751
FXUS63 KUNR 121743
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1143 AM MDT SUN JUL 12 2026
KEY MESSAGES
- VERY HOT TEMPERATURES WILL CONTINUE THROUGH MUCH OF NEXT WEEK,
WITH RECORD HIGH TEMPS POSSIBLE AND DANGEROUS HEAT.
- NEAR-CRITICAL TO CRITICAL FIRE WEATHER CONDITIONS WILL CONTINUE
INTO NEXT WEEK.
UPDATE
ISSUED AT 931 PM MDT SAT JUL 11 2026
03Z SURFACE ANALYSIS HAD LEE TROUGH FROM CENTRAL MT INTO WESTERN
CO AND HIGH OVER THE GREAT LAKES. MODEST PRESSURE GRADIENT
INBETWEEN WITH SOUTHERLY FLOW OVER THE CWA. WATER VAPOUR LOOP HAD
ROBUST UPPER RIDGE OVER WY/UT/CO. 00Z KUNR SOUNDING TELLS THE
STORY - HOT DOME IN PLACE OVER THE CWA.
LATEST GUIDANCE SHOWS LITTLE RELIEF IN SIGHT THROUGH MOST OF NEXT
WEEK. ROBUST UPPER/THERMAL RIDGE MOVES LITTLE OVER THE NORTHERN
PLAINS BRINGING DANGEROUS HEAT AND VERY DRY AIR PER DEEP BOUNDARY
LAYER MIXING. BREEZY SPOTS LIKELY SUNDAY GIVEN SURFACE PRESSURE
GRADIENT/MIXING, BUT UNCERTAINTY INCREASES MONDAY AS LEE TROUGH
SHIFTS EAST WHICH MAY TAMP DOWN GUSTS IN THE WEST. THUS, CURRENT
RED FLAG WARNING LOOKS GOOD FOR SUNDAY. AS FAR AS HEAT HEADLINES,
HEAT ADVISORY PAINTS DANGER WELL WITH PEAK APPARENT TEMPERATURES
NEAR 105F. HOWEVER, WE MAY APPROACH THE 4-DAY MARK FOR EXTREME
HEATING WARNING CRITERIA (MAX APPARENT TEMPS 100F+) BY WEDNESDAY
GIVEN LATEST ENSEMBLE GUIDANCE TRENDS, SO WE'LL KEEP AN EYE ON
THAT. SOME FOLKS MIGHT SEE ACTUAL TEMPERATURES OF AT LEAST 100F
THROUGH NEXT FRIDAY.
DISCUSSION
(THIS EVENING THROUGH SATURDAY)
ISSUED AT 233 PM MDT SAT JUL 11 2026
VERY STRONG RIDGING IS BUILDING INTO THE GREAT BASIN AND NORTHERN
PLAINS TODAY...AND WILL CONTINUE TO STRENGTHEN OVER THE REGION ON
SUNDAY THROUGH THE FIRST HALF OF NEXT WEEK. RIGHT NOW...SURFACE OBS
SHOW TEMPS IN THE UPPER 90S TO LOWER 100S ACROSS MOST LOCATIONS.
ACROSS THE BLACK HILLS...TEMPS ARE IN THE UPPER 80S TO MID 90S. KUNR
HAS REACHED 101F IN THE LAST 30 MINUTES, WHICH SETS A NEW DAILY
RECORD HIGH. SATELLITE AND KUDX RADAR SHOW ISOLATED CONVECTION
DEVELOPING ACROSS THE NORTHERN BLACK HILLS. NO LIGHTNING STRIKES
HAVE SEEN, BUT COULD SEE A FEW STRIKES BEFORE PRECIP DISSIPATES LATE
THIS AFTERNOON. IT DOES APPEAR THIS PRECIP IS REACHING THE GROUND,
WHICH IS HELPFUL CONSIDERING THE DRY LIGHTNING CONCERN. S/SW FLOW
WILL CONTINUE TO BRING VERY HOT TEMPERATURES TO THE AREA OVER THE
NEXT SEVERAL DAYS. DAILY H70 TEMPS OF 15-20C WILL BRING TEMPS WELL
ABOVE 100F THROUGH TUESDAY...AND NOW WEDNESDAY AND POSSIBLY
THURSDAY, AS MODELS ARE INCREASING TEMPS FOR THE SECOND HALF OF THE
WEEK. FUTURE SHIFTS WILL NEED TO CONSIDER EXTENDING HEAT-RELATED
HEADLINES. NO PRECIP IS EXPECTED UNTIL AT LEAST THURSDAY.
AVIATION
(FOR THE 18Z TAFS THROUGH 18Z MONDAY)
ISSUED AT 1140 AM MDT SUN JUL 12 2026
EXPECT VFR CONDITIONS THROUGH THE FORECAST PERIOD.
GUSTY SOUTH/SOUTHEAST WINDS WILL DEVELOP AGAIN THIS AFTERNOON,
STRENGTHENING TONIGHT OVER NORTHEAST WYOMING DUE TO A TIGHTENING
SURFACE GRADIENT.
FIRE WEATHER
ISSUED AT 233 PM MDT SAT JUL 11 2026
STRONG HIGH PRESSURE OVER THE REGION FOR THE NEXT SEVERAL DAYS
WILL BRING VERY HOT TEMPERATURES TO NORTHEASTERN WYOMING AND
WESTERN SOUTH DAKOTA, ALONG WITH DRY AIR AND BREEZY WINDS. ON
SUNDAY, WINDS WILL GUST UP TO 35 MPH, WHICH COMBINED WITH THE VERY
LOW HUMIDITY OF 15% OR LESS, WILL RESULT IN CRITICAL FIRE WEATHER
CONDITIONS ACROSS THE NORTHEASTERN WYOMING AND FAR WESTERN SOUTH
DAKOTA PLAINS. A RED FLAG WARNING HAS BEEN ISSUED FOR SUNDAY. WILL
CONTINUE TO MONITOR THE POTENTIAL FOR CRITICAL FIRE WEATHER
CONDITIONS NEXT WEEK, WHICH MAY REQUIRE EXTENDING THE RED FLAG
WARNING ADDITIONAL DAYS.
UNR WATCHES/WARNINGS/ADVISORIES
SD...HEAT ADVISORY UNTIL 9 PM MDT /10 PM CDT/ THURSDAY FOR SDZ001-002-
012>014-025>027-030>032-041>044-046-047-049-072>078.
RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR SDZ322>327-329-
332.
WY...HEAT ADVISORY UNTIL 9 PM MDT THURSDAY FOR WYZ054>056-058>060.
RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR WYZ314>317.
UPDATE...HELGESON
DISCUSSION...13
AVIATION...GS
FIRE WEATHER...13
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