505  
FXUS63 KUNR 300418  
AFDUNR  
 
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY  
NATIONAL WEATHER SERVICE RAPID CITY SD  
1018 PM MDT MON MAY 29 2017  
   
DISCUSSION
 
(THIS EVENING THROUGH MONDAY)  
ISSUED AT 134 PM MDT MON MAY 29 2017  
 
19Z SURFACE ANALYSIS HAD LOW OVER CENTRAL ON WITH UPPER LOW  
SPINNING JUST NORTH OF LAKE SUPERIOR. CYCLONIC FLOW ASSISTING  
CELLULAR CU FIELD OVER EASTERN HALF OF CWA. QUIET WEATHER.  
 
TONIGHT, UPPER LOW MOVES NORTHEAST AS UPPER RIDGE BUILDS OVER THE  
ROCKIES. 1024MB SURFACE HIGH CENTERED OVER SOUTHERN SK WITH RIDGE  
AXIS THROUGH THE CWA. CLEARING SKIES AND LIGHT WINDS WILL ALLOW  
UPSTREAM TD/S IN THE 30S TO BE REALIZED FOR OVERNIGHT LOWS OVER MUCH  
OF THE CWA. FROST LOOKS LIKE A GOOD BET ON THE NORTHWESTERN SD  
PLAINS, SO WILL HOIST HEADLINES. FEW LOW-LYING SPOTS MIGHT EVEN  
DROP 0C, BUT NOT WIDESPREAD OR LOW ENOUGH FOR FREEZE WARNING.  
THESE MINIMUMS ARE LOWER THAN GUIDANCE.  
 
TUESDAY, UPPER RIDGE AND SUBSIDENCE BRING A PLEASANT DAY TO THE AREA  
WITH TEMPERATURES NEAR GUIDANCE.  
 
WEDNESDAY, UPPER RIDGE MOVES TOWARD THE PLAINS AND WEAKENS, WITH  
A WEAK SHORTWAVE FORECAST TO MOVE THROUGH DURING PEAK HEATING.  
DECENT RETURN FLOW IS EXPECTED AS SURFACE HIGH MOVES INTO THE OH  
VALLEY. 1-2KJ/KG MLCAPE FORECAST IN A NARROW TONGUE FROM THE BLACK  
HILLS SOUTHWARD INTO NEBRASKA WITH 15-20M/S 0-6KM BULK SHEAR. IF  
A SHORTWAVE ACTUALLY MOVES THROUGH, 25-50 MLCIN COMBINED WITH  
TERRAIN SHOULD POP TS. SUPERCELLS WOULD BE POSSIBLE WITH VERY SLOW  
MOVEMENT, POSSIBLY BRING A FEW SEVERE REPORTS. TEMPERATURES WILL  
BE NOTICEABLY WARMER.  
 
THURSDAY, UPPER RIDGE OVERHEAD WITH CONVECTION LIKELY LIMITED TO THE  
BLACK HILLS IF ANY. TEMPERATURES WILL BE SUMMER-LIKE.  
 
FRIDAY THROUGH MONDAY, MOSTLY PROGRESSIVE SPLIT FLOW WILL BRING A  
SERIES OF DISTURBANCES THROUGH THE CWA WITH CONVECTION POSSIBLE EACH  
DAY. FRIDAY WILL BE WARMER THAN AVERAGE.  
 

 
   
AVIATION
 
(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)  
ISSUED AT 1016 PM MDT MON MAY 29 2017  
 
VFR CONDITIONS WILL CONTINUE THROUGH THE PERIOD WITH MOSTLY CLEAR  
SKIES.  
 

 
   
UNR WATCHES/WARNINGS/ADVISORIES
 
 
SD...FROST ADVISORY FROM 2 AM TO 8 AM MDT TUESDAY FOR SDZ001-002-  
012>014-031-073.  
 
WY...NONE.  

 
 

 
 
DISCUSSION...HELGESON  
AVIATION...10  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab SD Page
The Nexlab WY Page Main Text Page