Severe Thunderstorm Warning 54, NWS La Crosse, WI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
310 PM CDT THU JUNE 10 1999

INDIVIDUAL SHORTWAVES IN THE UPPER SOUTHWEST FLOW REGIME CONTINUE
TO INDUCE WAVES ALONG A FRONTAL BOUNDARY WHICH CURRENTLY EXTENDS
FROM CENTRAL IOWA... NORTHEAST... INTO CENTRAL WISCONSIN.   MESOSCALE
BOUNDARIES ACROSS THE FORECAST AREA HAVE PROVIDED AN ADDITIONAL
FOCUS FOR CONVECTION TO FIRE.  MAIN CHALLENGE THIS FORECAST PACKAGE
IS TO DETERMINE THE POSITION OF THE FRONTAL BOUNDARY AND RESOLVING
THE FORCING MECHANISMS WHICH WILL PROVIDE A FOCUS FOR CONVECTION.

RESOLVING THE INDIVIDUAL SHORTWAVES RATHER POINTLESS WITH THE
MODEL FORECASTS.  10/12Z ETA THE ONLY MODEL OF THIS MORNINGS RUNS TO
DEPICT THE SHORTWAVE ACROSS THE CENTRAL PLAINS BUT DAMPENS IT OUT
RATHER QUICKLY.  BASED ON RECENT TRENDS THIS AFTERNOON... THIS SEEMS
UNREALISTIC.

MODEL DERIVED QPF SHOWS THAT PRECIPITATION SHOULD REMAIN FOCUSED
ALONG THE FRONTAL BOUNDARY BUT THIS IS QUESTIONABLE.  DON'T THINK
PRECIPITATION WILL BE FROM PURE FRONTAL CONVERGENCE OR LARGE SCALE
FORCING AS THE MODEL SUGGESTS SINCE THE FLOW PARALLEL TO THE FRONT
IN THE BOUNDARY LAYER AND ANY LARGE SCALE FORCING REMAINS TO THE
NORTH.

BELIEVE THAT INDIVIDUAL SHORTWAVES IN THE SOUTHWEST FLOW WILL
CONTINUE TO INDUCE SURFACE WAVES ALONG THE QUASI-STATIONARY
FRONTAL BOUNDARY ACROSS THE FORECAST AREA.  THESE WILL ENHANCE
CONVERGENCE ALONG THE FRONT AS THEY PROPAGATE.  CONVECTION WILL
RESULT FROM THESE WAVES AND EXTEND INTO THE WARM SECTOR FIRING
ALONG OUTFLOW BOUNDARIES.

PRECIPITABLE WATER IN EXCESS OF 1.5 INCHES AND 850 MB DEWPOINTS
INDICATES THE POTENTIAL FOR SIGNIFICANT PRECIPITATION.  WITH THE
CONTINUED CONVECTIVE POTENTIAL... WILL8 EXTEND FLASH FLOOD WATCH
INTO FRIDAY.

COORDINATED WITH MPX/DMX/DVN.

.LSE...FLASH FLOOD WATCH TONIGHT AND FRIDAY
IAZ008>011-018-019-029-030-MNZ094>096.

KRC

IAZ029-030-WIZ061-102050-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
252 PM CDT THU JUN 10 1999

AT 250 PM CDT...THUNDERSTORMS...SOME PRODUCING LOCALLY HEAVY
RAINFALL...WERE DETECTED MAINLY TO THE SOUTH OF A LINE FROM OELWEIN
TO PRAIRIE DU CHIEN TO MUSCODA...45 MILES NORTH OF DUBUQUE. THE
HEAVIEST RAINFALL WAS OCCURRING ABOUT 5 MILES SOUTH OF PRAIRIE DU
CHIEN. THESE STRORM WILL BE MOVING OVER THE SAME AREAS OVER THE NEXT
SEVERAL HOURS...BRINGING A GOOD CHANCE FOR SOME LOCALIZED FLOODING.

STAY TUNED TO NOAA WEATHER RADIO...LOCAL RADIO OR TELEVISION...OR
CABLE TELEVISION FOR THE LATEST UPDATES CONCERNING THIS DEVELOPING
WEATHER SITUATION.

RLB

IAZ029-030-WIZ061-102050-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
252 PM CDT THU JUN 10 1999

AT 250 PM CDT...THUNDERSTORMS...SOME PRODUCING LOCALLY HEAVY
RAINFALL...WERE DETECTED MAINLY TO THE SOUTH OF A LINE FROM OELWEIN
TO PRAIRIE DU CHIEN TO MUSCODA...45 MILES NORTH OF DUBUQUE. THE
HEAVIEST RAINFALL WAS OCCURRING ABOUT 5 MILES SOUTH OF PRAIRIE DU
CHIEN. THESE STRORM WILL BE MOVING OVER THE SAME AREAS OVER THE NEXT
SEVERAL HOURS...BRINGING A GOOD CHANCE FOR SOME LOCALIZED FLOODING.

