907
FXUS63 KFSD 270134
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
834 PM CDT MON OCT 26 2026
KEY MESSAGES
- RAIN AND DRIZZLE CONTINUE THROUGH THE EVENING, SLOWLY
TAPERING OFF FROM SOUTHWEST TO NORTHEAST OVERNIGHT.
- LOW (20-30%) CHANCES FOR PATCHY FOG INTO TUESDAY MORNING. VISIBILITY
MAY BRIEFLY DECREASE TO 2 MILES OR LESS, WITH CONDITIONS
IMPROVING BY MID MORNING.
- AN ACTIVE PATTERN LEADS TO ADDITIONAL RAIN CHANCES ON WEDNESDAY
AND OVER THE WEEKEND. MONITOR YOUR LOCAL FORECAST IF YOU HAVE
ANY OUTDOOR PLANS.
- NEAR TO ABOVE NORMAL TEMPERATURES RETURN FROM WEDNESDAY ONWARD
WITH HIGHS IN THE 60S TO LOWER 70S.
UPDATE
ISSUED AT 832 PM CDT MON OCT 26 2026
NO SIGNIFICANT CHANGES TO THE FORECAST THIS EVENING. RAIN AND PATCHY
DRIZZLE CONTINUE TO LIFT NORTH ACROSS THE AREA, WITH CLEARING FROM
SOUTHWEST TO NORTHEAST EXPECTED OVERNIGHT AS LOW PRESSURE LIFTS
NORTH. ALTHOUGH TEMPERATURES ARE ON THE COOLER SIDE (UPPER 30S TO
UPPER 40S), WE'RE WARM ENOUGH TO STAY ALL RAIN HERE - UNLIKE
LOCATIONS ACROSS WESTERN SD THAT HAVE SEEN SNOW TODAY.
GUIDANCE STILL SHOWS THE POTENTIAL FOR SOME FOG, MAINLY IN THE
VALLEYS NEAR AND WEST OF THE JAMES RIVER, AND ACROSS THE HIGHER
ELEVATIONS OF THE BUFFALO RIDGE THANKS TO HOW LOW THE CLOUD BASES
ARE. DRIZZLE MAY ALSO BE MORE PREVALENT THAN FOG, AS SOUNDINGS SHOW
A LOW BUT RELATIVELY DEEP SATURATED LAYER. REGARDLESS, IMPACT WILL
BE THE SAME WITH REDUCED VISIBILITY, AS OR BELOW TWO MILES AT TIMES
IF FOG/DRIZZLE DEVELOPS.
DREARY CONDITIONS CONTINUE INTO TUESDAY, EVEN AFTER THE RAIN COMES
TO AN END. STILL LOOKING AT A COOLER DAY AS STRATUS LINGERS INTO THE
AFTERNOON, DESPITE INCREASING SOUTHERLY WINDS AND SOUTHWESTERLY FLOW
ALOFT LATER IN THE DAY. HIGHS TUESDAY IN THE 50S TO MID 60S WITH
WIND GUSTS WEST OF THE JAMES AROUND 25 MPH.
DISCUSSION
ISSUED AT 306 PM CDT MON OCT 26 2026
LIGHT, PERIODIC RAIN SHOWERS WILL CONTINUE THROUGH THE REMAINDER OF
THIS AFTERNOON AND INTO THE OVERNIGHT, GRADUALLY DISSIPATING
FROM SOUTHWEST TO NORTHEAST. A PERIOD OF LIGHT DRIZZLE IS
POSSIBLE AS MOISTURE WRAPS AROUND THE LOW IN THE EARLY MORNING
HOURS OF TUESDAY. THERE IS POTENTIAL FOR FOG TO DEVELOP
OVERNIGHT ALONG RIVER VALLEYS AND LOW AREAS. THERE IS
APPROXIMATELY A 20-30% PROBABILITY THAT VISIBILITY MAY BRIEFLY
FALL TO 2 MILES OR LESS. ALL SHOWER ACTIVITY SHOULD BE NORTHEAST
OF THE CWA BY AROUND SUNRISE, AND FOG SHOULD BURN OFF SHORTLY
AFTER. OVERNIGHT LOWS WILL DIP INTO THE UPPER 30S TO MID 40S.
THICK, LOW STRATUS CLOUDS LINGER INTO EARLY TUESDAY AFTERNOON
BEFORE BEING SWEPT AWAY BY A SECOND SHORTWAVE MOVING THROUGH
WESTERN NORTH DAKOTA. WINDS BECOME SOUTHERLY AND INCREASE IN
RESPONSE TO THE TIGHTENED SPG. GUSTS OF 20-30 MPH ARE POSSIBLE
ALONG AND WEST OF THE JAMES RIVER VALLEY, WITH GUSTS GENERALLY
LESS THAN 20 MPH TO THE EAST. SHALLOW MIXING WILL TAP INTO
STRONG WAA IN THE 925-850 MB LAYER. AT THE SURFACE WE CAN EXPECT
HIGHS TO WARM NICELY INTO THE LOW 50S TO LOW 60S. THE WARMEST
TEMPERATURES ARE EXPECTED OVER CENTRAL SOUTH DAKOTA AND
NORTHEASTERN IOWA.
WEDNESDAY MORNING LOWS WILL BE WARM FOR LATE OCTOBER, IN THE 40S TO
LOW 50S. AVERAGE LOWS THIS TIME OF YEAR ARE IN THE LOWER 30S.
