770  
FXUS63 KARX 201945  
AFDARX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LA CROSSE WI  
245 PM CDT SUN SEP 20 2026  
   
KEY MESSAGES
 
 
- SHOWER CHANCES (30-60%) RETURN ON MONDAY FOR AREAS PRIMARILY  
ALONG AND SOUTH OF I-90.  
 
- COOLER THAN NORMAL CONDITIONS ARE EXPECTED THROUGHOUT MUCH OF  
THE WEEK WITH HIGHS IN THE 60S.  
 

 
   
DISCUSSION
 
 
ISSUED AT 245 PM CDT SUN SEP 20 2026  
 
MONDAY: SHOWER CHANCES RETURN  
 
AS WE HEAD INTO THE DAY ON MONDAY, AN UPPER-LEVEL TROUGH/CUT-OFF LOW  
WILL EJECT INTO THE REGION INCREASING POTENTIAL FOR SHOWER CHANCES  
DURING THIS PERIOD. OVERALL, HIGHEST CONFIDENCE FOR SEEING ANY  
PRECIPITATION POTENTIAL GENERALLY REMAINS SOUTH OF I-90 GIVEN THE  
POSITION OF THIS UPPER-LEVEL LOW AND WHERE THE CAMS LARGELY PAINT  
PRECIPITATION DURING THE AFTERNOON AND EVENING ON MONDAY.  
CONSEQUENTLY, MUCH OF THE HIGHER PROBABILITIES (50-80%) IN THE  
HREF FOR MEASURABLE PRECIPITATION REMAIN LARGELY SOUTH OF I-90  
DURING THIS TIMEFRAME. ADDITIONALLY, WITH THE OVERALL WEAKER  
Q-VECTOR CONVERGENCE DURING THIS TIMEFRAME BEING THE PRIMARY  
FORCING REGIME, PROBABILITIES IN THE HREF FOR RAINFALL TOTALS  
OVER 1 INCH ARE VERY LOW (UNDER 10%).  
 
TUESDAY - FRIDAY: STAYING COOL AND DRIER  
 
BY THE TIME WE GET PAST MONDAY, NORTHEASTERLY SURFACE FLOW AND HIGH  
PRESSURE SOUTH OF THE HUDSON BAY WILL ALLOW FOR COOLER AND  
DRIER CONDITIONS TO ADVECT INTO OUR REGION. AS A RESULT, MEDIAN  
HIGH TEMPERATURES IN THE NBM THROUGHOUT THE WEEK GENERALLY  
REMAIN IN THE 60S FOR MOST OF THE LOCAL AREA. AS WE HEAD INTO  
WEDNESDAY MORNING, UPPER-LEVEL RIDGING WILL PUSH INTO THE LOCAL  
AREA WHICH IN TURN SHOULD BOTH ALLOW FOR A GRADUAL WARMING TREND  
AND CLEARING SKIES DURING THIS PERIOD. CONSEQUENTLY, NOT SEEING  
MUCH FOR PRECIPITATION CHANCES TILL LATER INTO THE WEEK WHEN  
MAYBE SOME SHORTWAVE PERTURBATIONS TRY TO SNEAK BACK INTO THE  
REGION DURING THE THURSDAY AND FRIDAY TIMEFRAME. HOWEVER,  
PREDICTABILITY WITH THESE WAVES REMAINS VERY LOW AT THIS TIME.  
IN ANY CASE, WILL HAVE TO WATCH WEDNESDAY MORNING FOR SOME FROST  
POTENTIAL ACROSS NORTH-CENTRAL WI WITH MEDIAN LOW TEMPERATURES  
IN THE MIDDLE TO UPPER 30S.  
 

 
   
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
 
 
ISSUED AT 1250 PM CDT SUN SEP 20 2026  
 
VFR CONDITIONS ARE EXPECTED THROUGHOUT MUCH OF THE TAF PERIOD WITH  
LOW-LEVEL CLOUDS SCATTERING OUT OVER THE AFTERNOON. WINDS WILL  
GENERALLY REMAIN FROM THE NORTHEAST THROUGH THE TAF PERIOD AT AROUND  
8-15 KTS. MVFR CIGS MAY BE POSSIBLE (30-50% CHANCE IN THE HREF)  
AFTER 15Z ACROSS PORTIONS OF SOUTHEAST MN AND NORTHEAST IA AS SOME  
LIGHT RAIN MOVES THROUGH THE REGION ASSOCIATED WITH AN UPPER-LEVEL  
SYSTEM, HOWEVER CONFIDENCE IN PRECIPITATION POTENTIAL IS LOW AT THIS  
TIME.  
 

 
   
HYDROLOGY
 
 
ISSUED AT 245 PM CDT SUN SEP 20 2026  
 
SOME AREA RIVER SITES CONTINUE TO SEE RISES SUCH AS ALONG THE ROOT,  
CEDAR AND TURKEY RIVERS. VOLGA AT LITTLEPORT IS THE ONLY SITE  
THAT REMAINS IN MODERATE FLOOD STAGE WITH MULTIPLE SITES  
REMAINING IN MINOR FLOOD STAGE. RISES AT SOME SITES WILL PERSIST  
INTO MONDAY BEFORE STAGE LEVELS CONTINUE TO RECEDE THROUGHOUT  
THE WEEK. THE ONLY SHOT FOR PRECIPITATION IN THE NEXT FEW DAYS  
IS ON MONDAY WHERE RAINFALL TOTALS GENERALLY AROUND 0.25" OR  
LESS ARE EXPECTED WHICH SHOULD NOT CONTRIBUTE TO ADDITIONAL  
RISES. OTHERWISE, MOSTLY DRY CONDITIONS ARE EXPECTED THROUGH THE  
MIDDLE OF THIS WEEK.  
 

 
   
ARX WATCHES/WARNINGS/ADVISORIES
 
 
WI...NONE.  
MN...NONE.  
IA...NONE.  
 

 
 

 
 
DISCUSSION...NAYLOR  
AVIATION...NAYLOR  
HYDROLOGY...NAYLOR  
 
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