192
FXUS63 KIND 130531
AFDIND
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
131 AM EDT TUE OCT 13 2026
KEY MESSAGES
- RECORD WARMTH TODAY WITH HIGHS REACHING THE UPPER 80S TO LOW 90S
- MULTIPLE ROUNDS OF RAIN AND SCATTERED THUNDERSTORMS TUESDAY
NIGHT THROUGH THURSDAY NIGHT
- SHARPLY COLDER FRIDAY WITH NORTHWEST WIND GUSTS OF 30 TO 40 MPH
- FROST AND LOCALIZED FREEZE POTENTIAL LATE SATURDAY NIGHT INTO
EARLY SUNDAY MORNING
DISCUSSION (TODAY THROUGH MONDAY)
ISSUED AT 130 AM EDT TUE OCT 13 2026
TODAY THROUGH WEDNESDAY.
BROAD MID-LEVEL RIDGING CENTERED OVER THE SOUTHEAST EXPANDS ACROSS
THE OHIO VALLEY TODAY WHILE A DEEP TROUGH DIGS ACROSS SOUTH-CENTRAL
CANADA AND THE UPPER MIDWEST. SOUTH-SOUTHWESTERLY BOUNDARY LAYER
FLOW DOWNSTREAM OF AN APPROACHING SURFACE COLD FRONT WILL REINFORCE
WARM THERMAL ADVECTION ACROSS CENTRAL INDIANA. FORECAST SOUNDINGS
INDICATE 850MB TEMPERATURES CLIMBING TO 16-17C WITH DEEP DIURNAL
MIXING UP TO 800MB. THE COMBINATION OF WAA AND PLENTY OF SUN WILL
ALLOW FOR TEMPERATURES TO RISE INTO THE UPPER 80S TO POTENTIALLY LOW
90S, BREAKING RECORDS. MOMENTUM TRANSFER WITHIN THE MIXED LAYER WILL
SUPPORT SUSTAINED SOUTHWESTERLY SURFACE WINDS OF 15 TO 20 MPH WITH
GUSTS PEAKING BETWEEN 25 AND 30 MPH.
THE SYNOPTIC SURFACE COLD FRONT WILL DECELERATE TUESDAY NIGHT AS
UPPER-LEVEL FLOW ORIENTS QUASI-PARALLEL TO THE BOUNDARY. MESOSCALE
GUIDANCE, INCLUDING THE HRRR AND HREF MEMBERS, FOCUSES INITIAL PRE-
FRONTAL CONVECTIVE DEVELOPMENT ACROSS NORTHWESTERN COUNTIES AFTER
MIDNIGHT AS A 35 KT LOW-LEVEL JET INTERCEPTS THE FRONTAL ZONE.
INSTABILITY REMAINS LARGELY ELEVATED AND DIURNALLY CAPPED, WITH
MUCAPE VALUES GENERALLY UNDER 500 J/KG, LIMITING SEVERE CONVECTIVE
POTENTIAL TO ISOLATED GENERAL THUNDER OUTSIDE OF A LOW-END THREAT
FOR GUSTY WINDS.
THE FRONTAL ZONE SAGS INTO CENTRAL INDIANA WEDNESDAY, SERVING AS A
FOCUS FOR PRECIPITATION AS MID-LEVEL FRONTOGENESIS TIGHTENS.
HIGH-RESOLUTION GUIDANCE SHOWS PRECIPITABLE WATER VALUES SURGING
TO 1.4 TO 1.6 INCHES ALONG THE BOUNDARY, EXCEEDING THE 90TH
CLIMATOLOGICAL PERCENTILE FOR MID-OCTOBER. RIGHT-ENTRANCE REGION
UPPER JET DYNAMICS AND CONTINUOUS MOISTURE TRANSPORT WILL SUPPORT
WIDESPREAD RAIN AND EMBEDDED CONVECTIVE CLUSTERS THROUGHOUT
WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT. AFTERNOON HIGHS WEDNESDAY
WILL EXHIBIT A MARKED THERMAL GRADIENT, RANGING FROM THE LOW TO
MID- 60S IN THE NORTHWEST BEHIND THE FRONT TO UPPER 70S AND LOWER
80S ACROSS SOUTH-CENTRAL INDIANA.
THURSDAY THROUGH MONDAY.
A SECONDARY SHORTWAVE ROTATES THROUGH THE BASE OF THE DEEPENING
EASTERN LONGWAVE TROUGH THURSDAY, INDUCING A WEAK WAVE OF LOW
PRESSURE ALONG THE STALLED BAROCLINIC ZONE OVER THE OHIO VALLEY.
