236
FXUS63 KFSD 090653
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
153 AM CDT FRI OCT 9 2026
KEY MESSAGES
- WARM AND PREDOMINANTLY DRY CONDITIONS WILL PERSIST INTO THE
WEEKEND. HOWEVER, SCATTERED SHOWERS AND THUNDERSTORMS WILL
CONTINUE TO DEVELOP EARLY THIS MORNING SOUTH OF I-90. SOME
STORMS COULD BE STRONG TO SEVERE WITH LARGE HAIL UP TO THE
SIZE OF PING PONG BALLS.
- WARM, DRY, AND BREEZY CONDITIONS OVER THE WEEKEND LOOK TO LEAD
TO ELEVATED FIRE CONCERNS, ESPECIALLY ON SATURDAY. MAKE SURE
TO LIMIT ANY ACTIVITIES THAT COULD CREATE A SPARK!
- BOTH HIGH AND LOW TEMPERATURES ON SATURDAY WILL APPROACH
RECORD TERRITORY.
- A RETURN TO AN ACTIVE PATTERN BY NEXT WEEK WILL LEAD TO
MULTIPLE RAIN CHANCES (30%-70%) THROUGHOUT THE WEEK, HIGHEST
ON WEDNESDAY AND THURSDAY.
UPDATE
ISSUED AT 153 AM CDT FRI OCT 9 2026
FOCUS FOR THIS PAST EVENING AND SO FAR EARLY THIS MORNING HAS
BEEN ON ELEVATED STORMS WHICH CONTINUE TO DEVELOP AND TRACK TO
THE EAST-SOUTHEAST NEAR AN 850MB BOUNDARY, EXTENDING FROM FAR
SOUTHEAST SOUTH DAKOTA ACROSS NORTHWEST IOWA, MAINLY BETWEEN
U.S. HIGHWAY 18 AND IA HIGHWAY 3. MULTIPLE ELEVATED SUPERCELLS
HAVE TRACKED OVER OR VERY NEAR THE SAME LOCATIONS, ESPECIALLY
PORTIONS OF CLAY/UNION/SOUTHERN LINCOLN COUNTIES IN SD, AND
SIOUX/PLYMOUTH/CHEROKEE COUNTIES IN IA. SOME LOCATIONS MAY HAVE
SEEN MULTIPLE ROUNDS OF HAIL, THOUGH IN MOST CASES, THE TRACKS
OF STORM CORES WERE JUST SLIGHTLY DISPLACED FROM PREVIOUS ROUNDS.
MODELS INDICATE THIS ACTIVITY SHOULD BEGIN WINDING DOWN OVER THE
NEXT 1-3 HOURS AS THE AXIS OF THE LOW LEVEL JET IMPINGING ON THE
ABOVE-MENTIONED BOUNDARY SLOWLY SHIFTS EAST, ALONG WITH A SUBTLE
MID-LEVEL WAVE WHICH IS LIKELY AIDING IN DEVELOPMENT.
ONCE THIS ACTIVITY SHIFTS EAST OF THE AREA PRIOR TO DAYBREAK,
FOCUS WILL THEN SHIFT TOWARD WARMER AND WINDIER CONDITIONS WHICH
DEVELOP INTO THIS WEEKEND. GIVEN THE PERSISTENT STORM ACTIVITY,
DID NOT HAVE MUCH TIME TO EXAMINE THE LATEST MODELS OR MAKE MANY
SIGNIFICANT ADJUSTMENTS TO THE FORECAST. HOWEVER, GIVEN RECENT
TRENDS ON WELL-MIXED DAYS, DID FAVOR HIGHS CLOSER TO THE 90TH
PERCENTILE OF THE NBM FOR SATURDAY, WHILE SIMILARLY NUDGING DEW
POINTS DOWNWARD TOWARD THE HRRR/RAP. THIS CONTINUES TO PRODUCE A
BROAD AREA OF HIGH GRASSLAND FIRE DANGER ACROSS SOUTHEAST SD AND
SOUTHWEST MN, AND WILL HAVE TO MONITOR TRENDS FOR POSSIBLE FIRE
WEATHER HEADLINES AS RH DOES DROP BELOW 25 PERCENT IN SOME AREAS
WITH WINDS GUSTING OVER 30-35 MPH.
DISCUSSION
ISSUED AT 152 PM CDT THU OCT 8 2026
DRY CONDITIONS BENEATH PARTLY CLOUDY SKIES CONTINUE THIS AFTERNOON.
