385
FXUS63 KFSD 211351
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
751 AM CST FRI NOV 21 2025
KEY MESSAGES
- PATCHY DENSE FOG ACROSS THE AREA THIS MORNING HAS LED TO
VISIBILITIES OF LESS THAN A HALF MILE AT TIMES. A SPECIAL
WEATHER STATEMENT IS IN EFFECT UNTIL 10 AM FOR LOCATIONS ALONG
AND WEST OF I-29.
- WARM CONDITIONS ARE EXPECTED TODAY THROUGH THE WEEKEND. HIGHS
WILL BE IN THE 50S TODAY, WITH 50S AND 60S SATURDAY AND
SUNDAY.
- A CHANGE IS COMING FOR NEXT WEEK. THERE IS A MODERATE (40-70%)
CHANCE FOR PRECIPITATION BEGINNING MONDAY MORNING AND
CONTINUING THROUGH TUESDAY MORNING. UNCERTAINTY REMAINS IN
TIMING AND LOCATION OF HIGHEST AMOUNTS, BUT TEMPERATURE
PROFILES INDICATE THAT THE PRECIPITATION TYPE WILL BE RAIN.
- THE CHANGES CONTINUES WITH MUCH COLDER TEMPERATURES EXPECTED
BEGINNING THE MIDDLE OF NEXT WEEK THROUGH THE WEEKEND.
UPDATE
ISSUED AT 744 AM CST FRI NOV 21 2025
PATCHY DENSE FOG HAS RESULTED IN VISIBILITIES DOWN TO A HALF MILE
OR LESS MAINLY NEAR RIVERS, BODIES OF WATER, AND LOW-LYING
AREAS. A SPECIAL WEATHER STATEMENT HAS BEEN ISSUED FOR AREAS
ALONG AND WEST OF I-29 TO ACCOUNT FOR THE REDUCTIONS IN
VISIBILITY UNTIL 10 AM. BE SURE TO USE EXTRA CAUTION ON THE
ROADS, MAKING SURE TO USE YOUR LOW BEAM HEADLIGHTS AND LEAVING
PLENTY OF SPACE BETWEEN YOU AND THE CAR IN FRONT OF YOU. DUE TO
TEMPERATURES INTO THE 20S, SOME LIGHT ICING MAY OCCUR ON
ELEVATED SURFACES SUCH AS BRIDGES AND OVERPASSES, ALONG WITH
VEHICLES, AND SIDEWALKS.
DISCUSSION
ISSUED AT 333 AM CST FRI NOV 21 2025
PATCHY DENSE FOG HAS DEVELOPED ACROSS THE REGION. WITH LOWS FALLING
TO BELOW FREEZING, THERE IS ALSO RISK OF FOG FREEZING ON FLAT
SURFACES AND ROADWAYS, CREATING SLIPPERY SPOTS. VISIBILITY MAY FALL
TO LESS THAN ONE MILE AT TIMES. THE LOWEST VISIBILITIES ARE MOSTLY
CONFINED TO LOW LAYING AREAS AND RIVER VALLEYS, WEST OF THE JAMES
RIVER, AND IN NORTHWESTERN IOWA. BE PREPARED FOR RAPIDLY CHANGING
CONDITIONS AS YOU MAKE YOUR WAY THIS MORNING. FOG SHOULD BURN OFF BY
MID-MORNING.
TODAY WILL BE A PLEASANT DAY THANKS TO SURFACE HIGH PRESSURE AND
MODERATE WARMING IN THE MID-LEVELS. THE 925 MB LAYER IS EXPECTED TO
WARM BETWEEN 6 AND 8 DEGREES C. MIXING THIS DOWN TO THE SURFACE WILL
RESULT IN HIGHS IN THE UPPER 40S TO A FEW 50S OVER SOUTH CENTRAL
SOUTH DAKOTA. LOWS WILL FALL TO THE UPPER 20S AND MID 30S OVERNIGHT.
SCATTERED TO BROKEN CLOUDS WILL HANG AROUND FOR MOST OF THE DAY AS A
MID-LEVEL WAVE PASSES TO OUR SOUTH. THICKEST CLOUDS ARE EXPECTED
THROUGH THE HIGHWAY 20 CORRIDOR AND SOUTH. WINDS WILL BE LIGHT AND
VARIABLE THROUGH THE AFTERNOON, GRADUALLY BECOMING SOUTHERLY AS THE
HIGH PRESSURE PROGRESSES EAST OF THE REGION. SATURDAY WILL BE EVEN
WARMER THANKS TO WAA AND PLENTIFUL SUNSHINE. THE LATEST 21.00Z
GUIDANCE HAS REMAINED ON TRACK WITH PREVIOUS RUNS INDICATING HIGH
TEMPERATURES WILL CLIMB INTO THE 50S, WITH 60S POSSIBLE ALONG THE
SOUTHERN MISSOURI RIVER COUNTIES. A WEAK FRONTAL BOUNDARY MAKES ITS
WAY SOUTHEAST THROUGH THE REGION DURING THE DAY, GRADUALLY TURNING
WINDS TO THE NORTHWEST BY THE AFTERNOON. WINDS WILL BE SLIGHTLY
BREEZY BEHIND THE BOUNDARY, GUSTING 15 TO 20 MPH. WINDS BECOME LIGHT
AND VARIABLE AGAIN OVERNIGHT. MOSTLY CLEAR SKIES WILL ALLOW FOR GOOD
RADIATIONAL COOLING, AND SO LOWS WILL FALL INTO THE UPPER 20S TO LOW
30S. PATCHY DENSE FOG MAY BE POSSIBLE AGAIN SATURDAY MORNING. SUNDAY
A SURFACE HIGH PRESSURE PASSES THROUGH THE REGION, GRADUALLY TURNING
WINDS SOUTHERLY AND WARMING HIGHS ONCE AGAIN INTO THE 50S. A FEW
MORE 60S MAY BE POSSIBLE, THIS TIME OVER SOUTH CENTRAL SOUTH DAKOTA.
