671
FXUS63 KIND 171748
AFDIND
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
148 PM EDT WED JUN 17 2026
KEY MESSAGES
- ANOTHER ROUND OF STORMS EXPECTED THIS EVENING INTO THE EARLY
OVERNIGHT
- DAMAGING WINDS AND TORNADOES ARE THE MAIN THREATS WITH LARGE HAIL
ALSO POSSIBLE
- FLOOD WATCH THROUGH 2AM WITH RAIN AMOUNTS LOCALLY AS HIGH AS 4
INCHES
- BELOW NORMAL TEMPERATURES WILL CONTINUE FOR MUCH OF THE PERIOD
DISCUSSION (THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 148 PM EDT WED JUN 17 2026
OVERVIEW.
A WIDESPREAD AND SIGNIFICANT SEVERE WEATHER OUTBREAK IS EXPECTED FOR
TODAY WITH THE FIRST ROUND OF MOSTLY SUB-SEVERE STORMS MOVING
THROUGH INDIANA AND WESTERN ILLINOIS AT THIS TIME. EXPECTATIONS ARE
FOR A SECOND ROUND OF SEVERE STORMS TOWARDS THE EVENING AND EARLY
OVERNIGHT HOURS WITH THE THREAT FOR DAMAGING WINDS, TORNADOES, LARGE
HAIL, AND FLASH FLOODING. THE THREAT FOR HIGHER-END TORNADOES WILL
BE DEPENDENT ON HOW LONG STORMS REMAIN DISCRETE, WHICH CURRENTLY
LOOKS LIKELY THROUGH AT LEAST ILLINOIS AND PORTIONS OF WESTERN
INDIANA. FLASH FLOODING WILL ALSO BECOME A CONCERN, ESPECIALLY
TOWARDS SOUTHERN INDIANA AS THE CONVECTIVE LINE SLOWS.
FOLLOWING TONIGHT, THE PATTERN WILL TRANSITION TOWARD A QUIETER AND
MORE STABLE STATE. WHILE LINGERING MOISTURE MAY CAUSE SOME
CLOUDINESS EARLY THURSDAY, THE OVERALL TREND THROUGH THE REMAINDER
OF THE WEEK AND INTO EARLY NEXT WEEK IS QUIET WITH HIGH PRESSURE AND
SEASONAL TEMPERATURES.
REST OF TODAY.
THE SYNOPTIC PATTERN REMAINS HIGHLY ANOMALOUS FOR MID-JUNE,
CHARACTERIZED BY A DEEP MID-LEVEL TROUGH AND A ROBUST 130+ KT JET
STREAK TRANSLATING INTO THE SOUTHERN GREAT LAKES. SURFACE ANALYSIS
REVEALS A DEEPENING LOW TO OUR NORTHWEST WITH AN ADVANCING COLD
FRONT THAT WILL SERVE AS THE PRIMARY FOCUS FOR CONVECTIVE INITIATION
THIS EVENING. HIGH-RESOLUTION GUIDANCE, INCLUDING THE 12Z AND LATEST
HRRR RUNS, CONFIRMS A SIGNIFICANT SEVERE WEATHER THREAT, WITH A
HEIGHTENED CONCERN FOR DISCRETE SUPERCELLULAR DEVELOPMENT ACROSS
WEST-CENTRAL INDIANA WITH THE 2ND ROUND OF STORMS. THE ENVIRONMENT
IS UNDERGOING A RAPID, EFFICIENT MOISTURE SURGE, WITH DEW POINTS
ALREADY RISING INTO THE LOW 60S TOWARDS SOUTHWESTERN INDIANA. THIS
INFLUX OF HIGH-THETA-E AIR IS EXPECTED TO COMPENSATE FOR ANY
LINGERING MORNING CLOUD COVER OR CONVECTIVE INHIBITION, PROVIDING
SUFFICIENT BUOYANCY FOR SURFACE-BASED CONVECTION.
