912  
FXUS63 KABR 121117 AAA  
AFDABR  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE ABERDEEN SD  
617 AM CDT WED AUG 12 2026  
   
KEY MESSAGES  
 
- THERE IS A SLIGHT RISK (LEVEL 2 OF 5) FOR SEVERE STORMS TO  
DEVELOP LATE THIS AFTERNOON ACROSS SOUTHWEST SOUTH DAKOTA AND  
MIGRATING INTO SOUTH CENTRAL SOUTH DAKOTA DURING THE EVENING  
HOURS. MAIN THREATS INCLUDE UP TO 1 INCH IN DIAMETER HAIL  
AND WIND GUSTS OF 60 TO 70 MPH.  
 
- THERE IS A MARGINAL RISK (LEVEL 1 OF 5) FOR SEVERE STORMS TO  
DEVELOP LATE THIS AFTERNOON WEST RIVER, MIGRATING EAST IN THE  
EVENING AND OVERNIGHT. MAIN THREATS INCLUDE UP TO 1 INCH IN  
DIAMETER HAIL AND WIND GUSTS UP TO 60 MPH.  
 
 
   
UPDATE  
 
ISSUED AT 610 AM CDT WED AUG 12 2026  
 
SEE BELOW FOR AN AVIATION FORECAST DISCUSSION FOR THE 12Z TAFS.  
 
 
   
DISCUSSION  
 
ISSUED AT 1238 AM CDT WED AUG 12 2026  
 
THE 4-CORNERS UPPER HIGH WEAKENS AND SHIFTS INTO THE SOUTHEAST  
CONUS, THOUGH WE STILL REMAIN UNDER A BROAD WEST/NORTHWEST FLOW  
REGIME. A PLUME OF MID LEVEL MOISTURE LIFTING OUT OF THE  
INTERMOUNTAIN WEST CROSSES SOUTH DAKOTA DURING THE DAY. YOU CAN SEE  
THIS BROAD AREA OF MID LEVEL CLOUDS OVER NEVADA/UTAH IDAHO/WYOMING.  
THIS MOISTURE, 600MB AND ABOVE, ALSO HAS A VERY DRY SUBCLOUD  
LAYER RESULTING INVERTED V TYPE SOUNDINGS. PROFILES ALSO HAVE  
WARM AIR ALOFT AND WHILE 700MB TEMPERATURES ARE ONLY +8 TO +11C  
WHICH DOESN'T JUMP OUT AS A STRONG CAP, 750MB TEMPERATURE ARE  
CLOSER TO +13 TO +15C SO NAM PROFILES INDICATE IT WILL BE  
DIFFICULT FOR SURFACE BASED CONVECTION BUT ELEVATED CONVECTION  
IS DEPICTED IN CAMS FOR THE EVENING/OVERNIGHT HOURS. HREF MUCAPE  
IS ONLY ABOUT 1500J/KG. GIVEN THE PROFILES, WINDS ARE THE MAIN  
CONCERN WITH ANY CONVECTION. GIVEN HOW DRY ITS BEEN, DRY  
LIGHTING AND FIRES ALSO ARE A CONCERN.  
 
THERE IS ANOTHER PLUME OF MID LEVEL MOISTURE FOR MAINLY THURSDAY  
NIGHT INTO EARLY FRIDAY AS WELL. PROFILES ARE CLOSE TO MOIST  
ADIABATIC THANKS TO COOLER MID LEVEL TEMPERATURES WITH EASTERLY  
STABLE LOW LEVEL FLOW WITH THE SURFACE HIGH JUST ACROSS THE BORDER  
IN CANADA. NAM BUFKIT PROFILES SHOW ITS UNSTABLE DURING THE DAY,  
THOUGH THERE IS AN UPPER RIDGE MOVING OVERHEAD WITH INCREASING  
HEIGHTS AT THAT PARTICULAR TIME.  
 
A SOUTHWEST FLOW REGIME RUNS THROUGH SATURDAY BEFORE FLOW ALOFT  
BECOMES MORE WESTERLY, AND ULTIMATELY NORTHWESTERLY FOR NEXT WEEK.  
NBM POPS HAVE TRENDED DOWN THIS WEEKEND AND NEXT WEEKEND IN  
RESPONSE, ESPECIALLY AS A SURFACE HIGH MOVES ACROSS THE REGION  
SUNDAY/MONDAY. OTHERWISE TEMPERATURES WITH THIS COOLER AIRMASS WILL  
BE RUNNING ABOUT 5 TO 10 DEGREES BELOW NORMAL THURSDAY THROUGH  
SUNDAY.  
 
 
   
AVIATION /12Z TAFS THROUGH 12Z THURSDAY/  
 
ISSUED AT 610 AM CDT WED AUG 12 2026  
 
TERMINALS KABR,KATY,KPIR,KMBG  
 
LOW STRATUS AND FOG (SUB-VFR CONDITIONS) ARE DEVELOPING AGAIN  
THIS MORNING, PRIMARILY OVER PORTIONS OF CENTRAL AND NORTH  
CENTRAL SOUTH DAKOTA. VFR CONDITIONS ARE EXPECTED TO BE RESTORED  
PRIOR TO 18Z TODAY (KPIR AND KMBG?), AND VFR CONDITIONS ARE  
FORECAST FOR THE REST OF THE TAF VALID PERIOD.  
 
CAVEAT: THUNDERSTORMS ARE POSSIBLE BY LATE THIS AFTERNOON/EARLY  
EVENING AND WILL PROBABLY CARRY WITH THEM A SUB-VFR VISBY IN  
HEAVY RAINFALL. THUNDERSTORMS INTO WEDNESDAY EVENING/NIGHT COULD  
ALSO PRODUCE STRONG WIND GUSTS IN EXCESS OF 50KTS.  
 
 
   
ABR WATCHES/WARNINGS/ADVISORIES  
 
SD...NONE.  
MN...NONE.  
 
 
 
 
 
UPDATE...10  
DISCUSSION...07  
AVIATION...10  
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