782
FXUS63 KUNR 280447
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1047 PM MDT WED MAY 27 2026
KEY MESSAGES
- CONTINUED WARM, BREEZY, AND MOSTLY DRY THIS WEEK SUPPORTING
ELEVATED TO NEAR-CRITICAL FIRE WEATHER CONDITIONS AT TIMES.
- THUNDERSTORM POTENTIAL REMAINS LOW/ISOLATED THURSDAY, BEFORE
INCREASING FOR FRIDAY, SATURDAY, AND SUNDAY. PATTERN REMAINS
UNSETTLED INTO NEXT WEEK.
DISCUSSION
(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 126 PM MDT WED MAY 27 2026
THE SYNOPTIC PATTERN REMAINS UNCHANGED AS LONGWAVE RIDGING OVER THE
CENTRAL CONUS LARGELY CONTROLS OUR WEATHER WHILE LONGWAVE TROUGHING
WITH A NEARLY STATIONARY LARGE/SPRAWLING LOW PRESSURE SYSTEM SPINS
TO OUR WEST OVER CALIFORNIA AND NEVADA. THIS WILL SUPPORT CONTINUED
WARM TEMPERATURES AND DRY AND BREEZY CONDITIONS LEADING TO ELEVATED
TO NEAR-CRITICAL FIRE WEATHER CONCERNS EACH DAY. THE FORECAST
REMAINS DRY TODAY, BUT THE (ALBEIT STILL LOW) CHANCE OF A FEW
ISOLATED THUNDERSTORMS HAS PERHAPS INCREASED A TOUCH THURSDAY
AFTERNOON/EVENING AS A "TONGUE" OF SURFACE LOW PRESSURE TO OUR SOUTH
LIFTS NORTH ACROSS NEBRASKA AND EASTERN WYOMING...TRENDING A BIT
FURTHER NORTH COMPARED TO YESTERDAY'S MODEL RUNS, ACCOMPANIED BY A
SLIGHT UPTICK IN SIMULATED REFLECTIVITY IN THE 12Z HREF SUITE OF
CAMS. ANY ACTIVITY WILL DEVELOP IN AN ENVIRONMENT DEVOID OF SHEAR
WITH CAPE LESS THAN 1,000 J/KG, SUGGESTING ANY ISOLATED
THUNDERSTORMS SHOULDN'T BE PARTICULARLY STRONG AND WILL BE PULSE-
MODE. OUR POTENTIAL FOR DAILY SHOWERS AND THUNDERSTORMS STILL LOOKS
TO INCREASE QUITE A BIT FRIDAY, SATURDAY, AND SUNDAY AS THE WESTERN
LOW WEAKENS AND FINALLY EJECTS/LIFTS NORTHEAST ACROSS THE ROCKIES AS
MORE OF AN OPEN SHORTWAVE TROUGH, RESULTING IN HEIGHT FALLS AND
BETTER ASCENT. THIS FEATURE WILL BECOME NEGATIVELY-TILTED, PERHAPS
SUPPORTING SOME MORE ROBUST CONVECTION AS WELL AS WE GET INTO THAT
FRIDAY-SUNDAY TIMEFRAME...LONG-RANGE MODEL SOUNDINGS DO SUGGEST
INCREASING INSTABILITY/CAPE, AND POSSIBLY SOME INCREASE IN SHEAR
ESPECIALLY BY SATURDAY. PROGRESSION OF THE LOW WILL BE SLOW, AND
WILL CONTINUE TO SUPPORT UNSETTLED CONDITIONS/DAILY PRECIP CHANCES
INTO THE MIDDLE OF NEXT WEEK WITH TEMPERATURES ONLY SLIGHTLY COOLING
WITH TIME. 500MB HEIGHT ENSEMBLE CLUSTER ANALYSIS UNIVERSALLY
SUPPORTS CONTINUED PRESENCE OF SOME SORT OF LOW/TROUGH WITH IT'S
CENTER/AXIS STILL WEST/NORTHWEST OF OUR CWA THROUGH AT LEAST TUESDAY.
WITH THE ABOVE IN MIND, LARGELY HELD WITH NBM GUIDANCE THROUGHOUT
THE FORECAST, EXCEPT ADDED LOW 10-20% POPS AND INCREASED THUNDER
PROBS THURSDAY AFTERNOON AND EVENING ACROSS NORTHEAST WYOMING AND
GENERALLY ALONG AND SOUTH OF I-90 IN SOUTH DAKOTA TO INTRODUCE THAT
CHANCE OF ISOLATED THUNDERSTORMS. ALSO SLIGHTLY REDUCED WINDS/WIND
SPEEDS OVER THE NEXT 3 DAYS AS NBM GUIDANCE IS COMING IN A BIT
EXCITED, ESPECIALLY GIVEN S/SE FLOW WHICH DOESN'T USUALLY
"OVERPERFORM" FOR OUR AREA. STILL, BREEZY CONDITIONS ARE EXPECTED,
AND GUSTS OF 30-45 MPH WILL BE QUITE COMMON WITH A LOCALIZED GUST TO
50 MPH NOT OUT OF THE QUESTION DURING PEAK DIURNAL MIXING EACH
AFTERNOON.
AVIATION
(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1045 PM MDT WED MAY 27 2026
VFR CONDITIONS ARE EXPECTED THOUGH THE FORECAST PERIOD. WINDY
CONDITIONS ARE EXPECTED TO CONTINUE IN NORTHEASTERN WY THROUGH THE
NIGHT. WIDESPREAD GUSTY (>35KT) WINDS WILL REDEVELOP THURSDAY
AFTERNOON.
FIRE WEATHER
ISSUED AT 126 PM MDT WED MAY 27 2026
WARM, MOSTLY DRY, AND VERY BREEZY CONDITIONS ARE EXPECTED ACROSS
THE REGION THIS WEEK, RESULTING IN ELEVATED TO NEAR-CRITICAL FIRE
WEATHER CONDITIONS. RH VALUES WILL BE THE MAIN WEATHER-DRIVEN
LIMITING FACTOR PRECLUDING RED FLAG CONDITIONS, WITH MINIMUM
VALUES GENERALLY 16-25 PERCENT EACH AFTERNOON. IN ADDITION, WE'RE
IN THE MIDDLE OF GREEN-UP...SUCH AS IT IS THIS YEAR...WITH
VARYING FUEL CONDITIONS CURRENTLY ACROSS THE FORECAST AREA. A
COUPLE ISOLATED THUNDERSTORMS ARE POSSIBLE THURSDAY AFTERNOON AND
EVENING ACROSS NORTHEAST WYOMING AND GENERALLY ALONG/SOUTH OF I-90
IN SOUTH DAKOTA. SEVERE THUNDERSTORMS ARE GENERALLY NOT EXPECTED
OVER THE NEXT SEVERAL DAYS. OVERALL RH VALUES WILL MODERATE
(RISE) A BIT THIS WEEKEND AS A TROUGH OF LOW PRESSURE SUPPORTS
INCREASED CHANCES OF SHOWERS AND THUNDERSTORMS (STARTING FRIDAY),
WITH WETTING RAINS POSSIBLE FOR SOME AREAS.
UNR WATCHES/WARNINGS/ADVISORIES
SD...NONE.
WY...NONE.
DISCUSSION/KEY MESSAGES...KSMITH
AVIATION...SCHWEIGERT
FIRE WEATHER...KSMITH
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