589  
FXUS63 KABR 122323 AAA  
AFDABR  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE ABERDEEN SD  
623 PM CDT WED AUG 12 2020  
   
UPDATE
 
 
ISSUED AT 622 PM CDT WED AUG 12 2020  
 
FORECAST IS ON TRACK THIS EVENING. NO MAJOR CHANGES ARE PLANNED.  
 

 
   
SHORT TERM
 
(THIS EVENING THROUGH THURSDAY NIGHT)  
ISSUED AT 352 PM CDT WED AUG 12 2020  
 
FORECAST CHALLENGES INCLUDE TEMPERATURES AND PRECIPITATION CHANCES  
THURSDAY AND THURSDAY NIGHT.  
 
CURRENTLY, IT'S PARTLY TO MOSTLY SUNNY OVER THE CWA, WITH  
TEMPERATURES IN THE 70S AND 80S EAST OF THE MISSOURI RIVER VALLEY.  
THROUGHOUT AND WEST OF THE MISSOURI RIVER VALLEY, TEMPERATURES ARE  
WARMING THROUGH THE 80S AND 90S. THERE IS ALSO A LEE-OF-THE-BLACK  
HILLS SURFACE TROF HANGING OUT OVER THE REGION, EXTENDING FROM THE  
BLACK HILLS EAST TOWARD HURON AND SOUTHEAST TOWARD SIOUX CITY, IOWA.  
 
THERE APPEARS TO BE A SMALL WINDOW OF TIME THIS EVENING, WHEN ONE OR  
TWO THUNDERSTORMS COULD DEVELOP ON THE NOSE OF A LOW LEVEL JET  
FORECAST TO FORM OVER THE CWA THIS EVENING AND SPREAD NORTH/EAST  
THROUGH THE REGION OVERNIGHT. LOW/MID-LEVEL THERMAL ADVECTION AND  
LOW LEVEL MOISTURE ADVECTION IS CONTINUING ACROSS CENTRAL/SOUTH  
CENTRAL SODAK THIS EVENING WHERE THE NOSE OF THE DEVELOPING LOW  
LEVEL JET IS FORECAST TO BE. ALTHOUGH, BY LATE THIS EVENING, THE  
ATMOSPHERE, ALOFT, MAY BE TOO WARM TO SUPPORT CONVECTIVE  
DEVELOPMENT. EVEN IF A STORM COULD GET GOING, DEEP-LAYER SHEAR IS  
PROGGED AT LESS THAN 20KNOTS. SO, OTHER THAN A PULSE-THREAT FOR  
PERHAPS SOME HAIL, SEVERE WEATHER POTENTIAL TONIGHT IS RATHER  
LIMITED.  
 
OTHERWISE, THE FORECAST APPEARS TO BE A DRY ONE UNTIL THURSDAY  
AFTERNOON/NIGHT WHEN A BOUNDARY BEGINS TO MOVE INTO THE CWA. PLENTY  
OF INSTABILITY AROUND AND BETTER DEEP-LAYER SHEAR ALONG/BEHIND THE  
BOUNDARY. SOME GSM OUTPUT AND HI-RES CAM OUTPUT SUPPORTS A FEW  
THUNDERSTORMS TRYING TO GO UP RIGHT ON THE BOUNDARY THURSDAY  
AFTERNOON/EVENING WHILE THE MID-LEVEL THERMAL CAPPING INVERSION IS  
SLOWLY ERODED BY FALLING HEIGHTS ALOFT AS THE LARGE WESTERN NOAM  
UPPER TROF APPROACHES THE REGION. IF CONVECTION DEVELOPS ON THIS  
BOUNDARY, MAINLY THE EASTERN HALF/THIRD OF THE CWA WOULD POTENTIALLY  
BE IMPACTED FOR A FEW HOURS. A SECOND/SEPARATE ROUND OF POTENTIAL  
CONVECTION COULD BE APPROACHING/WORKING INTO THE WESTERN CWA LATE IN  
THE THURSDAY NIGHT PERIOD. A STRONGER SHORTWAVE/UPPER JET STREAK MAY  
BE SUPPORTING THE DEVELOPMENT OR FURTHERANCE OF CONVECTION OUT OVER  
THE NORTHERN HIGH PLAINS ALONG OR ON THE NORTHERN FRINGE OF A  
SURFACE LOW PROGGED TO BE EDGING INTO THE WESTERN DAKOTAS BY EARLY  
FRIDAY MORNING. THE NOSE OF A LOW LEVEL JET IS PROGGED TO BE OVER  
THE CWA LATE THURSDAY NIGHT AS WELL.  
 
OPERATIONAL MODEL THERMAL PROGS AND ENSEMBLES 850HPA STANDARDIZED  
ANOMALIES SUPPORT TEMPERATURE TONIGHT THROUGH THURSDAY NIGHT  
REMAINING ABOVE NORMAL.  
   
LONG TERM
 
(FRIDAY THROUGH WEDNESDAY)  
ISSUED AT 352 PM CDT WED AUG 12 2020  
 
THE EXTENDED PERIOD BEGINS WITH AN UPPER LEVEL SHORTWAVE TROUGH  
SLIDING ACROSS THE AREA FRIDAY INTO FRIDAY NIGHT. A SURFACE FRONT  
WILL ALSO BE MOVING THROUGH, WITH FAIRLY WARM AND MOIST AIR BEING  
PULLED NORTHWARD AHEAD OF IT. THIS COMBINATION OF FACTORS LOOKS TO  
ALLOW FOR THE FRONT TO BECOME THE FOCUS FOR THUNDERSTORM DEVELOPMENT  
FRIDAY AFTERNOON AND EVENING, MAINLY ACROSS THE EASTERN PART OF THE  
CWA. THE ONE HINDERING FACTOR MAY BE A BIT OF A CAP, WITH H7 TEMPS  
OF +11 TO +13 C ACROSS THE FAR EAST DURING THE AFTERNOON HOURS. SPC  
HAS HIGHLIGHTED THE EASTERN CWA WITH A MARGINAL TO SLIGHT RISK FOR  
NOW. CONDITIONS THEN LOOK FAIRLY QUIET FOR THE SATURDAY THROUGH  
TUESDAY TIME FRAME AS THE UPPER LEVEL FLOW REMAINS OUT OF THE  
NORTHWEST, BUT WITH LITTLE IN THE WAY OF SHORTWAVE ENERGY MOVING  
THROUGH AND WITH SURFACE HIGH PRESSURE DOMINATING. THE HIGH EXITS TO  
THE EAST TUESDAY NIGHT, WITH SOME MODELS HINTING AT THE POTENTIAL  
FOR A FEW SHOWERS OR STORMS ON WEDNESDAY.  
 
HIGH TEMPERATURES WILL BE IN THE 80S EVERYWHERE FRIDAY, SATURDAY AND  
SUNDAY, THEN WILL RANGE FROM THE MID TO UPPER 70S EAST, TO THE MID  
TO UPPER 80S WEST MONDAY, TUESDAY AND WEDNESDAY. OVERNIGHT LOWS WILL  
BE IN THE MID 50S TO LOWER 60S THROUGH THE PERIOD.  
 

 
   
AVIATION
 
(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)  
ISSUED AT 622 PM CDT WED AUG 12 2020  
 
TERMINALS KABR,KATY,KPIR,KMBG  
 
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. WINDS WILL BECOME  
BREEZY OUT OF THE SOUTH ON THURSDAY.  
 

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

 
 

 
 
UPDATE...WISE  
SHORT TERM...DORN  
LONG TERM...PARKIN  
AVIATION...WISE  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab SD Page
The Nexlab MN Page Main Text Page