326
FXUS63 KFSD 262321
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
621 PM CDT TUE AUG 26 2025
KEY MESSAGES
- TODAY WILL BE THE LAST FALL LIKE DAY WITH TEMPERATURES WARMING
TO NEAR SEASONABLE FOR WEDNESDAY AND THURSDAY.
- ADDITIONAL CHANCES FOR RAIN RETURN TONIGHT AFTER MIDNIGHT
TONIGHT AND PERSIST THROUGH WEDNESDAY. SOME STRONGER STORMS
ARE POSSIBLE WEDNESDAY AFTERNOON WITH THE POTENTIAL FOR SMALL
HAIL AND GUSTY WINDS.
- MORE WIDESPREAD RAIN CHANCES AND COOLER CONDITIONS RETURN BY
FRIDAY NIGHT THROUGH THE UPCOMING HOLIDAY WEEKEND. DETAILS CAN
STILL CHANGE HEADING INTO THE WEEKEND SO PLEASE CONTINUE TO
MONITOR THE LATEST FORECAST FOR THE MOST UP TO DATE
INFORMATION.
DISCUSSION
ISSUED AT 250 PM CDT TUE AUG 26 2025
QUIET CONDITIONS PERSIST THIS AFTERNOON. HIGH TEMPERATURES HAVE
WARMED A BIT MORE TO THE 70S WHILE WINDS REMAIN LIGHT OUT OF THE
SOUTH/SOUTHEAST. TODAY WILL BE OUR LAST FALL LIKE DAY SO GET OUT
THERE AND ENJOY IT! THE QUIET CONDITIONS WILL COME TO AN END TONIGHT
AS WARM AIR ADVECTION (WAA) STRENGTHENS ALOFT. WITH ENOUGH
SATURATION IN PLACE, WEAK INSTABILITY WILL BE PRESENT VIA TALL
SKINNY CAPE PROFILES WITH MAGNITUDES OF ABOUT 500 J/KG. THIS WILL
PROMOTE SCATTERED SHOWERS MAINLY ALONG AND EAST OF THE JAMES RIVER
AFTER MIDNIGHT. NO SEVERE STORMS ARE EXPECTED BUT SOME OF THESE
SHOWERS COULD BE CAPABLE OF A FEW RUMBLES OF THUNDER OR STRAY
LIGHTNING STRIKE. THESE SHOWERS WILL PERSIST THROUGH THE REST OF THE
OVERNIGHT HOURS BEFORE WANING TOMORROW MORNING. LOW TEMPERATURES
WILL FALL TO THE 50S.
REMNANT CLOUD COVER AND WEAKENING SHOWERS ARE EXPECTED TOMORROW
MORNING. SHOULD SEE A DECENT BREAK IN CLOUD COVER FOR THE AFTERNOON
HOURS THOUGH. THIS WILL ALLOW FOR HIGH TEMPERATURES TO WARM TO THE
70S AND 80S ACROSS THE AREA. A WEAK BOUNDARY WILL BE SLOWLY SLIDING
INTO THE AREA DURING THE AFTERNOON HOURS. WHERE THIS BOUNDARY SETS
UP IS A BIT UNCERTAIN AT THIS TIME BUT IT IS LOOKING TO LIE ALONG
AND SOUTH OF HIGHWAY-14. THIS BOUNDARY LOOKS TO SPARK ANOTHER ROUND
OF CONVECTION DURING THE AFTERNOON HOURS. WITH CAPE VALUES UP TO
AROUND 1,000 J/KG AND SOME VERTICAL SHEAR, A COUPLE OF STRONGER
STORMS ARE POSSIBLE WITH GUSTY WINDS AND SMALL HAIL. THAT SAID,
DESPITE AN ENTRANCE REGION OF AN UPPER LEVEL JET RESIDING OVER THE
FORECAST AREA, SUFFICIENT VERTICAL SHEAR WILL NOT BE PRESENT UNTIL
ABOVE 7 KM. THIS LOOKS TO ALLOW FOR SOME TILTING OF UPDRAFTS BUT
THINK THAT IT WILL NOT BE SUFFICIENT ENOUGH FOR STORMS TO BECOME
SEVERE. ON TOP OF THE MARGINAL SHEAR, A SHORTWAVE TROUGH WILL BE
PASSING THROUGH THE AREA THROUGHOUT THE DAY. THE TIMING OF THIS WAVE
LOOKS TO BE A BIT OFF AS WELL SINCE THIS WAVE MAY BE A BIT TOO FAST
AND EXIT THE AREA BY THE LATE AFTERNOON OR EARLY EVENING HOURS. THAT
SAID, HAVE INCLUDED CHANCE POPS (30-50%) FOR THE SHOWERS AND STORMS.
ANY CHANCE FOR RAIN WILL COME TO AN END DURING THE EVENING HOURS.