THE DRY CONDITIONS LOOK TO PERSIST FOR THE REST OF THE AFTERNOON AND
INTO THE EVENING HOURS BEFORE CHANCES FOR SHOWERS AND STORMS RETURN
TO THE FORECAST AREA. A WEAK MID LEVEL SHORTWAVE TROUGH WILL PUSH
INTO THE FORECAST AREA, STRENGTHENING THE LOW LEVEL JET (LLJ) AND
LOW LEVEL WARM AIR ADVECTION (WAA). THE LLJ AND WAA WILL STEEPEN MID
LEVEL LAPSE RATES, RESULTING IN SUFFICIENT BUOYANCY BETWEEN 700 TO
1,200 J/KG OF CAPE. THUS, THUNDERSTORMS ARE EXPECTED ON THE NOSE OF
THE LLJ. EFFECTIVE SHEAR VALUES WILL BE SUFFICIENT AT 35 TO 40
KNOTS. THE LINGERING UNCERTAINTY IS WHERE STORMS WILL DEVELOP.
LATEST GUIDANCE HAS COME IN WITH A FURTHER EAST SOLUTION. SHOULD
THIS SOLUTION PAN OUT, THEN LITTLE TO NO STORMS WOULD DEVELOP IN THE
FORECAST AREA. THINK THE MOST LIKELY SCENARIO IS THAT THE BROAD WAA
IN PLACE WILL DEVELOP A FEW STORMS IN THE CWA, MAINLY IN NORTHWEST
IOWA THIS EVENING AND NIGHT. A FEW OF THESE STORMS COULD BE STRONG
TO SEVERE WITH LARGE HAIL UP TO THE SIZE OF PING PONG BALLS. SHOULD
SEE STORMS PUSH EAST OF THE FORECAST AREA BY 5 TO 6 AM.
FRIDAY WILL SEE WARMING HIGHS UP TO THE 70S AND 80S THANKS TO THE
PREVIOUSLY MENTIONED WAA. WINDS WILL ALSO BE STRENGTHENING
THROUGHOUT THE DAY AS LOW LEVEL PRESSURE GRADIENTS TIGHTEN WITH
SOUTHEASTERLY WINDS GUSTING TO 20-30 MPH. WITH THE TIGHTER PRESSURE
GRADIENTS IN PLACE, BREEZY WINDS WILL PERSIST THROUGH THE EVENING
AND NIGHT, THIS WILL KEEP LOW TEMPERATURES VERY MILD, WITH LOWS ONLY
FALLING TO THE 60S OVERNIGHT. THESE WARM OVERNIGHT LOWS WILL BE
NEAR OR MAY BREAK WARM LOW TEMPERATURES RECORDS.
THE THERMAL RIDGE AXIS WILL REMAIN PARKED OVER THE NORTHERN PLAINS
ON SATURDAY, RESULTING IN THE WARMEST TEMPERATURES OVER THE WEEKEND.
HIGH TEMPERATURES WILL WARM TO THE 80S ACROSS THE AREA WITH A FEW
LOCATIONS ACROSS CENTRAL AND SOUTH CENTRAL SOUTH DAKOTA SEEING HIGHS
POTENTIALLY REACH 90F. THESE WARM HIGH TEMPERATURES ARE NEAR RECORDS
CURRENTLY. COULD SEE TEMPERATURES CREEP TOWARDS RECORD TERRITORY IF
HIGHS CONTINUE TO WARM HEADING INTO SATURDAY. THE HEAT WILL BE
ACCOMPANIED BY STRONGER SOUTHERLY WINDS AND LOWER HUMIDITY, YIELDING
ELEVATED FIRE DANGER ACROSS THE AREA. THE LOWEST HUMIDITY AND
HOTTEST TEMPERATURES CONTINUES TO LOOK TO RESIDE OVER CENTRAL AND
SOUTH CENTRAL SOUTH DAKOTA WHERE HUMIDITY VALUES LOOK TO FALL BELOW
25%. HOWEVER, WINDS WILL BE WEAKENING IN THIS AREA THROUGH THE
DAYLIGHT HOURS AS THE LOW LEVEL PRESSURE GRADIENT IS SHUNTED A BIT
EASTWARD. LOCATIONS ALONG AND EAST OF THE JAMES RIVER WILL SEE THE
STRONGEST WINDS WITH GUSTS UP TO 30-40 MPH. ISOLATED HIGHER GUSTS UP
TO ABOUT 45 MPH IS POSSIBLE ALONG THE BUFFALO RIDGE IN SOUTHWEST
MINNESOTA. THIS WILL RESULT IN AN OFFSET OF THE STRONGEST WINDS AND
LOWEST HUMIDITY. FUELS CONTINUE TO REMAIN GREEN, THOUGH CONTINUE TO
SLOWLY CURE. THAT SAID, THE OFFSET OF HIGHEST WINDS AND LOWEST
HUMIDITY ALONG WITH THE MAINLY GREEN FUELS WILL KEEP FIRE DANGER
CAPPED AT HIGH. FIRE DANGER WILL COME TO AN END SATURDAY EVENING AS
HUMIDITY INCREASES. WINDS WILL SLOWLY WEAKEN THROUGH THE EVENING AND
OVERNIGHT HOURS, CONTINUING ANOTHER NIGHT OF MILD LOW TEMPERATURES
IN THE 60S. THESE LOW TEMPERATURES WILL AGAIN COME CLOSE TO RECORD
WARM LOWS.
