342  
FXUS63 KUNR 252009  
AFDUNR  
 
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY  
NATIONAL WEATHER SERVICE RAPID CITY SD  
209 PM MDT FRI APR 25 2025  
   
KEY MESSAGES  
 
-WARMING UP THIS WEEKEND WITH GUSTY SOUTHEAST WINDS SATURDAY  
 
-STRONG LOW PRESSURE WILL CROSS THE REGION SUNDAY-MONDAY,  
BRINGING POTENTIALLY SEVERE WEATHER SUNDAY, WITH GOOD CHANCE OF  
RAIN MOST PLACES  
 
-DRIER AND SEASONAL NEXT WEEK AFTER MONDAY  
 
 
   
DISCUSSION  
(THIS EVENING THROUGH FRIDAY)  
ISSUED AT 208 PM MDT FRI APR 25 2025  
 
DEEP UPPER TROUGH WILL PUSH INTO THE ROCKIES THIS WEEKEND AND SET  
THE STAGE FOR A POTENT LOW PRESSURE SYSTEM EARLY NEXT WEEK, WITH  
A PATTERN SHIFT TO MEAN WESTERN CONUS TOUGHING AFTER. EASTERLY  
FLOW HAS BECOME ESTABLISHED ACROSS THE REGION AS THE SFC HIGH  
SHIFTS EAST. EXPECT THAT LOW CLOUDS AND AREAS OF DRIZZLE WILL  
DEVELOP AGAIN TONIGHT, ESP ALONG THE EASTERN SLOPES OF THE BLACK  
HILLS AS MOIST EASTERLY UPSLOPE FLOW CONTINUES OTHERWISE, A WEAK  
EMBEDDED IMPULSE WILL MOVE THROUGH THE REGION TONIGHT INTO SAT AND  
MAY SUPPORT A FEW ISOLATED SHOWERS WITH POS THETA-E ADV ENSUING.  
DEEP UPPER TROUGH WILL THEN DIG INTO THE WESTERN CONUS SAT.  
PRESSURE FALLS WILL INCREASE ACROSS THE REGION SAT, SUPPORTING  
GUSTY SE WINDS, WITH POTENTIAL ADV LEVEL WINDS OVER NW SD. THIS  
SYSTEM WILL SHIFT EAST SUNDAY WITH THE WARM SECTOR SPREADING OVER  
THE REGION. THIS WILL SUPPORT VERY WARM TEMPS WITH HIGHS IN THE  
70S AND 80S, WARMEST ON THE SD PLAINS. PREFRONTAL TROUGH WILL  
SUPPORT THUNDERSTORM CHANCES IN THE LATE AFTERNOON/EVENING WITH  
SOME POTENTIAL FOR SEVERE WEATHER AS SUFFICIENT CAPE AND BULK  
LAYER SHEAR WILL BE IN PLACE. TS DEVELOPMENT IS HIGHLY CONDITIONAL  
AND WILL HINGE ON THE SCOPE AND DEPTH OF MOISTURE RETURN. THERE  
IS PLENTY OF GULF MOISTURE THAT WILL WRAP INTO THIS SYSTEM, WHICH  
WILL TEND TO FAVOR A GOOD SETUP FOR APPRECIABLE RAINS AND  
THUNDERSTORMS. WRAP AROUND RAINS (HIGH ELEVATION SNOW) WILL THEN  
MOVE INTO THE REGION FROM THE NW SUNDAY NIGHT AS THE COLD FRONT  
SHIFTS EAST. RAIN WILL CONTINUE MONDAY IN THE NORTHWEST HALF, WITH  
CONVECTION POSSIBLE IN THE VIGOROUS DEFORMATION ZONE. THINGS DRY  
OUT SOME THE REMAINDER OF NEXT WEEK WITH ADDITIONAL CHANCES FOR  
SHOWERS LATER IN THE WEEK AS MORE IMPULSES TRAVERSE THE FLOW, WITH  
SEASONAL TEMPS EXPECTED. GIVEN EXPECTED WESTERN CONUS TROUGHING  
TOWARD THE END OF NEXT WEEK, A PERIOD OF VERY WARM TEMPS WILL BE  
POSSIBLE BY NEXT WEEKEND.  
 
 
   
AVIATION  
(FOR THE 18Z TAFS THROUGH 18Z SATURDAY)  
ISSUED AT 1122 AM MDT FRI APR 25 2025  
 
IFR TO MVFR CONDITIONS WILL CONTINUE AROUND THE BLACK HILLS DUE TO  
LOW CLOUDS/FOG/DZ. CONDITIONS WILL IMPROVE THIS AFTERNOON ACROSS  
MUCH OF WESTERN SOUTH DAKOTA, BUT MVFR/IFR CONDS WILL REDEVELOP  
OVER FAR WESTERN SD/BLACK HILLS AND NORTHEAST WYOMING TONIGHT.  
EXPECT GUSTY SOUTHEAST WINDS TO ALSO DEVELOP TONIGHT AND PERSIST  
THROUGH SATURDAY.  
 
 
   
UNR WATCHES/WARNINGS/ADVISORIES  
 
SD...NONE.  
WY...NONE.  
 
 
 
 
DISCUSSION/KEY MESSAGES...JC  
AVIATION...JC  
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