040  
FXUS63 KABR 091928  
AFDABR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE ABERDEEN SD  
228 PM CDT SUN AUG 9 2026  
   
KEY MESSAGES  
 
- THERE IS A SLIGHT RISK (LEVEL 2 OUT OF 5) FOR SEVERE THUNDERSTORMS  
LATE THIS EVENING THROUGH THE OVERNIGHT HOURS ACROSS CENTRAL SD.  
LARGE HAIL OF 1 TO 2+ INCHES IN DIAMETER AND THUNDERSTORM WIND GUSTS  
IN EXCESS OF 60 MPH ARE POSSIBLE. HOWEVER, CONSIDERABLE UNCERTAINTY  
ON WHETHER STORMS WILL FORM OR NOT EXISTS DUE TO DISAGREEMENTS UPON  
THE MODELS.  
 
- THERE IS A MARGINAL RISK, LEVEL 1 OUT OF 5, FOR SEVERE STORMS  
ACROSS THE ENTIRE FORECAST AREA FOR BOTH MONDAY AND TUESDAY DURING  
THE EVENING AND OVERNIGHT HOURS. MAIN THREATS INCLUDE LARGE HAIL OF  
1 TO 2" IN DIAMETER AND WIND GUSTS IN EXCESS OF 60 MPH.  
 
- WILDFIRE SMOKE ALOFT IS EXPECTED TO PERSIST THE NEXT SEVERAL DAYS,  
HOWEVER THERE IS LITTLE POTENTIAL FOR THE SMOKE AT THE SURFACE.  
 
 
   
DISCUSSION  
 
ISSUED AT 219 PM CDT SUN AUG 9 2026  
 
WEST/NORTHWEST FLOW ALOFT CONTINUES OVER THE REGION ON THE  
DOWNSTREAM SIDE OF A LOW AMPLITUDE RIDGE OVER THE WESTERN CONUS AND  
SOUTHWEST OF THE ONGOING LARGE LOW/TROUGH OVER THE HUDSON BAY. THIS  
EVENING THROUGH THE OVERNIGHT HOURS, ANOTHER WEAK EMBEDDED SHORTWAVE  
(35-50KTS) WILL MOVE IN OUT OF MT/WY AND TRACK EAST/SOUTHEAST ACROSS  
THE DAKOTAS/MN THROUGH MONDAY MORNING. AT THE SURFACE THE CWA IS  
SANDWICHED BETWEEN A HIGH TO OUR NORTH WITH AN ELONGATED NORTHWEST  
TO SOUTHEAST FRONTAL BOUNDARY ALONG THE LEE OF THE ROCKIES (AND  
SEVERAL WEAK LOWS ALONG IT) CONNECTING TO A WESFOR  
EXAMPLE HRRR/RAP DO NOT SHOW ANY DEVELOPMENT OF STORMS, LIKE AT  
ALL, WITH NAMNEST KEEPING ANY CONVECTION OVER NORTH CENTRAL SD  
WHILE FV3 KEEPS CONVECTION OVER SOUTH CENTRAL SD AND SOUTH OF  
THE CWA WITH MORE OF A EASTERLY TRACK.T TO EAST FRONTAL  
BOUNDARY, AND ITS LOW, OVER THE CENTRAL PLAINS. THIS LEAVES THE  
NORTHERN PLAINS ON THE NORTHERN SIDE OF THIS SYSTEM WITH EAST TO  
NORTHEAST WINDS AT THE SURFACE TO 850MB. WAA WILL FILTER IN  
OVERNIGHT AS THESE WINDS WILL SHIFT SOUTH/SOUTHEASTERLY ACROSS THE  
CWA THROUGH MONDAY MORNING WITH SURFACE DEWPOINTS IN THE UPPER 50S  
AND 60S ACROSS THE CWA.  
 
