931
FXUS63 KUNR 231732
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1132 AM MDT SAT MAY 23 2026
KEY MESSAGES
- ISOLATED SHOWERS/THUNDERSTORMS POSSIBLE LATER SAT AFTERNOON AND
EVENING NORTHEAST WY INTO SW SD
- INCREASING TEMPERATURES THROUGH MEMORIAL DAY
- CHANCES OF SHOWERS AND THUNDERSTORMS WILL RETURN TUESDAY NIGHT
AND CONTINUE THROUGH THE REST OF THE WEEK
UPDATE
ISSUED AT 925 PM MDT FRI MAY 22 2026
MINOR CHANGES TO THE PREVIOUS FORECAST. LIMITED POPS ISOLATED
MENTION SAT AFTERNOON AND EVENING AND EXPANDED THEM WEST INTO
NORTHEAST WY. STEEP LAPSE RATES COUPLED WITH A WEAK IMPULSE WILL
BE SUFFICIENT TO SUPPORT CONVECTION WITH GUSTY WINDS POSSIBLE WITH
ANY CELLS. WARMER WITH HIGHS IN THE 70S. OTHERWISE, MAINLY DRY
THROUGH TUES WITH WARMER TEMPS EACH DAY. STAUNCH SE FLOW EXPECTED
TUE, WHICH WILL BRING DEEPER MOISTURE BACK INTO THE FA ALONG WITH
LOW CHANCES FOR SHOWERS/STORMS.
DISCUSSION
(THIS EVENING THROUGH FRIDAY)
ISSUED AT 204 PM MDT FRI MAY 22 2026
RADAR/SATELLITE/SURFACE OBS SHOW THE STACKED LOW PRESSURE OVER
CENTRAL SD, CONTINUING TO MOVE NE. BEHIND THE LOW, MID-LEVEL CLOUDS
HAVE DEVELOPED WITHIN THE RESULTING COLD POOL. LIKEWISE, KUDX RADAR
SHOWS THE STRATIFORM RAIN THIS MORNING BECOMING MORE CONVECTIVE
SHOWERS ACROSS EASTERN MEADE/PENNINGTON, AND HAAKON COUNTIES. NW
WINDS OVER THE WESTERN SD PLAINS HAVE MOSTLY BEEN GUSTING UP TO 40-
45 MPH, BUT WE ARE STARTING TO SEE OCCASIONAL HIGHER GUSTS IN THE
SHOWERS...EVEN OUTSIDE OF THE WIND ADVISORY AREA. KNOWING THESE
GUSTS WILL BE ISOLATED AND ONLY THROUGH THE AFTERNOON...AND SINCE
GUSTS ARE NOT OTHERWISE REACHING ADVISORY CRITERIA, WILL CANCEL THE
ADVISORY EARLY. WINDS WILL WEAKEN THIS EVENING AND SKIES WILL CLEAR
OVERNIGHT. THERE WAS SOME CONCERN ABOUT FROST DEVELOPING ACROSS THE
NE WY PLAINS IN THE EARLY SATURDAY MORNING HOURS. HOWEVER, WITH WARM
AIR ADVECTION MOVING IN AND VARIABLE WINDS BECOMING SOUTHWESTERLY AT
5-10MPH, THINK THE ONLY PLACES THAT MAY SEE FROST DEVELOP WILL BE
WIND SHELTERED AREAS/RIVER VALLEYS. AND IT LOOKS LIKE TEMPS MAY
REACH THE LOWER TO MID 30S ONLY FOR AN HOUR OR TWO BEFORE SUNRISE,
SO WILL NOT ISSUE ANY HEADLINES. THE EVENING SHIFT CAN TAKE A SECOND
LOOK, BUT AS OF NOW, IT LOOKS TOO MARGINAL. DRIER WEATHER IS
EXPECTED OVER THE HOLIDAY WEEKEND INTO THE FIRST PART OF NEXT WEEK.
THE EXCEPTION IS ISOLATED THUNDERSTORMS ACROSS PORTIONS OF THE BLACK
HILLS WHERE THERE COULD BE ENOUGH INSTABILITY TO GET A FEW STORMS TO
DEVELOP. SEVERE WEATHER IS NOT EXPECTED. WARM AIR ADVECTION THROUGH
THE WEEKEND WILL BRING WARMER TEMPERATURES EACH DAY. THE WARMEST DAY
WILL BE ON MEMORIAL DAY, WITH HIGHS IN THE MID 80S TO LOWER 90S
ACROSS MOST LOCATIONS. THE SECOND HALF OF NEXT WEEK LOOKS
INTERESTING. GFS/ECMWF ARE SHOWING A REX BLOCK SETTING UP OVER THE
CENTRAL CONUS. THIS COULD BRING ACTIVE SOUTHERLY FLOW WITH DECENT
MOISTURE TO THE AREA...WHICH WOULD SUPPORT SHOWERS AND THUNDERSTORMS.
AVIATION
(FOR THE 18Z TAFS THROUGH 18Z SUNDAY)
ISSUED AT 1130 AM MDT SAT MAY 23 2026
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD. WEAK
UPPER FORCING OVER MARGINAL INSTABILITY MAY SUPPORT LIGHT SHOWERS
AND SCATTERED THUNDERSTORMS LATER SATURDAY AFTERNOON ACROSS
NORTHEAST WY AND SOUTHWEST SD.
UNR WATCHES/WARNINGS/ADVISORIES
SD...NONE.
WY...NONE.
UPDATE...JC
DISCUSSION/KEY MESSAGES...13
AVIATION...SCHWEIGERT
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