619
FXUS63 KIND 251905
AFDIND
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
305 PM EDT SAT JUL 25 2026
KEY MESSAGES
- AREAS OF DENSE FOG POSSIBLE TONIGHT
- HOT AND HUMID CONDITIONS EXPECTED SUNDAY INTO MONDAY
- ONE OR MORE THUNDERSTORM COMPLEXES POSSIBLE SUNDAY NIGHT AND
MONDAY NIGHT, WITH DAMAGING WINDS AND HEAVY RAINFALL THE
PRIMARY THREATS
DISCUSSION (THIS EVENING THROUGH SATURDAY)
ISSUED AT 304 PM EDT SAT JUL 25 2026
THIS EVENING THROUGH SUNDAY NIGHT...
WIDESPREAD LOW CLOUDS WILL CONTINUE ACROSS THE AREA THIS AFTERNOON
INTO THIS EVENING, ALONG WITH A FEW SPRINKLES OR LIGHT SHOWERS
DURING THE DAYLIGHT HOURS, AS A WARM FRONT APPROACHES AND A SUBTLE
SHORTWAVE PASSES THROUGH THE AREA. SOME CLEARING MAY OCCUR THIS
EVENING BEFORE AMPLE LOW LEVEL MOISTURE IN THE PRESENCE OF BOTH A
STOUT INVERSION ALOFT AND THE AFOREMENTIONED BOUNDARY, ALONG WITH
LIGHT TO CALM TO SURFACE WINDS, PROMOTES THE REDEVELOPMENT OF LOW
CLOUDS AND FOG, WHICH MAY BECOME DENSE IN SPOTS LATE TONIGHT.
CLOUD COVER AND FOG MAY BE SLOW TO MIX OUT TOMORROW UNDERNEATH THE
AFOREMENTIONED INVERSION, COURTESY OF A STOUT ELEVATED MIXED LAYER,
BUT WE SHOULD SEE BREAKS OF SUNSHINE BY MIDDAY AS THE BOUNDARY MOVES
FURTHER INTO THE REGION AND PBL MIXING INCREASES. THE INVERSION WILL
KEEP A STRONG LID ON AN OTHERWISE FAIRLY STRONGLY UNSTABLE AIRMASS
THROUGH THE DAY, WITH CHANCES FOR THUNDERSTORMS INCREASING DURING
THE EVENING AND INTO THE OVERNIGHT HOURS SUNDAY NIGHT.
PLENTIFUL INSTABILITY AND SHEAR WILL BE PRESENT, THOUGH SIGNIFICANT
UNCERTAINTY EXISTS REGARDING EXACTLY WHERE UPSTREAM THUNDERSTORM
ACTIVITY WILL INITIATE, HOW EXACTLY THESE STORMS WILL ORGANIZE, AND
THE ORIENTATION OF THE INSTABILITY GRADIENT THAT WILL LARGELY DRIVE
THEIR MOTION. CAMS ARE STRUGGLING TO CONVERGE ON A SCENARIO, WHICH
IS NOT SURPRISING GIVEN THE PATTERN AND TIME OF YEAR. A WIDE
ENVELOPE OF SCENARIOS EXISTS FOR TOMORROW NIGHT INTO EARLY MONDAY,
FROM LITTLE TO NO CONVECTION, TO A POTENT QLCS PUSHING INTO THE AREA
WITH DAMAGING WIND POTENTIAL.
TEMPERATURES WILL DEPEND HEAVILY UPON CLEARING TOMORROW AND
THUNDERSTORM ACTIVITY TOMORROW NIGHT, SO UNCERTAINTY IS HIGHER THAN
WOULD PREFER, BUT ASSUMING WE SEE GOOD SUN TOMORROW AFTERNOON, HIGHS
WILL LIKELY RISE WELL INTO THE 80S, WITH OVERNIGHT LOWS LIMITED BY
DEWPOINTS LARGELY TO THE LOW 70S.
MONDAY AND MONDAY NIGHT...
