576
FXUS63 KFSD 230142
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
842 PM CDT MON JUN 22 2026
KEY MESSAGES
- ISOLATED SPRINKLES TO SHOWERS ARE POSSIBLE THIS AFTERNOON AND
MAY CONTINUE INTO THE EVENING.
- SHOWERS AND EMBEDDED THUNDERSTORMS ARRIVE BY DAYBREAK TUESDAY
AND SPREAD EASTWARD IN THE DAY. VERY ISOLATED STRONG STORM
REDEVELOPMENT IS POSSIBLE IN THE AFTERNOON WITH A RISK OF
HAIL.
- BELOW NORMAL TEMPERATURES CONTINUE THROUGH MID WEEK BEFORE
MORE SEASONABLE TEMPERATURES RETURN FROM LATE WEEK INTO THE
WEEKEND.
UPDATE
ISSUED AT 841 PM CDT MON JUN 22 2026
LIGHT SCATTERED SHOWERS/DRIZZLE ARE DISSIPATING THIS EVENING AS WHAT
LITTLE ELEVATED INSTABILITY WANES. WINDS ARE LIGHT AND VARIABLE, BUT
WITH SOMEWHAT PERSISTENT CLOUD COVER TONIGHT LOWS WILL BE ON
THE WARM SIDE, IN THE UPPER 50S. OVERNIGHT, MODEST TO MODERATE
MOISTURE INFLUX WILL BEGIN TO SATURATE AND WEAKLY DESTABILIZE
THE LOW TO MID- LEVELS. NEAR SUNRISE TUESDAY WINDS IN THE
BOUNDARY LAYER BECOME SOUTHERLY AS WAA AND A WEAK 25-30 KT LLJ
SET UP OVER CENTRAL SOUTH DAKOTA. A SERIES OF WEAK SHORTWAVES
WILL APPROACH OUT OF THE WEST, TRIGGERING SCATTERED SHOWERS AND
WEAK THUNDERSTORMS. SEVERE WEATHER IS NOT ANTICIPATED BUT AN
ISOLATED STRONGER THUNDERSTORM COULD PRODUCE 30-40 MPH WIND
GUSTS. STORMS WILL MOVE EAST TO SOUTHEAST ACROSS THE REGION
THROUGH THE MORNING.
SOME DISAGREEMENT IN GUIDANCE ABOUT AFTERNOON CLOUDS RESULTS IN
UNCERTAINTY IN THE AFTERNOON FORECAST. SOME GUIDANCE SHOWS MORE
SUBSTANTIAL CLEARING AHEAD OF AN APPROACHING COLD FRONT, WHILE
OTHERS KEEP CLEARING TO ISOLATED POCKETS. CURRENT SOUNDINGS INDICATE
A MODEST 500-1000 J/KG MUCAPE. SHOULD THE BETTER CLEARING BE
REALIZED INSTABILITY WILL LIKELY INCREASE. MID-LEVEL LAPSE RATES
REMAIN MARGINAL AT 6.5 C/KM, HOWEVER 0-6 KM BULK SHEAR IS ROUGHLY 35-
45 KTS. THIS IS ENOUGH TO SUPPORT A FEW MORE ORGANIZED STORMS.
CONSIDERING ALL THIS THERE ARE TWO MOST LIKELY SCENARIOS FOR TUESDAY
AFTERNOON. THE SCENARIO WITH LESS CLEARING WILL RESULT IN WEAK
SHOWERS AND ISOLATED THUNDERSTORMS CAPABLE OF PRODUCING SMALL HAIL.
THE SCENARIO WITH MORE CLEARING COULD RESULT IN THUNDERSTORMS, A FEW
OF WHICH COULD BECOME STRONG TO SEVERE. THREATS WITH THE HIGH END
SCENARIO INCLUDE HAIL UP TO THE SIZE OF A HALF DOLLAR AND WIND GUSTS
TO 50 MPH. TIMING OF STORMS WILL BE MID TO LATE AFTERNOON AND INTO
THE EVENING HOURS TUESDAY.
DISCUSSION
ISSUED AT 1256 PM CDT MON JUN 22 2026
THIS AFTERNOON/EVENING: ISOLATED TO WIDELY SCATTERED SPRINKLES TO
SHOWERS WILL PERSIST INTO EARLY EVENING, AS SOUNDINGS INDICATE SHARP
LOW-LVL LAPSE RATES AND A SMALL POCKET OF INSTABILITY. THE LACK OF
LOW-LVL FLOW WOULD SUGGEST NO STRONG ORGANIZATION TO THIS ACTIVITY.
THESE SPRINKLES/SHOWERS MAY LINGER INTO THE EVENING GIVEN WEAK
PERTURBATIONS IN THE MID-LVL FLOW, BUT QPF WILL BE MINIMAL.
