430
FXUS63 KFSD 190753
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
253 AM CDT MON OCT 19 2026
KEY MESSAGES
- VERY ISOLATED VALLEY FOG MAY DEVELOP THROUGH THE MONDAY
MORNING COMMUTE, WITH A LOW (30% OR LESS) CHANCE OF VISIBILITY
FALLING BELOW 6 MILES.
- ABOVE TO WELL ABOVE NORMAL TEMPERATURES EXPECTED INTO THE
WEEKEND. TEMPERATURES FROM 10 TO 20 DEGREES ABOVE NORMAL
WEDNESDAY THROUGH SATURDAY MORNING. NORMAL HIGHS ARE UPPER 50S
WITH NORMAL LOWS IN THE MID/UPPER 30S.
- PRECIPITATION CHANCES REMAIN VERY LOW (LESS THAN 10%) UNTIL LATE
WEEK.
- CONTINUED DRY, WARM, AND PERIODICALLY BREEZY CONDITIONS COULD
LEAD TO ELEVATED FIRE CONCERNS THROUGH THE WEEK.
UPDATE
ISSUED AT 252 AM CDT MON OCT 19 2026
GUIDANCE REMAINS QUITE SPLIT ON FOG DEVELOPMENT THIS MORNING, BUT
MAJORITY OF GUIDANCE INCLUDING SHORT TERN ENSEMBLES LIMITS COVERAGE
TO RIVER VALLEYS. BOTH THE REFS AND HREF PROBABILITY OF VISIBILITY
AT ANY ONE LOCATION AROUND OR BELOW 30%, WITH GENERALLY LOWER
PROBABILITY OF VISIBILITY BELOW 2 MILES. CONFIDENCE IS LOW A BIT
LOWER AS WE HAVE AN INCREASE IN HIGH CLOUDS, WHICH THUS FAR HAS BEEN
KEEPING TEMPERATURES A FEW DEGREES WARMER. WE'LL COOL INTO THE UPPER
30S TO MID 40S WITH LIGHT WINDS.
RAISED HIGH TEMPERATURES CLOSER TO THE NBM 90TH FOR THE NEXT THREE
DAYS, WHICH RESULTS IN HIGHS ANYWHERE FROM 2-6 DEGREES WARMER EACH
DAY THAN THE BLEND. WARMER TEMPERATURES AND PERIODICALLY BREEZY
CONDITIONS WILL HELP FUELS CURE, WHICH MAY LEAD TO ADDITIONAL FIRE
CONCERNS THIS WEEK. HIGHS TODAY IN THE 60S, AND LIGHT WINDS LIMIT
FIRE CONCERNS TODAY. TEMPERATURES CONTINUE TO WARM INTO MID WEEK.
DRY CONDITIONS PREVAIL INTO LATE WEEK, WITH CONTINUED DOWNWARD TREND
AND SOUTHERN SHIFT IN ENSEMBLE PROBABILITY OF MEASURABLE
PRECIPITATION WEDNESDAY INTO WEDNESDAY NIGHT - LESS THAN 10% OUTSIDE
OF THE GEFS WHICH IS AROUND 20%.
DISCUSSION
ISSUED AT 120 PM CDT SUN OCT 18 2026
QUIET WEATHER AHEAD FOR THE NEXT SEVERAL DAYS. A WEAK FRONT SETTLES
INTO THE AREA TONIGHT INTO MONDAY MORNING. THIS SHOULD BRING LIGHTER
WINDS AND A BIT COOLER LOW TEMPERATURES, MAINLY FROM THE UPPER 30S
TO LOWER 40S. WITH THE LIGHT WINDS AND SOME WEAK SURFACE CONVERGENCE
ALONG THE BOUNDARY, SOME PATCHY FOG WILL BE POSSIBLE. FOR NOW THE
FOG APPEARS AS THOUGH IT WILL MAINLY BE IN LOW LYING LOCATIONS.
MONDAY SHOULD PROVE THE BE A FAIRLY MILD DAY WITH WINDS GENERALLY
BELOW 15 MPH. HIGHS MOSTLY MID 60S.
STRONGER SOUTHERLY FLOW WILL BE IN PLACE ON TUESDAY WHICH COULD
BRING SOME ELEVATED FIRE WEATHER CONCERNS AS TEMPERATURES CLIMB INTO
THE 70S. A WEAK BOUNDARY SETTLE SOUTH ON WEDNESDAY, WITH WINDS
EXPECTED TO BE MUCH WEAKER THAN TUESDAY. WITH SOME HEATING AHEAD OF
THE INCOMING FRONT, HIGHS SHOULD CLIMB INTO THE MID 70S IN MOST
LOCATIONS WITH AN 80 DEGREE READING NOT OUT OF THE QUESTION.
STRONGER TROUGHING DEVELOPS TO THE WEST THURSDAY INTO FRIDAY WHICH
WILL BRING AN INCREASE IN SOUTHERLY FLOW TO THE AREA, WITH SOME
ELEVATED FIRE WEATHER CONCERNS ONCE AGAIN. HIGHS BOTH DAYS WILL BE
IN THE 70S.
RAIN CHANCES INCREASE FRIDAY INTO SATURDAY MORNING AS THIS TROUGH
SPREADS ON THE NORTHERN PLAINS. FOR NOW RAINFALL AMOUNTS LOOK
FAIRLY LIGHT WITH THE 50TH PERCENTILE FROM THE EC/CANADIAN AND GFS
ENSEMBLE OUTPUT ALL LESS THAN A QUARTER OF AN INCH, WITH THE
CANADIAN AND EC ENSEMBLE GENERALLY LESS THAN A TENTH OF AN INCH. LOW
TEMPERATURES ON FRIDAY AND SATURDAY MORNINGS WILL BE VERY MILD WITH
STRONGER SOUTHERLY FLOW IN PLACE. LOWS BOTH MORNINGS WILL BE JUST A
TOUCH BELOW THE SEASONAL NORMALS FOR HIGH TEMPERATURES.
SATURDAY AND SUNDAY WILL SEE COOLER TEMPERATURES BUT FOR NOW THE AIR
MASS BEHIND THIS SYSTEM IS NOT LOOKING TOO COLD, SO ANTICIPATING
HIGHS IN THE 60S BOTH DAYS.
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
ISSUED AT 1044 PM CDT SUN OCT 18 2026
VFR CONDITIONS ARE EXPECTED FOR THE TAF PERIOD. LIGHT AND VARIABLE
WINDS ARE EXPECTED TONIGHT. THIS COULD LEAD TO THE DEVELOPMENT OF
PATCHY FOG ACROSS THE AREA. HOWEVER, THIS POTENTIAL REMAINS LOW (<=
20%) BECAUSE OF HIGH LEVEL CIRRUS BEGINNING TO OVERSPREAD THE AREA
NOW. THE CIRRUS IS EXPECTED TO PERSIST THROUGH THE NIGHT. WILL
MONITOR TRENDS THROUGH THE NIGHT. WINDS WILL PICK UP OUT OF THE
SOUTHEAST TOMORROW WITH SPEEDS UP TO 5 TO 10 KNOTS. THESE SOUTHEAST
WINDS WILL FINISH OUT THE TAF PERIOD.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
UPDATE...SG
DISCUSSION...08
AVIATION...MEYERS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page