601
FXUS63 KFSD 012329
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
629 PM CDT FRI AUG 1 2025
KEY MESSAGES
- SMOKE REMAINS A FACTOR IN THE FORECAST, POSSIBLY LINGERING
OVER PARTS OF THE AREA INTO THE WEEKEND.
- OCCASIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH
EARLY NEXT WEEK. ONLY ISOLATED SEVERE WEATHER IS EXPECTED.
TUESDAY NIGHT MAY SEE A SLIGHTLY HIGHER THREAT.
- BELOW NORMAL TEMPERATURES CONTINUE THROUGH EARLY NEXT WEEK.
- A SEASONALLY STRONG WESTERLY UPPER LEVEL JET MAY REMAIN IN
PLACE THROUGHOUT NEXT WEEK, WHICH COULD BRING ADDITIONAL
CHANCES FOR SHOWERS AND STORMS THROUGH THE END OF THE WEEK.
DISCUSSION
ISSUED AT 229 PM CDT FRI AUG 1 2025
LATEST SATELLITE SHOWING A SMALL WAVE IN NORTHWEST SD THAT WILL MOVE
EAST TONIGHT AND LIKELY HELP SPARK A FEW SHOWERS AND THUNDERSTORMS
IN CENTRAL AND WESTERN SD. AS THIS ACTIVITY DRIFTS EAST LATER
TONIGHT INTO SATURDAY MORNING IT WILL BE MET WITH LESS UNSTABLE AIR
SO A GENERAL WEAKENING TREND IS EXPECTED. THERE IS SOME DRY AIR INT
HE LOWER LEVELS WHICH COULD AID IN SOME GUSTY WINDS BUT FOR NOW
GIVEN THE WEAK INSTABILITY, GENERALLY LESS THAN 500 J/KG, THESE GUSTS
SHOULD NOT BE SEVERE.
OTHERWISE SMOKE WILL BE A CONCERN IN THE FORECAST NOT JUST FOR
TONIGHT BUT INTO THE WEEKEND. SURFACE SMOKE TRAPPED BELOW THE
INVERSION WILL ONLY SLOWLY DRIFT EAST AS A SURFACE RIDGE OF HIGH
PRESSURE IS SLOW TO DRIFT EAST. SUNDAY INTO MONDAY BRINGS A BIT MORE
TURNING OF THE LOW LEVEL FLOW TOWARDS THE SOUTHWEST WHICH BRINGS THE
BETTER CHANCE TO FLUSH OUT SOME OF THIS SMOKE. ON TOP OF THE SURFACE
BASED SMOKE THERE ARE INDICATIONS THAT SOME ELEVATED SMOKE WILL
STREAM ACROSS THE AREA TONIGHT INTO SATURDAY AS WELL.
BROAD/WEAK TROUGHINESS SPREADS INTO CENTRAL SD ON SATURDAY AND
SATURDAY NIGHT WHICH SHOULD CONTINUE THE THREAT FOR SHOWERS AND
THUNDERSTORMS. ONCE AGAIN INSTABILITY IS ON THE WEAK SIDE AND ON TOP
OF THIS CAPPING APPEARS TO BE A POTENTIAL ISSUE AS WELL. LAPSE RATES
ALOFT IN THE MORNING MAY SUPPORT SOME ACTIVITY BUT THE AFTERNOON
APPEARS AS THOUGH ACTIVITY WILL BE MINIMAL. BY SATURDAY NIGHT THE
LLJ DOES INCREASE AND VEER WHICH SHOULD BRING INCREASED CHANCES FOR
SHOWERS AND STORMS. SOME INDICATIONS THAT CAPE COULD PUSH 1000-1500
J/KG LATER AT NIGHT INTO SUNDAY MORNING WHICH MIGHT SUPPORT SOME
ISOLATED SEVERE STORMS. SHEAR IS VERY WEAK HOWEVER SO ANYTHING
ORGANIZED OR ON THE HIGHER END IS NOT EXPECTED.
