Flash Flood Warning 11, NWS Indianapolis, IN

Area Forecast Discussion
National Weather Service Indianapolis IN
135 AM EDT Thu Jun 18 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

&&

.FORECAST UPDATE...
Issued at 1006 PM EDT Wed Jun 17 2026

In terms of the forecast, only a few changes were needed. First was
temperatures so that they match observations better as the north has
cooled off while across the south is still on the warmer side. Next
was to update the PoPs and clear out our NW from much of the showers
and storms as they have pushed south.

As of 10pm, severe weather is ongoing with numerous strong storms
and even a tornado warning in effect. Storms will continue to drift
ESE as the night goes on and should weaken or move out by around or
shortly after 2am. Continue to monitor warnings.

&&

.MESOSCALE UPDATE...
Issued at 730 PM EDT Wed Jun 17 2026

Surface mesoanalysis shows strongest pressure falls are located
across central Indiana with between 3-4 mb/2 hr. This is collocated
with the core of the 50-60 kt 850 mb jet per objective analysis and
recent IND VWP data. Thanks to locally backed low level flow and
moderately strong 700 mb flow, strong low level shear currently
exists across the region. An incredible 0-1 KM SRH from 700-800
M2/S2 and 0-3 KM SRH around 1200 M2/S2 has been noted recently on
VWP data.

So far the main limiting factors for a more significant tornado
threat across IL/IN with ongoing convection is substantial mid level
warming (700 mb temps around 10 C per STL ACARS sounding) combined
with modest surface based convective inhibition leading to weak 0-3
KM lapse rates under 6 C/KM, modest instability /1000-1500 MUCAPE/
and 50-100 J/KG OF MU/SBCINH/. The existence of this mid level
warming with forced ascent through the inhibition layer centered
from 850-700 mb combined with the strong 0-3 km shear has been
confirmed from recent storm chaser video feeds showing a classic
large base with laminar shape and limited low level vertical
motion/vorticity generation.

Continued low level moistening with dewpts rising into the lower 70s
per downstream obs in southern MO/IL combined with slight mid level
cooling (likely reason for renewed CI over wcentral IL) should
support a increasing surface based storm threat in the next 1-3 hrs.
Therefore there still remains a significant tornado threat, as low
level shear will remain near current values through 11 PM EDT before
gradually weakening from the west. The significant tornado threat
will include all of central Indiana, with the likelihood for
scattered very large hail and damaging winds gusts.

&&

.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 (06Z TAF Issuance)...
Issued at 134 AM EDT Thu Jun 18 2026

Impacts:

- Showers and thunderstorms continuing for the first couple of hours
of the period for BMG

- Wind gusts over 20kt into the early morning hours.

Discussion:

Showers and storms, some severe continue across south-central
Indiana and will mainly impact BMG the first few hours of the period
with some lingering VCSH/TS at IND. Otherwise, the rest of the TAF
sites will see dry weather the remainder of the period.

Outside of convection winds gusts will be up to 25-35kt likely
across our south for the next few hours. For tomorrow, widespread
periodic gusts of up to 20 kts possible.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 4 AM EDT early this morning for INZ021-028>031-
035>049-051>057-060>065-067>072.

&&

UPDATE...KF
AVIATION...KF
DISCUSSION...White

Hazardous Weather Outlook
National Weather Service Indianapolis IN
543 PM EDT Wed Jun 17 2026

INZ021-028>031-035>049-051>057-060>065-067>072-182145-
Carroll-Warren-Tippecanoe-Clinton-Howard-Fountain-Montgomery-Boone-
Tipton-Hamilton-Madison-Delaware-Randolph-Vermillion-Parke-Putnam-
Hendricks-Marion-Hancock-Henry-Vigo-Clay-Owen-Morgan-Johnson-Shelby-
Rush-Sullivan-Greene-Monroe-Brown-Bartholomew-Decatur-Knox-Daviess-
Martin-Lawrence-Jackson-Jennings-
543 PM EDT Wed Jun 17 2026

This hazardous weather outlook is for central Indiana.

.DAY ONE...Tonight.

Another round of storms will be moving through until the early
overnight hours with a Tornado Watch in effect until 1am EDT. Damaging
winds, large hail, tornadoes, and heavy rain are all possible.