STRONG MULTI-LEVEL DEFORMATION AND MID-LEVEL FGEN COMBINED WITH DEEP
MOISTURE WILL MAINTAIN HIGH POPS THROUGH THURSDAY EVENING BEFORE THE
BOUNDARY FINALLY CLEARS THE FORECAST AREA TO THE SOUTHEAST. MULTI-
MODEL ENSEMBLE CONSENSUS ALIGNS WITH WPC GUIDANCE DEPICTING
WIDESPREAD EVENT-TOTAL QPF BETWEEN 1.00 AND 2.00 INCHES ACROSS
CENTRAL INDIANA, PROVIDING MUCH-NEEDED DROUGHT RELIEF.
COLD AIR ADVECTION STRENGTHENS DRASTICALLY THURSDAY NIGHT INTO
FRIDAY BEHIND THE FRONTAL PASSAGE AS AN AMPLIFIED 500MB POLAR TROUGH
SETTLES OVER THE GREAT LAKES AND EASTERN CONUS. AN INTENSE SURFACE
PRESSURE GRADIENT BETWEEN THE DEPARTING LOW AND A 1028MB CANADIAN
SURFACE HIGH WILL COMBINE WITH STEEP LOW-LEVEL LAPSE RATES TO
PROMOTE DEEP BOUNDARY LAYER MIXING ON FRIDAY. SOUNDING PROFILES SHOW
35 TO 40 KT WINDS AT THE TOP OF THE MIXED LAYER, WHICH WILL EASILY
TRANSLATE TO SURFACE GUSTS OF 35 TO 40 MPH THROUGHOUT FRIDAY
AFTERNOON. HIGHS ON FRIDAY WILL BE HELD IN THE MID-50S TO NEAR 60°F
DESPITE CLEARING SKIES AS A RESULT OF THE STRONG CAA.
THE CORE OF THE THERMAL TROUGH CROSSES THE REGION FRIDAY NIGHT INTO
SATURDAY, WITH 850MB TEMPERATURES DROPPING TO BETWEEN -2C AND
0C. HIGHS SATURDAY WILL STRUGGLE TO REACH THE LOW TO MID-50S
UNDER COLD NORTHWEST FLOW. THE PRIMARY FROST/FREEZE WINDOW REMAINS
SATURDAY NIGHT INTO EARLY SUNDAY MORNING. THE CANADIAN SURFACE
ANTICYCLONE SETTLES DIRECTLY OVER THE OHIO VALLEY BY 09Z SUNDAY,
RESULTING IN CLEAR SKIES AND A DECOUPLED WIND FIELD. RADIATIONAL
COOLING WITHIN THIS DRY CONTINENTAL AIRMASS WILL CAUSE SURFACE
TEMPERATURES TO DROP INTO THE LOW TO MID-30S ACROSS CENTRAL
INDIANA. WIDESPREAD FROST APPEARS LIKELY ACROSS RURAL AND
SHELTERED AREAS, WITH A LOCALIZED FREEZE PROBABLE IN TYPICALLY
COLDER DRAINAGE BASINS.
THE SURFACE RIDGE AXIS SHIFTS TOWARD THE MID-ATLANTIC ON SUNDAY AND
MONDAY, ALLOWING LOW-LEVEL FLOW TO VEER TO THE SOUTH-SOUTHWEST.
HEIGHT RISES ALOFT DOWNSTREAM OF A WESTERN TROUGH WILL PROMOTE
THERMAL MODERATION, RETURNING HIGHS TO THE LOWER 60S SUNDAY AND
UPPER 60S BY MONDAY UNDER DRY CONDITIONS.
AVIATION (06Z TAF ISSUANCE)
ISSUED AT 130 AM EDT TUE OCT 13 2026
IMPACTS:
- LLWS THROUGH 12Z
- SOUTHWESTERLY WINDS TO GUST UP TO 20KT 16Z TO 23Z
DISCUSSION:
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD WITH ONLY PASSING
CIRRUS ALOFT. LLWS IS EXPECTED TO CONTINUE THROUGH DAYBREAK WITH
40KT WINDS AT 020 AND WINDS UNDER 10KT AT THE SURFACE. SOUTHWESTERLY
WINDS WILL GRADUALLY RAMP UP IN SPEED THROUGH THE MORNING HOURS WITH
GUST UP TO 20KT AT TIMES THROUGH THE AFTERNOON AND EARLY EVENING.
THOSE WINDS WILL THEN DROP BACK TO NEAR CALM TONIGHT WITH HIGH
CLOUDS GRADUALLY INCREASING IN COVERAGE THROUGH THE NIGHT AHEAD OF
RAINFALL WEDNESDAY MORNING.
IND WATCHES/WARNINGS/ADVISORIES
NONE.
AVIATION...WHITE
DISCUSSION...WHITE
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