897  
FXUS63 KARX 190853  
AFDARX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LA CROSSE WI  
353 AM CDT FRI JUL 19 2019  
   
UPDATE
 
 
ISSUED AT 348 AM CDT FRI JUL 19 2019  
 
DECIDED TO EXPAND EXCESSIVE HEAT WARNING TO INCLUDE ALL BUT TAYLOR  
COUNTY IN NORTH CENTRAL WISCONSIN. TAYLOR COUNTY IS NOW IN A HEAT  
ADVISORY TODAY. SEE LATEST NPW PRODUCT OR WATCHES, WARNING,  
ADVISORY SECTION AT BOTTOM FOR DETAILS.  
 

 
   
SHORT TERM
 
(TODAY THROUGH SATURDAY NIGHT)  
ISSUED AT 256 AM CDT FRI JUL 19 2019  
 
CURRENTLY WATCHING ONGOING PROBLEMATIC HEAVY RAIN PRODUCING  
THUNDERSTORMS LINED UP MAINLY ALONG THE I-90 CORRIDOR AND JUST  
SOUTH. CAMS SHOW THIS CONVECTION EVENTUALLY MOVING EAST OF THE AREA  
BY 7-8AM AS THE LLJ BENDS FURTHER EAST AND TAPERS.  
 
ATTENTION THEN TURNS TO HEAT TODAY AND THEN ENHANCED SEVERE THREAT  
LATE THIS AFTERNOON INTO TONIGHT. A WARM FRONT WILL BE LINED UP  
APPROXIMATELY BETWEEN THE I-90/94 CORRIDORS. RAP SHOWING 925MB  
TEMPERATURES INCREASING INTO THE 29-31C RANGE BY THIS AFTERNOON WITH  
PARTLY TO MOSTLY SUNNY SKIES. THIS IS EXPECTED TO TRANSLATE TO HIGHS  
WELL INTO THE 90S ACROSS MUCH OF THE AREA ALONG WITH UNCOMFORTABLE  
DEWPOINTS IN THE 70S. RESULTING HEAT INDICES WILL GENERALLY BE IN  
THE 100-105 RANGE NORTH OF I-90, AND 105-110 ACROSS PORTIONS OF  
NORTHEAST IA/FAR SOUTHWEST WI. WILL LEAVE HEAT HEADLINES ALONE AS  
THEY COVER THIS WELL.  
 
HIGH HEAT AND HUMIDITY (CAPE OF 5000+ KJ/KG) + WARM FRONTAL BOUNDARY  
+ AMPLE BULK SHEAR (35-50KT) WILL LEAD TO AN ENHANCED RISK OF SEVERE  
THUNDERSTORMS BY THIS EVENING INTO THE OVERNIGHT HOURS. ALL SEVERE  
THREATS (DAMAGING WINDS, LARGE HAIL, TORNADOES) WILL POTENTIALLY BE  
EXPERIENCED AS WELL AS A FLASH FLOOD RISK IF STORMS TRAIN OVER THE  
SAME AREA. THE HIGHEST SEVERE THREAT LOOKS TO BE NORTH OF THE I-90  
CORRIDOR WHERE THAT WARM FRONT WILL BE HANGING OUT. WILL BE  
MONITORING THIS SITUATION CLOSELY!  
 
LIKELIHOOD OF THUNDERSTORM CONTINUE INTO SATURDAY/SATURDAY NIGHT AS A  
MID-LEVEL TROUGH CROSSING THE NORTHERN PLAINS BEGINS TO DRIVE A  
SURFACE COLD FRONTAL BOUNDARY SOUTHWARD INTO THE AREA. WILL AGAIN  
HAVE TO BE SITUATIONALLY AWARE OF SEVERE/FLASH FLOODING THREAT AS  
THERE WILL STILL BE PLENTY OF CAPE AND SHEAR TO WORK WITH.  
   
LONG TERM
 
(SUNDAY THROUGH THURSDAY)  
ISSUED AT 256 AM CDT FRI JUL 19 2019  
 
COULD STILL BE A CHANCE OF SHOWER/THUNDERSTORMS SOUTH OF I-90 SUNDAY  
MORNING AS THAT COLD FRONTAL BOUNDARY SAGS SLOWLY SOUTHWARD OUT OF  
THE AREA. OTHERWISE, COOLER/DRIER AIR FILTERING INTO THE AREA AS  
CANADIAN HIGH PRESSURE BUILDS INTO THE REGION. QUIET/COOLER WEATHER  
CONTINUES THROUGH THURSDAY AS THE CANADIAN HIGH SETTLES OVER THE  
REGION.  
 

 
   
AVIATION
 
FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)  
ISSUED AT 100 AM CDT FRI JUL 19 2019  
 
CIGS: GENERALLY EXPECTING VFR THROUGH THE PERIOD, WITH MORE OF A  
SCATTERING OUT TOWARD MORNING ON FRIDAY. THAT SAID, A FEW MODELS  
SUGGEST THAT MVFR CIGS WILL DEVELOP MOSTLY POST THE CURRENT  
CONVECTION - AND SOME HINTS OF THIS. FOR NOW WILL HOLD MOSTLY VFR  
AND ADJUST IF NEEDED.  
 
WX/VSBY: WEST-EAST RUNNING FRONTAL BOUNDARY CONTINUES TO SERVE AS A  
FOCUS FOR SHRA/TS DEVELOPMENT WITH LOW LEVEL JET IMPINGING/FUELING  
IT. AS THE JET NOSES INTO SOUTHEAST WI OVERNIGHT, SO SHOULD THE  
PCPN. EXPECT MOST TO SHIFT EAST/SOUTHEAST OF THE TAF SITES BY 09Z.  
 
COULD SEE ANOTHER ROUND OF SHRA/TS OVERNIGHT FRIDAY NIGHT AS THE  
CURRENT BOUNDARY PUSHES NORTH ON FRIDAY, BUT THEN TAKES A TURN BACK  
SOUTH AS A SHORTWAVE UPPER LEVEL TROUGH TRACKS EAST ACROSS NORTHERN  
PORTIONS OF THE REGION. BETTER CHANCES COULD HOLD OFF UNTIL AFTER  
12Z SAT.  
 
WINDS: MOSTLY SOUTH AND ON THE LIGHTER SIDE. SHOULD INCREASE FOR  
FRIDAY AFTERNOON AS SFC PRESSURE GRADIENT STARTS TO TIGHTEN.  
 

 
   
ARX WATCHES/WARNINGS/ADVISORIES
 
 
WI...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT SATURDAY FOR WIZ054-061.  
 
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR WIZ029-  
032>034-041>044-053-055.  
 
HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING  
FOR WIZ017.  
 
MN...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR MNZ079-  
086>088-094>096.  
 
IA...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT SATURDAY FOR IAZ011-018-  
019-029-030.  
 
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR  
IAZ008>010.  
 

 
 

 
 
UPDATE...DAS  
SHORT TERM...DAS  
LONG TERM...DAS  
AVIATION...RIECK  
 
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