CLOUDS BUILD IN AS AN UPPER LOW PRESSURE SYSTEM APPROACHES FROM
THE DESERT SOUTHWEST, KEEPING LOWS A BIT WARMER IN THE MID TO
UPPER 30S.
MEANWHILE, THE PREVIOUSLY MENTIONED UPPER LOW LOCATED OVER THE
DESERT SOUTHWEST WILL EJECT OUT ONTO THE CENTRAL PLAINS LATE SUNDAY
AFTERNOON AND PROGRESS NORTHEASTWARD TOWARD OUR AREA. THERMODYNAMIC
PROFILES INDICATE THE AIR COLUMN TO BE SOLIDLY ABOVE FREEZING,
THEREFORE THE PRECIPITATION TYPE WILL BE RAIN. RAIN BEGINS AS EARLY
AS DAYBREAK MONDAY AND CONTINUES THROUGH EARLY TUESDAY MORNING.
DESPITE CLOUDS AND RAIN, SOUTHERLY WINDS AND WAA KEEP MONDAY'S HIGHS
IN THE 50S FOR MOST OF THE REGION. AS THE SYSTEM DEPARTS TUESDAY
MORNING ANOTHER WILL BE RIGHT ON ITS HEELS. A TROUGH DIGGING SOUTH
OVER THE EASTERN ROCKIES AND ASSOCIATED SURFACE LOW PRESSURE WILL
DRAG A STRONG COLD FRONT THROUGH MUCH OF THE CENTRAL AND NORTHERN
PLAINS TUESDAY. WINDS WILL TURN WEST-NORTHWESTERLY AND BECOME
STRONG. BY TUESDAY AFTERNOON GUSTS OF 25-35 MPH WILL BE COMMON FOR
AREAS ALONG AND EAST OF THE JAMES RIVER. EVEN STRONGER WINDS ARE
POSSIBLE FOR THE WEST, WITH GUSTS 35-40 MPH OR STRONGER. WITH THE
WINDS COMES STRONG CAA THAT BEGINS TO COOL THE MID-LEVELS. HIGHS
WILL BE MUCH CLOSER TO SEASONAL AVERAGES, IN THE UPPER 30S TO LOW
40S. CONTINUED STRONG CAA OVERNIGHT WILL DECREASE LOWS BY
WEDNESDAY MORNING INTO THE LOW 20S WITH WIND CHILLS IN THE
SINGLE DIGITS.
AS THE TROUGH AXIS PASSES OVERHEAD DURING THE DAY WEDNESDAY THERE IS
A LOW CHANCE FOR PRECIPITATION ALONG AND NORTH OF HIGHWAY 14. MID-
TERM GUIDANCE IS IN LOW AGREEMENT ON HOW FAR SOUTH PRECIPITATION
WILL INTRUDE. WHAT THEY ARE IN AGREEMENT ON IS THE CONTINUED COLD
WEATHER AND GUSTY WINDS. HIGHS FOR WEDNESDAY WILL ONLY CLIMB TO THE
UPPER 20S TO LOW 30S NORTH OF I-90, AND MID 30S TO THE SOUTH. WIND
CHILLS WILL BE IN THE TEENS TO LOW 20S. COLD WEATHER CONTINUES AS
YOU GATHER FOR YOUR FAVORITE MEALS THURSDAY, WITH HIGHS ONLY
CLIMBING TO THE UPPER 20S AND LOW 30S. FRIDAY HIGHS WILL BE VERY
SIMILAR. PLEASE ENSURE YOU ARE PREPARED FOR THE COLD WEATHER NEXT
WEEK.
AVIATION /12Z TAFS THROUGH 12Z SATURDAY/
ISSUED AT 542 AM CST FRI NOV 21 2025
A MIX OF MVFR ALL THE WAY DOWN TO LIFR AS PATCHY DENSE FOG HAS
SETTLED IN THE REGION. REDUCTIONS IN VISIBILITY DOWN TO LESS THAN 1
MILE AT TIMES IS POSSIBLE. LOW VISIBILITIES ARE MAINLY CONFINED TO
LOW LYING AREAS AND RIVER VALLEYS, WEST OF THE JAMES RIVER, AND
NORTHWESTERN IOWA. CONFIDENCE IN FOG IMPACTING ANY OF THE TAF SITES
IS LOW. FOG SHOULD BURN OFF BY MID-MORNING AND BRING A RETURN TO
VFR FOR THE REST OF THE PERIOD.
A STORM SYSTEM TO OUR SOUTH HAS PUSHED HIGH BASED CLOUDS INTO THE
SOUTHERN PORTION OF OUR REGION. THESE CLOUDS WILL DISSIPATE THROUGH
THE DAY AS THAT SYSTEM PUSHES EAST. WINDS ARE EXPECTED TO BE LIGHT
AND VARIABLE TO LIGHT AND SOUTHERLY FOR THE DURATION OF THE PERIOD.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
UPDATE...SAMET
DISCUSSION...AJP
AVIATION...AJP
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