748
FXUS63 KFSD 260532
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1232 AM CDT FRI JUN 26 2026
KEY MESSAGES
- NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES PREVAIL THROUGH
SATURDAY. A COUPLE SPOTTY SHOWER AND STORM CHANCES WILL ALSO
BE POSSIBLE DURING THIS TIME.
- AN EXTENDED PERIOD OF HEAT AND HUMIDITY IS EXPECTED STARTING
SUNDAY INTO NEXT WEEK. HEAT INDICES UP TO THE LOW 100S COULD
LEAD TO MODERATE TO MAJOR HEAT RISK AT TIMES.
- AN ACTIVE PATTERN ALOFT WILL LEAD TO ISOLATED CHANCES FOR
STRONGER STORMS BY EARLY TO MIDWEEK. HOWEVER, SOME UNCERTAINTY
REMAINS.
UPDATE
ISSUED AT 955 PM CDT THU JUN 25 2026
STILL HAVE SOME VERY SPOTTY SPRINKLES ALONG THE MISSOURI RIVER
VALLEY WEST OF VERMILLION, WITH ADDITIONAL SPOTTY LIGHT SHOWERS
IN CENTRAL SD DRIFTING NORTHEAST. WITH RELATIVELY HIGH CLOUD
BASES, CHANCES FOR MEASURABLE RAIN OVERNIGHT INTO FRIDAY SEEM
SLIM, BUT COULD SEE SCATTERED SPRINKLES OVER MAINLY SOUTHEAST SD
THROUGH MIDDAY FRIDAY.
CLOUD COVER WILL DIMINISH IN THE AFTERNOON, ALLOWING FOR BETTER
WARMING THAN MANY AREAS SAW TODAY, WITH HIGHS FRIDAY IN THE
UPPER 70S-LOWER 80S MOST AREAS. SLIGHTLY WARMER SATURDAY, THOUGH
HIGHS ARE SOMEWHAT UNCERTAIN AS THERE ARE HINTS THAT WE COULD
SEE STRATUS BECOME MORE EXPANSIVE IN A MOIST SOUTHEAST-SOUTHERLY
LOW LEVEL FLOW.
A MUCH MORE SIGNIFICANT WARM-UP IS STILL ON TAP EARLY NEXT WEEK,
THOUGH JUST HOW WARM IS THE QUESTION. LREF MEAN ENSEMBLE TEMPS
ARE A FEW DEGREES SHY OF THE LATEST NBM DATA, THOUGH THIS WOULD
STILL PUT HIGHS WELL INTO THE 90S SUNDAY/MONDAY. WHILE THESE
LOOK TO BE THE WARMEST DAYS OF THE UPCOMING WEEK, WE ARE LIKELY
LOOKING AT A PROLONGED STRETCH OF DAYS WITH HIGHS IN THE 90S AS
WE HEAD INTO THE FIRST DAYS OF JULY. MODERATE TO HIGH HUMIDITY
LEVELS AND PERSISTENT SOUTHERLY BREEZES WILL LIMIT TEMPERATURE
DROPS AT NIGHT, WITH DAILY LOWS IN THE UPPER 60S/70S PROVIDING
LITTLE RELIEF. AS A RESULT, HEAT RISK LEVELS LOOK TO PUSH INTO
THE MODERATE TO MAJOR CATEGORY (LEVEL 2/3 OF 4) ON SUNDAY, AND
REMAIN THERE WITH POCKETS OF EXTREME (LEVEL 4 OF 4) HEAT RISK
POSSIBLE FROM MONDAY ONWARD. THOSE WITH OUTDOOR ACTIVITIES OR
WORK PLANNED, OR VULNERABLE INDIVIDUALS WITH HIGHER SENSITIVITY
TO HEAT, SHOULD BE PREPARING FOR MULTIPLE DAYS OF POTENTIAL HEAT
IMPACTS.
DISCUSSION
ISSUED AT 215 PM CDT THU JUN 25 2026
CURRENTS & TONIGHT: BEAUTIFUL CONDITIONS CONTINUE! TAKING A LOOK
ACROSS THE AREA, FALL-LIKE CONDITIONS CONTINUE THIS AFTERNOON WITH
MANY SITES REPORTING TEMPERATURES IN THE LOW TO UPPER 70S WITH
LIGHTER WINDS AS OF 1 PM. WE'RE ALSO STARTING TO SEE SOME SCATTERED
SHOWERS PROGRESS INTO THE MISSOURI RIVER VALLEY MAINLY IN RESPONSE
TO WEAK SHORTWAVE AND WEAKENING LLJ. WHILE SEVERE WEATHER IS NOT
EXPECTED, COULD SEE THIS FESTERING ACTIVITY CONTINUE THROUGH THE
EARLY EVENING MAINLY ACROSS THE SAME AREAS BEFORE THINGS GRADUALLY
DISSIPATE WITH THE LOSS OF DIURNAL HEATING. OTHERWISE, COULD SEE
ADDITIONAL SHOWERS DEVELOP OVERNIGHT INTO FRIDAY MORNING AS ANOTHER
WAVE INTERACTS WITH A STRENGTHENING NOCTURNAL LLJ. LASTLY, MORE
SEASONABLE TEMPERATURES ARE EXPECTED OVERNIGHT AS LOWS FALL
INTO THE MID TO UPPER 50S FOR THE NIGHT.
