300  
FXUS63 KUNR 232355  
AFDUNR  
 
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY  
NATIONAL WEATHER SERVICE RAPID CITY SD  
555 PM MDT SAT MAY 23 2026  
   
KEY MESSAGES
 
 
- WARM THROUGH MEMORIAL DAY WITH DAILY ISOLATED THUNDERSTORMS,  
MAINLY OVER THE BLACK HILLS  
 
- CHANCES OF SHOWERS AND THUNDERSTORMS WILL INCREASE TUESDAY NIGHT  
AND CONTINUE THROUGH THE REST OF THE WEEK  
 

 
   
DISCUSSION
 
(THIS EVENING THROUGH SATURDAY)  
ISSUED AT 103 PM MDT SAT MAY 23 2026  
 
CYCLONIC FLOW CONTINUES ACROSS THE NORTHERN PLAINS WITH SEVERAL WEAK  
WAVES CROSSING WESTERN SD. WATER VAPOR IMAGERY SHOWS SOME OF THESE  
IMPULSES CROSSING NW SD THROUGH THE BLACK HILLS. SATELLITE SHOWS CU  
FIELD HAS DEVELOPED OVER THE HILLS...AND KUDX RADAR HIGHER TILTS  
SHOW ISOLATED CONVECTION TRYING TO INITIATE ACROSS THE EASTERN EDGE  
OF THE HILLS. WATER VAPOR ALSO SHOWS SUBSIDENCE BEHIND THE WAVES  
CROSSING CENTRAL WY WHICH WOULD LIMIT NE WY DEVELOPMENT TO EXTENSIVE  
MID LEVEL CLOUDS. WILL MAKE FURTHER POP ADJUSTMENTS OVER THE NEXT  
COUPLE OF HOURS. QUIET WEATHER IS EXPECTED TONIGHT WITH LOWS  
GENERALLY IN THE 40S. WARM AIR ADVECTION WILL CONTINUE PUSHING IN  
FROM THE SOUTHWEST LATE TONIGHT THROUGH SUNDAY, WITH HIGHS EXPECTED  
TO REACH THE 80S ACROSS THE PLAINS AND 70S OVER THE BLACK HILLS.  
STEEP MIDLEVEL LAPSE RATES ARE AGAIN EXPECTED SUNDAY AFTERNOON WITH  
ANOTHER WEAK WAVE CROSSING THE AREA WITHIN ZONAL UPPER LEVEL FLOW.  
COULD SEE MORE CONVECTION DEVELOPING ACROSS THE BLACK HILLS, BUT  
WOULD BE ISOLATED IN NATURE. WITH HIGH BASES, PRECIP THAT DOES  
DEVELOP MAY NOT REACH THE GROUND. WARMER TEMPS ARE EXPECTED ON  
MEMORIAL DAY AS THE UPPER RIDGE AXIS CROSSES THE NORTHERN PLAINS.  
HIGHS ARE EXPECTED TO REACH THE UPPER 80S TO LOWER 90S. COULD AGAIN  
SEE ISOLATED STORMS OVER THE HILLS. TUESDAY THROUGH THE REST OF NEXT  
WEEK COULD BRING A BIG PATTERN SHIFT. MODELS ARE SHOWING A DEEP  
UPPER LOW OVER THE WESTERN CONUS WHILE STRONG RIDGING BUILDS WELL  
INTO THE NORTHERN/CANADIAN PLAINS. DEEP SOUTHERLY TO SOUTHEASTERLY  
FLOW WILL BRING GULF MOISTURE INTO THE CENTRAL AND NORTHERN GREAT  
PLAINS...AND AN INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS.  
HOW EXACTLY THIS PANS OUT REMAINS TO BE SEEN, ESPECIALLY GIVEN THE  
DIFFERENCES IN HOW THE ECM AND GFS SHOW PRECIP DEVELOPING EACH DAY  
THROUGH THE WEEK. BUT THIS WILL BRING BETTER CHANCES FOR MUCH-NEEDED  
PRECIPITATION...AND PERHAPS BETTER CHANCES FOR STRONG/SEVERE  
WEATHER.  
 

 
   
AVIATION
 
(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)  
ISSUED AT 536 PM MDT SAT MAY 23 2026  
 
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD.  
 
MAINLY QUIET SKIES TONIGHT THROUGH TOMORROW. CAN'T RULE OUT  
ISOLATED SHOWERS LATE TONIGHT AND AGAIN SUNDAY AFTERNOON IN AND  
AROUND THE BLACK HILLS.  
 
OTHER CHANGES IN FLYING CONDITIONS WILL BE CENTERED AROUND THE  
WINDS. LIGHT WINDS EXPECTED TONIGHT WITH INCREASING WINDS TOMORROW  
BUT EVEN AFTER THE INCREASE IN WINDS, THEY'LL STILL BE AROUND 5 TO  
10 KNOTS.  
 

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

 
 

 
 
DISCUSSION/KEY MESSAGES...13  
AVIATION...GS  
 
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