THIS POTENTIAL ACTIVITY LEAVES QUITE A FEW QUESTION MARKS FOR SUNDAY
AFTERNOON AND EVENING AS THERE MAY BE SOME PRECIPITATION AS WELL AS
CLOUD COVER LEFT BEHIND WHICH COULD LIMIT HEATING AND THE POTENTIAL
DEVELOPMENT OF STRONGER UPDRAFTS. CURRENT SOUNDINGS SUGGEST THAT
AREAS NEAR AND WEST OF HIGHWAY 81 IN SD WOULD SEE THE BEST POTENTIAL
FOR HEATING. IF ANY STORMS CAN DEVELOP ON SUNDAY AFTERNOON AND
EVENING THERE IS PLENTY OF INSTABILITY, LIKELY 1500-2000 J/KG, WITH
SOME MARGINAL LOW TO MID LEVEL SHEAR THAT SHOWS SOME TURNING IN THE
LOWEST KM OR 2. CONFIDENCE PRETTY LOW ON EVOLUTION OF ANYTHING ON
SUNDAY BUT STILL COMES ACROSS AS THE MAIN DAY TO WATCH THROUGH THE
WEEKEND.
SHOWER AND THUNDERSTORM POTENTIAL CONTINUES ON MONDAY WITH WEAK LOW
PRESSURE TO THE NORTH. SOME UPPER LEVEL RIDGING BEGINS TO BUILD BY
MONDAY AFTERNOON AND CONTINUES INTO MONDAY NIGHT SO MAY SEE
PRECIPITATION CHANCES DIMINISH IF THIS TREND CONTINUES.
STILL PRETTY GOOD MODEL AGREEMENT FOR THE STRONGER JET EXPECTED TO
MOVE ONTO THE NORTHERN AND CENTRAL PLAINS TUESDAY AFTERNOON WITH
SOME SEVERE WEATHER POTENTIAL EXISTING. TEMPERATURES BEGIN TO WARM
BACK TO AROUND NORMAL.
WEDNESDAY THROUGH FRIDAY LOOKS TO KEEP FAIRLY FAST WESTERLY UPPER
LEVEL FLOW IN PLACE WITH PERIODIC CHANCES FOR THUNDERSTORMS. TUESDAY
INTO FRIDAY MAY [ROVE TO BE ANOTHER PERIOD OF BUSY WEATHER ACROSS
THE AREA AS TEMPERATURES CLIMB BACK TO A BIT ABOVE NORMAL PROVIDING
SOME DEEPER INSTABILITY FOR THE AREA.
AVIATION /00Z TAFS THROUGH 00Z SUNDAY/
ISSUED AT 629 PM CDT FRI AUG 1 2025
SMOKE PERSISTS ACROSS THE AREA EARLY THIS EVENING. MOST LOCATIONS
CONTINUE TO SHOW VISIBILITIES AT VFR LEVELS THOUGH A FEW HAVE
REPORTED MVFR VISIBILITIES. THE SMOKE IS EXPECTED TO PERSIST
THROUGHOUT THE ENTIRE TAF PERIOD THOUGH CONFIDENCE REMAINS TOO LOW
TO INCLUDE MVFR VISIBILITIES IN A TAF. SHOWERS AND THUNDERSTORMS AVE
DEVELOPED ACROSS NORTHWEST SOUTH DAKOTA AND WILL PUSH INTO LOCATIONS
WEST OF THE JAMES RIVER AFTER MIDNIGHT. HAVE INCLUDED A PROB30 GROUP
IN KHONS TAF. SOUTHEAST WINDS ARE EXPECTED TO REMAIN FOR THE DAY
TOMORROW WITH GUSTS UP TO 20-25 KNOTS. THE STRONGEST GUSTS WILL
OCCUR WEST OF I-29. ASIDE FROM THE SMOKE PERSISTING THROUGH THE DAY,
THERE COULD BE AN ISOLATED SHOWER AND STORM THAT DEVELOPS BEFORE THE
END OF THE TAF PERIOD. CONFIDENCE IN THIS POTENTIAL IS LOW THOUGH SO
WILL MONITOR TRENDS FOR NOW.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
DISCUSSION...08
AVIATION...MEYERS
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