083
FXUS63 KUNR 281827
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1227 PM MDT TUE JUL 28 2026
KEY MESSAGES
- ISOLATED STRONG THUNDERSTORMS THIS AFTERNOON/EVENING WITH
PRIMARY CONCERN GUSTY WINDS
- MARGINAL TO SLIGHT (1-2 OUT OF 5) RISK OF SEVERE THUNDERSTORMS LATE
WEDNESDAY AFTERNOON/EVENING WITH THE PRIMARY RISK OF DAMAGING
WINDS, BUT LARGE HAIL MAY ALSO OCCUR
- HOT WEATHER (SUNDAY LOOKS HOTTEST) WILL CONTINUE THROUGH THE
WEEKEND WITH DAILY CHANCES FOR ACTIVE THUNDERSTORMS AS RIDGE-
RIDERS ROTATE THROUGH THE NORTHERN PLAINS
DISCUSSION
(THIS EVENING THROUGH TUESDAY)
ISSUED AT 1224 PM MDT TUE JUL 28 2026
18Z SURFACE ANALYSIS HAD WEAK TROUGH FROM ND INTO CENTRAL WY.
WATER VAPOUR LOOP HAD UPPER RIDGE OVER CO/NM AND BUILDING HEIGHTS
OVER THE NORTHERN PLAINS - A DISTINCT WAVE HARD TO FIND. 0.5KM
VISIBLE SATELLITE LOOP HAD CU/TCU OVER CAMPBELL COUNTY, AND THEN
NEAR THE WESTERN FOOTHILLS OF THE BLACK HILLS PER DOWNSTREAM
CONVERGENCE GIVEN EAST/SOUTHEAST FLOW ON THE WESTERN SD PLAINS.
UPPER RIDGE CONTINUES TO DOMINATE THE WEATHER THIS WEEK.
THIS AFTERNOON/EVENING, 0.5-1KJ/KG MLCAPE WILL DEVELOP OVER
NORTHEASTERN WY/SOUTHWESTERN SD WITH 25-35KTS EFFECTIVE SHEAR AND
LIMITED MLCIN. ISOLATED/SCATTERED TSRA WILL DEVELOP WITH A FEW
STORMS CAPABLE OF GUSTY WINDS. CAMS NOT PARTICULARLY EXCITED ABOUT
ORGANIZED CONVECTIVE PROSPECT, PROBABLY OWING TO THE RISING MID-
LEVEL HEIGHTS. GUIDANCE TEMPERATURES LOOK FINE.
WEDNESDAY LOOKS A LITTLE MORE INTERESTING. DISTINCT SHORTWAVE
TROUGH WILL ROTATE AROUND RIDGE AND REACH EASTERN MT/WY DURING
PEAK INSOLATION, IMPINGING ON SURFACE TROUGH. 1-1.5KJ/KG MLCAPE
WILL HAVE 25-35KTS 0-6KM BULK SHEAR AVAILABLE. FORECAST SOUNDINGS
SUGGEST DAMAGING WIND WILL BE THE MAIN THREAT, ESPECIALLY OVER
NORTHWESTERN SD, BUT SOME LARGE HAIL NOT OUT OF THE QUESTION. NBM
POPS ROBUST, BUT SEEM WARRANTED GIVEN AVAILABLE SYNOPTIC SCALE
FORCING. TEMPERATURES WILL BE NEAR GUIDANCE.
THURSDAY THROUGH THE WEEKEND WILL BE VERY WARM/HOT. SUNDAY LOOKS
HOTTEST RIGHT NOW PER ROBUST THERMAL RIDGE AND PREPONDERANCE OF
ENSEMBLE GUIDANCE. PERHAPS SOME RECORD HIGHS IN JEOPARDY BY
SUNDAY. ANY DAY COULD FEATURE ACTIVE THUNDERSTORMS. THE "COOLDOWN"
FOR THE BEGINNING/MIDDLE OF NEXT WEEK STILL LOOKS LIKE IT IS
THERE, BUT THE SIGNAL KEEPS GETTING MUTED BY DIFFERING ENSEMBLE
SOLUTIONS. CONFIDENCE REMAINS LOW IN SUSTAINED HEAT RELIEF.
AVIATION
(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY)
ISSUED AT 1119 AM MDT TUE JUL 28 2026
OVERALL, VFR CONDITIONS ARE EXPECTED THROUGHOUT THE FORECAST
PERIOD. PREVIOUSLY MENTIONED TS IN THE NORTHEAST WY AND BLACK
HILLS AREAS ARE STILL POSSIBLE AFTER 19Z, HOWEVER CONFIDENCE IS
STILL LOW REGARDING IMPACTS TO KRAP AND KGCC, SO THEY REMAIN OUT
OF THE TAFS. SHOULD STORMS SURVIVE OFF THE BLACK HILLS, STRONGER
CELLS MAY PRODUCE BRIEF DROPS TO MVFR ALONG WITH GUSTY/ERRATIC
OUTFLOW WINDS. SMOKE ALSO REMAINS IN THE AREA WITH NO EXPECTED
VISIBILITY IMPACTS.
FIRE WEATHER
ISSUED AT 1224 PM MDT TUE JUL 28 2026
ELEVATED FIRE WEATHER CONDITIONS ARE EXPECTED MUCH OF THIS WEEK
DUE TO HOT TEMPERATURES AS WELL AS MINIMUM RELATIVE HUMIDITY IN
THE TEENS AND 20S. THE JOINT PROBABILITY OF MINRH <15% AND WINDS
>25MPH IS LOW AT THIS POINT THROUGH FRIDAY. HOWEVER, AN
INCREASING SIGNAL EXISTS FOR CRITICAL FIRE WEATHER CONDITIONS FOR
SATURDAY THROUGH MONDAY IF STRONGER WINDS ARE PRESENT. THE CORES
OF THUNDERSTORMS THAT OCCUR THIS WEEK SHOULD CONTAIN WETTING RAIN,
BUT LIGHTNING STRIKES OUTSIDE OF THE CORES AS WELL AS STRONG,
ERRATIC WINDS MAY CREATE OPPORTUNITIES FOR NEW FIRES.
UNR WATCHES/WARNINGS/ADVISORIES
SD...NONE.
WY...NONE.
DISCUSSION...HELGESON
AVIATION...SCHWEIGERT
FIRE WEATHER...HELGESON
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