TONIGHT: EJECTING SHORTWAVES OFF THE CENTRAL/NORTHERN ROCKIES WILL
DEVELOP SEVERAL CLUSTERS OF CONVECTION OVER THE WESTERN DAKOTAS AND
NEBRASKA PANHANDLE THIS EVENING. WITH THIS ACTIVITY OUTRUNNING MOST
OF IT'S MEAGER INSTABILITY BY MIDNIGHT, IT WILL BEGIN TO CROSS INTO
THE WESTERN CWA BY DAYBREAK. WHILE A LOW CHANCE, A FEW 30 TO 40 MPH
GUSTS MAY BE POSSIBLE.
TUESDAY: SHOWERS AND EMBEDDED THUNDERSTORMS MOVE EAST THROUGH THE
CWA ON TUESDAY. EVENTUALLY BY MID-DAY TO THE EARLY EVENING A FEW
POCKETS OF CLEARING MAY TRY TO DEVELOP ALONG AND AHEAD OF A WEAK
COLD FRONT DRIFTING EASTWARD. WHILE SOUNDINGS SUGGEST INSTABILITY IS
MARGINAL (700-1000 J/KG), IF THOSE LARGER POCKETS DEVELOP (WHERE THE
UNCERTAINTY IN THE FORECAST REMAINS), SLIGHTLY MORE UNSTABLE AIRMASS
COULD DEVELOP. SHEAR THROUGHOUT THE EFFECTIVE LAYER SUPPORTS SOME
STORM ORGANIZATION, HOWEVER MID-LVL LAPSE RATES ARE MARGINAL.
ALL THAT SAID, A CONTINUED POTENTIAL FOR ISOLATED STRONG STORMS
WITH HAIL WILL BE POSSIBLE TUESDAY AFTERNOON AND EARLY EVENING.
WEDNESDAY: HIGH PRESSURE ARRIVING WILL LEAD TO A VERY PLEASANT AND
DRY WEDNESDAY. TEMPERATURES RISE INTO THE MIDDLE TO UPPER 70S.
THURSDAY-FRIDAY: SLIGHTLY COOLER THAN NORMAL TEMPERATURES REMAIN IN
PLACE FOR THE END OF THE WEEK AS THE MID-LVL FLOW REMAINS WESTERLY.
A SUBTLE TROUGH PASSING THROUGH THE CENTRAL PLAINS MAY CAST AN
INCREASE IN CLOUD COVER AND PERHAPS A FEW SHOWERS THROUGH THE MO
RIVER VALLEY THURSDAY . A STRONGER UPPER WAVE EJECTS TO THE
NORTHEAST BY FRIDAY BRINGING WITH IT AN INCREASED CHANCE FOR SHOWERS
AND THUNDERSTORMS (60+%) BY FRIDAY. GREATEST POTENTIAL APPEARS TO BE
NORTH OF I-90, BUT QUIET A BIT OF VARIABILITY REMAINS WITH THE TRACK
OF THIS WAVE.
SATURDAY-SUNDAY: THE LONGWAVE PATTERN APPEARS TO SHIFT FOR THE
UPCOMING WEEKEND, WITH THIS PATTERN AMPLIFYING INTO NEXT WEEK. BY
SATURDAY A LONG WAVE TROUGH FORMS OVER THE WESTERN THIRD OF THE
CONUS, WITH AN INCREASING RIDGE IN THE SOUTHEASTERN PART OF THE
CONUS. SHARPENING SOUTHWEST FLOW OVER THE PLAINS WILL HELP PUSH
BOTH WARMER TEMPERATURES AND INCREASING CONVECTION RISKS THROUGH
CENTRAL CANADA AND THE NORTHERN PLAINS. TEMPERATURES WILL ALSO RISE
BACK TO NORMAL OR ABOVE NORMAL LEVELS TOWARDS THE 90 DEGREE
MARK.
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
ISSUED AT 627 PM CDT MON JUN 22 2026
VFR CONDITIONS ARE EXPECTED TO PREVAIL FOR THE MAJORITY OF THE
PERIOD. CURRENTLY A FEW ISOLATED LIGHT SHOWERS ARE ONGOING. THESE
ARE EXPECTED TO TAPER OFF OVER THE NEXT FEW HOURS. NEAR SUNRISE A
COLD FRONT IS EXPECTED TO ENTER OUR NORTHWEST COUNTIES BRINGING
RENEWED CHANCES FOR SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS.
THESE STORMS WILL MOVE SOUTHEAST THROUGH THE REGION TUESDAY, EXITING
IN THE LATE AFTERNOON TO EARLY EVENING. FOR THE MOST PART CEILINGS
WILL REMAIN VFR, BUT UNDER AN ISOLATED STRONGER STORM, BRIEF PERIODS
OF MVFR ARE POSSIBLE.
WINDS WILL BE LIGHT AND VARIABLE OVERNIGHT, BECOMING SOUTHERLY
SHORTLY AFTER SUNRISE. WINDS BECOME BREEZY AHEAD OF THE COLD FRONT,
GUSTING 17-24 KTS. BEHIND THE FRONT WINDS TURN WESTERLY AND
DECREASE.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
UPDATE...AJP
DISCUSSION...DUX
AVIATION...AJP
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