OF PRIMARY METEOROLOGICAL CONCERN IS THE HIGHLY ANOMALOUS KINEMATIC
ENVIRONMENT. MODEL SOUNDINGS CONTINUE TO DEPICT ELONGATED, HIGHLY
CURVED LOW-LEVEL HODOGRAPHS WITH BACKED SURFACE WINDS AND NEARLY 70
KT FLOW AT 1 KM, CREATING AN ENVIRONMENT FAVORABLE FOR SIGNIFICANT,
LONG-LIVED TORNADOES IF THE CELLS CAN REMAIN DISCRETE. CURRENT CAM
CONSENSUS SUGGESTS THAT WEST-CENTRAL INDIANA REMAINS THE PRIMARY
CORRIDOR FOR POTENTIAL TORNADOGENESIS, AS STORMS HERE WILL BE BEST
POSITIONED TO INTERACT WITH MAXIMIZED LOW-LEVEL HELICITY AND
LOCALIZED OUTFLOW BOUNDARIES BEFORE UPSCALE GROWTH INTO A MORE
LINEAR MODE OCCURS. WHILE THE POTENTIAL FOR DISCRETE, SUPERCELLULAR
CELLS IS THE IMMEDIATE PRIORITY, THE TRANSITION TO A BOWING LINE
SEGMENT LATER THIS EVENING BRINGS AN INCREASING RISK OF DESTRUCTIVE
STRAIGHT-LINE WINDS, POTENTIALLY ENHANCED BY WAKE LOW DEVELOPMENT.
FLASH FLOODING ALSO REMAINS A SECONDARY BUT SERIOUS HAZARD, AS HIGH
PWAT VALUES AND POTENTIAL TRAINING OF CONVECTIVE ELEMENTS MAY LEAD
TO RAPID, LOCALIZED RAINFALL ACCUMULATIONS. THE SITUATION REMAINS
HIGHLY DYNAMIC AND WARRANTS CLOSE MONITORING OF CONVECTIVE
INITIATION TIMING AND THE EXACT POSITIONING OF THE SURFACE WARM
FRONT AS THE AFTERNOON PROGRESSES.
OUTSIDE OF THE SEVERE WEATHER, BOTH FLOODING AND STRONG GRADIENT
WINDS WILL BE A CONCERN WITH THE GRADIENT WIND THREAT MAINLY THROUGH
00Z AND THE FLOODING THREAT MAINLY ASSOCIATED WITH THE SECOND ROUND
OF CONVECTION. HREF PMMS SHOW POCKETS OF 4+ INCHES WITH SOME
UNCERTAINTY AS TO WHERE THE AXIS OF HEAVIEST RAIN WILL FALL.
CONFIDENCE IS CURRENTLY HIGHEST ACROSS SOUTHERN INDIANA BUT WITH THE
UNCERTAINTY, WE PLAN ON ISSUING A FLOOD WATCH THROUGH THE ENTIRE
FORECAST AREA, ESPECIALLY CONSIDERING THE VERY HEAVY RAINS SO FAR
THIS JUNE.
THURSDAY THROUGH SATURDAY.
AS THE POTENT COLD FRONT RESPONSIBLE FOR THE WEDNESDAY STORMS PUSHES
WELL TO OUR EAST, A DEEP, DRY NORTHWESTERLY FLOW WILL BECOME
ESTABLISHED ACROSS THE OHIO VALLEY. ON THURSDAY, ANY LINGERING CLOUD
COVER FROM THE OVERNIGHT PERIOD WILL QUICKLY SCATTER AND DISSIPATE,
GIVING WAY TO ABUNDANT SUNSHINE. MODEL GUIDANCE SHOWS A NOTICEABLE
DROP IN DEW POINTS THROUGHOUT THE DAY, LEADING TO A VERY COMFORTABLE
AFTERNOON WITH HIGH TEMPERATURES IN THE LOWER TO MIDDLE 70S.
