573  
FXUS63 KBIS 032025  
AFDBIS  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BISMARCK ND  
325 PM CDT MON AUG 3 2020  
   
SHORT TERM
 
(THIS EVENING THROUGH TUESDAY)  
ISSUED AT 232 PM CDT MON AUG 3 2020  
 
PRECIPITATION CHANCES ENTER THE FORECAST AREA LATE TONIGHT AND  
SPREAD ACROSS CENTRAL ND ON TUESDAY.  
 
CONVECTION CURRENTLY MOVING FROM WESTERN INTO CENTRAL MT WILL  
HAVE A HARD TIME MAINTAINING ITSELF AS IT MOVES INTO A LESS  
FAVORABLE, DRIER ENVIRONMENT OVER WESTERN ND LATER THIS EVENING.  
HOWEVER, A STRENGTHENING LOW LEVEL JET AND INCREASED FORCING FOR  
ASCENT WITH AND APPROACHING SHORTWAVE, SHOULD ALLOW FOR SHOWERS  
AND POSSIBLY A FEW THUNDERSTORMS TO PUSH INTO WESTERN ND TOWARD  
MORNING. THE SHORTWAVE THEN PUSHES TO THE SOUTHERN SASK/MANITOBA  
BORDER BY 00 UTC WEDNESDAY. THE QUESTION THEN BECOMES WHAT ABOUT  
STRONG TO SEVERE CONVECTION ON TUESDAY INTO TUESDAY EVENING. THERE  
IS STILL SOME DISAGREEMENT IN THE DETERMINISTIC MODEL SOLUTIONS,  
BUT A SURFACE TROUGH IS LIKELY TO BE SITUATED SOMEWHERE OVER  
WESTERN ND TUESDAY AFTERNOON. MOST OF THE MODELS AND CAMS THAT GO  
OUT THAT FAR, PUSH THE MORNING CONVECTION EAST INTO CENTRAL ND,  
AND THEN IT'S A MATTER OF WHETHER THE ATMOSPHERE CAN RECOVER  
ENOUGH TUESDAY AFTERNOON TO SUPPORT SOME STRONGER CONVECTION IN  
THE WEST. CONVECTION MODE LOOKS MESSY WITH NEITHER DIRECTLY  
PERPENDICULAR, NOR PARALLEL BULK SHEAR VECTORS WITH THE SURFACE  
BOUNDARY. ALSO, SOME CONVECTION MIGHT FIRE BACK WEST OF THE  
BOUNDARY. THIS LOOKS LIKE IT COULD BE THE BEST LOCATION FOR  
STRONGER STORMS JUST BASED ON FORECAST SOUNDINGS. WEST OF THE  
BOUNDARY LATER WEDNESDAY AFTERNOON OR EARLY EVENING. YOU HAVE  
UNIDIRECTIONAL SHEAR BUT DECENT SPEED SHEAR, 30-40 KNOTS OF BULK  
SHEAR AND 1000-2000 J/KG OF CAPE. ENOUGH TO SUPPORT SOME STRONG  
CONVECTION. HOWEVER, THERE APPEARS TO BE QUITE A BIT OF WARM AND  
DRY AIR AROUND 500MB SO AT THIS TIME DO NOT THINK THE THREAT FOR  
SEVERE STORMS IS THAT HIGH. SPC MAINTAINS A GENERAL RISK EXCEPT  
FOR A MARGINAL RISK IN THE FAR SOUTHWEST/SOUTH CENTRAL WITH  
BETTER INSTABILITY AS YOU GO FARTHER SOUTH INTO SD. ALSO WOULD NOT  
COMPLETELY RULE OUT A STRONGER CELL TO THE NORTH, CLOSER TO THE  
AFOREMENTIONED SHORTWAVE TROUGH. SOME GUIDANCE ALSO KEEPS STRONGER  
CONVECTION ALONG AND AHEAD OF THE TROUGH TUESDAY AFTERNOON, AND  
THINK EITHER SCENARIO IS POSSIBLE. BUT IN GENERAL THE SEVERE  
THREAT LOOKS TO BE LIMITED TUESDAY INTO TUESDAY NIGHT.  
   
LONG TERM
 
(WEDNESDAY NIGHT THROUGH MONDAY)  
ISSUED AT 232 PM CDT MON AUG 3 2020  
 
THE EXTENDED FORECAST IS HIGHLIGHTED BY A CHANCE OF THUNDERSTORMS  
WEDNESDAY, AND AGAIN OVER THE WEEKEND, ALONG WITH TEMPERATURES  
INCREASING TO NEAR TO ABOVE AVERAGE.  
 
SLIGHT CHANCE TO CHANCE POPS CONTINUES WEDNESDAY MORNING AND  
AFTERNOON WITH SOME GUIDANCE CONTINUING TO WRAP SHOWERS AND  
THUNDERSTORMS AROUND THE BACK SIDE OF THE SHORTWAVE, AND STILL  
WANT TO KEEP THE CHANCE IN FOR NOW.  
 
HIGHS WILL GENERALLY BE IN THE UPPER 70S TO MID 80S TUESDAY AND  
WEDNESDAY, BEFORE QUICKLY WARMING UP TO THE LOWER 80S EAST TO NEAR  
90 WEST ON THURSDAY AS UPPER RIDGING BEGINS TO BUILD AGAIN OVER  
THE NORTHERN PLAINS. MAYBE A SLIGHT CHANCE FOR A FEW THUNDERSTORMS  
IN THE WEST ON THURSDAY AFTERNOON, BUT A BETTER CHANCE EMERGES  
FRIDAY WITH ANOTHER SHORTWAVE AND FRONTAL SYSTEM MOVING THROUGH.  
FOR THE WEEKEND AND INTO NEXT WEEK, LOOKING LIKE NEAR DAILY  
CHANCES FOR SHOWERS AND THUNDERSTORMS ALONG WITH TEMPERATURES  
GENERALLY IN THE 80S.  
 

 
   
AVIATION
 
(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)  
ISSUED AT 232 PM CDT MON AUG 3 2020  
 
VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD. MODERATE  
SOUTHEAST FLOW 15 TO 30KT AT KXWA AND KDIK TODAY. OTHERWISE SUNNY  
WITH A FEW VFR CUMULUS CLOUDS AND POSSIBLY SOME THIN HIGH CLOUDS  
MOVING IN FROM THE WEST. CLOUDS INCREASE SIGNIFICANTLY LATE  
TONIGHT WEST WITH SHOWERS AND POSSIBLY A THUNDERSTORM MOVING INTO  
KDIK AND KXWA AFTER 12 UTC. GIVEN THE UNCERTAINTY OF THUNDER AT  
THIS TIME, JUST KEPT A VCSH AT THESE SITES 12-18 UTC.  
 

 
   
BIS WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
SHORT TERM...TWH  
LONG TERM...TWH  
AVIATION...TWH  
 
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