256
FXUS63 KFSD 300337
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1037 PM CDT MON SEP 29 2025
KEY MESSAGES
- WELL ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE
UPCOMING WEEK AND INTO NEXT WEEKEND. A FEW RECORD TEMPERATURES
ARE POSSIBLE THIS WEEK.
- DRY CONDITIONS ARE ALSO EXPECTED TO CONTINUE THROUGH MOST OF
THE WEEK AHEAD. A FEW DAYBREAK SPRINKLES/SHOWERS COULD BE
POSSIBLE THROUGH THE FIRST HALF OF THE WEEK, BUT CHANCES
REMAIN <20%.
- DRY AND OCCASIONALLY BREEZY AFTERNOON CONDITIONS COULD LEAD
TO LOW END FIRE WEATHER CONCERNS AS FIRE FUELS CONTINUE TO DRY
OUT.
- NEXT REASONABLE RISK FOR WIDESPREAD RAIN ARRIVES AT SOME POINT
NEXT WEEKEND, WITH A COOLDOWN IN TEMPERATURES TO FINISH THE
WEEKEND. HIGHEST RAIN PROBABILITIES ARE FOCUSED SATURDAY NIGHT
INTO SUNDAY.
DISCUSSION
ISSUED AT 144 PM CDT MON SEP 29 2025
THIS AFTERNOON: SOUTHERLY WINDS CONTINUE TO INCREASE THIS AFTERNOON
WITH A STRONG THERMAL RESPONSE AT THE SURFACE. TEMPERATURES HAVE
RISEN WELL INTO THE 80S WITH A FEW 90S POPPING UP. AS WE CONTINUE TO
MOVE THROUGH THIS EXTENDED WARM AND DRY STRETCH, WE'LL CONTINUE TO
SEE FEEDBACK FROM THE WARM/DRY GROUND TO PUSH TEMPERATURES OVER MOST
GUIDANCE BY A DEGREE OR TWO. BY THE END OF THE DAY, A FEW RECORD
HIGH TEMPERATURES WILL BE BROKEN.
TONIGHT: THE PERSISTENT SOUTHERLY WIND IS LIKELY TO KEEP
TEMPERATURES WELL ABOVE NORMAL IN MOST AREAS BY TUESDAY MORNING. A
THICKENING CIRRUS CLOUD DECK, AND EVENTUAL DEVELOPMENT OF A MID-LVL
CLOUD DECK WILL FURTHER PREVENT TEMPERATURES FROM DROPPING. WOULD
NOT BE SURPRISED TO SEE A FEW SPRINKLES TO VERY LIGHT SHOWERS
DEVELOPING OVER NORTHWESTERN IOWA AND SEPARATELY IN AN AREAS OF
NORTHERN NEBRASKA AND SOUTH CENTRAL SOUTH DAKOTA BY DAYBREAK.
MINIMAL ACCUMULATION IS EXPECTED.
TUESDAY: TEMPERATURES MAY FALL A HANDFUL OF DEGREES ON TUESDAY AS
THE WARMEST POCKET OF LOW-LVL TEMPERATURES MOVES NORTHWARD, AND A
PERSISTENT BLANKET OF MID-UPR CLOUDS MAY CONTINUE. AN INCREASING
SPG ACROSS THE DAKOTAS IN RESPONSE TO LEE SIDE CYCLOGENESIS
OVER THE HIGH PLAINS MAY LEAD TO AFTERNOON GUSTS IN THE 20 TO 30
MPH RANGE. WHILE RH VALUES STAY ABOVE 30%, SOME SLIGHTLY
ELEVATED FIRE DANGER MAY DEVELOP WEST OF I-29 IN THE AFTERNOON.
MORNING SPRINKLES/SHOWERS COULD LINGER DEEPER IN THE MORNING,
GIVEN PERSISTENT LAYER OF MOISTURE BETWEEN 7-10K FT.
WEDNESDAY: MID-LVL SOUTHWESTERLY FLOW BEGINS TO INCREASE EARLY
WEDNESDAY, WITH MODEST LOW-LVL CONVERGENCE AT 850MB THROUGH CENTRAL
NEBRASKA AND CENTRAL SOUTH DAKOTA BY DAYBREAK. ISOLATED SHOWERS AND
PERHAPS AN ISOLATED THUNDERSTORM COULD DEVELOP AFTER MIDNIGHT AND
LINGER WEST OF THE JAMES RIVER THROUGH WEDNESDAY MORNING. FURTHER
EAST, THE CONTINUATION OF THE SAME FLOW REGIME WILL LEAD TO HIGHS
AGAIN IN THE LOWER TO MIDDLE 80S, AND BREEZY AFTERNOON WINDS. WITH
THE PASSAGE OF A VERY MINOR MID-LVL WAVE BY THURSDAY MORNING,
ANOTHER AXIS OF VERY LIGHT RAIN COULD DEVELOP THROUGH DAYBREAK
THURSDAY MORNING OVER WESTERN MN AND FAR EASTERN SD.
