO A COMBINATION OF STRONG
DYNAMICS FOR THIS TIME OF YEAR..AND A GREAT DEAL OF AIRMASS
INSTABILITY.

IT IS IMPORTANT TO STAY ABREAST OF THE WEATHER SITUATION THIS
EVENING AS WEATHER CONDITIONS ARE LIKELY TO CHANGE QUITE RAPIDLY
AT ANY ONE SPOT AS THESE STORMS MOVE IN.

POWERFUL THUNDERSTORMS HAVE FORMED IN WEST CENTRAL MINNESOTA AND
THERE IS NO REASON THAT THEY WILL NOT HOLD TOGETHER AND
SWEEP ACROSS ALL OF SOUTH MINNESOTA BEFORE THE EVENING IS OVER.

THE TWIN CITIES IS LIKELY TO GET INTO THE ACTION AFTER ABOUT 8 PM
CDT THIS EVENING..BUT THE AIRMASS IS UNSTABLE ENOUGH FOR SEVERE
STORMS TO DEVELOP BEFORE THAT TIME.

TOGSTAD

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 21, 5:03 PM CDTSevere Thunderstorm WarningMPXSwift42 min
Aug 21, 6:17 PM CDTSevere Thunderstorm WarningMPXMille Lacs, Morrison, Sherburne23 min
Aug 21, 6:49 PM CDTSevere Thunderstorm WarningMPXWright56 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 1989Every severe thunderstorm warning in 1989

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.