FRIDAY AND SATURDAY WILL FEATURE PLEASANT EARLY-SUMMER WEATHER WITH
A SURFACE HIGH-PRESSURE SYSTEM TRACKING ACROSS THE GREAT LAKES AND
INTO THE OHIO VALLEY. THIS SYSTEM WILL SUPPRESS ANY POTENTIAL FOR
CONVECTIVE DEVELOPMENT, ENSURING CLEAR TO MOSTLY SUNNY SKIES AND
LIGHT, VARIABLE WINDS. WITH THE LACK OF ANY SIGNIFICANT FORCING
MECHANISMS AND A VERY DRY AIR COLUMN, THE FORECAST REMAINS DRY WITH
HIGH CONFIDENCE. DAYTIME TEMPERATURES WILL BE PLEASANT, RANGING FROM
THE MID-70S ON FRIDAY TO NEAR 80 DEGREES BY SATURDAY, WHILE
OVERNIGHT LOWS WILL SETTLE INTO THE COOL AND REFRESHING 50S.
SUNDAY THROUGH WEDNESDAY.
THE QUIET CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE SECOND HALF
OF THE WEEKEND AND INTO THE EARLY PART OF NEXT WEEK. ENSEMBLE
GUIDANCE REMAINS IN STRONG AGREEMENT THAT AN UPPER-LEVEL RIDGE OF
HIGH PRESSURE WILL AMPLIFY ACROSS THE CENTRAL UNITED STATES,
EFFECTIVELY KEEPING THE PATTERN DRY AND STABLE PATTERN FOR INDIANA.
SUNDAY WILL BE ANOTHER BEAUTIFUL DAY, WITH TEMPERATURES NUDGING
SLIGHTLY HIGHER INTO THE LOW 80S UNDER MOSTLY SUNNY SKIES.
LOOKING TOWARD THE BEGINNING OF THE NEW WORK WEEK, THIS RIDGE WILL
SHIFT EASTWARD, ALLOWING FOR A GRADUAL WARMING TREND. BY MONDAY AND
TUESDAY, AFTERNOON HIGHS ARE EXPECTED TO REACH THE MID-80S. WHILE
SOME LONG-RANGE ENSEMBLE MEMBERS SUGGEST A POTENTIAL BREAKDOWN OF
THE RIDGE BY NEXT WEDNESDAY, THE CURRENT MOISTURE PROFILE INDICATES
THAT ANY RETURN TO A MORE ACTIVE, UNSETTLED PATTERN WILL BE DELAYED
UNTIL THE LATTER HALF OF THE WEEK.
AVIATION (18Z TAF ISSUANCE)
ISSUED AT 132 PM EDT WED JUN 17 2026
IMPACTS:
- SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND THEN AGAIN THIS
EVENING AND OVERNIGHT.
- WIND GUSTS OVER 30KT THIS AFTERNOON. LLWS TONIGHT.
DISCUSSION:
MAIN FOCUS WAS TRYING TO TIME CONVECTION AT THE TERMINALS. THE
STRATIFORM RAIN SHOULD LAST A FEW HOURS WITH GENERAL VFR CONDITIONS.
BUT A LINE OF CONVECTION IS ANTICIPATED AS THE FRONT PUSHES SOUTH.
THERE MAY BE A PERIOD OF MVFR CIGS MAINLY FOR LAF BEHIND THE FRONT.
ONCE THE FRONT PUSHES SOUTH WEST WINDS ARE EXPECTED TO REMAIN GUSTY
INTO THURSDAY MORNING.
IND WATCHES/WARNINGS/ADVISORIES
FLOOD WATCH FROM 5 PM EDT THIS AFTERNOON THROUGH LATE TONIGHT
FOR INZ021-028>031-035>049-051>057-060>065-067>072.
AVIATION...WFO TOP
DISCUSSION...WHITE
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