500  
FXUS63 KFSD 202335  
AFDFSD  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SIOUX FALLS SD  
635 PM CDT SAT JUN 20 2026  
   
KEY MESSAGES  
 
- SCATTERED SHOWERS WITH ISOLATED THUNDERSTORMS WILL DEVELOP  
THIS EVENING MAINLY ALONG THE MISSOURI RIVER THEN GRADUALLY  
BECOME MORE WIDESPREAD OVERNIGHT. WHILE SEVERE WEATHER IS NOT  
EXPECTED, POCKETS OF MODERATE TO HEAVY RAINFALL COULD LEAD TO  
RAPID ACCUMULATIONS AT TIMES.  
 
- BENEFICIAL ACCUMULATIONS OF 0.50" TO 1.00" ARE EXPECTED ALONG  
THE MISSOURI RIVER VALLEY WITH ISOLATED POCKETS OF HIGHER  
POSSIBLE ACROSS SOUTHCENTRAL SD. FLASH FLOODING IS NOT  
EXPECTED.  
 
- BELOW NORMAL TEMPERATURES AND PERIODIC RAIN CHANCES CONTINUE  
INTO THE START OF NEXT WEEK. SEVERE WEATHER CHANCES REMAIN LOW.  
 
 
   
DISCUSSION  
 
ISSUED AT 202 PM CDT SAT JUN 20 2026  
 
CURRENTS & TONIGHT: ANOTHER SEASONABLE DAY CONTINUES! TAKING A LOOK  
ACROSS THE AREA, MOSTLY CLEAR CONDITIONS PERSIST THIS AFTERNOON WITH  
MOST AREAS SITTING IN THE MID TO UPPER 70S AND LOW 80S. THIS ALONG  
WITH LIGHTER SURFACE WINDS HAS MADE FOR BEAUTIFUL CONDITIONS WEATHER-  
WISE. UNFORTUNATELY, THESE CONDITIONS WILL BE SHORT-LIVED AS CLOUD  
COVER BUILDS IN FROM SOUTHWEST TO NORTHEAST INTO THE EVENING AS OUR  
NEXT SYSTEM APPROACHES. FROM HERE, INCREASING DPVA/FRONTAL FORCING  
ALONG WITH A WEAK LLJ (20-35KTS) WILL LIKELY LEAD TO THE DEVELOPMENT  
OF SCATTERED SHOWERS WITH ISOLATED THUNDERSTORMS ALONG THE MISSOURI  
RIVER VALLEY AND PORTIONS OF SOUTHCENTRAL SD INITIALLY. EXPECT  
COVERAGE TO BECOME MORE WIDESPREAD OVERNIGHT AS THE PREVIOUSLY  
MENTIONED SHORTWAVE ZIPS EASTWARDS ACROSS NE JUST SOUTH OF THE SD/NE  
BOARDER LEADING TO A BLOSSOMING OF DEVELOPMENT.  
 
WHILE SEVERE WEATHER IS NOT EXPECTED; THE INCREASING LIFT AND SHEAR  
WILL LEAD TO POCKETS OF MODERATE TO HEAVY RAINFALL AT TIMES FROM  
LATE THIS EVENING THROUGH SUNDAY MORNING. NONETHELESS, ANY RAIN FOR  
THE PREVIOUSLY MENTIONED AREAS WILL BE WELCOMED ESPECIALLY SINCE  
THIS IS WHERE THE WORST CONDITIONS OF OUR D2-D3 DROUGHT ARE SET UP  
ACCORDING TO THE DROUGHT MONITOR. TAKING A CLOSER LOOK, DON'T THINK  
ANY OF THIS DEVELOPING ACTIVITY WILL TOUCH THE 2-3" IN/HR RATES  
NECESSARY FOR FLASH FLOODING SO WE SHOULD BE IN GOOD SHAPE OVERALL.  
OTHERWISE, EXPECT THE SCATTERED RAIN CHANCES TO CONTINUE THROUGH AT  
LEAST SUNDAY MORNING BEFORE ADDITIONAL RAIN CHANCES MOVE IN FROM  
CENTRAL SD WITH OUR NEXT SYSTEM. LASTLY, EXPECT ANOTHER MILD NIGHT  
WITH LOWS EXPECTED TO GRADUALLY DECREASE INTO THE MID TO UPPER 50S.  
 
