018  
FXUS63 KABR 131831  
AFDABR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE ABERDEEN SD  
131 PM CDT THU AUG 13 2026  
   
KEY MESSAGES
 
 
-ISOLATED SHOWERS AND WEAK STORMS WILL CONTINUE TO POP UP OVER  
PORTIONS OF SOUTH CENTRAL AND EAST CENTRAL SD THIS AFTERNOON INTO  
THE EVENING. IF A STORM DOES POP UP, IT IS EXPECTED TO REMAIN SUB-  
SEVERE AND SHORT IN DURATION.  
 
-20-30% CHANCE FOR SOME SCATTERED NON-SEVERE STORMS AND SHOWERS TO  
DEVELOP OR MOVE INTO PORTIONS OF CENTRAL SD LATE FRIDAY AFTERNOON  
INTO THE EVENING.  
 

 
   
DISCUSSION
 
 
ISSUED AT 131 PM CDT THU AUG 13 2026  
 
AS OF 18Z, THERE ARE CURRENTLY SOME ISOLATED SHOWERS LINGERING OVER  
PORTIONS OF SOUTH CENTRAL AND EAST CENTRAL SD. THESE SHOWERS ARE  
SLOWLY MOVING AROUND AND THEN DISSIPATING AFTER NOT TOO LONG. THE  
ENVIRONMENT HAS A TOUCH OF INSTABILITY, WITH BETWEEN 250-500 J/KG  
OVER SOUTH CENTRAL AND EAST CENTRAL SD. THIS COULD HELP WITH THE  
DEVELOPMENT OF OCCASIONAL SHOWERS AND WEAK & NON-SEVERE STORMS OVER  
PORTIONS OF CENTRAL AND EAST CENTRAL SD THIS AFTERNOON AND EVENING.  
OTHERWISE, CENTRAL AND NORTHEASTERN SD WILL STAY DRY AS SHOWERS AND  
STORMS STAY TO THE SOUTH AND WEST THROUGH THE OVERNIGHT HOURS.  
 
THE UPPER-LEVEL RIDGE THAT HAD KEPT NORTHWEST FLOW OVER SD THROUGH  
THE PAST WEEK HAS FINALLY SHIFTED TO THE EAST OVER THE SOUTHEASTERN  
US. WITH THIS RIDGE MOVING EAST, THE UPPER-LEVEL FLOW HAS SWITCHED  
TO BE FROM THE SOUTHWEST THROUGH THE WEEKEND. THIS SOUTHWEST FLOW  
WILL START TO PUSH THE WILDFIRE SMOKE ALOFT AND AT THE SURFACE OUT  
OF CENTRAL AND NORTHEASTERN SD TODAY AND INTO FRIDAY. THERE COULD BE  
A BIT OF SMOKE ALOFT OVER NORTHERN SD THROUGH THE EVENING BEFORE IT  
MOVES OUT. TEMPERATURES TODAY AND INTO THE WEEKEND WILL BE ABOUT 5-  
10 DEGREES BELOW NORMAL, WITH HIGHS IN THE 70S.  
 
THE LEE OF THE ROCKIES SURFACE TROUGH WILL SLOWLY BE PUSHED TO THE  
EAST BY THE SOUTHWEST FLOW FRIDAY. THIS SURFACE BOUNDARY IS FORECAST  
TO MOVE OVER CENTRAL SD LATE FRIDAY AFTERNOON AND INTO THE EVENING.  
THIS WILL PROVIDE SUPPORT FOR THE NEXT CHANCE FOR SHOWERS AND STORMS  
TO DEVELOP, AS THE BOUNDARY WILL MOVE INTO AN ENVIRONMENT WITH LOTS  
OF MOISTURE AND SOME WEAK INSTABILITY. THE NAM AND RAP SHOW CAPE  
VALUES IN WESTERN SD GETTING UP INTO THE 1000S J/KG WHILE CENTRAL SD  
WILL SEE VALUES AROUND 500 J/KG. WHILE THE VALUES ARE A BIT WEAKER,  
IT COULD STILL BE ENOUGH TO HELP STORMS DEVELOP IN CENTRAL SD OR  
HAVE STORMS DEVELOP IN WESTERN SD AND THEN MOVE INTO CENTRAL SD.  
THERE DOES LOOK TO BE LOWER LAPSE RATES AND SHEAR VALUES, WHICH  
HELPS TO INCREASE THE CONFIDENCE THAT IF ANY STORMS DEVELOP, THEN  
THEY WILL STAY NON-SEVERE. THESE STORMS COULD HAVE SOME STRONGER  
WIND GUSTS AT TIMES. AS THE SURFACE BOUNDARY SHIFTS EAST OVER  
NORTHEASTERN SD DURING THE OVERNIGHT HOURS, THE STORMS LOOK TO  
DISSIPATE. THIS IS BECAUSE THE ENVIRONMENT IS EVEN WEAKER AND THERE  
IS NOTHING TO SUPPORT THE STORM, SUCH AS A LOW LEVEL JET WHICH WILL  
DEVELOP IN ND. A COLD FRONT ALONG THE BACK SIDE OF THIS SURFACE  
BOUNDARY LOOKS TO MOVE THROUGH CENTRAL AND NORTHEASTERN SD SATURDAY  
MORNING. THIS COULD CAUSE AN ISOLATED SHOWER OR TWO TO POP UP  
THROUGH THE DAY SATURDAY.  
 

 
   
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
 
 
ISSUED AT 1225 PM CDT THU AUG 13 2026  
 
TERMINALS KABR,KATY,KPIR,KMBG  
 
THERE ARE SCATTERED SHOWERS OVER AND AROUND KATY EARLY THIS  
AFTERNOON WITH SOME ISOLATED RAIN SHOWERS POSSIBLE THROUGH THE  
OVERNIGHT OVER CENTRAL SOUTH DAKOTA, WHICH COULD AFFECT KMBG AND  
KPIR. WHILE THERE IS A HIGHER CLOUD DECK OVER KATY, KABR, AND KMBG,  
KPIR WILL BE DEALING WITH LOWER CEILINGS FOR A FEW MORE HOURS BEFORE  
THE CLOUD DECK RISES. VFR AND MVFR CONDITIONS ARE EXPECTED INTO  
FRIDAY. WINDS WILL BE FROM THE EAST THROUGH THE NIGHT, WITH GUSTS UP  
AROUND 25 MPH POSSIBLE OVER KPIR, KATY, AND KMBG THROUGH THE  
AFTERNOON AND OVER KABR, KATY, AND KMBG DURING FRIDAY MORNING.  
 

 
   
ABR WATCHES/WARNINGS/ADVISORIES
 
 
SD...NONE.  
MN...NONE.  
 

 
 

 
 
DISCUSSION...12  
AVIATION...12  
 
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