566
FXUS63 KUNR 121739
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1139 AM MDT MON OCT 12 2026
KEY MESSAGES
- COOLER THIS WEEK WITH PRECIPITATION CHANCES THROUGH MID-WEEK.
- NEAR-FREEZING TO FREEZING OVERNIGHT TEMPERATURES POSSIBLE
BEGINNING MONDAY NIGHT.
- BREEZY TONIGHT INTO MONDAY; WATCHING HIGH WIND POTENTIAL FOR
THURSDAY/FRIDAY.
UPDATE
ISSUED AT 950 PM MDT SUN OCT 11 2026
NO MAJOR CHANGES TO THE FORECAST THIS EVENING. RAIN SHOWERS AND
PATCHY FOG WILL CONTINUE TO MOVE ACROSS THE AREA THROUGH THE
OVERNIGHT HOURS WITH TEMPERATURES DROPPING INTO THE UPPER 30S TO LOW
40S ACROSS MUCH OF THE AREA. ANOTHER COOL DAY TOMORROW WITH HIGHS
RANGING FROM THE 50S ACROSS NORTHWESTERN SD TO THE UPPER 60S TO LOW
70S ACROSS SOUTHERN SD. NORTHWESTERLY WINDS WILL PICK UP THROUGH
TOMORROW AFTERNOON, ESPECIALLY ACROSS OUR USUALLY BREEZY AREAS FROM
STURGIS INTO THE PLAINS EAST OF RAPID CITY WHERE GUSTS OF UP TO 40
MPH ARE POSSIBLE. ANOTHER ROUND OF PRECIP EXPECTED MONDAY NIGHT INTO
EARLY TUESDAY. WHILE TEMPS MONDAY NIGHT WILL DROP INTO THE 30S,
PRECIP WILL FALL AS RAIN FOR THE MOST PART THOUGH CAN'T RULE OUT
A FEW FLAKES OF SNOW MIXING IN AT THE HIGHER ELEVATIONS.
DISCUSSION
(THIS EVENING THROUGH SUNDAY)
ISSUED AT 1249 PM MDT SUN OCT 11 2026
UPPER LEVEL ANALYSIS AND WATER VAPOR IMAGERY SHOW CLOSED UPPER
LOW OVER NORTHEASTERN OR/SOUTHEASTERN WA WITH TROUGH AXIS
EXTENDING SOUTHWARD. BROAD UPPER LEVEL ASCENT CONTINUES TO
OVERSPREAD THE NORTHERN PLAINS AS MOISTURE STREAMS INTO THE
REGION. THE SURFACE COLD FRONT SETTLED SOUTH OF THE FORECAST AREA
AND STRETCHES FROM UPPER MN THROUGH SOUTHEASTERN SD INTO NE.
CONSIDERABLE CLOUD COVER PERSISTS OVER THE FORECAST AREA; HAVE
DROPPED HIGH TEMPERATURES TO ACCOUNT WITH MOST AREAS (ESPECIALLY
ALONG AND NORTH OF I90) STRUGGLING TO PUSH OUT OF THE 50S TODAY.
INCREASING CHANCES OF RAIN LATER THIS AFTERNOON THROUGH THE
OVERNIGHT HOURS AS BETTER UPPER LEVEL ASCENT OVERSPREADS THE AREA,
ALTHOUGH HEAVIEST PRECIPITATION AMOUNTS WILL REMAIN NORTH OF THE
FORECAST AREA.
WINDS WILL TURN NORTHWESTERLY MONDAY WITH GUSTS AROUND 40 MPH ACROSS
THE WESTERN SD PLAINS AS SECONDARY FRONT PUSHES SOUTH OF THE AREA.
UPPER LEVEL LOW WILL SLOWLY EJECT FROM THE FOUR CORNERS REGION LATE
TUESDAY INTO WEDNESDAY WITH ADDITIONAL PRECIPITATION CHANCES,
ALTHOUGH BETTER CHANCES OF APPRECIABLE PRECIPITATION AMOUNTS WILL
REMAIN SOUTH OF THE CWA. COOLER AIR WILL LINGER THROUGH THE WEEK
WITH A THREAT OF NEAR-FREEZING TO FREEZING TEMPERATURES POSSIBLE
EACH NIGHT MONDAY NIGHT THROUGH THE WEEK.
THE NBM CONTINUES TO SHOW WIND GUSTS EXCEEDING 60 MPH ACROSS
NORTHWESTERN SD AND PORTIONS OF THE WESTERN SD PLAINS THURSDAY
AFTERNOON AND EVENING. HOWEVER, ENSEMBLE GUIDANCE IS NOT SUPPORTIVE,
WITH LOW PROBABILITIES OF HIGH WINDS (EPS GENERALLY ~40-50%
PROBABILITY OF EXCEEDING 40 MPH) AND MANY MEMBERS (EPS/GEFS) PEAKING
WELL BELOW 45 MPH. CURRENT THINKING IS THAT THE MOST FAVORABLE
INGREDIENTS AND STRONGEST WINDS WILL REMAIN DISPLACED TO OUR EAST,
ALTHOUGH CONFIDENCE IS LOW GIVEN THE LARGE ENSEMBLE SPREADS.
UPPER RIDGE IS FORECAST TO BUILD OVER THE WESTERN US BY THE END OF
THE WEEK INTO NEXT WEEKEND WITH TEMPERATURES TRENDING ABOVE AVERAGE
AVIATION
(FOR THE 18Z TAFS THROUGH 18Z TUESDAY)
ISSUED AT 1128 AM MDT MON OCT 12 2026
THE WIDESPREAD IFR TO LIFR CONDITIONS HAVE BEEN TRENDING UPWARD
OVER THE LAST FEW HOURS.
LOOKING AHEAD TO THE REST OF TODAY, MVFR TO LOW-END VFR
CONDITIONS ARE EXPECTED FOR NW SD INTO NE WY THROUGH THE DAY,
HIGHER CONDITIONS LIKELY FOR SW SD INTO CENTRAL SD.
WIDESPREAD MVFR TO LOCALIZED IFR CONDITIONS EXPECTED TONIGHT DUE
TO LOW CLOUDS BUT CAN'T RULE OUT LOW VISIBILITY ISSUES IN PARTS OF
NE WY AND AROUND THE BLACK HILLS.
FOR THE WINDS, EXPECT BREEZY NW WINDS THROUGH THE AFTERNOON
BEHIND THE PASSING FRONT, MAINLY ACROSS NORTHEAST WY AND SW SD.
WINDS WILL DIMINISH THIS EVENING WITH LIGHTER WINDS OVERNIGHT.
UNR WATCHES/WARNINGS/ADVISORIES
SD...NONE.
WY...NONE.
UPDATE...WONG
DISCUSSION...SE
AVIATION...GS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page