Severe Thunderstorm Warning 352, NWS Indianapolis, IN

Area Forecast Discussion
National Weather Service Indianapolis IN
330 PM EDT Wed Sep 16 2026

.KEY MESSAGES...

- Hot temperatures will continue at times into Saturday,
  especially south. Heat indices in the low 100s again today and
  Thursday.

- Narrow bands of 2 to 4 inches of rain will be possible tonight
  through Thursday morning within persistent rounds of
  thunderstorms over NE central Indiana. A Flood Watch has been
  issued from 12 AM to 2PM EDT.

- Shower and storm chances persist for much of the time into
  next week, with temperatures turning cooler next week

&&

.DISCUSSION (This evening through Wednesday)...
Issued at 329 PM EDT Wed Sep 16 2026

Today...

Much of weather over the last 36 hours has been dominated
by a large, broad area of high pressure over the SE CONUS. A
combination of a strong subgeostrophic upper jet and weak low
pressure over the Atlantic has subdued the amplitude and strength of
ridge, with the upper jet now dipping into portions of the Ohio
Valley.

In the lower levels, a closed low and associated SW jet is exiting
to the NE. This jet pushed large amounts of moisture into the
region, of which has created a broad area of instability over
central Indiana. Latest soundings indicate SBCAPE values of around
1500 J/kg, with 2500 J/kg expected by late this afternoon. With
convective temperatures around 90 degrees, a broad cirrus shield,
and a modest low level warm layer, convection is likely going to be
confined to weakly forced areas along residual outflow boundaries.

The severe threat today will be rather limited with bulk shear
values less than 20kt, but lapse rates in the mid to upper levels
are steep enough for a few isolated strong cores to develop. In
these cases, a brief area of enhanced winds (likely 40-50MPH) would
be possible.

Tonight...

As we head into the overnight period, a weak positively tilted
trough will approach from the NW. As this interacts with the high
pressure to the south, confluence will promote the development of a
nocturnal LLJ. This in combination with a modest low level boundary
and a saturated thermal profile will likely lead to a narrow (50-
100mi) corridor of persistent thunderstorms. Model guidance is still
widely varied on placement of these thunderstorms, with the latest
HREF LPMM highlighting a corridor of 3-5" over E/NE Indiana.
Confidence is not high on if NE central will be within this narrow
corridor, but the margin of error is low enough, and the impact
potential is high enough that a Flood Watch has been issued for far
N/NE central Indiana from midnight tonight until 2PM EDT tomorrow
encompassing the greatest timing concern of 4AM to 11AM EDT.

Severe weather a distant secondary concern overnight, but the mid
level lapse rates due remain steep enough for a few stronger cores
to be embedded within the persistent thunderstorm threat. For this
reason, isolated gusts of 40-50 MPH will be possible overnight.

The LLJ will weaken with diurnal heating on Thursday, of which
should dampen convective initiation late Thursday morning into the
early afternoon. This should lead to a lull in thunderstorms for a
portion of tomorrow before diurnal convection returns along remnant
boundaries in the late afternoon and evening.

Friday and beyond...

The upper high will continue to gradually retreat southwest. The
surface front will sink far enough south initially to keep PoPs low
on Friday, but it will return north again on Saturday as an upper
wave interacts with the front. This will bring more rain chances,
mainly north.

After a brief reprieve from heat for many areas Friday, hot
conditions return on Saturday as the front moves back north.

Sunday into next week, larger upper waves moving through will keep
chances for rain around. Cooler air will filter back into the area,
with highs by Tuesday in the upper 70s to middle 80s.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 121 PM EDT Wed Sep 16 2026

Impacts:

- Thunderstorms are possible at KIND/KHUF and KBMG this afternoon
  and evening.

- Thunderstorms are expected at KLAF late tonight and possibly again
  at KIND/KHUF Thu morning.

- MVFR ceilings expected to occur at KLAF towards 12Z Thu.

Discussion:

Convection is anticipated to develop over portions of central IN
generally near and south of I-70 over the next few hours along
residual outflow boundaries. Convective temps from morning
soundings suggested temp near 90 F was sufficient for development
and recent ACARS soundings from KIND suggest little inhibition
remaining. Recent radar trends are showing the first signs of
echoes to the west of KBMG. Have added PROB30s for -TSRA with MVFR
vis for BMG/IND/HUF this afternoon into the evening to account
for the expected scattered convection.

Overnight, the primary frontal boundary will have shifted northward
towards KLAF and northern portions of central IN. With an
approaching weak shortwave, thunderstorm activity is expected to be
more numerous around KLAF after 06Z as the low level jet increases
into the boundary enhancing convergence. There is some chance that
this greater coverage of TS will move towards KIND/KHUF by 12Z
Thursday and have introduced PROB30 for TSRA for this scenario
through 18Z.

