302  
FXUS63 KUNR 182013  
AFDUNR  
 
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY  
NATIONAL WEATHER SERVICE RAPID CITY SD  
213 PM MDT FRI JUL 18 2025  
   
KEY MESSAGES
 
 
- DAILY CHANCES FOR THUNDERSTORMS THROUGH EARLY NEXT WEEK.  
 
- TEMPERATURES AROUND OR ABOVE NORMAL EXPECTED THROUGH THE  
FORECAST PERIOD.  
 

 
   
DISCUSSION
 
(THIS EVENING THROUGH FRIDAY)  
ISSUED AT 149 PM MDT FRI JUL 18 2025  
 
CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE CENTERED OVER CENTRAL  
SD, WITH FRONTAL BOUNDARY RUNNING THROUGH SOUTH CENTRAL SD INTO  
WESTERN NE AND CENTRAL WY. UPPER MODELS SHOW ZONAL FLOW ALOFT.  
TEMPERATURES CURRENTLY SIT IN THE UPPER 70S AND 80S WITH  
RELATIVELY LIGHT NORTHWEST TO NORTHEAST WINDS BEHIND THE BOUNDARY.  
 
THIS AFTERNOON, BOUNDARY WRAPS UP INTO NORTHEASTERN WY, PROVIDING  
AN AREA OF FORCING AMID A STRONG CAP TODAY. IF STORMS ARE ABLE TO  
FIRE UP, EXPECTED OVER NORTHEASTERN WY DOWN INTO SOUTHWESTERN SD  
LATE THIS AFTERNOON OR EARLY EVENING. MODEST SHEAR BUT PLENTY OF  
CAPE COULD SUPPORT AN ORGANIZED SEVERE STORM OR TWO IF INITIATION  
IS ABLE TO OCCUR. LIKELY WONT SEE ANY DEVELOPMENT OUTSIDE OF THE  
IMMEDIATE FRONTAL ZONE. THREAT TODAY WOULD BE LARGE HAIL AND  
STRONG WINDS. SHORTWAVE MOVING ACROSS THE FA WILL SUPPORT  
ELEVATED SHOWERS/STORMS OVERNIGHT, HOWEVER NO ORGANIZED SEVERE IS  
EXPECTED.  
 
MODELS SHOW ZONAL TO QUASI-ZONAL FLOW PERSISTING THROUGH THE  
FORECAST PERIOD, WITH DISTURBANCES MARKING DAILY CHANCES FOR  
STORMS OVER THE AREA. WHILE WIDESPREAD SEVERE IS NOT EXPECTED,  
LOCALIZED STRONG STORMS WILL REMAIN A POSSIBILITY OVER THE  
WEEKEND. SHORTWAVE MOVES THOUGH AT A BETTER TIME SATURDAY TO  
SUPPORT ISOLATED SEVERE STORM POTENTIAL, COUPLED WITH 1000-2000  
J/KG ML CAPE AND 30-40 KT 0-6KM SHEAR, IF ABLE TO OVERCOME THE  
CAP. MAY SEE POTENTIAL FOR TERRAIN DRIVEN UPSLOPE BLACK HILLS  
DEVELOPMENT MOVING OFF INTO THE PLAINS. SIMILAR SET UP FOR SUNDAY  
WILL SUPPORT MORE ISOLATED STORM POTENTIAL. LONGER RANGE MODELS  
SHOW LITTLE CHANGE IN THE OVERALL PATTERN, KEEPING TEMPERATURES  
RELATIVELY STEADY, WITH DAILY (BUT LIMITED) CONVECTIVE ACTIVITY.  
 

 
   
AVIATION
 
(FOR THE 18Z TAFS THROUGH 18Z SATURDAY)  
ISSUED AT 1043 AM MDT FRI JUL 18 2025  
 
ISOLATED THUNDERSTORMS AROUND THE BLACK HILLS ARE EXPECTED THIS  
AFTERNOON WITH SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE  
ENTIRE AREA TONIGHT. MVFR CONDITIONS ARE EXPECTED WITH THE  
SHOWERS AND STORMS AS THEY MOVE FROM WEST TO EAST ACROSS THE AREA.  
OVER SOUTH CENTRAL SOUTH DAKOTA, AREA OF IFR VSBY/CIGS ARE LIKELY  
AFTER 06Z SATURDAY DUE TO LOW CLOUDS/FOG.  
 

 
   
UNR WATCHES/WARNINGS/ADVISORIES
 
 
SD...NONE.  
WY...NONE.  

 
 

 
 
DISCUSSION/KEY MESSAGES...DYE  
AVIATION...SMITH  
 
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