STAY TUNED TO NOAA WEATHER RADIO...LOCAL RADIO OR TELEVISION...OR
CABLE TELEVISION FOR THE LATEST UPDATES CONCERNING THIS DEVELOPING
WEATHER SITUATION.

RLB

IAZ008>011-018-019-029-030-WIZ043-044-053>055-061-102220-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
329 PM CDT THU JUN 10 1999

AT 320 PM CDT...THUNDERSTORMS...SOME PRODUCING LOCALLY HEAVY
RAINFALL...CONTINUED TO MOVE ACROSS NORTHEAST IOWA AND SOUTHWEST
WISCONSIN. THE STORMS WERE OCCURRING MAINLY SOUTH OF A LINE FROM
AUSTIM TO DECORAH IOWA TO RICHLAND CENTER...50 MILES SOUTHEAST OF
LA CROSSE...TO MAUSTON...40 MILES SOUTH OF WISCONSIN RAPIDS.

THESE THUNDERSTORMS WILL CONTINUE TO MOVE NORTHEAST AT AROUND
25 MPH. SOME OF THE STORMS WILL PRODUCE LOCALLY HEAVY
RAINFALL...WIND GUSTS TO 40 MPH AND SMALL HAIL. SOME LOCALLIZED
FLOODING WILL OCCUR WITH THESE STORMS.

PERSONS ALL ACROSS NORTHEAST IOWA AS WELL AS WESTERN WISCONSIN
SHOULD REMAIN ALERT TO DEVELOPING WEATHER CONDITIONS.

BREESER

IAZ008>011-018-019-029-030-WIZ043-044-053>055-061-102220-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
329 PM CDT THU JUN 10 1999

AT 320 PM CDT...THUNDERSTORMS...SOME PRODUCING LOCALLY HEAVY
RAINFALL...CONTINUED TO MOVE ACROSS NORTHEAST IOWA AND SOUTHWEST
WISCONSIN. THE STORMS WERE OCCURRING MAINLY SOUTH OF A LINE FROM
AUSTIM TO DECORAH IOWA TO RICHLAND CENTER...50 MILES SOUTHEAST OF
LA CROSSE...TO MAUSTON...40 MILES SOUTH OF WISCONSIN RAPIDS.

THESE THUNDERSTORMS WILL CONTINUE TO MOVE NORTHEAST AT AROUND
25 MPH. SOME OF THE STORMS WILL PRODUCE LOCALLY HEAVY
RAINFALL...WIND GUSTS TO 40 MPH AND SMALL HAIL. SOME LOCALLIZED
FLOODING WILL OCCUR WITH THESE STORMS.

PERSONS ALL ACROSS NORTHEAST IOWA AS WELL AS WESTERN WISCONSIN
SHOULD REMAIN ALERT TO DEVELOPING WEATHER CONDITIONS.

BREESER

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
358 PM CDT THU JUN 10 1999

...SEVERE THUNDERSTORM WATCH 431 ALLOWED TO EXPIRE AT 4 PM...

THE SEVERE THUNDERSTORM WATCH THAT WAS IN EFFECT FOR A PORTION OF
NORTHEAST IOWA HAS BEEN ALLOWED TO EXPIRE AT 4 PM.  THE SPECIFIC
COUNTIES INCLUDED IN THE WATCH WERE:

CLAYTON
FAYETTE

THE IMMEDIATE THREAT FOR SEVERE THUNDERSTORMS HAS PASSED.  REMEMBER
THAT A FLASH FLOOD WATCH DOES REMAIN IN EFFECT THROUGH TONIGHT FOR
NORTHEAST IOWA AND MORE THUNDERSTORMS MAY AFFECT THE AREA.

DB

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
358 PM CDT THU JUN 10 1999

...SEVERE THUNDERSTORM WATCH 431 ALLOWED TO EXPIRE AT 4 PM...

THE SEVERE THUNDERSTORM WATCH THAT WAS IN EFFECT FOR A PORTION OF
NORTHEAST IOWA HAS BEEN ALLOWED TO EXPIRE AT 4 PM.  THE SPECIFIC
COUNTIES INCLUDED IN THE WATCH WERE:

CLAYTON
FAYETTE

THE IMMEDIATE THREAT FOR SEVERE THUNDERSTORMS HAS PASSED.  REMEMBER
THAT A FLASH FLOOD WATCH DOES REMAIN IN EFFECT THROUGH TONIGHT FOR
NORTHEAST IOWA AND MORE THUNDERSTORMS MAY AFFECT THE AREA.

DB