Outside of thunderstorms, winds will gust to around 40 mph this
evening.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Thunderstorms are possible Sunday into Monday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is requested into the early overnight hours.

&&

More information, along with other weather, hydrological and climate
information can be found at http://weather.gov/ind

Preliminary Local Storm Report
National Weather Service Indianapolis IN
1116 PM EDT Wed Jun 17 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1051 PM     Rain             3 WNW Lake Lemon        39.27N 86.44W
06/17/2026  M1.80 Inch       Monroe             IN   Cocorahs

            Accumulation over the past 51 minutes.

&&

BH

Special Weather Statement
National Weather Service Indianapolis IN
1148 PM EDT Wed Jun 17 2026

INZ051>053-060-061-180445-
Clay IN-Owen IN-Greene IN-Vigo IN-Sullivan IN-
1148 PM EDT Wed Jun 17 2026

...A strong thunderstorm will impact portions of southern Vigo,
northern Sullivan, southern Clay, southwestern Owen and northwestern
Greene Counties through 1245 AM EDT...

At 1148 PM EDT, Doppler radar was tracking a strong thunderstorm 7
miles north of Hutsonville, or 12 miles south of Marshall, moving
east at 50 mph.

HAZARD...Wind gusts up to 50 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

Locations impacted include...
Linton, Sullivan, Bloomfield, Jasonville, Worthington, Shelburn,
Prairie Creek, Farmersburg, Dugger, Clay City, Hymera, Fairbanks,
Switz City, Coal City, Graysville, Patricksburg, Coalmont, Pimento,
and Vicksburg.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Tornado Watch remains in effect until 100 AM EDT for southwestern
and west central Indiana.

&&

LAT...LON 3917 8764 3917 8762 3918 8762 3920 8759
      3922 8757 3924 8758 3925 8757 3925 8760
      3928 8761 3930 8760 3931 8762 3932 8760
      3936 8696 3901 8694 3910 8765 3911 8765
      3912 8763 3913 8766
TIME...MOT...LOC 0348Z 272DEG 43KT 3922 8769

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...50 MPH

GM

Special Weather Statement
National Weather Service Indianapolis IN
1224 AM EDT Thu Jun 18 2026

INZ056-057-064-065-180500-
Rush IN-Decatur IN-Bartholomew IN-Shelby IN-
1224 AM EDT Thu Jun 18 2026

...A strong thunderstorm will impact portions of southeastern Shelby,
southern Rush, Decatur and northeastern Bartholomew Counties through
100 AM EDT...

At 1224 AM EDT, Doppler radar was tracking a strong thunderstorm 9
miles south of Shelbyville, moving east at 40 mph.

HAZARD...Wind gusts up to 50 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

Locations impacted include...
Greensburg, Adams, Flat Rock, Milford, Geneva, St. Paul, Clarksburg,
Burney, Waldron, Moscow, Newpoint, Sandusky, and Lake Santee.

This includes Interstate 74 between mile markers 120 and 144.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Tornado Watch remains in effect until 100 AM EDT for central
Indiana.

&&

LAT...LON 3925 8534 3933 8588 3949 8586 3949 8530
      3927 8530
TIME...MOT...LOC 0424Z 274DEG 36KT 3940 8578

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH

GM

Preliminary Local Storm Report
National Weather Service Indianapolis IN
207 AM EDT Thu Jun 18 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1209 AM     Tstm Wnd Dmg     2 NNE Freetown          39.00N 86.12W
06/18/2026                   Jackson            IN   Public

            Damage occurred on W County Road 840 N and N
            County Road 425 W that includes structural
            and tree damage. A house was flipped over.
            Time is estimated from radar.

&&

BH

Preliminary Local Storm Report
National Weather Service Indianapolis IN
208 AM EDT Thu Jun 18 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1207 AM     Tstm Wnd Dmg     1 N Freetown            38.99N 86.13W
06/18/2026                   Jackson            IN   Public

            Several trees were blown down. Time is
            estimated from radar.

&&

BH

Preliminary Local Storm Report
National Weather Service Indianapolis IN
209 AM EDT Thu Jun 18 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1207 AM     Tstm Wnd Dmg     1 N Freetown            38.99N 86.13W
06/18/2026                   Jackson            IN   Public

            Damage of an unspecified nature. Time is
            estimated from radar.

&&

BH