134  
FXUS63 KUNR 022349  
AFDUNR  
 
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY  
NATIONAL WEATHER SERVICE RAPID CITY SD  
549 PM MDT WED APR 2 2025  
   
KEY MESSAGES  
 
-WESTERN CONUS TROUGH WILL EJECT EAST THUR-FRI AND SUPPORT ONE  
LAST ROUND OF RAIN/SNOW BEFORE THE PATTERN GRADUALLY CHANGES  
 
-TEMPERATURES TO REMAIN MAINLY BELOW SEASONAL NORMS THROUGH THE  
WEEK  
 
-WARMING UP NEXT WEEK  
 
 
   
DISCUSSION  
(THIS EVENING THROUGH WEDNESDAY)  
ISSUED AT 126 PM MDT WED APR 2 2025  
 
STUBBORN MEAN TROUGHING WILL FINALLY END THIS WEEK AS THE LONG  
WAVE UPPER TROUGH IS REPLACED BY WESTERN CONUS RIDGING. THIS WILL  
ALLOW FOR ONE MORE ROUND OF COOL TEMPS WITH RAIN AND SNOW CHANCES  
THUR NIGHT INTO FRIDAY. POTENT TROUGH NOW EXITING THE REGION WITH  
THE COLD CORE UPPER TROUGH AND WRAP AROUND MOISTURE SUPPORTING  
SCATTERED RAIN AND SNOW SHOWERS. STEEP LAPSE RATES HAVE ALLOWED A  
STRONG CONVECTIVE COMPONENT TO THE ACTIVITY, WITH SOME SHOWERS  
CONTAINING GRAUPEL AS WELL. SHOWERS WILL TAPER OFF THIS EVENING AS  
DRY AIR WORKS INTO THE REGION AND THE BL COOLS. COLD CYCLONIC  
FLOW WILL PERSIST THROUGH THUR AS THE NEXT TROUGH APPROACHES.  
ENOUGH INSTABILITY WILL BE PLACE FOR A FEW RAIN OR SNOW SHOWERS  
OVER THE BLACK HILLS AND ACROSS THE FAR WESTERN FA IN THE  
AFTERNOON. SLIGHTLY WARMER TOMORROW AS WELL, BUT STILL COOL WITH  
HIGHS IN THE 40S AND LOW 50S OUTSIDE THE BH. THE NEXT SYSTEM WILL  
MOVE INTO THE REGION THU NIGHT, WITH POS THETA-E ADV SUPPORTING  
INCREASING CHANCES FOR RAIN OVER SCENTRAL SD. MEANWHILE THE  
NORTHERN STREAM COUNTERPART WILL BRING A GOOD CHANCE OF RAIN AND  
SNOW TO THE NORTHWEST FA. AS THE TWO TOUGHS MOVE EAST AND PHASE,  
THE BULK OF LIFT WILL QUICKLY SHIFT EAST WITH THE MIDDLE OF THE FA  
LIKELY NOT SEEING MUCH PRECIP AT ALL. HENCE THE HIGHEST POPS WILL  
BE CONFINED TO THE NORTHWEST AND SOUTHEAST FA. MARGINAL THERMAL  
FIELDS WILL ONCE AGAIN SUPPORT TEMPS COOL ENOUGH FOR SNOW MOST  
AREAS, BUT ACCUMS WILL BE DIFFICULT GIVEN LACK OF A STRONG FORCING  
AND TIMING OF RAIN TO SNOW CHANGEOVER. VERY COOL ONCE AGAIN  
FRIDAY WITH HIGHS GENERALLY IN THE 30S AND LOW 40S. AFTER THIS  
TROUGH EXITS, THINGS WILL THEN DRY OUT FOR THE WEEKEND WITH TEMPS  
SLOWLY RECOVERING. WARMER WEATHER WILL RETURN NEXT WEEK AS A RIDGE  
BUILDS INTO THE WESTERN CONUS AND GRADUALLY SHIFTS EAST. PRECIP  
CHANCES LOOK TO RETURN BY TUE-WED OF NEXT WEEK WITH THE NEXT  
IMPULSE OR ROUND OF IMPULSES.  
 
 
   
AVIATION  
(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)  
ISSUED AT 537 PM MDT WED APR 2 2025  
 
IFR/MVFR CIGS WILL GRADUALLY IMPROVE TO VFR TONIGHT AS PRECIP  
ENDS. HOWEVER, IFR/PATCHY FOG WILL BE POSSIBLE EARLY THURSDAY  
MORNING, ESPECIALLY ACROSS THE BLACK HILLS AREA. VFR CONDITIONS  
ARE EXPECTED THURSDAY. THE NEXT SYSTEM WILL BRING CHANCES OF RAIN  
AND SNOW THURSDAY EVENING ALONG WITH MVFR/IFR CONDITIONS.  
 
 
   
UNR WATCHES/WARNINGS/ADVISORIES  
 
SD...NONE.  
WY...NONE.  
 
 
 
 
DISCUSSION/KEY MESSAGES...JC  
AVIATION...13  
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