046
FXUS63 KFSD 170338
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1038 PM CDT WED JUL 16 2025
KEY MESSAGES
- THERE IS A LOW CHANCE FOR LIGHT RAIN SHOWERS/SPRINKLES LATE
THIS AFTERNOON, MAINLY NORTH OF I-90. ANY ACCUMULATION WILL BE
A COUPLE HUNDREDTHS AT BEST.
- DECREASING CLOUDS THIS EVENING AND OVERNIGHT WITH PARTLY
SUNNY, DRY, AND COOL CONDITIONS ON THURSDAY WITH AFTERNOON
HIGHS IN THE LOW TO MID 70S.
- SHOWER AND THUNDERSTORM CHANCES OF 30 TO 60 PERCENT RETURN
FRIDAY AND FRIDAY NIGHT.
- NEAR DAILY 20-30 PERCENT PRECIPITATION CHANCES THIS WEEKEND
INTO EARLY NEXT WEEK, ALTHOUGH PREDICTABILITY IS LOW.
TEMPERATURES WILL RISE TO NEAR OR ABOVE 90 DEGREES IN MANY
LOCATIONS BY NEXT TUESDAY.
DISCUSSION
ISSUED AT 236 PM CDT WED JUL 16 2025
LATE THIS AFTERNOON, A FEW STRAY LIGHT RAIN SHOWERS/SPRINKLES
ARE POSSIBLE MAINLY NORTH OF I-90. ANY ACCUMULATION SHOULD BE NO
MORE THAN A COUPLE HUNDREDTHS. CLOUDS WILL THEN BE SLOW TO MOVE
OUT LATE EVENING AND OVERNIGHT, BUT MODEL SOUNDINGS SUGGEST
INCREASING SUN THROUGH THE DAY ON THURSDAY AS SURFACE HIGH
PRESSURE SETTLES ACROSS THE REGION. TEMPERATURES WILL BE A BIT
WARMER THAN TODAY, BUT STILL A SOLID 10 DEGREES BELOW MID-JULY
NORMALS WITH HIGHS IN THE LOW TO MID 70S.
SOUTHERLY SURFACE RETURN FLOW INCREASES THURSDAY NIGHT INTO
FRIDAY AS HIGH PRESSURE SLIDES EASTWARD. THIS WILL ALLOW FOR
INCREASING TEMPERATURES/MOISTURE WITH AFTERNOON DEWPOINTS BACK
INTO THE UPPER 60S TO LOW 70S. AS A RESULT, MUCAPE SOARS UPWARDS
OF 3000 J/KG DEPENDING ON THE MODEL, BUT VERY STRONG HEATING IN
THE 5-10 KFT AGL LAYER ALSO RESULTS IN A STOUT CAP. 12Z MODEL
SUITE SUGGESTS A WEAK WAVE IN QUASI-ZONAL FLOW ALOFT FRIDAY
AFTERNOON/EVENING, WHICH MAY BE ENOUGH TO BREAK THE CAP, OR AT
LEAST RESULT IN SOME ELEVATED THUNDERSTORMS. FOR NOW, INCREASING
POPS THROUGH THE DAY ON FRIDAY, PEAKING IN THE 30-60 PERCENT
RANGE IN THE EVENING SEEMS REASONABLE.
PRECIPITATION PREDICTABILITY THIS WEEKEND INTO EARLY NEXT WEEK
REMAINS QUITE LOW GIVEN MESSY SYNOPTIC PATTERN. 500 HPA HEIGHTS
BUILD THROUGH THIS PERIOD, BUT PERIODIC ILL-RESOLVED SHORT-WAVES
MAY BE ENOUGH FOR NEAR DAILY CONVECTIVE CHANCES. QUESTIONS
ABOUND CONCERNING TIMING/COVERAGE OF ANY THUNDERSTORMS, SO WILL
KEEP WITH THE IDEA OF BROAD-BRUSHED 20-40 POPS. THIS PATTERN,
HOWEVER, DOES FAVOR INCREASING TEMPERATURES. GFS/ECMWF ENSEMBLES
SHOW A 50-70 PERCENT CHANCE FOR AFTERNOON HIGHS TO RISE ABOVE
90 DEGREES FOR MUCH OF THE SOUTHERN AND WESTERN PORTIONS OF THE
FORECAST AREA BY TUESDAY.
AVIATION /06Z TAFS THROUGH 06Z FRIDAY/
ISSUED AT 1030 PM CDT WED JUL 16 2025
A MIX OF VFR AND MVFR CONDITIONS WILL LIKELY TRANSITION TO
MOSTLY VFR CONDITIONS THIS TAF PERIOD. TAKING A LOOK AT
SATELLITE IMAGERY, AREAS OF STRATUS CONTINUES TO MOVE SOUTH
THIS EVENING WITH KHON RETURN TO VFR CONDITIONS. EXPECT THE
STRATUS DECK TO CONTINUE PUSHING SOUTHWARDS OVERNIGHT POTENTIALLY
LEAVING THE AREA BY DAYBREAK ON THURSDAY. COULD SEE SOME PATCHY
FOG DEVELOP ACROSS AREAS EAST OF I-29 AND OUR RIVER VALLEYS
OVERNIGHT. HOWEVER, CONFIDENCE IN WIDESPREAD FOG IS LOW.
OTHERWISE, LIGHT NORTHERLY WINDS WILL BECOME MORE SOUTHEASTERLY
BY THURSDAY AFTERNOON TO END THE TAF PERIOD.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
DISCUSSION...ROGERS
AVIATION...05
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