060
FXUS63 KUNR 081108
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
508 AM MDT WED JUL 8 2026
KEY MESSAGES
- ACTIVE THROUGH THURSDAY AS A SERIES OF DISTURBANCES MOVE
THROUGH THE REGION.
- A FEW SEVERE THUNDERSTORMS AGAIN POSSIBLE THIS AFTERNOON AND
EVENING, ESPECIALLY OVER NORTHEAST WYOMING, THE BLACK HILLS, AND
SOUTHWEST SOUTH DAKOTA.
- VERY HOT THIS WEEKEND INTO EARLY NEXT WEEK WITH RECORD HIGH
TEMPERATURES POSSIBLE AND DANGEROUS HEAT.
UPDATE
ISSUED AT 1052 PM MDT TUE JUL 7 2026
MASSAGED POPS AND QPF THIS EVENING THROUGH THE OVERNIGHT AND
WEDNESDAY TO BETTER MATCH RADAR TRENDS AND THE NEW 00Z SUITE OF
CAMS. ONGOING SHOWERS AND THUNDERSTORMS SHOULD WEAKEN A BIT
OVERNIGHT AND TREND EAST, ENDING/EXITING THE REGION BY SUNRISE. A
BREAK FOLLOWS BEFORE OUR NEXT ROUND OF CONVECTION DEVELOPS AROUND
1-2PM WEDNESDAY AFTERNOON ACROSS NORTHEAST WYOMING, THE BLACK
HILLS, AND SOUTHWEST SOUTH DAKOTA. WHILE A COUPLE STORMS MAY
SPILL JUST EAST OF THESE AREAS, THIS REGION SHOULD SEE MOST OF
THE ACTIVITY AND THE BEST CHANCE FOR A FEW STRONG TO SEVERE
STORMS. SPC MAINTAINS A MARGINAL RISK (LEVEL 1 OF 5) OF SEVERE
THUNDERSTORMS IN THIS CORRIDOR. SHEAR AROUND 35KTS AND DECENT
INSTABILITY SHOULD SUPPORT PULSING SINGLE CELLS AND TRANSIENT
SUPERCELL STRUCTURES WITH LIGHTNING, WIND GUSTS OF 50 TO 65 MPH,
AND DIME TO GOLF BALL SIZE HAIL. STORMS MAY TEND TO CLUSTER A BIT
IN THE EVENING, AND LARGELY END BY 11 PM. SIGNIFICANT HEAT ALONG
WITH POSSIBLE CRITICAL FIRE WEATHER CONDITIONS STILL EXPECTED TO
START SATURDAY AND CONTINUE INTO EARLY NEXT WEEK.
DISCUSSION
(THIS AFTERNOON THROUGH MONDAY)
ISSUED AT 1025 AM MDT TUE JUL 7 2026
IMPULSE FILLED WESTERLY FLOW WILL BE IN PLACE OVER THE REGION
THROUGH THURSDAY AS A FRONTAL BOUNDARY REMAINS IN PLACE. NEAR
DAILY CHANCES FOR THUNDERSTORMS CAN BE EXPECTED WITH SEVERE STORMS
POSSIBLE AT TIMES, BEST CHANCES TODAY. SFC FRONT STALLED ACROSS
THE FA TODAY. THE FRONT HAS SETTLED FURTHER SOUTH THAT PREVIOUS
MODEL RUNS INDICATED YESTERDAY, WITH A SOUTHWARD SHIFT OF THE BEST
SEVERE POTENTIAL. MODERATELY STRONG IMPULSE WILL KICK OUT OF
WY/MT IN THE THE AFTERNOON AND EVENING AND WILL DRIVE CI THERE.