ANOTHER DAY OF LIGHT TO BREEZY SOUTHERLY WINDS AND STRONG WAA WILL
WARM OUR AFTERNOON HIGHS IN THE 60S AND 70S. SIMILAR TO THE LOWS, WE
ARE QUITE WARM FOR THIS TIME OF YEAR WHEN AVERAGE HIGHS ARE
GENERALLY IN THE MID 50S. AROUND MID-MORNING A BROAD UPPER WAVE AND
WEAK SURFACE LOW WILL TAKE SHAPE OVER CENTRAL CANADA. AN ASSOCIATED
COLD FRONT WILL DRAPE FROM THERE SOUTHWEST THROUGH CENTRAL SOUTH
DAKOTA INTO SOUTHEAST WYOMING. LIGHT RAIN IS EXPECTED TO DEVELOP
ALONG THE FRONT, MAINLY WEST OF THE JAMES RIVER LATE IN THE MORNING.
AS THE WAVE AND FRONTAL SYSTEM MOVE SOUTHEAST RAIN WILL MOVE INTO
THE I-29 CORRIDOR AND INTO WESTERN MINNESOTA AND IOWA. RAIN IS
EXPECTED TO BE SPOTTY IN NATURE WITH LITTLE ACCUMULATION. ONLY A FEW
HUNDREDTHS TO A TENTH OR TWO. SHOWERS CLEAR OUT TO THE EAST AFTER
MIDNIGHT. BEHIND THE FRONT WINDS BECOME NORTHWESTERLY AND LIGHT.
THIS WILL ALLOW FOR GOOD RADIATIONAL COOLING AND LOWS WILL DROP INTO
THE MID 30S OVER CENTRAL SOUTH DAKOTA TO THE UPPER 40S EAST OF I-29.
THURSDAY WINDS ALOFT WILL BECOME ZONAL TO SOUTH-SOUTHWEST. AT THE
SURFACE HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. WINDS WILL TURN
SOUTHEASTERLY AS THAT HIGH SCOOTS OFF TO THE EAST, BUT REMAIN LIGHT.
DRY AND MOSTLY SUNNY CONDITIONS WITH HIGHS IN THE LOW TO MID 60S.
THE MAJORITY OF THE DAY FRIDAY WILL BE DRY WITH HIGHS IN THE 60S.
FRIDAY LATE AFTERNOON AND INTO SATURDAY ANOTHER SHORTWAVE SYSTEM
MOVES THROUGH BRINGING ADDITIONAL CHANCES FOR RAIN. WHILE CURRENTLY
RAINFALL LOOKS TO BE SPOTTY AND LIGHT, THIS COULD IMPACT OUTDOOR
HALLOWEEN PLANS. A BRIEF BREAK ON SUNDAY BEFORE A MUCH MORE
PRONOUNCED UPPER TROUGH BRINGS WIDE SPREAD CHANCES FOR
ACCUMULATING RAINFALL TO THE AREA MONDAY INTO LATE TUESDAY.
WHILE UNCERTAINTY IS VERY HIGH AT THIS JUNCTURE, LONG TERM
ENSEMBLE GUIDANCE INDICATES THE POTENTIAL FOR WIDESPREAD 0.5 TO
1 INCH. STAY TUNED AS WE MONITOR THE TRENDS WITH THIS SYSTEM AND
DETAILS EMERGE.
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
ISSUED AT 633 PM CDT MON OCT 26 2026
RAIN SHOWERS HAVE DIMINISHED OVER SOUTH CENTRAL SD THIS EVENING,
BUT WILL CONTINUE TO LIFT NORTH THROUGH THE OVERNIGHT HOURS,
TAPERING OFF FROM SOUTHWEST TO NORTHEAST.
MAIN CONCERN THROUGH THE PERIOD WILL BE THE VISIBILITY
RESTRICTIONS (MVFR TO IFR AT TIMES) FOR RAIN/DRIZZLE AND
POTENTIALLY SOME PATCHY OVERNIGHT FOG. ADDITIONALLY, MVFR AND
IFR STRATUS, WITH PATCHY LIFR STRATUS REMAINS IN PLACE THROUGH
TUESDAY MORNING INTO THE AFTERNOON, WITH GUIDANCE QUITE VARIED
ON HOW QUICKLY CEILINGS IMPROVE. FOR THIS FORECAST, GENERALLY
TRENDED TOWARD SOME OF THE MORE OPTIMISTIC ENSEMBLE GUIDANCE FOR
TIMING TO UPPER MVFR/LOWER VFR CEILINGS TUESDAY AFTERNOON.
CEILINGS ARE ALSO EXPECTED TO IMPROVE FROM SOUTHWEST TO
NORTHEAST TUESDAY.
WINDS WILL BE QUITE VARIED IN DIRECTION THROUGH THE PERIOD,
ALTHOUGH EXPECT SOME BRIEF LIGHT AND VARIABLE WINDS OVERNIGHT
INTO TUESDAY MORNING. SOUTHERLY WINDS RETURN LATER IN THE
PERIOD, WITH GUSTS NEAR AND WEST OF THE JAMES RIVER 20 TO 25
KNOTS TUESDAY AFTERNOON/EVENING.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
UPDATE...SG
DISCUSSION...AJP
AVIATION...SG
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