823  
FXUS63 KARX 181043  
AFDARX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LA CROSSE WI  
543 AM CDT SUN OCT 18 2026  
   
KEY MESSAGES  
 
- MOSTLY DRY WEEK WITH GRADUAL WARMING TO SLIGHTLY ABOVE NORMAL  
TEMPERATURES BY MIDWEEK. WINDS WEAKEN FOR MONDAY.  
 
- PRECIPITATION CHANCES INCREASE FOR NEXT WEEKEND.  
 
 
   
DISCUSSION  
 
ISSUED AT 1219 AM CDT SUN OCT 18 2026  
 
SLIGHTLY LESS BREEZY AND WARMER END TO THE WEEKEND:  
 
WHILE NOT AS STRONG AS SATURDAY, ANOTHER DAY OF BREEZY SOUTHWEST  
WINDS WITH GUSTS NEARING 30+ MPH PRIMARILY WEST OF THE MISSISSIPPI  
RIVER VALLEY EXPECTED TODAY. UPSTREAM LOW LEVEL TROUGHOLYSIS NEAR  
THE MISSOURI RIVER VALLEY THROUGH SUNDAY CAUSES A LOW LEVEL  
STRETCHING AXIS TO EVENTUALLY SUCCUMB TO ANTICYCLONIC FLOW THROUGH  
THE START OF THE WEEK, RESULTING IN SLIGHTLY WARMER TEMPERATURES, A  
FEW DEGREES ABOVE NORMAL BY MIDWEEK, AND LIGHTER WINDS THROUGH THE  
START OF THE WEEK.  
 
MOSTLY MILD WEEK:  
 
HAVE LOWERED SURFACE DEWPOINT TEMPERATURES A COUPLE OF DEGREES TODAY  
BASED ON SATURDAY'S OBSERVATIONS AND RESIDUAL LOW LEVEL DRY AIR.  
OTHERWISE, A BAND OF SLIGHTLY INCREASED LOW LEVEL MOISTURE WILL  
RESIDE OVER THE FORECAST AREA THROUGH THE NEW WEEK, TIED BETWEEN THE  
EXITING UPPER LEVEL LOW OVER HUDSON BAY AND RETURN TROPICAL FLOW  
THROUGH SOUTHERN TO CENTRAL PLAINS. MAIN LOCAL IMPACT WILL BE BOUTS  
OF INCREASED CLOUD COVER COMPARED TO CURRENTLY FORECASTED NBM DUE TO  
POTENTIAL LOW BIAS GIVEN A MAXIMUM 40% THURSDAY OUTSIDE OF A  
SPLOTCHY 40-50% FOR MONDAY. WHILE CURRENTLY FORECASTED PRECIPITATION  
POTENTIAL REMAINS LESS THAN 10% THROUGH MIDWEEK, RECENT LREF MEMBERS  
(GEFS 17.18Z/EPS 17.18Z) HAVE EXHIBITED A 10-20% INCREASE FOR  
MEASURABLE PRECIPITATION (0.01") COMPARED TO THEIR RESPECTIVE  
PREVIOUS RUNS, NEARING 20-40%/10-30%, RESPECTIVELY WEDNESDAY NIGHT  
INTO THURSDAY MORNING. MINIMAL IMPACT REGARDLESS GIVEN OVERALL HIGH  
CONFIDENCE IN ABOVE FREEZING SURFACE TEMPERATURES.  
 
WEEKEND PRECIPITATION POTENTIAL:  
 
SUBSEQUENT MORE WIDESPREAD PRECIPITATION CHANCES REACH THE UPPER  
MISSISSIPPI RIVER VALLEY THIS WEEKEND AS A QUASI WEAK OMEGA BLOCK  
BREAKS DOWN AND MID LEVEL POSITIVE VORTICITY ADVECTION LIFTS  
NORTHEAST THROUGH THE CENTRAL CONUS. LREF MEMBER PROBABILITIES  
ABSTAIN CERTAIN PROBABILITIES WELL TO THE WEST/NORTHWEST OF THE  
FORECAST AREA CLOSER TO THE AREA OF STRONGEST SYNOPTIC FORCING WITH  
50% PROBABILITIES FOR 0.01" OF RAINFALL SEEN OVER THE WESTERN HALF  
OF THE LOCAL FORECAST AREA.  
 
 
   
AVIATION /12Z TAFS THROUGH 12Z MONDAY/  
 
ISSUED AT 543 AM CDT SUN OCT 18 2026  
 
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD WITH WINDS OF 12-  
18 KTS FROM THE SOUTH/SOUTHWEST TO START THE TAF PERIOD. WINDS WILL  
SLIGHTLY INCREASE INTO THE MID-MORNING HOURS WITH GUSTS OF 20-30 KTS  
POSSIBLE, WITH THE HIGHEST GUSTS PRIMARILY WEST OF THE MISSISSIPPI  
RIVER. WINDS WILL GRADUALLY DIMINISH THIS EVENING AND INTO THE  
OVERNIGHT TO AROUND 5-10 KTS AND REMAIN FROM THE SOUTH-  
SOUTHWEST.  
 
 
   
ARX WATCHES/WARNINGS/ADVISORIES  
 
WI...NONE.  
MN...NONE.  
IA...NONE.  
 
 
 
 
 
DISCUSSION...JAR  
AVIATION...NAYLOR  
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