558
FXUS63 KFSD 230830
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
330 AM CDT THU JUL 23 2026
KEY MESSAGES
- LOCALIZED FOG WILL CONTINUE MAINLY IN OUR WATERWAYS AND LOW
LAYING AREAS THROUGH MID-MORNING.
- LIGHT TO MODERATE SHOWERS WILL PROGRESS THROUGH AREAS ALONG
AND SOUTH OF I-90 AS EARLY AS THIS AFTERNOON. ACCUMULATIONS OF
A 0.25" TO 0.50" OF AN INCH WILL BE POSSIBLE ALONG THE MISSOURI
RIVER VALLEY.
- AFTER ANOTHER DAY OF BELOW NORMAL TEMPERATURES, THE SUMMER HEAT
WILL RETURN OVER THE WEEKEND WITH MULTIPLE DAYS OF HIGHS IN
THE 90S TO LOW 100S AHEAD. HEAT-REALATED HEADLINES MAY BE
NEEDED.
UPDATE
ISSUED AT 328 AM CDT THU JUL 23 2026
TAKING A LOOK ACROSS THE AREA, QUIETER CONDITIONS PERSIST AS CLOUD
COVER CONTINUES TO FILL IN WEST OF HURON TO SIOUX FALLS TO STORM
LAKE, IA LINE. WHILE THE FORECAST STILL REMAINS ON TRACK, A DREARIER
DAY IS AHEAD AS CLOUD COVER GRADUALLY SPREADS EASTWARDS. HOWEVER,
WITH INCREASING SOUTHERLY SURFACE WINDS IN PLACE, EXPECT HIGHS TO
TOP OUT IN THE UPPER 70S TO LOW 80S FOR THE DAY. SHIFTING GEARS
HERE, WE'LL SEE THE RETURN OF LIGHT TO MODERATE SHOWERS DURING THE
SECOND HALF THE DAY AS ANOTHER SHORTWAVE PROGRESSES THROUGH THE
AREA. WHILE AREAS AS FAR NORTH AS THE I-90 CORRIDOR COULD SEE LIGHT
ACCUMULATIONS, THE HIGHEST ACCUMULATIONS ARE EXPECTED ALONG THE
MISSOURI RIVER VALLEY WHERE A 0.25" TO 0.50" OF AN INCH WILL BE
POSSIBLE. WHILE FLASH FLOODING IS NOT EXPECTED, DEEP WARM CLOUD
PROCESSES COULD LEAD TO LOCALIZED PONDING IF HEAVIER SHOWERS
PERSIST OVER CERTAIN AREAS. LASTLY, COULD SEE THIS ACTIVITY
PERSIST ACROSS PORTION OF THE HIGHWAY-20 CORRIDOR AND THE LOWER
MISSOURI RIVER VALLEY THROUGH EARLY FRIDAY MORNING.
DISCUSSION
ISSUED AT 142 PM CDT WED JUL 22 2026
LIGHT RAIN SHOWERS CONTINUE TO DRIFT THROUGH PART OF THE AREA THIS
AFTERNOON. THE ABUNDANT CLOUD COVER HAS KEEP HIGH TEMPERATURES ON
THE COOLER SIDE WITH HIGHS ONLY WARMING TO 60S AND 70S. RAINFALL
AMOUNTS UP TO A FEW HUNDREDTHS TO A TENTH OR SO REMAIN MAINLY ACROSS
SOUTH CENTRAL SOUTH DAKOTA. ANY CHANCE FOR RAIN WILL COME TO AN END
BY THIS EVENING, LEAVING PARTLY CLOUDY TO CLOUDY SKIES FOR THE
OVERNIGHT HOURS. DESPITE THE CLOUD COVER, A SURFACE HIGH PUSHING
THROUGH THE AREA WILL KEEP LIGHT EAST/SOUTHEAST FLOW GOING THROUGH
THE OVERNIGHT TIMEFRAME, ALLOWING FOR LOW TEMPERATURES TO FALL TO
THE 50S TO LOW 60S ACROSS THE AREA.
CLOUDY SKIES WILL PERSIST THROUGH THE DAY TOMORROW, KEEPING HIGH
TEMPERATURES NEAR TO BELOW AVERAGE AGAIN IN THE 70S WITH A FEW SPOTS
REACHING INTO THE LOW 80S. SOUTHERLY RETURN FLOW WILL PICK UP AS THE
PREVIOUSLY MENTIONED SURFACE HIGH DEPARTS TO THE SOUTHEAST. WINDS
WILL STILL REMAIN ON THE LIGHTER SIDE BUT A FEW GUSTS UP TO 20-25
MPH IS EXPECTED. ANOTHER SHORTWAVE TROUGH WILL PUSH THROUGH THE
FORECAST AREA, RESULTING IN SHOWERS ACROSS THE AREA ONCE AGAIN.