THURSDAY-FRIDAY: MID-LVL HEIGHTS BEGIN TO CLIMB QUICKLY FOR THE END
OF THE WEEK, AND THIS WILL RESULT IN THE MODEST INCREASE IN
SOUTHERLY LOW-LVL WINDS, BUT ALSO ANOTHER SURGE OF VERY WARM LOW
LEVEL TEMPERATURES INTO THE PLAINS. HIGHS ON THURSDAY CLIMB INTO THE
UPPER 80S TO LOWER 90S, WITH HIGHS ON FRIDAY EVEN WARMER,
POTENTIALLY CLIMBING INTO THE LOWER 90S. IT'S POSSIBLE TO SEE A FEW
RECORD HIGHS AGAIN FRIDAY AFTERNOON. WHILE EVENING TEMPERATURES
WILL FALL INTO THE LOWER 80S, THOSE OUTDOOR ACTIVITIES IN THE REGION
STARTING LATE AFTERNOON OR EARLY EVENING FRIDAY MAY WANT TO
TAKE A FEW EXTRA PRECAUTIONS.
SATURDAY-MONDAY: A DEEPER UPPER TROUGH REMAINS ON TRACK TO CROSS THE
ROCKIES AND ENTER THE PLAINS THIS WEEKEND. THOUGH SOME DIFFERENCES
REMAIN, LATEST GUIDANCE HAS SLOWED THE ARRIVAL OF THIS SYSTEM AND
ASSOCIATED FRONT. THIS WILL RESULT IN GREATER PROBABILITIES OF 85-
90 DEGREE TEMPERATURES ON SATURDAY ALONG WITH A MUCH STRONGER
SOUTHWESTERLY SURFACE WIND THROUGH THE DAY. THE GREATEST UNKNOWN IS
THE MERIDIONAL ORIENTATION OF THE BOUNDARY WHICH WILL IMPACT BOTH
TEMPERATURES, WIND GUST POTENTIAL, AND LATE DAY STORM CHANCES.
ECMWF/GEM BOTH SUGGEST A SHEARING OUT MID-LVL WAVE WHICH RESULTS IN
MOSTLY POST FRONTAL RAIN SATURDAY NIGHT INTO SUNDAY. THE MORE
NEGATIVELY TILTED GFS PRODUCES MORE PRE-FRONTAL CONVECTION SATURDAY
EVENING WITH LINGERING RAIN INTO SUNDAY. DETERMINISTIC MODELS SWEEP
THE FRONT SOUTHEAST ON SUNDAY WITH COOLER AND DRY CONDITIONS MOVING.
INTO THE REGION. ENSEMBLES POINT TO A WIDER VARIETY OF SOLUTIONS
THROUGH THE WEEKEND, BUT POINT TO THE GREATEST RAIN POTENTIAL (>40%
OF 0.10") SATURDAY NIGHT INTO SUNDAY. THE NBM MAY BE A BIT TOO
AGGRESSIVE IN BRINGING IN RAIN CHANCES FRIDAY.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1037 PM CDT MON SEP 29 2025
VFR CONDITIONS ARE EXPECTED FOR THE TAF PERIOD. LIGHT SOUTHERLY
WINDS PERSISTS LATE THIS EVENING. THE LIGHT SOUTHERLY WINDS WILL
PREVAIL THROUGH THE NIGHT WITH SPEEDS OF ABOUT 5-10 KNOTS. CLOUDS
ARE THICKENING ALOFT NOW WHICH MAY LEAD TO SPRINKLES GENERALLY ALONG
AND EAST OF I-29 TONIGHT. CONFIDENCE REMAINS TOO LOW TO INCLUDE IN
ANY TAFS BUT WILL MONITOR TRENDS THROUGH THE NIGHT. HIGH LEVEL
CLOUDS AND BROAD SOUTHERLY WINDS WILL PERSIST THROUGH THE DAY
TOMORROW. GUSTS UP TO 15-30 KNOTS IS EXPECTED TOMORROW AFTERNOON
WITH THE STRONGEST GUSTS OCCURRING WEST OF I-29. WINDS WILL SLOWLY
WEAKEN TO END THE TAF PERIOD.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
DISCUSSION...DUX
AVIATION...MEYERS
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