277
FXUS63 KUNR 232020
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
220 PM MDT SAT AUG 23 2025
KEY MESSAGES
- MILD TEMPERATURES CONTINUE THROUGH EARLY NEXT WEEK (70S-80S).
- A FEW SHOWERS AND STORMS POSSIBLE ACROSS THE SOUTHERN HILLS AND
FAR SOUTHERN AREAS THROUGH WEDNESDAY (15-25%).
- MORE WIDESPREAD SHOWER AND THUNDERSTORM CHANCES (30-40%) ARRIVE
FOR THURSDAY AND FRIDAY.
DISCUSSION
(THIS EVENING THROUGH SATURDAY)
ISSUED AT 219 PM MDT SAT AUG 23 2025
VISIBLE SATELLITE IMAGERY SHOWS MOST OF THE MID CLOUD DECK BURNING
OFF ACROSS THE CWA THIS AFTERNOON, WHILE SURFACE OBSERVATIONS SHOW
LIGHT WINDS WITH TEMPERATURES RUNNING IN THE LOW TO MID 70S. WATER
VAPOR IMAGERY SHOWS SHORTWAVE ENERGY PUSHING SOUTHEASTWARD ACROSS
THE CANADIAN PRAIRIES TOWARD NORTHEASTERN NORTH DAKOTA AND NORTHERN
MINNESOTA.
UPPER RIDGING WILL REMAIN IN PLACE ACROSS MUCH OF THE WEST/SOUTHWEST
CONUS WITH DEEPER TROUGHING IN PLACE ACROSS THE ENTIRE EASTERN
CONUS. THAT PLACES WESTERN SOUTH DAKOTA AND NORTHEASTERN WYOMING ON
THE INFLECTION POINT BETWEEN THE TWO (NORTHWEST FLOW) THROUGH AT
LEAST TUESDAY MORNING BEFORE THE RIDGE BUILDS A BIT FARTHER EAST
TOWARD THE MIDDLE OF THE UPCOMING WEEK.
THE AFOREMENTIONED WAVE ACROSS THE CANADIAN PRARIES THIS AFTERNOON
WILL DRIFT ACROSS THE NORTHERN PLAINS TONIGHT. THE MAIN ENERGY FROM
THE WAVE IS EXPECTED TO REMAIN WELL NORTHEAST OF THE AREA (ACROSS
MN); THE COMBINATION OF WAA, INCREASING LLJ AND SOME SUBTLE
SHORTWAVE ENERGY MAY HELP TO TOUCH OFF A FEW SHOWERS AND STORMS
ACROSS SOUTHERN PORTIONS OF THE AREA TONIGHT. MOST OF THE AREA
SHOULD REMAIN DRY.
VERY SMALL CHANCES OF SHOWERS OR ISOLATED STORMS (15-25%) WILL
REMAIN IN THE FORECAST INTERMITTENTLY FOR FAR SOUTHERN SD THROUGH
TUESDAY WITH WEAK/SUBTLE SHORTWAVE ENERGY DRIFTING THROUGH THE
NORTHWEST FLOW. MUCH OF THE REST OF THE FORECAST AREA WILL REMAIN
DRY. HIGH TEMPERATURES ARE EXPECTED TO REMAIN BELOW AVERAGE THROUGH
TUESDAY. FOR COMPARISON, AVERAGE HIGHS FOR THIS TIME OF YEAR ARE
IN THE MID 80S FOR RAPID CITY, SD AND GILLETTE, WY.
THE RIDGE AXIS WILL SLIDE DIRECTLY OVERHEAD ON WEDNESDAY ALLOWING
TEMPERATURES TO WARM TO THE MID 80S (CLOSER TO OR MAYBE EVEN ABOVE
NORMAL) ACROSS MUCH OF THE AREA. THIS WILL BE SHORT-LIVED AS
GUIDANCE CONTINUES TO SHOW SHORTWAVE ENERGY DAMPENING THE RIDGE AXIS
FOR THURSDAY AND ESPECIALLY INTO FRIDAY. THAT ENERGY COUPLED WITH A
RETURN OF MONSOONAL MOISTURE WILL HELP TO FOCUS SCATTERED SHOWERS
AND STORMS ACROSS A GOOD PORTION OF THE AREA FOR BOTH DAYS AND MAYBE
EVEN LINGERING INTO NEXT SATURDAY.
AVIATION
(FOR THE 18Z TAFS THROUGH 18Z SUNDAY)
ISSUED AT 1141 AM MDT SAT AUG 23 2025
GOOD FLYING CONDITIONS EXPECTED WITH VFR CEILINGS AND
VISIBILITIES. CLOUD DECK AROUND 5KFT AT THE BEGINNING OF THE TAF
SITES WILL DISSIPATE OVER THE NEXT COUPLE HOUR. ADDITIONAL MID
CLOUD DEVELOPMENT MAY APPROACH THE TAF SITES OVERNIGHT, BUT KEPT
SCT COVERAGE WITH LOWER CONFIDENCE IN NORTHWARD EXTENT. WINDS ARE
EXPECTED TO REMAIN LIGHT.
UNR WATCHES/WARNINGS/ADVISORIES
SD...NONE.
WY...NONE.
DISCUSSION/KEY MESSAGES...COOLEY
AVIATION...COOLEY
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