Alert archive / Wisconsin / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 5, NWS La Crosse, WI

July 20, 1987Jackson County, Wisconsin

NWS La Crosse, WI issued this severe thunderstorm warning at Jul 20, 1987, 2:44 PM CDT for Jackson County, Wisconsin. It was in force for 41 min.

The area

The counties it named.

The facts

Issued
Jul 20, 1987, 2:44 PM CDT (19:44 UTC)
Expired
Jul 20, 1987, 3:25 PM CDT
In force
41 min
Issued by
NWS La Crosse, WI
Area
Whole counties

County Jackson County, WI

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

Green Bay/Straub, WI (KGRB), launched 12:00Z, 7.7 hours before the alert went out and 216 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, Green Bay/Straub, WI at 12:00Z on 1987-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3840 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, Green Bay/Straub, WI at 12:00Z on 1987-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 20 square meters per square second.1939Sfc1 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
3840 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
653 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
20 m²/s²
0-3 km storm-relative helicity
73 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 KLSE 201943
SVRLSE
WIC053-112025-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
244 PM CDT MON JUL 20 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM
WARNING EFFECTIVE UNTIL 325 PM CDT FOR PEOPLE IN THE FOLLOWING
COUNTY OF

WEST CENTRAL WISCONSIN...WESTERN HALF JACKSON COUNTY

WEATHER RADAR SHOWED A LINE OF SEVERE THUNDERSTORMS MOVING INTO
NORTHERN JACKSON COUNTY.  THESE SEVERE THUNDERSTORMS WILL BE MOVING
INTO THE TOWNS OF HIXTON AND BLACK RIVER FALLS IN JACKSON COUNTY BY
350 PM CDT THIS AFTERNOON.

THE WARNING IS IN EFFECT AREAS NEAR AND WEST OF THE CITY OF BLACK
RIVER FALLS IN JACKSON COUNTY.

PERSONS IN THE PATH OF THESE THUNDERSTORMS SHOULD SEEK SHELTER
IMMEDIATELY IF THREATING WEATHER IS SIGHTED.

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR..DEADLY LIGHTNING..HAIL 3/4 INCH OR MORE IN DIAMETER..AND
HEAVY RAIN THAT CAN QUICKLY FLOOD LOW LYING AREAS.

REMEMBER..SEVERE THUNDERSTORMS CAN PRODUCE TORNADOES WITHOUT WARNING.

IF THREATENING WEATHER APPROACHES..GO FOR SAFE SHELTER IN A
REINFORCED BUILDING SUCH AS YOUR HOME.  IF CAUGHT OUTSIDE..
LIE IN A DITCH OR CULVERT AND STAY AWAY FROM TREES AND
TELEPHONE POLES.

SCHNEIDER

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 20, 1:45 PM CDT, 59 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
145 PM CDT MON JUL 20 1987

...VERY INTENSE THUNDERSTORMS DEVELOPING IN WEST CENTRAL WISCONSIN...

A WEAK FRONTAL BOUNDARY ACROSS CENTRAL MINNESOTA AND WISCONSIN HAS
BEEN KEEPING SOMEWHAT COOLER AIR TO THE NORTH AND WARM MOIST AIR TO
THE SOUTH. THIS HAS SET UP A VERY UNSTABLE WEATHER PATTERN OVER THE
TWO STATES AND THIS MORNING THE THUNDERSTORMS WERE SET OFF.

VERY INTENSE THUNDERSTORMS HAVE BEEN MOVING EAST TO SOUTHEASTWARD
THROUGH THE NORTHERN THIRD OF MINNESOTA AND WISCONSIN THROUGHOUT THE
MORNING AND EARLY AFTERNOON HOURS. THE INTENSE THUNDERSTORMS ARE
EXPECTED TO CONTINUE TO MOVE EAST SOUTHEASTWARD AT 40 MILES AN HOUR
THIS AFTERNOON. THE THUNDERSTORMS SHOULD MOVE INTO NORTHERN BUFFALO
COUNTY BY 200 PM AND NORTHERN PORTIONS OF TEMPEALEAU AND JACKSON
COUNTIES OF WEST CENTRAL WISCONSIN BY 230 PM CDT.

THESE INTENSE THUNDERSTORMS HAVE BEEN PRODUCING WINDS GUSTS BETWEEN
50 TO 60 MILES AN HOUR AND HEAVY DOWNPOURS.

PERSONS IN PORTIONS OF WEST CENTRAL WISCONSIN SHOULD ALSO BE ALERT
FOR POSSIBLE HAIL..LIGHTNING AND EVEN A TORNADO WITH THESE VERY
STRONG STORMS.

THE NATIONAL WEATHER SERVICE WILL BE CLOSELY MONITORING THESE STORMS
FOR THE NEXT FEW HOURS.

STAY TUNED TO RADIO..TELEVISION..OR WEATHER RADIO FOR THE
LATEST INFORMATION.

SCHNEIDER

The office that day

Everything else NWS La Crosse, WI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 20, 2:28 PM CDTSevere Thunderstorm WarningARXBuffalo, Trempealeau57 min

Nearby

Severe Thunderstorm Warnings in Wisconsin, 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.