SUNDAY-TUESDAY: LOOKING INTO SUNDAY, THE DREARIER CONDITIONS WILL  
PERSIST THROUGHOUT THE DAY AS ADDITIONAL RAIN CHANCES (40%-80%)  
DEVELOP WITH THE AN APPROACHING MID-LEVEL LOW. WHILE SEVERE WEATHER  
IS NOT EXPECTED, AMPLE MOISTURE AND STRENGTHENING DPVA/FRONTAL  
FORCING SHOULD DO JUST ENOUGH TO KEEP THE SCATTERED SHOWERS GOING  
DURING THE DAY WITH A FEW ADDITIONAL POCKETS OF MODERATE RAINFALL.  
NONETHELESS, SHOULD SEE MUCH OF THE SHOWER ACTIVITY BEGIN TO TAPER  
OFF DURING THE EVENING WITH THE LOSS OF DIURNAL HEATING AND AS THE  
PREVIOUSLY MENTIONED SYSTEM TRACKS INTO THE NORTHCENTRAL NE.  
OTHERWISE, QUIETER CONDITIONS SHOULD RETURN BY MONDAY AS ZONAL FLOW  
RETURNS ALOFT. OUR NEXT CHANCE FOR PRECIPITATION WILL LIKELY COME BY  
TUESDAY AS A COLD FRONT PROGRESSES THROUGH THE AREA. WHILE THE  
BETTER FORCING WILL LIKELY BE TO OUR NORTH ACROSS NORTHEASTERN SD,  
WE COULD GET JUST ENOUGH INSTABILITY/SHEAR TO GET A CONDITIONAL RISK  
FOR STRONGER STORMS DURING THE AFTERNOON TO EVENING HOURS. HOWEVER,  
THERE IS STILL SOME UNCERTAINTY. EITHER WAY, THIS WOULD BE THE NEXT  
PERIOD TO WATCH FOR ANY ORGANIZED CONVECTION. LASTLY, NEAR TO BELOW  
NORMAL TEMPERATURES WILL CONTINUE ACROSS THE AREA THROUGH TUESDAY  
WITH HIGHS MAINLY IN THE LOW TO UPPER 70S.  
 
WEDNESDAY ONWARDS: HEADING INTO THE MIDWEEK, QUIETER CONDITIONS  
SHOULD RETURN FOR WEDNESDAY AND THURSDAY AS A SURFACE HIGH TRACKS  
THROUGH OUR AREA. FROM HERE, THE WAVE TRAIN RETURNS BY FRIDAY AS  
QUASI-ZONAL FLOW HELPS USHER IN MULTIPLE SHORTWAVES INCREASING  
THE CHANCES FROM SHOWERS AND POTENTIALLY THUNDERSTORMS ALMOST  
DAILY (EVERY 24-36 HOURS) INTO THE FOLLOWING WEEK. WHILE THE  
CHANCES FOR SEVERE WEATHER ARE STILL UNCERTAIN AT THIS TIME,  
THIS IS ANOTHER PERIOD THAT WILL NEED TO BE MONITORED CLOSELY  
MOVING FORWARD. LASTLY, WE'LL CONTINUE TO SEE TEMPERATURES BUILD  
TOWARDS MORE SEASONAL CONDITIONS WITH HIGHS INCREASING FROM THE  
LOW TO MID 70S ON WEDNESDAY TO THE LOW TO MID 80S BY SATURDAY.  
 
 
   
AVIATION /00Z TAFS THROUGH 00Z MONDAY/  
 
ISSUED AT 635 PM CDT SAT JUN 20 2026  
 
VFR CONDITIONS ARE EXPECTED TO DECAY OVER THE NEXT FEW HOURS AND  
SHOWERS AND POSSIBLY THUNDERSTORMS MOVE IN FROM THE SOUTHWEST.  
SEVERE WEATHER IS NOT ANTICIPATED BUT VISIBILITY AND CEILINGS ARE  
EXPECTED TO DECREASE PERIODICALLY TO MVFR AND POSSIBLY IFR OVERNIGHT  
TONIGHT AND THROUGH THE END OF THE PERIOD.  
 
WINDS WILL BE LIGHT AND EASTERLY TO SLIGHTLY VARIABLE THROUGH  
SUNRISE SUNDAY. WINDS THEN BECOME EAST AND BREEZY WITH GUSTS 15-25  
KTS. BREEZY WINDS WILL DECREASE TOWARD THE END OF THE PERIOD.  
 
 
   
FSD WATCHES/WARNINGS/ADVISORIES  
 
SD...NONE.  
MN...NONE.  
IA...NONE.  
NE...NONE.  
 
 
 
 
 
DISCUSSION...05  
AVIATION...AJP  
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