Severe Thunderstorm Warning 132, NWS La Crosse, WI

Issued

Jul 20, 1997, 8:02 PM CDT (01:02 UTC)

Expired

Jul 20, 1997, 9:05 PM CDT

In force

63 min

Issued by

NWS La Crosse, WI

Area

Whole counties

County Winona County, 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.

000 
TTAA00 KLSE 210105 RRA
SVRLSE
MNC169-210205-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
802 PM CDT SUN JUL 20 1997

* SEVERE THUNDERSTORM WARNING FOR
    WINONA COUNTY - SOUTHEASTERN MINNESOTA

* UNTIL 905 PM CDT
 
* SOME LOCATIONS AFFECTED
    WINONA
    LEWISTON
    ALTURA

* AT 800 PM NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM NEAR RIDGEWAY...ABOUT 10 MILES SOUTH OF
  WINONA...AND OTHER SEVERE THUNDERSTORMS ABOUT 25 MILES SOUTHEAST
  OF ROCHESTER. THE STORMS WERE MOVING EAST AT 10 MPH.

* ONE STORM WILL BE NEAR NODINE AT 830 PM.

THE MAIN THREAT FROM THIS STORM IS LARGE HAIL. DO NOT GO OUTDOORS.


RIECK/NELSON

NWS La Crosse, WI wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 20, 2:23 PM CDT, 5 hours 39 minutes earlier.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
223 PM CDT SUN JUL 20 1997

MAIN CONCERNS OF THE NIGHT ARE BOUNDARIES...BOUNDARIES...BOUNDARIES.

SATELLITE IMAGERY AND SURFACE ANALYSIS SHOW OLD CONVECTIVE BOUNDARIES
LAYING ALL OVER THE FORECAST AND SURROUNDING AREAS. DEWPOINTS RISING
INTO THE LOWER TO MIDDLE 70S AND TEMPERATURES INTO THE LOWER TO MIDDLE
80S ACROSS THE ENTIRE FORECAST AREA THIS AFTERNOON EXCEPT FOR
TEMPERATURES IN THE LOWER 70S EXTREME NORTH. LATEST KARX RADAR IMAGERY
HAS A FEW SHOWERS AND THUNDERSTORMS OVER NORTHEASTERN PORTION OF THE
CWA AND MOVING TO THE EAST SOUTHEAST.

12Z ETA/NGM DIFFER ON WHERE MAIN AREA OF FOCUS WILL BE TONIGHT.  NGM
SHOWS FORCING WITH BAND OF FRONTOGENESIS IN THE 1000 TO 850 MB LAYER
DURING THE NIGHT OVER CENTER OF FORECAST AREA. ETA HAS VERY LITTLE IN
TERMS OF BOUNDARY FOCUS BUT KEEPS MOST PRECIPITATION WITH VORTICITY
MAXIMA OVER KANSAS MOVING TO THE NORTHEAST. LOOKING AT FORECAST
SOUNDINGS FOR 00Z AND MODIFYING FOR EXPECT CONDITIONS SEEM A MODERATE
AMOUNT OF CAPE WITH VALUES APPROACHING 2000 J/KG ACROSS THE FORECAST
AREA.

WITH MANY BOUNDARIES AND UNSTABLE AIR OVER THE AREA...SCATTERED
THUNDERSTORMS MAY DEVELOP ALONG ANY OF THESE BOUNDARIES AS THE FOCUS
FROM OUTFLOWS CHANGES DURING THE EVENING HOURS. WITH DEWPOINTS AT OR
SLIGHTLY HIGHER THAN NGM MOS GUIDANCE EXPECT OVERNIGHT LOWS TEMPATURES
TO BE AT OR SLIGHTLY HIGHER THAN NGM MOS.

NELSON

Severe Thunderstorm Warnings in Minnesota, 1997Every severe thunderstorm warning in 1997

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.