REGARDING POTENTIAL CONVECTION TONIGHT, THE LATEST RUNS OF THE 12Z  
MODELS HAVE BACKED OFF QUITE A BIT ON THE DEVELOPMENT AND EVOLUTION  
OF THUNDERSTORMS RESULTING IN VERY LOW CONFIDENCE IN POTENTIAL  
OUTCOME. DUE TO THIS, STUCK WITH NBM FOR MUCH OF THE NEAR SHORT TERM  
IN TERMS OF POPS. AS OF NOW, HREF MEAN INDICATES THE DEVELOPMENT OF  
STORMS MOVING IN OVER NORTH CENTRAL SD (AROUND ~3-5Z), WHICH IS  
ABOUT THE SAME TIME WE HAVE WEAK SHORTWAVE PULSES OVER THIS AREA. IF  
THESE CELLS DO IN FACT FORM INITIALLY, THE ENVIRONMENT IS FAVORABLE  
FOR SUPERCELLS AS MUCAPE/MLCAPE IS FORECAST BETWEEN 1000-2500J/KG  
(RAP HIGHER WITH VALUES 2500-3500 J/KG OVER POTIONS OF CENTRAL SD)  
WITH BULK SHEAR BETWEEN 40-50KTS (AGAIN RAP HIGHER AT 50-60KTS) AND  
STEEP MID LEVEL LAPSE RATES BETWEEN 7-8C/KM INTO THE COOLER AIR  
ALOFT. GIVEN THE ELEVATED NATURE AND PARAMETERS MENTIONED, LARGE  
HAIL WILL BE THE MAIN THREAT EARLY ON, ESPECIALLY WITH ANY  
DEVELOPMENT OF ELEVATED SUPERCELLS OR SPLITTING SUPERCELLS PER  
ELONGATED HODOGRAPHS ABOVE THE SURFACE. WITHIN THE SLIGHT RISK OVER  
CENTRAL SD, THE PROBABILITY OF SEVERE HAIL IS 15-29%, WITH A CIG 1  
HATCH (2"+ IN DIAMETER POTENTIAL), OVER NORTH CENTRAL SD, MAINLY  
LOCATIONS ALONG AND WEST OF THE MO RIVER. IF ADDITIONAL CONVECTION  
DEVELOPS THROUGH THE NIGHT, THIS COULD RESULT IN MERGERS AND  
CLUSTERS THAT COULD GROW UPSCALE AS THE SYSTEM TRACKS EAST OR  
SOUTHEAST. IF THIS OCCURS, THEN THE MAIN THREAT WOULD BECOME  
MORE OF A DAMAGING WIND GUST OF 60-70 MPH OR POTENTIALLY HIGHER  
GUSTS ABOVE 75 MPH IF A RIJ/BOW FORMS. SPC HIGHLIGHTS THIS  
THREAT AS WELL OVER CENTRAL SD GIVING THE CIG 1 HATCHED (74MPH+  
WIND THREAT) PER SPC ALONG AND SOUTH OF A LINE FROM MOBRIDGE TO  
REDFIELD. HOWEVER, THE CAVEAT TO ALL OF THIS IS THAT EVERYTHING  
NEEDS TO COME TOGETHER AND LINE UP TIMING WISE AN THERE SEEMS TO  
BE QUITE A BIT OF DISAGREEMENT BETWEEN THE CAMS AS MENTIONED ON  
TIMING, STORM MODE, AND TRACK WITH THE POSSIBILITY OF NOTHING  
DEVELOPING.  
 
NOT TOO MUCH CHANGE IN THE PATTERN ALOFT FOR MONDAY AND TUESDAY WITH  
THE REGION IN OVERALL ZONAL TO NORTHWEST FLOW. WEAK EMBEDDED  
SHORTWAVE/PULSES WILL TRACK EAST/SOUTHEAST OVER THE AREA MONDAY  
EVENING INTO TUESDAY MORNING AND AGAIN TUESDAY EVENING INTO  
WEDNESDAY MORNING IN TANDEM WITH CAPE OF 1500+J/KG AND WIND  
SHEAR 30+KTS ALONG WITH ONGOING LOW LEVEL MOISTURE. HIGHER  
AMOUNTS OF CAPE AND DEWPOINTS POTENTIALLY IN THE LOWER 70S LOOK  
POSSIBLE TUESDAY AFTERNOON/EVENING. THE PATTERN OF DISCRETE  
CELLS POTENTIALLY GROWING UPSCALE LOOKS TO CONTINUE, THEREFORE  
LARGE HAIL AND WIND GUSTS OF 60-70+ MPH WILL BE THE MAIN  
THREATS. A MARGINAL RISK FOR SEVERE WEATHER IS OUTLOOKED OVER  
THE ENTIRE CWA MONDAY AND TUESDAY. OTHERWISE, THIS ONGOING  
PATTERN RESULTS IN CHANCES OF PRECIP THROUGH THE END OF THE  
WEEK. THIS FLOW WILL LEAD TO ONGOING SMOKE ALOFT WITH NOT MUCH  
IN THE WAY OF NEAR SURFACE SMOKE. WITH THIS SETUP, TEMPS WILL BE  
NEAR NORMAL (RANGING IN THE 80S) WITH STRONGER CAA DEVELOPING  
FOR THE END OF THE WEEK (STRENGTHENING TROUGH OUT EAST) WITH  
HIGHS A GOOD 5-10 DEGREES BELOW AVERAGE AND FORECAST HIGHS IN  
THE 70S!  
 
 
   
AVIATION /18Z TAFS THROUGH 18Z MONDAY/  
 
ISSUED AT 1206 PM CDT SUN AUG 9 2026  
 
TERMINALS KABR,KATY,KPIR,KMBG  
 
SMOKE ALOFT CONTINUES THROUGH THE TAF PERIOD, RESULTING IN  
ONGOING HAZY SKIES. VFR CIGS ARE FORECAST THROUGH THE END OF  
THE TAF PERIOD AS WELL. WINDS ARE OUT OF THE NORTHEAST TO EAST  
AND WILL SWITCH TO MORE SOUTHEASTERLY EARLY MONDAY MORNING.  
ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE LATE TONIGHT  
INTO MONDAY MORNING THAT COULD PASS OVER THE KMBG AND KPIR  
TERMINALS. HOWEVER, DIFFERENCES BETWEEN THE MODELS RESULT IN  
LOW CONFIDENCE ESPECIALLY IN TRACK AND LOCATION OF ANY STORMS  
THAT MAY FORM. IF STORMS CAN GROW VERTICALLY ENOUGH AND  
STRENGTHEN, THEN LARGE HAIL (POTENTIALLY 2+ INCHES IN DIAMETER)  
AND WIND GUSTS OF 60-70 MPH IS POSSIBLE.  
 
 
   
ABR WATCHES/WARNINGS/ADVISORIES  
 
SD...NONE.  
MN...NONE.  
 
 
 
 
 
DISCUSSION...MMM  
AVIATION...MMM  
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