566
FXUS63 KUNR 252001
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
201 PM MDT WED JUN 25 2025
KEY MESSAGES
- CHANCE FOR THUNDERSTORMS TODAY, SOME STORMS MAY BE MARGINALLY
SEVERE WITH LARGE HAIL (1+" DIAMETER) AND DAMAGING WINDS AS THE
MAIN HAZARDS.
- CHANCES FOR THUNDERSTORMS CONTINUE THURSDAY, THOUGH NO SEVERE
WEATHER IS EXPECTED AT THIS TIME.
- THERE IS A SLIGHT RISK (LEVEL 2 OF 5) FOR SEVERE THUNDERSTORMS
FRIDAY AFTERNOON. MAIN HAZARDS WILL BE LARGE HAIL (1+" IN
DIAMETER) AND DAMAGING WINDS.
- VERY WARM TEMPERATURES ON FRIDAY AND SATURDAY WITH HIGHS IN THE
MID TO UPPER 90S.
DISCUSSION
(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 200 PM MDT WED JUN 25 2025
UPPER LEVEL TROF SITS CENTERED OVER THE WESTERN US WITH THE
NORTHERN PLAINS UNDER SOUTHWEST FLOW. WATER VAPOR IMAGERY DEPICTS
UPPER LEVEL WAVE CROSSING THE CWA WHILE UPPER LEVEL ANALYSIS SHOWS
AN 80-100KT JET STREAK AT H250. 12Z NAM DEPICTS CORRIDOR OF
1000-2000 J/KG SBCAPE IN AN UNCAPPED ENVIRONMENT DEVELOPING ACROSS
PORTIONS OF WESTERN SD INTO NORTHEASTERN WY WITH 0- 6KM BULK
SHEAR VALUES AT 35-40KT, A SIGNIFICANT DEVIATION FROM PREVIOUS NAM
RUNS. MOST RECENT HRRR RUNS HAVE BEEN FAIRLY CONSISTENT IN
SHOWING STORMS DEVELOPING OVER THE BLACK HILLS AND FAR WESTERN SD
BY MID AFTERNOON. GIVEN THE MODEST SHEAR (35-40KT), MAY SEE A
MARGINAL SEVERE THREAT FOR WIND AND HAIL THIS AFTERNOON.
UPPER TROUGH AXIS CROSSES THE CWA ON THURSDAY. LOW LEVEL THETA-E
ADVECTION WILL SUPPORT INSTABILITY IN THE AFTERNOON, HOWEVER
DEEPER LAYER MOISTURE WILL BE LACKING WHICH SHOULD LIMIT
THUNDERSTORM DEVELOPMENT. THUNDERSTORM CHANCES WILL BE MOSTLY
CONFINED TO THE BLACK HILLS.
SHORTWAVE RIDGING BUILDS INTO THE REGION FRIDAY WITH SOUTHERLY
FLOW BRINGING WARM, MOIST AIR INTO THE REGION. LOW LEVEL THERMAL
RIDGE DEVELOPS WITH TEMPERATURES SOARING INTO THE 90S ACROSS MUCH
OF THE REGION. STORMS MAY DEVELOP ALONG A SFC TROF CROSSING THE
REGION FRIDAY AFTERNOON. SHEAR LOOKS MODEST WITH 30-40KT BULK
SHEAR DEVELOPING ACROSS WESTERN SD. INSTABILITY, SHEAR, AND STEEP
LOW TO MID LEVEL LAPSE RATES SHOULD BE ENOUGH TO SUPPORT A SEVERE
WIND/HAIL THREAT ACROSS WESTERN SD FRIDAY AFTERNOON.
WEAK RIDGING REMAINS OVER THE REGION FOR SATURDAY, SUPPORTING
ANOTHER DAY WITH HIGHS IN THE 90S. UPPER RIDGE BUILDS INTO THE
WESTERN CONUS, WHICH WILL PUT THE NORTHERN PLAINS UNDER NORTHWEST
FLOW AND BRINGING A SLIGHT COOLING TREND TO THE CWA FOR THE LATTER
HALF OF THE WEEKEND.
AVIATION
(FOR THE 18Z TAFS THROUGH 18Z THURSDAY)
ISSUED AT 1142 AM MDT WED JUN 25 2025
ISOLATED/SCATTERED TSRA WILL DEVELOP THIS AFTERNOON AND EVENING.
ANY TSRA WILL HAVE LOCAL IFR CONDITIONS AS WELL AS GUSTY, ERRATIC
WINDS AND POSSIBLE HAIL. MVFR/IFR CIGS CONDITIONS MAY DEVELOP LATE
TONIGHT/THURSDAY MORNING ACROSS THE NORTHWESTERN TO CENTRAL SD
PLAINS.
UNR WATCHES/WARNINGS/ADVISORIES
SD...NONE.
WY...NONE.
DISCUSSION/KEY MESSAGES...WONG
AVIATION...13
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page