060
FXUS63 KFSD 151743
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1243 PM CDT WED OCT 15 2025
KEY MESSAGES
- LOW SHOWER/DRIZZLE CHANCES REMAIN THROUGH TODAY AND TONIGHT,
THOUGH ADDITIONAL RAINFALL AMOUNTS WILL BE LESS THAN A TENTH
OF AN INCH THROUGH THE PERIOD.
- WARM AND BREEZY ON THURSDAY AHEAD OF AN INCOMING SYSTEM THAT
WILL BRING ADDITIONAL SHOWERS ALONG A COLD FRONT THURSDAY
NIGHT INTO FRIDAY.
- TEMPERATURES FALL BACK TO NEAR SEASONAL AVERAGES FOR THE
UPCOMING WEEKEND, WITH ONLY LOW RAIN CHANCES - MAINLY ON
SATURDAY.
DISCUSSION
ISSUED AT 340 AM CDT WED OCT 15 2025
SEEING SPOTTY LIGHT SHOWERS AND DRIZZLE REMAINING ACROSS THE AREA
VERY EARLY THIS MORNING, WITH HI-RES GUIDANCE SUGGESTING THIS
CONTINUING THROUGH AT LEAST MID TO LATE MORNING. THE OVERALL TREND
THROUGH THE REMAINDER OF THE DAY, HOWEVER, WILL BE FOR LESSENING
COVERAGE WITH INCREASING SUBSIDENCE AS AN UPPER LEVEL RIDGE
AMPLIFIES OVER THE REGION. ADDITIONAL RAINFALL AMOUNTS WILL
AVERAGE LESS THAN 0.05" - AND THIS WOULD MAINLY OCCUR DURING THE
MORNING. DEVELOPING LOW PRESSURE OVER CO WILL BEGIN TO USHER
WARMER AIR NORTHWARD THROUGH THE DAY, AND TEMPERATURES THIS
AFTERNOON WILL BE 15 TO 20 DEGREES WARMER THAN YESTERDAY. HIGHS
WILL RANGE FROM THE LOWER TO MID 60S NORTH, TO THE 70S THROUGH
THE MO RIVER CORRIDOR WHERE THERE MAY BE MORE BREAKS IN THE
CLOUDS BY AFTERNOON.
LOW PRESSURE CONTINUES TO DEEPEN INTO WESTERN NE/SD TONIGHT, AND IN
AN INCREASING SURFACE PRESSURE GRADIENT SOUTHEASTERLY WINDS WILL
BEGIN TO PICK UP OVERNIGHT. RAINFALL CHANCES WILL REMAIN LOW (20% OR
LESS) FOR THE MUCH OF TONIGHT, THOUGH MAY BUMP UP A BIT (30-40%)
THROUGH OUR NORTH AND WEST LATER IN THE NIGHT AS AN ELEVATED WARM
FRONT LIFTS TO THE NORTH AND A LLJ DEVELOPS THROUGH CENTRAL NE AND
SD. IT WILL BE A MILDER NIGHT IN RESPONSE TO THE WARM AIR ADVECTION
WITH LOWS IN THE 50S TO LOWER 60S.
FOR THURSDAY THROUGH FRIDAY, AN UPPER LEVEL TROUGH ORIENTED THROUGH
THE ROCKIES LIFTS INTO THE NORTHERN PLAINS THROUGH THE PERIOD. AT
THE SURFACE, THE LOW PRESSURE TO OUR WEST LIFTS INTO ND AND FINALLY
INTO SOUTH CENTRAL CANADA BY FRIDAY, PULLING A COLD FRONT THROUGH
OUR AREA AS IT DOES SO. OUT AHEAD OF THE FRONT, A STRONG SOUTHERLY
FLOW WILL RESULT IN A BREEZY DAY ON THURSDAY, ALONG WITH
TEMPERATURES CLIMBING INTO THE MID AND UPPER 70S. ENSEMBLES AND
DETERMINISTIC MODELS CONTINUE TO INDICATE THE BETTER RAIN CHANCES
WITH THIS FRONT OCCURRING ON THURSDAY EVENING AS THE MAIN UPPER
LEVEL LOW EJECTS NORTHWARD OUT OF THE TROUGH - TRACKING OVER THE
WESTERN DAKOTAS DURING THIS TIME FRAME AND ENHANCING MIDLEVEL
FRONTOGENESIS WEST OF INTERSTATE 29. CURRENT RAINFALL AMOUNTS DURING
THIS PERIOD ARE PROJECTED TO AVERAGE 0.2" TO 0.3" WEST OF I-29, WITH
ENSEMBLES ON THE LOWER END OF THIS AMOUNT. RAINFALL CHANCES MAY
LINGER INTO FRIDAY AS THE FRONT FINALLY SWEEPS THROUGH THE AREA,
THOUGH RAINFALL AMOUNTS WILL MOST LIKELY BE LESS WITH APPRECIABLE
FORCING WEAKENING. WITH COLD AIR ADVECTION BEHIND THE FRONT,
TEMPERATURES WILL COOL SLIGHTLY FOR FRIDAY WITH HIGHS INTO THE 60S
AND LOWER 70S.