THE WEEKEND: LOOKING INTO THE WEEKEND, WE'LL CONTINUE TO SEE A FEW
LINGERING SHOWERS IN OUR FAR NORTHWESTERN ZONES TO START THE DAY ON
FRIDAY. AS THE LLJ WEAKENS, THIS ACTIVITY SHOULD GRADUALLY DIMINISH
BY MID-MORNING. QUIETER CONDITIONS WILL RETURN FOR THE REST OF
FRIDAY INTO THE FIRST HALF OF SATURDAY AS HIGHS CONTINUE TO SIT IN
THE LOW TO MID 80S. OTHERWISE, CLOUD COVER WILL GRADUALLY BUILD
DURING THE DAY ON SATURDAY AS WARM AIR ADVECTION (WAA) STRENGTHENS.
WITH SOUTHWESTERLY FLOW IN PLACE ALOFT, INCREASES IN ISENTROPIC LIFT
WITH AN APPROACHING WAVE COULD LEAD TO A FEW POCKETS OF DRIZZLE TO
LIGHT SHOWER DEVELOPING IN THE LOWER CLOUD DECK. HOWEVER, SEVERE
WEATHER IS NOT EXPECTED MAINLY DUE TO STRONG CAP ACCORDING TO
SOUNDINGS. LOOKING INTO SUNDAY, THE FOCUS WILL SHIFT TO THE BUILDING
HEAT AS SOUTHERLY SURFACE WINDS AND INCREASING MID-LEVEL WAA LEADS
TO A PUSH TOWARDS HIGHS MAINLY IN THE LOW TO UPPER 90S. THIS
COMBINED WITH DEW POINTS CLOSER TO UPPER 60S TO LOW 70S WILL LEAD TO
HEAT INDICES IN THE 90S TO LOW 100S FOR PARTS OF THE AREA WITH THE
WARMEST CONDITIONS ACROSS NORTHWESTERN IA. WHILE A HEAT HEADLINE
COULD BE NEEDED, DECIDED TO FORGO IT AT THIS TIME MAINLY DUE TO
UNCERTAINTY WITH SPACIAL EXTENT. NONETHELESS, WITH MUGGY CONDITIONS
EXPECTED THROUGH SUNDAY EVENING MAKE SURE TO STAY HYDRATED AND TO
LIMIT ANY STRENUOUS ACTIVITIES!
NEXT WEEK: HEADING INTO THE EXTENDED PERIOD, THE FOCUS WILL CONTINUE
TO BE ON THE HEAT AS UPPER-LEVEL RIDGING CONTINUES TO BUILD OVER THE
EASTERN CONUS. WITH SOUTHERLY SURFACE WINDS IN PLACE AND MULTIPLE
PUSHES OF WARMER AIR ALOFT, EXPECT TEMPERATURES TO CONTINUE TO HOVER
IN THE LOW TO UPPER 90S FROM MONDAY ONWARDS WITH HEAT INDICES (HI)
IN THE 90S TO LOW 100S DEGREE MARKS AT TIMES. WHILE CONDITIONS WON'T
QUITE MAKE IT INTO EXCESSIVE HEAT TERRITORY, WE COULD SEE MANY AREAS
TOUCH HEAT ADVISORY CRITERIA (HI>100) AT TIMES EACH DAY SO THIS WILL
BE SOMETHING TO WATCH MOVING FORWARD. EITHER WAY, THE CONDITIONS
WILL LEAD TO MODERATE TO MAJOR HEAT RISK FOR MOST AREAS FROM MONDAY
THROUGH WEDNESDAY SO MAKE SURE TO DRINK PLENTY OF WATER AND TO TAKE
PLENTY OF BREAKS WHEN WORKING OUTDOORS! OTHERWISE, WE'LL ALSO HAVE
TO KEEP ANY EYE TO THE SKIES THROUGH MIDWEEK AS SOUTH-SOUTHWESTERLY
FLOW ALOFT HELP USHERS IN MULTIPLE PIECES OF ENERGY INTO THE AREA
THROUGH WEAK PERTURBATION. WITH PLENTY OF HEAT IN THE FORECAST, ALL
THAT'S NEEDED IS A STRONG ENOUGH TRIGGER TO BREAK THROUGH THE CAP TO
GET SOMETHING STRONG TO SEVERE. NONETHELESS, ITS STILL UNCERTAIN IF
THIS CAN HAPPEN GIVEN THE WARMER TEMPERATURES +20 TO +28 DEGREES C
AT 800 MB THROUGH MIDWEEK. WITH ALL THIS IN MIND, MAKE SURE TO
MONITOR YOUR LOCAL FORECAST AS THINGS WILL BE SUBJECT TO CHANGE
MOVING FORWARD.
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 1230 AM CDT FRI JUN 26 2026
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD WITH SCATTERED
LIGHT SHOWERS OR SPRINKLES MAINLY ALONG/WEST OF I-29 AT TIMES
THROUGH MIDDAY FRIDAY. LIGHT AND VARIABLE WINDS WILL SETTLE
AROUND TO SOUTHEAST BY MID-LATE MORNING WITH OCCASIONAL GUSTS
AROUND 20KT WEST OF I-29 FRIDAY AFTERNOON THROUGH SUNSET.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
UPDATE...JH
DISCUSSION...05
AVIATION...JH
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