046  
FXUS63 KFSD 170338  
AFDFSD  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SIOUX FALLS SD  
1038 PM CDT WED JUL 16 2025  
   
KEY MESSAGES  
 
- THERE IS A LOW CHANCE FOR LIGHT RAIN SHOWERS/SPRINKLES LATE  
THIS AFTERNOON, MAINLY NORTH OF I-90. ANY ACCUMULATION WILL BE  
A COUPLE HUNDREDTHS AT BEST.  
 
- DECREASING CLOUDS THIS EVENING AND OVERNIGHT WITH PARTLY  
SUNNY, DRY, AND COOL CONDITIONS ON THURSDAY WITH AFTERNOON  
HIGHS IN THE LOW TO MID 70S.  
 
- SHOWER AND THUNDERSTORM CHANCES OF 30 TO 60 PERCENT RETURN  
FRIDAY AND FRIDAY NIGHT.  
 
- NEAR DAILY 20-30 PERCENT PRECIPITATION CHANCES THIS WEEKEND  
INTO EARLY NEXT WEEK, ALTHOUGH PREDICTABILITY IS LOW.  
TEMPERATURES WILL RISE TO NEAR OR ABOVE 90 DEGREES IN MANY  
LOCATIONS BY NEXT TUESDAY.  
 
 
   
DISCUSSION  
 
ISSUED AT 236 PM CDT WED JUL 16 2025  
 
LATE THIS AFTERNOON, A FEW STRAY LIGHT RAIN SHOWERS/SPRINKLES  
ARE POSSIBLE MAINLY NORTH OF I-90. ANY ACCUMULATION SHOULD BE NO  
MORE THAN A COUPLE HUNDREDTHS. CLOUDS WILL THEN BE SLOW TO MOVE  
OUT LATE EVENING AND OVERNIGHT, BUT MODEL SOUNDINGS SUGGEST  
INCREASING SUN THROUGH THE DAY ON THURSDAY AS SURFACE HIGH  
PRESSURE SETTLES ACROSS THE REGION. TEMPERATURES WILL BE A BIT  
WARMER THAN TODAY, BUT STILL A SOLID 10 DEGREES BELOW MID-JULY  
NORMALS WITH HIGHS IN THE LOW TO MID 70S.  
 
SOUTHERLY SURFACE RETURN FLOW INCREASES THURSDAY NIGHT INTO  
FRIDAY AS HIGH PRESSURE SLIDES EASTWARD. THIS WILL ALLOW FOR  
INCREASING TEMPERATURES/MOISTURE WITH AFTERNOON DEWPOINTS BACK  
INTO THE UPPER 60S TO LOW 70S. AS A RESULT, MUCAPE SOARS UPWARDS  
OF 3000 J/KG DEPENDING ON THE MODEL, BUT VERY STRONG HEATING IN  
THE 5-10 KFT AGL LAYER ALSO RESULTS IN A STOUT CAP. 12Z MODEL  
SUITE SUGGESTS A WEAK WAVE IN QUASI-ZONAL FLOW ALOFT FRIDAY  
AFTERNOON/EVENING, WHICH MAY BE ENOUGH TO BREAK THE CAP, OR AT  
LEAST RESULT IN SOME ELEVATED THUNDERSTORMS. FOR NOW, INCREASING  
POPS THROUGH THE DAY ON FRIDAY, PEAKING IN THE 30-60 PERCENT  
RANGE IN THE EVENING SEEMS REASONABLE.  
 
PRECIPITATION PREDICTABILITY THIS WEEKEND INTO EARLY NEXT WEEK  
REMAINS QUITE LOW GIVEN MESSY SYNOPTIC PATTERN. 500 HPA HEIGHTS  
BUILD THROUGH THIS PERIOD, BUT PERIODIC ILL-RESOLVED SHORT-WAVES  
MAY BE ENOUGH FOR NEAR DAILY CONVECTIVE CHANCES. QUESTIONS  
ABOUND CONCERNING TIMING/COVERAGE OF ANY THUNDERSTORMS, SO WILL  
KEEP WITH THE IDEA OF BROAD-BRUSHED 20-40 POPS. THIS PATTERN,  
HOWEVER, DOES FAVOR INCREASING TEMPERATURES. GFS/ECMWF ENSEMBLES  
SHOW A 50-70 PERCENT CHANCE FOR AFTERNOON HIGHS TO RISE ABOVE  
90 DEGREES FOR MUCH OF THE SOUTHERN AND WESTERN PORTIONS OF THE  
FORECAST AREA BY TUESDAY.  
 
 
   
AVIATION /06Z TAFS THROUGH 06Z FRIDAY/  
 
ISSUED AT 1030 PM CDT WED JUL 16 2025  
 
A MIX OF VFR AND MVFR CONDITIONS WILL LIKELY TRANSITION TO  
MOSTLY VFR CONDITIONS THIS TAF PERIOD. TAKING A LOOK AT  
SATELLITE IMAGERY, AREAS OF STRATUS CONTINUES TO MOVE SOUTH  
THIS EVENING WITH KHON RETURN TO VFR CONDITIONS. EXPECT THE  
STRATUS DECK TO CONTINUE PUSHING SOUTHWARDS OVERNIGHT POTENTIALLY  
LEAVING THE AREA BY DAYBREAK ON THURSDAY. COULD SEE SOME PATCHY  
FOG DEVELOP ACROSS AREAS EAST OF I-29 AND OUR RIVER VALLEYS  
OVERNIGHT. HOWEVER, CONFIDENCE IN WIDESPREAD FOG IS LOW.  
OTHERWISE, LIGHT NORTHERLY WINDS WILL BECOME MORE SOUTHEASTERLY  
BY THURSDAY AFTERNOON TO END THE TAF PERIOD.  
 
 
   
FSD WATCHES/WARNINGS/ADVISORIES  
 
SD...NONE.  
MN...NONE.  
IA...NONE.  
NE...NONE.  
 
 
 
 
 
DISCUSSION...ROGERS  
AVIATION...05  
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