612
FXUS63 KUNR 050507
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1107 PM MDT MON AUG 4 2025
KEY MESSAGES
- SEVERE STORMS POSSIBLE THIS AFTERNOON AND EVENING ACROSS THE
BLACK HILLS AREA AND PORTIONS OF SOUTHWESTERN SOUTH DAKOTA.
- WARMING TEMPERATURES TUESDAY AND WEDNESDAY, HOT TEMPERATURES
THURSDAY. HIGHS IN THE MID 90S TO LOW 100S THURSDAY.
- COLD FRONT MOVES THROUGH LATE THURSDAY AND THURSDAY NIGHT.
DISCUSSION
(THIS EVENING THROUGH MONDAY)
ISSUED AT 225 PM MDT MON AUG 4 2025
UPPER LEVEL ANALYSIS HAS A RIDGE CENTERED OVER THE WESTERN HIGH
PLAINS WITH A TROUGH OVER THE PACIFIC NORTHWEST AND DOWN THROUGH
THE MISSISSIPPI RIVER VALLEY, RESULTING IN A SOUTHWEST FLOW
PATTERN ACROSS THE FORECAST AREA. AT THE SURFACE, A TROUGH
EXTENDS DOWN THE EAST SIDE OF BIGHORNS AND A BOUNDARY IS ORIENTED
EAST TO WEST ACROSS NORTHWESTERN SOUTH DAKOTA. RADAR IS SHOWING
SOME STORMS FIRING OVER THE BIGHORNS WITH SOME HIGH BASED
CONVECTION OVER THE BOUNDARY IN NORTHWESTERN SOUTH DAKOTA, WHILE
LATEST SATELLITE IMAGERY HAS SOME CONGESTED CU ALONG THE WEST SIDE
OF THE BLACK HILLS.
FOR THIS AFTERNOON AND EVENING, EXPECT TO SEE SOME STORMS DEVELOP
OVER THE BLACK HILLS AND ACROSS THE HIGHER TERRAIN IN WYOMING.
DEW POINTS ARE MAINLY 50 TO 55 DEGREES, WITH TEMPS IN THE 80S.
THUS, STORMS WILL LIKELY BE HIGH BASED. CAMS ARE ALL OVER THE
PLACE, BUT WITH MODERATE DEEP LAYER SHEAR, CAPE OF 1500-2500 J/KG,
AND BULK SHEAR GREATER THAN 40KTS, COULD HAVE A FEW ISOLATED
SUPERCELLS ANYWHERE FROM SOUTHEAST MONTANA DOWN THROUGH
SOUTHWESTERN SOUTH DAKOTA. MAIN THREAT FOR THE STORMS WOULD BE
STRONG WINDS AND HAIL.
ANOTHER ROUND OF NOCTURNAL CONVECTION IS POSSIBLE ACROSS THE
WESTERN SOUTH DAKOTA PLAINS TONIGHT AS POSITIVE THETA-E ADVECTION
DEVELOPS AHEAD OF THE NEXT SHORTWAVE COUPLED WITH THE LOW LEVEL
JET. SHOWERS/STORMS WILL LINGER INTO TUESDAY MORNING.
ON TUESDAY THE SURFACE LOW OVER SOUTHEASTERN MONTANA WILL SHIFT
INTO SOUTHWESTERN/SOUTH CENTRAL SOUTH DAKOTA AS A STRONG UPPER
WAVE PUSHES ACROSS MONTANA AND CLIPS THE NORTHERN PORTION OF THE
FORECAST AREA. A FEW STORMS WILL BE POSSIBLE AND ANY STORM THAT
DOES DEVELOP COULD BE STRONG TO SEVERE.
FOR WEDNESDAY, THE RIDGE CONTINUES TO BUILD, BUT MODELS SHOW A
WAVE TRYING TO INITIATE CONVECTION ACROSS SOUTHWESTERN SOUTH
DAKOTA. HAVE ADDED SOME LOW END POPS TO ACCOUNT FOR THIS.
TEMPERATURES WILL BE WARM, WITH HIGHS RANGING FROM THE MID 80S TO
MID 90S.
THERMAL RIDGE PASSES OVER THE AREA THURSDAY, LEADING TO HOT
TEMPERATURES IN THE 90S TO LOW 100S. A COLD FRONT WILL PUSH
THROUGH THURSDAY AFTERNOON AND OVERNIGHT, LEADING TO A GOOD
CHANCE FOR STORMS LATE THURSDAY AND FRIDAY.
AVIATION
(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1102 PM MDT MON AUG 4 2025
SCATTERED TSRA ARE POSSIBLE ACROSS WESTERN SD THROUGH THE
OVERNIGHT HOURS WITH ASSOCIATED MVFR CONDITIONS AND GUSTY WINDS.
OUTSIDE OF STORMS, BREEZY SOUTHERLY WINDS EXPECTED THROUGH THE
OVERNIGHT HOURS WITH GUSTS OF UP TO 30KT. SOME LOW STRATUS IS
POSSIBLE EARLY THIS MORNING ACROSS NORTHEASTERN WY INTO THE BLACK
HILLS AND WESTERN SD.
UNR WATCHES/WARNINGS/ADVISORIES
SD...NONE.
WY...NONE.
DISCUSSION/KEY MESSAGES...SMITH
AVIATION...WONG
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