THESE SHOWERS LOOK TO BE MORE WIDESPREAD THOUGH REMAINING ALONG AND
SOUTH OF I-90 FOR THE DAY. FORCING WILL BE A BIT STRONGER WITH THIS
CHANCE FOR RAIN ALONG WITH VERY MINOR INSTABILITY BEING PRESENT AT
OR BELOW 100 J/KG. THIS WILL BRING OVERALL HIGHER RAINFALL AMOUNTS
TO LOCATIONS ALONG AND SOUTH OF A CHAMBERLAIN, SOUTH DAKOTA TO
BERESFORD, SOUTH DAKOTA TO STORM LAKE, IOWA WHERE RAINFALL AMOUNTS
BETWEEN A QUARTER TO A HALF AN INCH ARE POSSIBLE (20-60%). LIGHTER
AMOUNTS ARE EXPECTED NORTH OF THIS LINE. WITH THE VERY MINOR
INSTABILITY IN PLAY, AN ISOLATED RUMBLE OF THUNDER IS POSSIBLE. THIS
LIGHT RAIN WILL PERSIST INTO THE NIGHT BEFORE PUSHING SOUTHEAST OF
THE AREA BY FRIDAY MORNING.
UPPER LEVEL RIDGING WILL BEGIN TO BUILD OVER THE CENTRAL PLAINS ON
FRIDAY, RAISING HIGH TEMPERATURES BACK TO THE UPPER 70S, 80S, AND
LOW 90S. THIS TREND WILL CONTINUE THROUGH THE WEEKEND AS THE THERMAL
RIDGE SLIDES EASTWARDS. HIGH TEMPERATURES LOOK TO RETURN TO ABOVE
AVERAGE WITH HIGHS IN THE 90S TO LOW 100S. THE ENSEMBLES SUPPORT
THIS AS THEY SHOW HIGH PROBABILITIES (60-100% CHANCE) FOR HIGH
TEMPERATURES TO EXCEED 90F ALONG AND WEST OF I-90 OVER THE WEEKEND.
THEIR PROBABILITIES DROP TO A 30-40% CHANCE FOR HIGHS TO BREAK 100F
OVER THE SAME AREA. THE EFI ALSO SUPPORTS THIS AS IT SHOWS 60-100%
OF ITS MEMBERS SUGGESTING ANOMALOUSLY WARM TEMPERATURES THIS WEEKEND
AND A SHIFT OF TAILS EXCEEDING 1. THUS, WILL HAVE TO CONTINUE TO
MONITOR THE POTENTIAL FOR HEAT HEADLINES BEING NEEDED, ESPECIALLY AS
DEW POINTS LOOK TO REMAIN IN THE 60S AND 70S.
THE HEAT LOOKS TO BEGIN TO WANE ON MONDAY AS HIGH TEMPERATURES LOOK
TO ONLY WARM TO THE 90S. HIGHS WILL SLIGHTLY COOL INTO THE MIDDLE OF
NEXT WEEK. WITH THE FORECAST AREA BEING JUST ON THE NORTHERN
GRADIENT OF THE UPPER LEVEL RIDGE, RIDGE RIDING SHORTWAVES COULD
BRING RAIN AND PERHAPS STORM CHANCES BACK TO THE AREA. THE ENSEMBLES
ONLY SHOW LOW PROBABILITIES RANGING FROM 0 TO 30% SO CONFIDENCE IS
LOW IN THIS POTENTIAL AS OF NOW. MACHINE LEARNING GUIDANCE ALSO ONLY
SHOWS A HALF A PERCENT TO ABOUT A 5% CHANCE FOR SEVERE STORMS SUNDAY
THROUGH THE MIDDLE OF NEXT WEEK. SOMETHING TO KEEP AN EYE ON AS WE
HEAD INTO ANOTHER HOT AND HUMID PATTERN.
AVIATION /06Z TAFS THROUGH 06Z FRIDAY/
ISSUED AT 1229 AM CDT THU JUL 23 2026
VFR CONDITIONS EXPECTED FOR THE MAJORITY OF THE PERIOD. WINDS ARE
LIGHT AND VARIABLE. PATCHY FOG IS POSSIBLE JUST BEFORE SUNRISE THIS
MORNING ALONG WATER WAYS AND LOW AREAS, MOSTLY EAST OF I-29. FOG IS
EXPECTED TO BURN OFF BY MID MORNING.
WINDS BECOME SOUTHERLY AND INCREASE AFTER SUNRISE. GUSTS OF 15-25
KTS ARE EXPECTED WEST OF I-29, WITH THE HIGHEST GUSTS OVER CENTRAL
SOUTH DAKOTA. GUSTS TO THE EAST OF I-29 SHOULD BE 15 KTS OR LESS.
STORMS BEGIN TO MOVE IN FROM THE WEST THIS MORNING AND WILL SLOWLY
MAKE THEIR WAY EAST-SOUTHEAST THROUGH THE END OF THE PERIOD. SEVERE
WEATHER IS NOT ANTICIPATED BUT A FEW STORMS COULD PRODUCE LIGHTNING
AND BRIEF, HEAVY DOWNPOURS. THE MAJORITY OF THE ACTIVITY SHOULD
REMAIN ALONG AND SOUTH OF I-90. KFSD HAS A LOW CHANCE (30%) OF
PERIODIC STORMS THIS AFTERNOON AND EVENING. KSUX HAS A 40-50% CHANCE
FOR STORMS THIS AFTERNOON, WITH CHANCES INCREASING TO 70-80% IN THE
LATE EVENING HOURS. UNDER STORMS CEILINGS AND VISIBILITY MAY BRIEFLY
BE REDUCED TO MVFR AND POSSIBLY IFR STATUS.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
UPDATE...05
DISCUSSION...MEYERS
AVIATION...AJP
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