636
FXUS63 KFSD 241845
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
145 PM CDT MON AUG 24 2026
KEY MESSAGES
- AN ISOLATED SEVERE STORM IS POSSIBLE THIS EVENING INTO THE
OVERNIGHT, WITH BETTER CHANCES IN CENTRAL SD AND ALSO NEAR
AND NORTH OF HIGHWAY 14. AN ISOLATED STRONGER STORM MAY ALSO
DEVELOP ACROSS PORTIONS OF NORTHWEST IOWA/SOUTHWEST MINNESOTA
LATE TUESDAY AFTERNOON.
- SEASONABLE TEMPERATURES THROUGH THE WEEK AHEAD WITH HIGHS IN
THE UPPER 70S AND 80S, AND LOWS IN THE UPPER 50S TO MID 60S.
DISCUSSION
ISSUED AT 143 PM CDT MON AUG 24 2026
SHOWERS AND THUNDERSTORMS ARE POSSIBLE TONIGHT INTO EARLY TUESDAY
MORNING AS A WAVE SKIRTS BY TO THE NORTH AND WEST. FOR EARLY THIS
EVENING, INSTABILITY GROWS ACROSS CENTRAL SD, WITH CAPE VALUES OF
2000-3000 J/KG, BUT ONLY MARGINAL SHEAR. INITIALLY STORMS WILL BE
MOST LIKELY WEST OF THE AREA, BUT SOME DEVELOPMENT COULD CREEP INTO
GREGORY AND BRULE COUNTIES. CAPPING MAY PRECLUDE ANY DEVELOPMENY,
SO ONLY LOW CONFIDENCE IN STORMS ACTUALLY DEVELOPING. LATER TONIGHT
INTO EARLY TUESDAY MORNING A TAIL OF CONVECTION COULD BUILD SOUTH
TOWARDS HIGHWAY 14 AND INTO PARS OF SOUTHWEST MN. HERE CAPE VALUES
OF ABOUT 1000-1500 J/KG WILL BE POSSIBLE WITH MINOR-MODERATE SHEAR.
SPOME QUESTION AS THE WHETHER WE SEE AN INCREASE IN MOISTURE AROUND
800 MB WHICH APPEARS TO BE NEEDED TO PRODUCE A FEW UPDRAFTS. ONCE
AGAIN THIS IS SOMEWHAT LOWER CONFIDENCE SET UP. ISOLATED SEVERE
WEATHER WILL BE POSSIBLE IN BTH AREAS, HALF DOLLARS AND 70 MPH WINDS
IN CENTRAL SD AND QUARTERS AND 60 MPH WINDS IN SOUTHWEST MN.
WARMER AIR ALOFT BUILDS INTO THE AREA TUESDAY, BUT OTHER THAN NORTHWEST
IA THE THREAT FOR SHOWERS AND THUDNERSTORMS WILL BE FAIRLY LOW. IF
THERE IS SOME ELEVATED MOISTURE THERE COULD BE A LITTLE ACTIVITY IN
THE MORNING. NORTHWEST IA MAY SEE JUST ENOUGH INSTABILITY AND SHEAR
ON TUESDAY AFTERNOON FOR A COUPLE OF STRONG TO SEVERE UPDRAFTS.
BEHIND THIS COOLER AND DRIER AIR BUILDS INTO THE AREA WHICH APPEARS TO
BRING DRY AND SEASONALLY MILD CONDITIONS FOR WEDNESDAY AND THURSDAY.
STRONGER WESTERLY WINDS ALOFT WILL SPREAD ACROSS THE AREA FRIDAY INTO
THE WEEKEND. THIS SHOUDL BRING OCCASIONAL CHANCES FOR SHOWERS AND
THUNDERSTORMS DURING THIS TIME. FRIDAY NIGHT APPEARS TO BE A BETTER
CHANCE RIGHT NOW. AS THE WARMER CONDITIONS AND SOMEWHAT DEEPER
INSTABILITY BUILD IN FRIDAY NIGHT INTO SATURDAY ISOLATED SEVERE
STORMS WILL BE POSSILE.
AVIATION /12Z TAFS THROUGH 12Z TUESDAY/
ISSUED AT 630 AM CDT MON AUG 24 2026
SHOWERS CONTINUE TO PULL SOUTHEAST AS WE START THIS TAF PERIOD,
LINGERING IN PORTIONS OF NORTHWEST IOWA FOR ANOTHER 1-3 HOURS
(ONLY THROUGH ABOUT 13Z FOR KSUX). THE REMAINDER OF THE PERIOD
SHOULD SEE VFR CONDITIONS PREVAIL, WITH LOW CONFIDENCE CHANCES
FOR ISOLATED THUNDERSTORMS DURING THE LATTER HALF OF THE PERIOD.
KHON HAS A SLIGHTLY BETTER CHANCE AT SEEING CONVECTION AFTER
SUNSET THAN KFSD/KSUX, BUT EVEN THERE CONFIDENCE IS TOO LOW TO
INCLUDE MENTION OF TS AT THIS TIME.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
DISCUSSION...08
AVIATION...
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page