LOWS WILL FALL TO THE 50S OVERNIGHT.
THURSDAY WILL BE A DRY DAY ACROSS THE NORTHERN PLAINS AS SHORTWAVE
RIDGING WILL PUSH INTO THE AREA ALOFT. HIGHS WILL REMAIN IN THE 70S
AND 80S WITH LOWS FALLING TO THE 50S. FRIDAY LOOKS TO BEGIN DRY BUT
LATEST TRENDS HAVE RAIN BEGINNING FRIDAY AFTERNOON ACROSS PORTIONS
OF CENTRAL AND SOUTH CENTRAL SOUTH DAKOTA AS A MID LEVEL WAVE BEGINS
TO ENCROACH ON THIS AREA. WITH CLOUDS AND RAIN POSSIBLE DURING THE
DAYLIGHT HOURS, HIGHS WILL REMAIN IN THE 70S TO LOW 80S THOUGH BE A
BIT COOLER THAN THURSDAY'S HIGHS.
RAIN CHANCES WILL INCREASE FRIDAY NIGHT, NOW UP TO A 20-40% CHANCE
AND EVEN FURTHER ON SATURDAY AS THE PREVIOUSLY MENTIONED MID AND
UPPER LEVEL WAVE PUSHES FURTHER EAST INTO THE FORECAST AREA. CHANCES
FOR RAIN WILL INCREASE UP TO A 30-60% CHANCE. RAIN AND ABUNDANT
CLOUD COVER WILL KEEP HIGH TEMPERATURES COOLER, DOWN TO THE 70S
THROUGHOUT THE DAY. THE LOW WILL BE PUSHING EASTWARDS ON SUNDAY
WHICH WILL RESULT IN DECREASING CHANCES FOR RAIN THROUGHOUT THE DAY.
SUNDAY WILL AGAIN BE A COOLER DAY WITH HIGHS REMAINING IN THE 70S.
LITTLE IF ANY INSTABILITY WILL BE PRESENT SO WHILE A FEW RUMBLES OF
THUNDER ARE POSSIBLE, PLAIN RAIN LOOKS TO BE ON THE TABLE FOR THE
WEEKEND. LATEST NBM 48 HOUR PRECIPITATION PROBABILITIES SHOW A 30-
50% CHANCE FOR RAINFALL TOTALS TO EXCEED A QUARTER OF AN INCH OVER
THE WEEKEND, HIGHEST TOWARDS CENTRAL AND SOUTH CENTRAL SOUTH DAKOTA.
ALL THIS TO SAY THAT THIS HOLIDAY WEEKEND IS LOOKING TO BE A
RAINY/DREARY WEEKEND. WHILE THIS IS WHAT THE GENERAL CONSENSUS OF
LATEST INFORMATION POINTS TO, DETAILS CAN STILL CHANGE HEADING INTO
THE HOLIDAY WEEKEND. PLEASE CONTINUE TO MONITOR THE LATEST FORECAST
FOR THE MOST UP TO DATE INFORMATION.
AVIATION /00Z TAFS THROUGH 00Z THURSDAY/
ISSUED AT 620 PM CDT TUE AUG 26 2025
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. POP-UP SHOWERS LOOK TO
DEVELOP AFTER MIDNIGHT MAINLY EAST OF THE JAMES RIVER, BUT THE
GREATEST CHANCE (30-40%) WILL BE EAST OF I-29 OVER SOUTHWEST
MINNESOTA. STILL, ENOUGH CONFIDENCE TO INCLUDE PROB30 GROUPS FOR
KFSD AND KSUX FOR VFR SHOWERS. WITH LATEST GUIDANCE HAVING SHIFTED
THE GREATER RAIN CHANCES EAST OF I-29, CHANGED PREVAILING -SHRA TO A
TEMPO GROUP AT KFSD FOR WEDNESDAY MORNING, THOUGH FURTHER UPDATES
MAY BE NEEDED AS NEW GUIDANCE COMES IN OVERNIGHT. ADDITIONAL SHOWERS
AND EVEN SOME THUNDERSTORMS LOOK TO DEVELOP TOWARDS THE END OF THE
PERIOD, THOUGH UNCERTAINTY IN TIME AND AREA OF DEVELOPMENT PRECLUDES
MENTION IN THE TAFS AT THIS TIME.
WINDS WILL BE OUT OF THE SOUTHEAST TONIGHT AROUND 5-10 KTS. A
BOUNDARY MOVING INTO THE HIGHWAY-14 CORRIDOR WILL TURN WINDS TO THE
NORTHEAST TOMORROW AFTERNOON FOR KHON, WHILE WINDS SHIFT TO THE
SOUTHWEST FOR KFSD AND KSUX.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
DISCUSSION...MEYERS
AVIATION...SAMET
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