CHANCES FOR CONVECTION WILL BE HIGHER LATE MONDAY INTO MONDAY NIGHT,
AS SOMEWHAT MORE STRONGLY FORCED SCENARIO IS LIKELY WITH BOTH A
SURFACE COLD FRONT AND SHORTWAVE TROUGH SUPPORTING THUNDERSTORM
DEVELOPMENT. HOWEVER, UNCERTAINTY STILL REMAINS HIGH IN THE EXACT
TIMING AND DETAILS, GIVEN THE INFLUENCE THAT POTENTIAL PRIOR
CONVECTION WILL HAVE ON SUBSEQUENT EPISODES, AND THE HEAVY
DEPENDENCE UPON THE THERMODYNAMIC PARAMETER SPACE FOR DETERMINING
EXACTLY HOW AND WHERE THESE MCSS WILL IMPACT. SUFFICE TO SAY,
PLENTIFUL INSTABILITY AND SHEAR WILL LIKELY BE PRESENT ACROSS THE
REGION, AND ANY STORMS THAT MOVE INTO THE AREA WILL POSSESS
POTENTIAL FOR DAMAGING WINDS. ADDITIONALLY, PRECIPITABLE WATER
VALUES WILL APPROACH 2 INCHES AT TIMES, WHICH ALONG WITH DEEP AND
EFFICIENT WARM RAIN PROCESSES MAY SET THE STAGE FOR HEAVY RAINFALL
AND LOCALIZED FLASH FLOODING.
TEMPERATURES ARE AGAIN UNCERTAIN OWING PRIMARILY TO CONVECTIVE
POTENTIAL, BUT HIGHS WELL INTO THE LOW TO MID 90S ARE DEFINITELY ON
THE TABLE MONDAY, WHICH COULD DRIVE AFTERNOON HEAT INDEX VALUES WELL
INTO THE TRIPLE DIGITS IN SPOTS.
TUESDAY ONWARD...
COLD FRONTAL PASSAGE MONDAY NIGHT INTO EARLY TUESDAY WILL BRING
TEMPERATURES BACK DOWN CLOSER TO SEASONAL NORMALS FROM MID WEEK
ONWARD, WITH A LARGELY DRY FORECAST UNTIL VERY LATE IN THE WEEK AS
SURFACE HIGH PRESSURE DOMINATES THE AREA. AS THE RIDGE ALOFT
RETROGRADES SLIGHTLY, UPPER LEVEL DISTURBANCES LATE IN THE WEEK MAY
PROMOTE RAIN CHANCES, THOUGH SIGNIFICANT DISAGREEMENT ON THESE
SYSTEMS PRECLUDES MORE THAN A SLIGHT CHANCE AT THIS POINT.
AVIATION (18Z TAF ISSUANCE)
ISSUED AT 118 PM EDT SAT JUL 25 2026
IMPACTS:
- WIDESPREAD MVFR OR WORSE CONDITIONS EXPECTED MUCH OF THE PERIOD,
PARTICULARLY LATE TONIGHT AT THE OUTLYING SITES, WHEN LIFR
CONDITIONS APPEAR LIKELY
DISCUSSION:
WIDESPREAD MVFR OR WORSE CONDITIONS ARE EXPECTED MUCH OF THIS TAF
PERIOD, AND ARE CURRENTLY PRESENT JUST WEST OF IND, IMPACTING THE
OTHER 3 TAF SITES AS A WARM FRONT SLOWLY PUSHES INTO THE AREA.
SOME TEMPO IFR IS LIKELY EARLY IN THE PERIOD AT HUF/BMG. A BRIEF
PERIOD OF MVFR IS POSSIBLE THIS EVENING BEFORE FOG AND LOW CLOUDS
REDEVELOP AND WORSEN, WITH LIFR APPEARING LIKELY AT ALL BUT IND,
WHICH MAY REMAIN LOW END MVFR, THOUGH WILL CARRY A BCFG MENTION HERE
AS WELL.
WINDS ARE GENERALLY OUT OF THE SOUTH TO SOUTHWEST AT 5-6KT THIS
AFTERNOON. WINDS WILL LIKELY BE CALM AT THE OUTLYING SITES,
REMAINING LIGHT AND VARIABLE AT IND OVERNIGHT. POOR FLYING
CONDITIONS WILL IMPROVE SOMEWHAT LATE IN THE PERIOD BUT MAY REMAIN
RESTRICTED INTO SUNDAY AFTERNOON.
IND WATCHES/WARNINGS/ADVISORIES
NONE.
AVIATION...NIELD
DISCUSSION...NIELD
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