880
FXUS63 KUNR 040717
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
117 AM MDT MON AUG 4 2025
KEY MESSAGES
-SEASONALLY WARM WITH ISOLATED TO SCATTERED THUNDERSTORMS AT
TIMES
-SEVERE STORMS POSSIBLE THIS AFTERNOON FROM THE BLACK HILLS
SOUTHEAST INTO NEBRASKA
DISCUSSION
(TODAY THROUGH SUNDAY)
ISSUED AT 116 AM MDT MON AUG 4 2025
NORTHEAST PAC UPPER TROUGH WILL FORCE A RIDGE EAST INTO THE
PLAINS, AS ACTIVE NORTHERN PERIPHERY FLOW CONTINUES. MAIN STORM
TRACK WILL SLOWLY SHIFT NORTH THE NEXT COUPLE DAYS, WITH THE BULK
OF PRECIP CHANCES. HOWEVER, THUNDERSTORMS WILL IMPACT THE FA TODAY
AND TUES, WITH SEVERE STORMS POSSIBLE BOTH DAYS. POS THETA-E ADV
ONGOING ALOFT, SUPPORTING A CLUSTER OF TS OVER NORTHEAST WY. THIS
ACTIVITY MAY PERSIST INTO SD BEFORE WANING LATER THIS MORNING. LEE
SIDE TROUGH WILL SETUP OVER THE REGION, WITH INCREASING MOIST SE
FLOW TODAY. APPRECIABLE CAPE (1500-2500 J/KG) AND INCREASING BULK
LAYER SHEAR WILL BE IN PLACE BY THIS AFTERNOON, SUPPORTING A GOOD
SETUP FOR STORMS TO INITIATE ON THE NORTHERN BLACK HILLS. WITH
BULK SHEAR VALUES EXCEEDING 40 KNOTS THIS AFTERNOON, THE POTENTIAL
FOR STORMS TO ORGANIZE INTO SUPERCELLS WILL BE PRETTY GOOD.
CURRENT PROGS SUGGEST STORMS TO INITIATE OVER THE NORTHERN BH,
TURN RIGHT, THEN LIKELY ORGANIZING INTO CLUSTER OF STORMS AS THEY
PROGRESS SOUTHEAST. MAIN THREAT WITH THESE POTENTIAL STORMS WOULD
BE LARGE HAIL, POSSIBLY 2 INCHES OR LARGER, DAMAGING WINDS, AND
HEAVY RAIN. ANOTHER ROUND OF NOCTURNAL STORMS WILL BE POSSIBLE
ONCE AGAIN LATE TONIGHT ACROSS NORTHWEST SD AS POS THETA-E ADV
DEVELOPS AHEAD OF THE NEXT SHORTWAVE COUPLED WITH A LLJ. SFC
TROUGH WILL SHIFT EAST TUES WITH MORE STORMS POSSIBLE IN THE
AFTERNOON, MAINLY ACROSS NORTHWEST SD AND THE BLACK HILLS. ANY
STORMS THAT DO DEVELOP ON TUES COULD BE STRONG TO SEVERE WITH
APPRECIABLE CAPE, ALTHOUGH DEEP LAYER SHEAR LOOKS MARGINAL,
POSSIBLY LIMITING UPSCALE GROWTH. EXPECT HIGHS THROUGH WED INTO
THE 80S AND 90S MOST PLACES. UPPER RIDGE WILL BUILD OVER THE AREA
WED-THUR, PEAKING THUR WHEN THE THERMAL RIDGE PASSES OVER THE
REGION, SUPPORTING THE HOTTEST DAY THIS WEEK. EXPECT WIDESPREAD
90S THUR, WITH LOW 100S LIKELY ON PARTS OF THE PLAINS. GIVEN
LINGERING LL MOISTURE, EXPECT APPARENT T'S WILL BE CLOSE ENOUGH TO
WARRANT EXCESSIVE HEAT PRODUCTS, MAINLY ACROSS SCENTRAL SD. DRIER
WEATHER ALSO EXPECTED WED AND THUR AS THE STORM TRACK SHIFTS
NORTH. COLD FRONT MOVES THROUGH AT THE END OF THE WEEK, WITH A
GOOD CHANCE OF STORMS BY FRIDAY AND COOLER TEMPS FOR THE WEEKEND.
AVIATION
(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1019 PM MDT SUN AUG 3 2025
ONGOING ISOLATED STORM OVER NORTHEASTERN WY EXPECTED TO CONTINUE
TO MOVE EASTWARD AND IMPACT THE GCC TERMINAL WITHIN THE NEXT HOUR
OR SO. THIS STORM WILL DISSIPATE IN THE NEXT FEW HOURS AS IT
CONTINUES TO MOVE EAST. ISOLATED STORMS ARE POSSIBLE AGAIN ACROSS
NORTHEASTERN WY INTO WESTERN SD TOMORROW AFTERNOON. OTHERWISE,
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD.
UNR WATCHES/WARNINGS/ADVISORIES
SD...NONE.
WY...NONE.
DISCUSSION/KEY MESSAGES...JC
AVIATION...WONG
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