WARM TEMPERATURES WILL CONTINUE THROUGH SUNDAY THOUGH NOT AS WARM AS
A COLD FRONT BEGINS TO PUSH INTO THE FORECAST AREA FROM THE
NORTHWEST. MEDIUM RANGE GUIDANCE CONTINUES TO VARY ON HOW QUICKLY
THE FRONT PUSHES THROUGH THE FORECAST AREA. WINDS WILL REMAIN BREEZY
BUT MUCH WEAKER THAN SATURDAY'S WINDS. HUMIDITY WILL BE LOWER,
THOUGH ABOVE CRITICAL THRESHOLDS, SO SOME ELEVATED FIRE DANGER
REMAINS POSSIBLE.
AN UPPER LEVEL TROUGH WILL DIVE ACROSS THE WEST COAST ON MONDAY
BEFORE BEGINNING TO EJECT INTO THE PLAINS LATE TUESDAY AND
WEDNESDAY. THERE REMAINS SIGNIFICANT VARIANCE IN THE EVOLUTION OF
THIS WAVE BUT THE ENSEMBLES SHOW A CLEARER PICTURE WITH THE CLOSED
LOW TRANSITIONING TO AN OPEN WAVE AS IT PUSHES INTO THE PLAINS. THIS
WILL ALSO PUSH THE HIGHEST PROBABILITIES FOR RAIN TO THE MIDDLE OF
NEXT WEEK. THE ENSEMBLES SHOW A 30-70% CHANCE FOR RAINFALL TOTALS TO
EXCEED A TENTH OF AN INCH WEDNESDAY THROUGH THURSDAY. IN ADDITION TO
THE CHANCES FOR RAIN, TEMPERATURES WILL TREND TO NEAR SEASONABLE
WITH HIGHS IN THE 60S AND LOW SIN THE 40S AND 50S.
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 153 AM CDT FRI OCT 9 2026
THUNDERSTORMS CONTINUE AT THE START OF THIS PERIOD, MAINLY FROM
NEAR U.S. HIGHWAY 18 TO IOWA HIGHWAY 3 IN NORTHWEST IOWA. THIS
ACTIVITY IS EXPECTED TO SLOWLY SHIFT EAST THROUGH DAYBREAK, AND
IS NOT EXPECTED TO IMPACT KFSD/KSUX TAF LOCATIONS.
SOME HINT THAT LOW-END MVFR TO LOCALLY IFR CLOUDS COULD DEVELOP
NORTH OF THIS ACTIVITY THIS MORNING, POTENTIALLY STREAMING WEST
TOWARD THE I-29 CORRIDOR/KFSD. CONFIDENCE IS LOW THAT MVFR-IFR
CEILINGS WILL DEVELOP, BUT DID INCLUDE SCT010 FOR SEVERAL HOURS
AT KFSD TO INDICATE FAVORED WINDOW OF POTENTIAL SUB-VFR CEILINGS.
OTHERWISE VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD.
SOUTHEAST TO SOUTH WINDS MAY GUST 20-25KT THIS AFTERNOON AT
TIMES, AND LOW LEVEL WIND SHEAR IS EXPECTED TO DEVELOP AFTER
SUNSET AS A LOW LEVEL JET STRENGTHENS ATOP A STRONG SURFACE
INVERSION.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
UPDATE...JH
DISCUSSION...MEYERS
AVIATION...JH
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