531
FXUS63 KIND 281737
AFDIND
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
137 PM EDT TUE JUL 28 2026
KEY MESSAGES
- RAIN FREE TUESDAY-THURSDAY AMID NEAR TO SLIGHTLY BELOW NORMAL
TEMPERATURES/HUMIDITY
FORECAST UPDATE
ISSUED AT 918 AM EDT TUE JUL 28 2026
ONLY MINOR UPDATES TO THE FORECAST THIS MORNING MAINLY CONCERNING
SKY COVER. LOW STRATUS CONTINUES TO PERSIST ACROSS MOST OF CENTRAL
INDIANA WITH CLOUD BASES AROUND 1000 FEET AGL. HIGH-RESOLUTION
GUIDANCE SHOWS RAPID CLEARING AROUND 16-20Z, THOUGH STRATUS TENDS TO
BE MORE RESILIENT IN POST-FRONT ENVIRONMENTS SO WE WILL KEEP IT MORE
GRADUAL. STILL EXPECTING A GENERAL DECREASE IN CLOUD COVER THIS
AFTERNOON ALONG WITH DECREASING DEW POINTS.
DISCUSSION (TODAY THROUGH MONDAY)
ISSUED AT 231 AM EDT TUE JUL 28 2026
A VORT MAX IS CURRENTLY OVER THE EASTERN GREAT LAKES PUSHING
EASTWARD AHEAD OF A TROUGH. AN ASSOCIATED COLD FRONT WILL FOLLOW
ALLOWING FOR SOME LIFT AND CONVECTION OVER NORTHERN INDIANA AND
OHIO. THIS FORCING WILL NEAR NE PORTIONS OF CENTRAL INDIANA THIS
MORNING, LEADING TO SOME POTENTIAL FOR SCATTERED CONVECTION.
PARAMETER SPACING IS A BIT MORE LACK-LUSTER THAN YESTERDAY WITH
AROUND 1000 J/KG CAPE AND 20-30KT OF EFFECTIVE SHEAR. THIS SHOULD BE
ENOUGH FOR A FEW PERSISTENT CLUSTERS, BUT OVERALL ANY STORMS SHOULD
REMAIN RATHER WEAK WITH GUSTS BELOW 35 MPH.
THE OVERALL SYNOPTIC PATTERN WILL REMAIN MOSTLY SIMILAR FOR THE
MIDDLE OF THE WEEK WITH ONE CAVEAT. CYCLONIC VORTICITY ADVECTION ON
THE NORTHWARD SIDE OF THE UPPER JET WILL AID PRESSURE DEPLETION OVER
THE MID ATLANTIC, DIGGING THE TROUGH OVER EASTERN CANADA SOUTHWARD.
THIS, IN COMBINATION WITH A WEAK FRONTAL PASSAGE WILL SHIFT
TEMPERATURES BACK TOWARDS SEASONAL ACROSS THE AREA, AND INDUCE
SUBSIDENCE OVER THE REGION. THE RESULTING WEATHER WILL BE RATHER
MUNDANE, WITH HIGHS IN THE LOW TO MID 80S AND DEW POINTS IN THE LOW
TO MID 60S.
AS WE NEAR THE END OF THE WEEK A BROAD UPPER-LEVEL RIDGE CENTERED
OVER THE NORTHERN PLAINS WILL BEGIN TO PROPAGATE TOWARDS THE OHIO
VALLEY PROMOTING UPPER-LEVEL DIVERGENCE. DEWPOINTS SHOULD CLIMB ONCE
AGAIN INTO THE UPPER 60S AS THE MID-LEVEL FLOW FROM THE GULF
CONTINUES TO TRANSPORT MOIST AIR INTO THE REGION. LATER IN THE DAY,
A COLD FRONT WILL MOVE THROUGH INDIANA. THIS FRONT WILL BE WEAK, BUT
COULD PROVIDE ENOUGH FORCING FOR CONVECTIVE THUNDERSTORMS.
BY SATURDAY, THE UPPER-LEVEL TROUGH WILL HAVE STRENGTHENED INTO AN
AREA OF LOW PRESSURE OVER THE OHIO VALLEY REGION. THE INCREASE OF
CYCLONIC VORTICITY IN THE REGION ALONG WITH CONTINUED MOISTURE
ADVECTION FROM THE GULF MAY LEAD TO ADDITIONAL RAIN SHOWERS OVER THE
COURSE OF THE DAY. GUIDANCE SUPPORTS THE EXISTENCE OF WEAK
INSTABILITY IN THE REGION WITH MUCAPE VALUES GREATER THAN 500 J/KG,
AND THUS THUNDER WILL ALSO BE POSSIBLE FOR SATURDAY AND SUNDAY.
LONG-TERM GUIDANCE VARIES A BIT BEYOND SUNDAY, WITH TWO MAIN
SOLUTIONS REGARDING UPPER-LEVEL RIDGE AND TROUGH DYNAMICS. THE FIRST
SCENARIO PROPAGATES A RIDGE NORTHWESTWARD FROM GEORGIA INTO THE OHIO
VALLEY, EFFECTIVELY PINCHING OFF THE LOW OVER ARKANSAS. THE SECOND
SCENARIO TRACKS THE LOW EASTWARD, ALLOWING A BROAD RIDGE TO BUILD
OVER THE MIDWEST. EXPECTED TEMPERATURES WILL LIKELY DIFFER SOME
DEPENDING ON THE OUTCOME, BUT IN EITHER CASE, CONDITIONS FAVOR A
DRIER START TO THE WORKWEEK
AVIATION (18Z TAF ISSUANCE)
ISSUED AT 137 PM EDT TUE JUL 28 2026
IMPACTS:
- MVFR CEILINGS DIMINISHING THIS AFTERNOON
- WIND GUSTS UP TO 20KT THROUGH THIS EVENING
- LOW PROBABILITY PATCHY FOG TONIGHT
DISCUSSION:
SURFACE HIGH PRESSURE IS BUILDING IN FROM THE NORTH AND STRATUS IS
BEGINNING TO DISSIPATE. CEILINGS HAVE BEEN BETWEEN 2500 AND 3000
FEET AGL AND MAY OSCILLATE BETWEEN SCT AND BKN THIS AFTERNOON. VFR
CONDITIONS RETURN FOR ALL TERMINALS BY 00Z.
PATCHY FOG IS POSSIBLE OVERNIGHT BUT DRIER AIR FLOWING IN FROM THE
NORTH AND A RESIDUAL BREEZE MAY LIMIT COVERAGE. WILL NOT CARRY FOG
IN THE TAFS AS A PREVAILING GROUP DUE TO LOW COVERAGE AND LOW
CONFIDENCE OF DEVELOPMENT.
WINDS RETAIN A NORTHERLY COMPONENT THROUGH THE FORECAST PERIOD.
SPEEDS DIMINISH OVERNIGHT, POTENTIALLY BECOMING LIGHT AND VARIABLE,
BEFORE INCREASING AGAIN AFTER 12Z WEDNESDAY.
IND WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...ECKHOFF
AVIATION...ECKHOFF
DISCUSSION...UPDIKE/CH
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