560  
FXUS63 KFSD 280652  
AFDFSD  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SIOUX FALLS SD  
152 AM CDT SAT JUN 28 2025  
   
KEY MESSAGES  
 
- HOT AND HUMID DAY EXPECTED THROUGHOUT THE REGION. HEAT INDEX  
VALUES MAY REACH THE 100 DEGREE MARK, AND ANYONE SPENDING TIME  
OUTDOORS SHOULD TAKE EXTRA CAUTION TO PREVENT HEAT ILLNESS.  
 
- ISOLATED TO SCATTERED STRONG TO SEVERE THUNDERSTORMS AGAIN  
POSSIBLE LATE SATURDAY AFTERNOON INTO EARLY SUNDAY MORNING.  
STORM RISKS BEGIN AFTER 4-5PM, BRINGING BRIEF 2.0" HAIL RISKS,  
BUT LARGER POTENTIAL FOR 70 MPH DOWNBURST WINDS.  
 
- STORM RISKS CONTINUE INTO SUNDAY, THOUGH POTENTIAL REMAINS  
HIGHLY MURKY AND DEPENDS ON STORM DEVELOPMENT SATURDAY  
EVENING/NIGHT.  
 
- NEAR TO ABOVE NORMAL TEMPERATURES FOR MUCH OF THE UPCOMING  
WEEK, WITH STORM RISKS RETURNING BY THE MIDDLE OF THE WEEK.  
 
 
   
DISCUSSION  
 
ISSUED AT 150 AM CDT SAT JUN 28 2025  
 
THIS MORNING: CLUSTER OF STRONG THUNDERSTORMS PERSIST ACROSS AREAS  
EAST OF I-29 AS OF 2AM. THESE STORMS REMAINED TIED TO A WEAK LOBE OF  
VORTICITY MOVING THROUGH THE REGION, AND WILL CONTINUE TO MOVE EAST  
THROUGH DAYBREAK. WITH THE INCREASE IN THE LLJ SOME ISOLATED  
STRONGER CELLS REMAIN POSSIBLE IN THE SOUTHWESTERN PERIPHERY OF THIS  
WEAKENING MCS. ADDITIONAL SCATTERED THUNDERSTORMS MAY DEVELOP  
OVER THE NORTHERN HALF OF SOUTH DAKOTA ON THE NOSE OF THE LOW  
LVL JET THROUGH DAYBREAK. WELL TO THE NORTH OVER EASTERN NORTH  
DAKOTA AND WESTERN MINNESOTA, A SECOND DEVELOPING MCS MAY TRACK  
EAST SOUTHEAST INTO SATURDAY MORNING. WHILE THIS CONVECTION  
WON'T IMPACT THE TRI- STATE AREA, IT WILL LAY OUT AN OUTFLOW  
BOUNDARY OVER CENTRAL MN INTO NORTHERN SOUTH DAKOTA.  
 
TODAY: LINGERING MORNING SCATTERED SHOWERS AND THUNDERSTORMS NORTH  
OF HIGHWAY 14 WILL GRADUALLY DISSIPATE BY MID-MORNING. BY MID-DAY  
WE'LL HAVE A BETTER IDEA WHERE TWO PRIMARY FEATURES WILL FALL. ONE  
BEING AN WEST TO EAST RUNNING OUTFLOW BOUNDARY OVER CENTRAL MN INTO  
NORTHEASTERN SOUTH DAKOTA, AND SECOND AREA WILL BE A TRAILING COLD  
FRONT POTENTIALLY STRETCHING FROM VALENTINE TO HURON AND WATERTOWN  
BY EARLY AFTERNOON. SOUTH AND EAST OF THESE FEATURES, A VERY WARM  
AND HUMID DAY IS LIKELY. GIVEN INCREASE IN MOISTURE HAVE LOWERED  
HIGHS SLIGHTLY AND BUMPED DEW POINTS UP A BIT. THIS RESULTS IN HEAT  
INDEX VALUES APPROACHING THE 100 DEGREE MARK BY MID-AFTERNOON. AT  
THIS TIME, WILL HOLD OFF ON A HEAT ADVISORY, BUT IF MORNING  
TRENDS SHOW HIGHER TEMPERATURES/DEW POINTS AN ADVISORY COULD BE  
ISSUED.  
 
