269  
FXUS63 KFSD 242335  
AFDFSD  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SIOUX FALLS SD  
635 PM CDT FRI JUL 24 2026  
   
KEY MESSAGES
 
 
- PATCHY DENSE FOG IS POSSIBLE TONIGHT, ESPECIALLY FOR AREAS OF  
NORTHWEST IOWA. VISIBILITY MAY FALL TO 2 MILES OR LESS AT  
TIMES. PLEASE USE CAUTION AND BE PREPARED FOR RAPIDLY CHANGING  
VISIBILITY.  
 
- HEAT ADVISORY IN EFFECT AREA WIDE FOR SATURDAY AND SUNDAY.  
HEAT INDICES RUNNING FROM THE UPPER 90S TO AROUND 105.  
WILDFIRE SMOKE COULD BE A LIMITING FACTOR ON HIGHS, BUT FOR  
NOW DO NOT BELIEVE IT WILL BE THICK ENOUGH TO LOWER  
TEMPERATURES TOO MUCH.  
 
- ISOLATED SEVERE STORMS WILL BE POSSIBLE SATURDAY EVENING,  
WITH THE BETTER CHANCES WEST OF I-29.  
 
- WHILE DETAILS ARE UNCERTAIN, IF STORMS DEVELOP SUNDAY EVENING  
INTO SUNDAY NIGHT, SOME MAY BE STRONG TO SEVERE WITH DAMAGING  
WINDS, ISOLATED LARGE HAIL AND LOCALLY HEAVY RAIN POSSIBLE.  
 
- STILL A GOOD CHANCE FOR HIGHS IN THE 90S NEXT WEEK IN MOST  
LOCATIONS.  
 

 
   
DISCUSSION
 
 
ISSUED AT 1259 PM CDT FRI JUL 24 2026  
 
HEAT CONCERNS:  
 
HEAT AND HUMIDITY BUILD BACK INTO THE AREA THIS WEEKEND, WITH  
AFTERNOON AND EVENING HEAT INDICES AROUND A 100 OR MORE FOR MOST  
LOCATIONS BOTH SATURDAY AND SUNDAY. CONFIDENCE IN HIGHER HEAT  
INDICES FOR THIS WEEKEND COMPARED TO LAST WEEKEND IS A HIGHER AS DEW  
POINTS LOOK TO CLIMB INTO THE LOWER TO MID 70S, WHICH CAN FEEL VERY  
OPPRESSIVE. ONE LIMITING FACTOR MAY BE WILDFIRE SMOKE, BUT FOR NOW  
THE EXPECTATIONS ARE THAT THE SMOKE WILL BE SOMEWHAT LIMITED SO THE  
EFFECT ON TEMPERATURES WILL LIKELY NOT BE THAT GREAT. WILL HAVE A  
HEAT ADVISORY AREA WIDE FOR THE WEEKEND WITH SOME POTENTIAL FOR  
ADDITIONAL HEAT HEADLINES NEXT WEEK. AS CONFIDENCE GROWS, A HEAT  
WARNING MAY BE NEEDED ALONG THE JAMES AND MISSOURI RIVER VALLEYS  
SATURDAY AND SUNDAY WHERE HEAT INDICES COULD CLIMB TO AROUND 110.  
MOST DAYS NEXT WEEK LOOK TO HAVE HIGHS IN THE 90S, SO EVEN WITHOUT  
HEADLINES WILL STILL BE VERY WARM EACH DAY.  
 
THUNDERSTORM CONCERNS:  
 
THE LATEST MODELS CONTINUE TO HINT AT ISOLATED THUNDERSTORM  
POTENTIAL SATURDAY EVENING AND EARLY OVERNIGHT. FOR NOW CAPPING  
LOOKS TO BE A PROBLEM, BUT A WEAK WAVE IS EXPECTED TO MOVE INTO  
CENTRAL SD LATE AFTERNOON SO DEVELOPMENT MAY OCCUR TO THE WEST OF  
THE MO RIVER. AS THE WAVE SHIFTS EAST ISOLATED DEVELOPMENT WILL  
REMAIN POSSIBLE. RIGHT NOW THE MAIN CONCERNS LOOK TO BE QUARTER  
SIZED HAIL AND WIND GUSTS TO 65 MPH.  
 