MUCH COOLER TEMPERATURES PUSH INTO THE REGION FOR THE UPCOMING
WEEKEND AS THE UPPER LEVEL TROUGH DEEPENS OVER THE PLAINS AND
MISSISSIPPI VALLEY THROUGH THE PERIOD. COULD AGAIN SEE SOME LOW RAIN
CHANCES FOR SATURDAY, WITH BOTH THE GFS AND ECMWF SHOWING UPPER
LEVEL ENERGY TRACKING SOUTHEASTWARD ON THE BACKSIDE OF THE TROUGH,
ENDING UP IN THE CENTRAL PLAINS ON SATURDAY. TEMPERATURES FOR THE
WEEKEND LOOK TO BE IN THE 60S, WITH LOWS IN THE 30S.
AS WE MOVE INTO NEXT WEEK, CONFIDENCE IN THE FORECAST BECOMES LOW
WITH INCREASING MODEL DIVERGENCE IN SOLUTIONS. WHILE THE GFS WOULD
INDICATE AN UPPER LEVEL RIDGE BUILDING BACK OVER OUR REGION, BOTH
THE ECMWF AND CANADIAN HAVE A DEEPENING TROUGH THROUGH THE NORTHERN
PLAINS FOR THE BEGINNING OF NEXT WEEK. TEMPERATURES OVER OUR AREA
WILL BE DEPENDENT ON WHICH SOLUTION VERIFIES, THOUGH IT DOES LOOK
LIKE A DRIER PERIOD FOR MONDAY AND TUESDAY.
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
ISSUED AT 1243 PM CDT WED OCT 15 2025
LOW STRATUS AND IFR/MVFR CEILINGS WILL BE THE PRIMARY IMPACT AT
KHON/KFSD THROUGH THE PERIOD. CEILINGS WILL LIKELY HOVER AROUND
1000 FT AGL PLUS/MINUS A FEW HUNDRED FEET. DURING THIS TIME,
THERE COULD ALSO BE PERIODS OF LIGHT DRIZZLE, BUT NOT ENOUGH TO
SIGNIFICANTLY IMPACT VISIBILITY. THERE IS A 30-40 PERCENT CHANCE
FOR SHOWERS AT KHON BY THURSDAY MORNING AND WILL COVER THIS
POSSIBILITY WITH A PROB30 GROUP. WILL ALSO NEED TO WATCH FOR
POSSIBLE RE-DEVELOPMENT OF FOG AT KFSD OVERNIGHT.
WHILE STILL MOSTLY CLOUDY THROUGH THE PERIOD, CEILINGS AT KSUX
LIKELY TO REMAIN ABOVE 3000 FT AGL. THERE COULD BE A PASSING
LIGHT RAIN SHOWER THIS AFTERNOON, BUT NOT ENOUGH CONFIDENCE TO
INCLUDE IN THE 18Z FORECAST.
LIGHT EAST-SOUTHEAST WIND WILL BE THE RULE THROUGH THE AFTERNOON
WITH SOME INCREASING GUSTS FROM 20-25 KTS LATER THIS EVENING/
OVERNIGHT AND ESPECIALLY AFTER 12Z THURSDAY.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
DISCUSSION...JM
AVIATION...ROGERS
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