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FXUS63 KUNR 251817
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1217 PM MDT MON MAY 25 2026
KEY MESSAGES
- WARMER TEMPERATURES CONTINUE THIS WEEK, WITH HIGHS MAINLY IN THE
80S
- CHANCES OF SHOWERS AND THUNDERSTORMS WILL INCREASE TUESDAY NIGHT
AND CONTINUE THROUGH THE REST OF THE WEEK
DISCUSSION
(THIS EVENING THROUGH MONDAY)
ISSUED AT 1203 PM MDT MON MAY 25 2026
CURRENT UPPER-AIR ANALYSIS AND WATER VAPOR IMAGERY DEPICT LARGE-
SCALE RIDGING OVER THE ROCKIES AND TROUGHING ALONG THE PAC NW COAST.
A SURFACE LOW REMAINS POSITIONED JUST OFF THE COAST. WV IMAGERY
INDICATES INCREASED MOISTURE OVER SOUTH-CENTRAL SD, WHERE ISOLATED
THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EVENING, THOUGH
CONDITIONS ARE MORE FAVORABLE FARTHER EAST. RADAR CURRENTLY SHOWS A
FEW WEAK RETURNS ASSOCIATED WITH POSSIBLE DEVELOPING CONVECTION OVER
THE NORTHERN BLACK HILLS. SURFACE OBSERVATIONS SHOW TEMPERATURES
MAINLY IN THE 80S WITH LIGHT AND VARIABLE WINDS ACROSS THE REGION.
AS THE TROUGH PROPAGATES EASTWARD, INCREASED SOUTHERLY/SOUTHEASTERLY
LOW-LEVEL FLOW WILL BRING HIGHER DEWPOINTS INTO THE AREA THIS
AFTERNOON AND EVENING, ESPECIALLY ACROSS SOUTH-CENTRAL SD. HREF
GUIDANCE SHOWS DEWPOINTS RISING INTO THE 50S AND LOWER 60S ALONG
WITH 0-6KM BULK WIND SHEAR VALUES OF 25-35KTS. CURRENT CAM GUIDANCE
CONTINUES TO FAVOR CONVECTIVE INITIATION OVER NORTH-CENTRAL NE
BEFORE STORMS MOVE INTO SOUTHEASTERN SD. HOWEVER, AN ISOLATED
THUNDERSTORM OR TWO CAN'T BE RULED OUT FOR SOUTH-CENTRAL SD. SIMILAR
TO THE LAST COUPLE OF DAYS, POP-UP SHOWERS AND AN ISOLATED
THUNDERSTORM OR TWO MAY DEVELOP OVER AND AROUND THE BLACK HILLS
THROUGH THE AFTERNOON AND INTO THE EVENING HOURS. HIGH TEMPERATURES
WILL RANGE FROM THE 80S TO LOWER 90S TODAY AND PERSIST THROUGH THE
WEEK UNDER CONTINUED RIDGING ACROSS THE REGION.
BY TUESDAY AFTERNOON, ENSEMBLE GUIDANCE SHOWS THE TROUGH EVOLVING
INTO A CUT-OFF LOW OVER OR/NORTHERN CA. THIS PATTERN WILL SUPPORT A
MORE ACTIVE AND UNSETTLED WEATHER REGIME ACROSS THE REGION WITH NEAR-
DAILY THUNDERSTORM CHANCES THROUGH MUCH OF THE WEEK. CURRENT SPC
OUTLOOKS MAINTAIN GENERAL THUNDERSTORMS THROUGH WEDNESDAY WITH NO
ORGANIZED SEVERE WEATHER EXPECTED. THIS MORE ACTIVE PATTERN IS
EXPECTED TO CONTINUE THROUGH THE WEEKEND AND INTO NEXT WEEK.
AVIATION
(FOR THE 18Z TAFS THROUGH 18Z TUESDAY)
ISSUED AT 1109 AM MDT MON MAY 25 2026
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD. ISOLATED
SHOWERS OR THUNDERSTORMS MAY DEVELOP IN/NEAR BLACK HILLS, BUT
CONFIDENCE IN THE STORMS REACHING KRAP IS VERY LOW. INCREASING
SOUTHERLY WINDS EXPECTED NEAR THE END OF THE FORECAST PERIOD
(AFTER 26/12-14Z).
FIRE WEATHER
ISSUED AT 1203 PM MDT MON MAY 25 2026
EVEN WITHGREEN-UP OCCURRING ACROSS THE REGION, RELATIVE HUMIDITY
VALUES OVER THE NEXT COUPLE OF DAYS WILL FALL INTO THE MID-TEENS
TO LOW-20S ACROSS MUCH OF THE AREA SOUTH OF I-90. IN ADDITION TO
LOW RH VALUES, GUSTY SOUTHERLY/SOUTHEASTERLY WINDS ARE EXPECTED TO DEVELOP
TUESDAY MORNING, LEADING TO ELEVATED FIRE WEATHER CONDITIONS
SOUTH OF I-90.
UNR WATCHES/WARNINGS/ADVISORIES
SD...NONE.
WY...NONE.
DISCUSSION/KEY MESSAGES...SCHULTZ
AVIATION...SE
FIRE WEATHER...SCHULTZ
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