STORMS MAY ALSO FIRE ALONG THE PINE RIDGE AND INVOF OF THE FRONT
IF CAPPING CAN BE OVERCOME. ANOTHER LOCATION FOR CI WILL BE
NORTHERN BH IF THE INHIBITION IS ALSO OVERCOME. GIVEN PROGGED ML
CAPE OF 1-2.5 KJ/KG, DEEP BULK LAYER SHEAR OF 35 TO 45 KNOTS
(HIGHEST NORTH OF THE SFC FRONT), EXPECT SUPERCELLS TO BE POSSIBLE
WITH STRONG ROTATING UPDRAFTS, CAPABLE OF PRODUCING LARGE HAIL
AND DAMAGING WINDS. BEST CHANCES FOR ROTATING STORMS WILL BE ALONG
AND NORTH OF THE SFC FRONT. STILL A VERY SMALL WINDOW FOR
TORNADOES WITH ANY STORMS NEAR THE SFC FRONT, WHICH WILL START
SHIFTING SW INTO SW SD THIS AFTERNOON. STORMS WILL CARRY ACROSS
THE REGION THROUGH THE EVENING AND OVERNIGHT, POSSIBLY LINGERING
INTO THE MORNING WED AS ELEVATED ACTIVITY. MORE STORMS ARE
POSSIBLE WED AND THUR AS SUFFICIENT LL MOISTURE WILL BE IN PLACE
WITH WEAK STABILITY AND ADDITIONAL IMPULSES. THE BEST CHANCES FOR
STORMS WILL BE ACROSS THE WESTERN THIRD WED WITH CHANCES EXPANDING
TO THE ENTIRE FA THUR. UPPER RIDGE BUILDS INTO THE REGION THIS
WEEKEND, WITH DRY AND HOT CONDS EXPECTED. IMPRESSIVE TEMPS OF 35
TO ALMOST 40C AT H85 WITH CLOSE TO 6000 H5 HEIGHTS OVER WY, WILL
OFFER RECORD TO NEAR RECORD HIGHS WELL INTO THE 100S WITH 110 TO
115 POSSIBLE ON PORTIONS OF THE PLAINS, ESP SUNDAY AND MONDAY.
RIDGE BEGINS TO BREAKS DOWN ACROSS THE NORTHERN PLAINS THE MIDDLE
OF NEXT WEEK, WITH STORM CHANCES RETURNING AS THE ACTIVE NORTHERN
PERIPHERY OF THE RIDGE SETTLES SOUTH.
AVIATION
(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 508 AM MDT WED JUL 8 2026
LOW CIGS (IFR) ARE CURRENTLY BEING OBSERVED OVER SOME OF OUR SOUTH
DAKOTA PLAINS, LURKING JUST TO THE EAST OF KRAP. CONFIDENCE ON
THIS DECK CREEPING INTO THE TERMINAL IS LOW...PERHAPS 40 PERCENT
FOR/60 PERCENT AGAINST. HAVE ADDED SCT012 TO THE 12Z TAF AND WILL
MONITOR SATELLITE AND OBSERVATIONAL TRENDS FOR ANY NEEDED
AMENDMENTS. MOST GUIDANCE SUPPORTS THESE LOW CLOUDS THROUGH
15-16Z/9-10AM OVER THE PLAINS BEFORE THEY RAPIDLY BURN OFF WITH
DIURNAL HEATING. THEN, ATTENTION TURNS TO OUR NEXT PERIOD OF
THUNDERSTORM POTENTIAL, GENERALLY 19-05Z/1PM TO 11PM ACROSS THE
REGION TODAY. ONLY MINOR TWEAKS MADE TO ONGOING PROB30S FOR KGCC
AND KRAP BASED ON THE LATEST CAMS. FREQUENT LIGHTNING AND
GUSTY/ERRATIC WINDS CAN BE EXPECTED WITH ANY STRONGER CONVECTIVE
CORES, ALONG WITH TRANSIENT MVFR/IFR CONDITIONS. VFR CONDITIONS
ARE EXPECTED TONIGHT INTO THURSDAY MORNING AS SKIES PARTIALLY
CLEAR AND PRECIP CONCERNS END. A GLANCE AT RH/DEW POINT GUIDANCE
SUGGESTS THE POTENTIAL FOR FOG OR LOW STRATUS IS PERHAPS A BIT
LESS COMPARED TO THIS MORNING, BUT WE'LL CONTINUE TO EVALUATE AS
THAT PERIOD DRAWS CLOSER IN THE FORECAST.
UNR WATCHES/WARNINGS/ADVISORIES
SD...NONE.
WY...NONE.
UPDATE...KSMITH
DISCUSSION...JC
AVIATION...KSMITH
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