INSTABILITY IS EXPECTED TO GROW SUBSTANTIALLY THROUGH THE DAY,  
WITH MLCAPE APPROACHING 3000-4000 J/KG THROUGH MOST OF THE WARM  
SECTOR. THE BIGGEST QUESTION THAT MODELS CONTINUE TO STRUGGLE  
WITH IS THE DEGREE OF INHIBITION AND RESOLVING THE WEAK AND  
SUBTLE SHORTWAVES THAT COULD HELP SPUR DEVELOPMENT ALONG THE  
RESIDUAL OUTFLOW AND FRONTS AFTER 4-5PM. THE MOST FAVORED AREA  
FOR DEVELOPMENT WILL BE THROUGH CENTRAL MINNESOTA AND  
NORTHEASTERN SOUTH DAKOTA WHERE SYNOPTIC FORCING AND MID-LVL  
WINDS WILL BE STRONGER. DEVELOPMENT SOUTHEAST ON THE COLD FRONT  
INTO CENTRAL SD IS MORE CONDITIONAL. GIVEN THE POOL OF  
INSTABILITY, ANY STORM THAT DEVELOPS WILL BECOME STRONG TO  
SEVERE QUICKLY. HOWEVER WE'LL REMAIN ON THE SOUTHERN PERIPHERY  
OF STRONGER MID-LVL WINDS, LEAVING EFFECTIVE SHEAR ON THE LOWER  
END. MOST OF THE AREA ON THE COLD FRONT COULD SEE MULTI-  
CELLULAR DEVELOPMENT, WITH BETTER SUPERCELL CHANCES (AND  
ACCOMPANYING VERY LARGE HAIL/WIND/TORNADO POTENTIAL) FORM ALONG  
THE OUTFLOW TO OUR NORTH INTO MINNESOTA. MUCH LIKE FRIDAY  
EVENING, INITIAL STORMS MAY HAVE 1.5-2" HAIL, BEFORE SHIFTING  
TOWARDS 70+ MPH DOWNBURST WINDS. COLD POOL DEVELOPMENT COULD  
PUSH A CLUSTER OR TWO OF STORMS SOUTHEAST INTO THE EVENING AND  
EARLY OVERNIGHT HOURS.  
 
SATURDAY NIGHT: MODELS REMAIN LARGELY SPLIT ON A SECONDARY WAVE  
CROSSING THE ROCKIES OVERNIGHT AND DEVELOPING SOME SORT OF MCS OVER  
THE DAKOTAS. SHOULD THIS DEVELOP AN ATTENDANT WIND RISK COULD  
PERSIST THROUGH DAYBREAK SUNDAY.  
 
SUNDAY: CONFIDENCE REMAINS LOWER THAN NORMAL INTO SUNDAY GIVEN ALL  
THE SCATTERED CONVECTION RISKS UP TO THIS POINT. A BELT OF STRONGER  
MID-LVL WINDS ENTERS THE NORTHERN PLAINS EARLY SUNDAY, WITH  
INCREASING TROUGHING PUSHING THE COLD FRONT SOUTHEAST DURING THE  
DAY. IT'S NOT IMPOSSIBLE TO HAVE SOME CONVECTION REMAINING THROUGH  
SUNDAY MORNING AND ANY MCS THAT CROSSES THE STATE COULD PUSH THE  
EFFECTIVE FRONT FURTHER SOUTHEAST THROUGH THE CWA. HOWEVER IF NO  
OVERNIGHT CONVECTION FORMS, THEN AREAS ALONG AND EAST OF THE PASSING  
FRONT REMAIN IN A GOOD POSITION FOR SCATTERED DEVELOPMENT EARLY IN  
THE AFTERNOON SUNDAY. THIS ACTIVITY MAY AGAIN PRODUCE HAIL/WIND  
RISKS.  
 
MONDAY-FRIDAY: HIGH PRESSURE MOVES INTO THE PLAINS EARLY NEXT WEEK,  
PULLING TEMPERATURES DOWN SLIGHTLY, BUT KEEPING CONDITIONS DRY  
THROUGH TUESDAY. SOME SIGNALS FOR MODEST MID-LVL MOISTURE RETURN  
AND WARM ADVECTION INTO WEDNESDAY MORNING, OWING TO AN INCREASE IN  
POPS. MID-LVL HEIGHTS TRY TO BUILD FOR THE SECOND HALF OF THE WEEK,  
AND THAT WOULD LIKELY PUSH HIGH TEMPERATURES BACK TOWARDS THE 90S  
FOR THE 4TH OF JULY HOLIDAY. CONVECTION CHANCES REMAIN HIGHLY  
UNCERTAIN FOR THE HOLIDAY.  
 
 
   
AVIATION /06Z TAFS THROUGH 06Z SUNDAY/  
 
ISSUED AT 1213 AM CDT SAT JUN 28 2025  
 
SCATTERED CONVECTION CONTINUES TO MOVE THROUGH EASTERN SOUTH  
DAKOTA EARLY THIS MORNING. WITHIN THUNDERSTORMS, DROPS TO  
MVFR/IFR VISIBILITY IS POSSIBLE, WITH CIGS NEAR 3K FT AGL.  
 
INTO MID-MORNING, THE GREATEST CONVECTION RISKS WILL CONTINUE  
NEAR OR NORTH OF HIGHWAY 14, WITH SKIES CLEARING FURTHER SOUTH.  
 
A FRONTAL BOUNDARY SETS UP OVER EASTERN SOUTH DAKOTA, WITH  
ISOLATED TO SCATTERED CONVECTION FORMING ALONG THIS BOUNDARY  
AFTER 4-5PM. HIGHLY UNCERTAIN ON THE EVENTUAL TRACK OF THIS  
CONVECTION INTO THE EVENING, SO WILL CONTINUE TO REMAIN WITH  
PROB30 GROUPS AT ALL TAF LOCATIONS.  
 
 
   
FSD WATCHES/WARNINGS/ADVISORIES  
 
SD...NONE.  
MN...NONE.  
IA...NONE.  
NE...NONE.  
 
 
 
 
 
DISCUSSION...DUX  
AVIATION...DUX  
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