ANOTHER PIECE OF ENERGY MOVES INTO THE AREA ON SUNDAY AND SHOULD  
BRING ANOTHER CHANCE FOR SOME ISOLATED SEVERE STORMS. THE BETTER  
SHEAR AND INSTABILITY LOOK TO RESIDE OVER SOUTHWEST MN AND THIS  
SHOULD BE THE HIGHER THREAT FOR SEVERE STORMS. WILL ALSO NEED TO  
KEEP AN EYE OUT FOR SOUTH CENTRAL SD WHERE THE CAP COULD BE BROKEN  
AND AN ISOLATED STRONG TO SEVERE STORM COULD DEVELOP. OVERALL THERE  
MAY BE ENOUGH DRY AIR IN THE LOW LEVELS TO REALLY LIMIT THE  
INSTABILITY AND THEM MAIN CONCERN WOULD BE WIND IF SOMETHING COULD  
DEVELOP. CONFIDENCE FOR BOTH SATURDAY AND SUNDAY ARE FAIRLY LOW.  
 
OTHER CONCERNS:  
 
THE ONLY OTHER REAL CONCERN WILL BE THE POTENTIAL FOR SOME FOG LATER  
TONIGHT INTO SATURDAY MORNING. THE BETTER CHANCES WILL BE IN  
NORTHWEST IA, NORTHEAST NE AND FAR SOUTHEAST SD. FOR NOW NOT LOOKING  
LIKE WIDESPREAD DENSE FOG.  
 

 
   
AVIATION /00Z TAFS THROUGH 00Z SUNDAY/
 
 
ISSUED AT 634 PM CDT FRI JUL 24 2026  
 
MOSTLY MVFR CEILINGS FROM ROUGHLY HIGHWAY 81 AND EAST DUE TO LOW  
STRATUS. STRATUS WILL CONTINUE TO ERODE FROM WEST TO EAST THROUGH  
THE EVENING HOURS, EVENTUALLY RAISING CEILINGS BACK TO VFR.  
 
SOUTHERLY WINDS REMAIN ON THE BREEZY SIDE FOR MOST OF THE REGION,  
ESPECIALLY ALONG THE BUFFALO RIDGE IN SOUTHWEST MINNESOTA. SUSTAINED  
WINDS OF 9-13 KTS WITH GUSTS 15-22KTS ARE ON GOING. THIS WILL WORK  
TO LIMIT FOG FORMATION IN THESE AREAS. HOWEVER, AREAS OF NORTHWEST  
IOWA WHERE WINDS WILL BE LIGHTER HAS A LOW TO MEDIUM CHANCE (20-50%)  
FOR FOG DEVELOPMENT. HERE CEILINGS AND VISIBILITY MAY BRIEFLY FALL  
TO IFR TO LIFR. FOG IS EXPECTED TO BURN OFF BY MID-SATURDAY MORNING.  
A WARM FRONT IS EXPECTED TO PROGRESS THROUGH THE AREA SATURDAY LATE  
MORNING THROUGH THE AFTERNOON. AS IT PASSES WINDS WILL BECOME  
VARIABLE WITH GUSTS AROUND 15 KTS.  
 

 
   
FSD WATCHES/WARNINGS/ADVISORIES
 
 
SD...HEAT ADVISORY FROM NOON SATURDAY TO 8 PM CDT SUNDAY FOR  
SDZ038>040-050-052>071.  
MN...HEAT ADVISORY FROM NOON SATURDAY TO 8 PM CDT SUNDAY FOR MNZ071-  
072-080-081-089-090-097-098.  
IA...HEAT ADVISORY FROM NOON SATURDAY TO 8 PM CDT SUNDAY FOR  
IAZ001>003-012>014-020>022-031-032.  
NE...HEAT ADVISORY FROM NOON SATURDAY TO 8 PM CDT SUNDAY FOR NEZ013-  
014.  
 

 
 

 
 
DISCUSSION...08  
AVIATION...AJP  
 
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