950
FXUS63 KFSD 142313
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
613 PM CDT TUE OCT 14 2025
KEY MESSAGES
- SHOWERS TAPER OFF OVER THE NEXT FEW HOURS, BECOMING DRIZZLE
AND MORE ISOLATED. SHOWER/DRIZZLE CHANCES PERSIST THROUGH
WEDNESDAY.
- A BRIEF PERIOD OF PLEASANT WEATHER THURSDAY AHEAD OF AN
INCOMING SYSTEM THAT WILL BRING ADDITIONAL SHOWERS ALONG A
COLD FRONT THURSDAY NIGHT INTO FRIDAY.
- QUIET WEATHER WITH SEASONABLY WARM TEMPERATURES INTO NEXT
WEEK.
DISCUSSION
ISSUED AT 218 PM CDT TUE OCT 14 2025
THE RADAR HAS DIMINISHED IN COVERAGE OVER THE LAST COUPLE OF
HOURS, WITH FURTHER SHOWERS DEVELOPING BUT REMAINING MORE
ISOLATED THROUGH THE REST OF TODAY AND INTO WEDNESDAY. THE
FORCING CONTINUES DUE MAINLY TO LOW LEVEL WAA AS SURFACE HIGH
PRESSURE IS CENTERED TO OUR NORTH NEAR THE ND/MN/CANADIAN
BORDER, WITH SMALL LOBES OF VORTICITY ADDING A BIT OF LOCAL
PUNCH TO A FEW OF THE SHOWERS. CAM FORECAST SOUNDINGS SHOW A
SATURATED BOTTOM 500MB OF THE ATMOSPHERE PERSISTING THROUGH MOST
OF WEDNESDAY, HOWEVER THE FORCING FROM THE WAA WEAKENS SUCH THAT
WE SHOULD SEE LOWER COVERAGE AND INTENSITY OF SHOWERS EVENTUALLY
DWINDLING DOWN TO A BRIEF DRY PERIOD ON THURSDAY. INSTABILITY
LARGELY REMAINS ABSENT SO EVEN RUMBLES OF THUNDER SEEM UNLIKELY,
WITH THE ACTIVITY TODAY LARGELY ABSENT OF ANY THUNDER ACTIVITY.
AN UPPER LEVEL RIDGE CROSSES THE REGION THURSDAY WITH A BRIEF
BURST OF SUBSIDENCE AHEAD OF A DEVELOPING SURFACE LOW PRESSURE
SYSTEM AND UPPER LEVEL TROUGH FORMING OVER THE ROCKIES, ALLOWING
FOR A BIT OF SUNSHINE AND TEMPERATURES SURGING INTO THE MID TO
UPPER 70S ON THURSDAY AS LOW LEVEL WINDS INCREASE OUT OF THE
SOUTH/SOUTHWEST. THIS DEVELOPING LOW PRESSURE SYSTEM HAS BEEN
CONSISTENTLY FORECAST BY THE GLOBAL DETERMINISTIC GUIDANCE TO
PUSH NORTHWARDS ACROSS THE CENTRAL DAKOTAS BEFORE STRENGTHENING
AS IT STALLS NEAR THE CANADIAN BORDER, WITH A BROAD AND DIFFUSE
COLD FRONT PUSHING ACROSS THE FORECAST AREA LATE THURSDAY NIGHT
INTO FRIDAY MORNING. ENSEMBLES ARE RELATIVELY SPLIT ON QPF
AMOUNTS ALONG THE FRONT WITH AROUND 25% OF GEFS MEMBERSHIP
SHOWING ABOVE 0.1 INCHES, WITH ROUGHLY 75% SHOWING AT LEAST A
HUNDREDTH OR TWO AND ONLY A FEW MEMBERS COMPLETELY DRY. THE LAST
COUPLE OF FRONTS HAVE OVERPRODUCED CLOUD COVER AND SHOWERS
COMPARED TO THE GUIDANCE IN THE FEW DAYS LEADING UP, SO IF THIS
TREND CONTINUES WE CAN EXPECT A TENTH OF AN INCH OR TWO AS THE
FRONT PASSES THROUGH BY 12-15Z FRIDAY. THERE IS SOME ADDITIONAL
SHOWERY ACTIVITY POSSIBLE ON SATURDAY AS COLD AIR ADVECTION
WRAPS AROUND THE NOW OCCLUDED UPPER LEVEL TROUGH, WITH SHOWERS
POSSIBLE AS LONG AS WE HAVE THE MOISTURE TO SUPPORT THE WEAK
FORCING, WHICH APPEARS LIKELY GIVEN THE FORECAST SOUNDINGS AND
RAIN CHANCES LEADING UP TO SATURDAY.
AFTER THE RAIN CHANCES ON SATURDAY, THERE IS A SIGNIFICANT SPLIT
IN THE GUIDANCE FOR THE FOLLOWING WEEK, WITH THE GFS MARKEDLY
WARMER AS ANOTHER TROUGH DEVELOPS OVER THE ROCKIES AND LOW LEVEL
WAA RETURNS. THE ECMWF/CFS ARE MUCH COLDER WITH A BROAD AREA OF
CAA AND NORTHWESTERLY FLOW ALOFT, WITH THE ECMWF SHOWING A MORE
AMPLIFIED UPPER LEVEL PATTERN WHICH DRAGS COOLER AIR MUCH
FARTHER SOUTH. GIVEN THE DIFFERENCES, FORECAST CONFIDENCE IS
FAIRLY LOW AFTER THE WEEKEND WITH THE ONLY CONSENSUS BEING A
RELATIVELY DRY FORECAST.
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
ISSUED AT 611 PM CDT TUE OCT 14 2025
WIDESPREAD IFR THROUGH THE PERIOD WITH POTENTIALLY LIFR LATE
TONIGHT INTO EARLY WEDNESDAY MORNING. SPOTTY SHOWERS WILL REMAIN
POSSIBLE THROUGH THE PERIOD, BUT LIKELY BE A BIT MORE ISOLATED
THAN TODAY. WHILE SHOWERS WILL NOT BE AS WIDESPREAD, AREAS OF
FOG AND DRIZZLE WILL INCREASE OVERNIGHT, PROVIDING THE LOW
AVIATION CONDITIONS. SOME IMPROVEMENT IS EXPECTED LATE TOMORROW
MORNING INTO THE AFTERNOON.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
DISCUSSION...MPX
AVIATION...08
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