350
FXUS63 KUNR 122030
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
230 PM MDT SUN JUL 12 2026
KEY MESSAGES
- VERY HOT TEMPERATURES WILL CONTINUE THROUGH MUCH OF THIS WEEK,
WITH RECORD HIGH TEMPS POSSIBLE AND DANGEROUS HEAT.
- NEAR-CRITICAL TO CRITICAL FIRE WEATHER CONDITIONS WILL CONTINUE
THIS WEEK.
DISCUSSION
(THIS EVENING THROUGH SUNDAY)
ISSUED AT 228 PM MDT SUN JUL 12 2026
EXTREME UPPER RIDGE CONTINUES TO SIT ACROSS THE NORTHERN PLAINS
THROUGH THE CENTRAL ROCKIES. AT THE SURFACE...LOW PRESSURE ACROSS
WYOMING IS KEEPING WINDS AT 10KT OR LESS ACROSS MOST OF THE NE WY
PLAINS. AS EXPECTED, TEMPS ARE IN THE TRIPLE DIGITS. THE HOTTEST
TEMPS NEARBY ARE ACROSS FAR NORTHERN CAMPBELL COUNTY THROUGH
SOUTHEASTERN MT INTO BUTTE COUNTY, IN THE 105-110F RANGE.
UNOFFICIALLY, THE WARMEST TEMPERATURE IN THE CWA SO FAR IS 111F AT A
RAWS STATION IN NORTHERN CAMPBELL COUNTY. NOT MUCH CHANGE TO THE
PATTERN IS EXPECTED THROUGH THE NEXT SEVERAL DAYS, WITH HIGHS AT OR
ABOVE 100F ACROSS THE PLAINS EACH DAY THROUGH AT LEAST THURSDAY.
THEREFORE, HAVE EXTENDED THE HEAT ADVISORY THROUGH THEN.
CONTEMPLATED UPGRADING PART OF THE CWA TO A EXTREME HEAT WARNING
BASED ON LOCAL CRITERIA (100F+ APPARENT TEMP FOR FOUR DAYS OR
LONGER) BUT WILL KEEP IT SIMPLE W/ THE ADVISORY SINCE APPARENT TEMPS
BECOME MARGINAL PAST TUESDAY AS DRIER AIR MOVES IN FROM THE WEST,
DROPPING DEWPOINTS 10-15F. THIS WILL LOWER APPARENT TEMPS ACROSS THE
MAJORITY OF THE CWA TO NEAR OR BELOW WARNING THRESHOLDS. REGARDLESS,
IT'S SPLITTING HAIRS SINCE IT WILL STILL FEEL HOT. MEDIUM RANGE
MODELS SHOW SOME RELIEF COMING NEXT WEEKEND OR EARLY NEXT WEEK AS A
COLD FRONT FINALLY PUSHES THROUGH.
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 228 PM MDT SUN JUL 12 2026
STRONG HIGH PRESSURE OVER THE REGION FOR MUCH OF THE WEEK WILL
BRING VERY HOT TEMPERATURES, ALONG WITH DRY AIR AND BREEZY WINDS.
VERY LOW HUMIDITY AND BREEZY WINDS WILL CONTINUE THROUGH THIS
AFTERNOON AND EARLY EVENING, BRINGING CRITICAL FIRE WEATHER
CONDITIONS FROM THE NORTHEASTERN WYOMING TO THE FAR WESTERN SOUTH
DAKOTA PLAINS. ON MONDAY AND TUESDAY ACROSS MUCH OF THE WESTERN
SOUTH DAKOTA PLAINS, WINDS WILL AGAIN BECOME BREEZY WITH GUSTS UP
TO 35 MPH AND COMBINE WITH THE VERY LOW HUMIDITY OF 15% OR LESS TO
SUPPORT CRITICAL FIRE WEATHER CONDITIONS. IN ADDITION, POOR
HUMIDITY RECOVERIES ARE EXPECTED EACH NIGHT. A RED FLAG WARNING
HAS BEEN EXTENDED UNTIL TUESDAY EVENING. WILL CONTINUE TO MONITOR
THE POTENTIAL FOR CRITICAL FIRE WEATHER CONDITIONS FOR THE SECOND
HALF OF THE WEEK.
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 TUESDAY FOR SDZ322>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.
DISCUSSION...13
AVIATION...GS
FIRE WEATHER...13
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