046
FXUS63 KFSD 261111
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
611 AM CDT TUE AUG 26 2025
KEY MESSAGES
- ONE MORE DAY OF COOLER TEMPERATURES TODAY, WITH TEMPERATURES
NEAR SEASONAL AVERAGES FOR WEDNESDAY AND THURSDAY.
- PATCHY AND SHALLOW RIVER FOG MAY LEAD TO VISIBILITY BELOW TWO
MILES THROUGH MID MORNING.
- ISOLATED TO SCATTERED SHOWERS ALONG THE MISSOURI RIVER VALLEY
COME TO AN END LATE THIS MORNING. ADDITIONAL CHANCES RETURN
TONIGHT AND WEDNESDAY, MAINLY ALONG AND EAST OF I-29. RAINFALL
AMOUNTS REMAIN LIGHT (LESS THAN A TENTH OF AN INCH).
- MORE WIDESPREAD RAIN CHANCES AND COOLER CONDITIONS RETURN BY
FRIDAY NIGHT THROUGH THE UPCOMING HOLIDAY WEEKEND, ALTHOUGH
DETAILS REMAIN UNCERTAIN. CONTINUE TO MONITOR THE LATEST
FORECAST FOR UPDATES.
DISCUSSION
ISSUED AT 242 AM CDT TUE AUG 26 2025
NOW THROUGH TUESDAY NIGHT: PATCHY AND SHALLOW RIVER FOG MAY DEVELOP
AGAIN THIS MORNING, AND IS EXPECTED TO MIX OUT QUICKLY. SEEING A FEW
ISOLATED SHOWERS THIS MORNING ALONG THE WAA WING AND LLJ NEAR THE MO
RIVER VALLEY INTO NORTHERN NE, AND EXPECT THESE TO CONTINUE THROUGH
MID TO LATE MORNING. THUNDER CHANCES REMAIN LOW. LITTLE ACCUMULATION
IS EXPECTED, WITH A FAIRLY DRY SUB CLOUD LAYER. TEMPERATURES TODAY
WILL BE A COUPLE OF DEGREES WARMER THAN WE SAW YESTERDAY, ALTHOUGH
STILL BELOW SEASONAL NORMS. HIGHS TODAY IN THE 70S TO NEAR 80 IN
SOUTH CENTRAL SD WITH ANOTHER DAY OF DIURNALLY DRIVEN CUMULUS CLOUDS.
MAY SEE ADDITIONAL SHOWERS (AROUND A 25% CHANCE) TONIGHT INTO EARLY
WEDNESDAY MORNING WITH WAA, WEAK WAVE, AND LLJ OVERHEAD. SIMILAR TO
THIS MORNING, THINK THAT ACTIVITY REMAINS FAIRLY ISOLATED IN NATURE,
BUT SHOULD BE FOCUSED ALONG AND EAST OF I-29. CAN'T ENTIRELY RULE
OUT A COUPLE RUMBLES OF THUNDER. MILDER LOWS TONIGHT, FALLING IN THE
50S.
WEDNESDAY: SHOWER AND ISOLATED STORM CHANCES CONTINUE THROUGH THE
DAY WEDNESDAY WITH TONIGHT'S SHORT WAVE, AND ADDITIONAL
EVENING/NIGHTTIME CHANCES AS ANOTHER SHORT WAVE MOVES ACROSS THE
REGION. HOWEVER, COVERAGE IS UNCERTAIN AS WE MAY BE LIMITED BY LOW
LEVEL MOISTURE, SO HAVE KEPT MOST OF THE AREA DRY. ALOFT, RIDGE AXIS
BEGINS TO BUILD TO THE WEST, WHICH WITH WAA HELPS OUR TEMPERATURES
RETURN TO SEASONAL NORMALS. HIGHS IN THE MID 70S TO MID 80S WITH
LOWS IN THE MID 50S.
LATE WEEK: RIDGING ALOFT BUILDS LATE WEEK, MOVING EAST INTO FRIDAY.
RIDGE AXIS REMAINS OFF TO OUR SOUTH WITH THE STRONGEST PART OF THE
JET, BUT THIS PERIOD SHOULD STILL BRING NEAR NORMAL TEMPERATURES AND
MOSTLY DRY CONDITIONS.
FRIDAY EVENING ONWARD: ALTHOUGH GUIDANCE VARIES ON THE DETAILS, NEXT
WAVE AND MID/UPPER LOW PRESSURE BEGIN TO MOVE INTO THE REGION FRIDAY
NIGHT. WAVE DEEPENS WITH MID LEVEL CYCLOGENESIS OVER THE NORTHERN
PLAINS SATURDAY. THIS PATTERN SHOULD LEAD TO COOLER AND CLOUDY
CONDITIONS WITH PERIODS OF SHOWERS AND STORMS THROUGH INTO LABOR
DAY. SEVERE WEATHER IS NOT EXPECTED. CURRENTLY, THE HIGHEST
PROBABILITY (OVER 50%) OF GREATER THAN A TENTH OF AN INCH IS WEST OF
THE JAMES RIVER FRIDAY NIGHT THROUGH SATURDAY NIGHT.
AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/
ISSUED AT 607 AM CDT TUE AUG 26 2025
VERY PATCHY AND ISOLATED RIVER FOG THIS MORNING COULD LEAD TO
REDUCED VISIBILITY THROUGH ROUGHLY 14Z. OTHERWISE, AN AREA OF
SHOWERS NEAR KYKN TO KSUX TO KLCG CONTINUES TO SLIDE SOUTH-
SOUTHEAST AND SHOULD DIMINISH THROUGH THE MORNING HOURS. HAVE
INCLUDED -SHRA MENTION AT KSUX FOR A HOUR OR SO, BUT THINK THAT
CONDITIONS REMAIN VFR.
LIGHT WINDS AND VFR CONDITIONS PREVAIL THROUGH MUCH OF THE
PERIOD WITH DIURNAL CU DEVELOPING ONCE AGAIN. MAY SEE ISOLATED
SHOWERS THIS EVENING INTO TONIGHT, MAINLY ALONG AND EAST OF
I-29, BUT CONFIDENCE IS TOO LOW FOR MENTION AT KFSD OR KSUX AT
THIS TIME.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
DISCUSSION...SG
AVIATION...SG
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