There is decent agreement that ceilings will fall overnight with low
level cooling and saturation associated with both convective outflow
and rainfall further N-NW of central IN. Ceilings are expected to
fall into the MVFR range for KLAF towards 12Z with IFR ceilings
possible with convection.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
Flood Watch from midnight EDT tonight through Thursday afternoon
for INZ031-038-040>042-049.

&&

AVIATION...Crosbie
DISCUSSION...Updike/50

Hazardous Weather Outlook
National Weather Service Indianapolis IN
351 PM EDT Wed Sep 16 2026

INZ021-028>030-035>037-039-043>048-051>057-060>065-067>072-172000-
Carroll-Warren-Tippecanoe-Clinton-Fountain-Montgomery-Boone-Hamilton-
Vermillion-Parke-Putnam-Hendricks-Marion-Hancock-Vigo-Clay-Owen-
Morgan-Johnson-Shelby-Rush-Sullivan-Greene-Monroe-Brown-Bartholomew-
Decatur-Knox-Daviess-Martin-Lawrence-Jackson-Jennings-
351 PM EDT Wed Sep 16 2026

This hazardous weather outlook is for central Indiana.

.DAY ONE...Through Tonight.

Thunderstorms are possible across much of the area this afternoon and
evening. While severe storms are not expected, some storms will
contain gusty winds. Lightning and heavy rain are possible with any
storm.

Heat indices in the upper 90s to around 100 are expected across much
of the area this afternoon.

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

Chances for thunderstorms will continue for much of the time into
early next week. Locally heavy rain is possible with any storm.

Max heat indices in the upper 90s to around 100 are expected again
Thursday afternoon, especially across the southern half of the area.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated.

&&

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

INZ031-038-040>042-049-172000-
Howard-Tipton-Madison-Delaware-Randolph-Henry-
351 PM EDT Wed Sep 16 2026

This hazardous weather outlook is for central Indiana.

.DAY ONE...Through Tonight.

Thunderstorms are possible this afternoon and evening. Additional
storms are possible overnight into tomorrow morning. Persistent
nature of storms overnight could lead to narrow bands of high
rainfall amounts and flooding.

While severe storms are not expected, some storms will contain gusty
winds.

Heat indices in the upper 90s to around 100 are expected across much
of the area this afternoon.

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

Chances for thunderstorms will continue for much of the time into
early next week. Locally heavy rain is possible with any storm.

Max heat indices in the upper 90s to around 100 are expected again
Thursday afternoon, especially across the southern half of the area.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated.

&&

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
1201 PM EDT Wed Sep 16 2026

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

0800 AM     Rain             4 NW West Lafayette     40.48N 86.97W
09/16/2026  M2.29 Inch       Tippecanoe         IN   Cocorahs

            Cocorahs station IN-TP-96 West Lafayette 4.2
            NW.

0700 AM     Rain             8 WNW West Lafayette    40.47N 87.06W
09/16/2026  M2.04 Inch       Tippecanoe         IN   Cocorahs

            Cocorahs station IN-TP-9 Otterbein 2.3 SE.

0700 AM     Rain             8 WNW Shadeland         40.40N 87.09W
09/16/2026  M1.46 Inch       Tippecanoe         IN   Cocorahs

            Cocorahs station IN-TP-98 West Point 4.0 NW.

0700 AM     Rain             1 SW Kokomo             40.46N 86.15W
09/16/2026  M1.18 Inch       Howard             IN   Cocorahs

            Cocorahs station IN-HW-42 Kokomo 1.2 SW.

0700 AM     Rain             4 N Williamsport        40.34N 87.29W
09/16/2026  M1.15 Inch       Warren             IN   Cocorahs

            Cocorahs station IN-WR-4 Attica 4.2 NNW.

&&

Crosbie

Special Weather Statement
National Weather Service Indianapolis IN
355 PM EDT Wed Sep 16 2026

INZ042-162030-
Randolph IN-
355 PM EDT Wed Sep 16 2026

...A strong thunderstorm will impact portions of northeastern
Randolph County through 430 PM EDT...

At 355 PM EDT, Doppler radar was tracking a strong thunderstorm over
Union City, or 12 miles northwest of Greenville, 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...
Union City and Saratoga.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4014 8489 4022 8496 4031 8489 4031 8480
      4013 8481
TIME...MOT...LOC 1955Z 258DEG 34KT 4023 8479

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

AGM

Special Weather Statement
National Weather Service Indianapolis IN
425 PM EDT Wed Sep 16 2026

INZ060-067-162100-
Knox IN-Sullivan IN-
425 PM EDT Wed Sep 16 2026

...Strong thunderstorms will impact portions of southeastern Sullivan
and north central Knox Counties through 500 PM EDT...

At 424 PM EDT, Doppler radar was tracking a cluster of strong
thunderstorms near Lawrenceville Vincennes Airport, or near
Lawrenceville, moving east at 25 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Bicknell, Carlisle, Oaktown, Bruceville, and Freelandville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3888 8754 3889 8754 3889 8753 3890 8753
      3890 8752 3891 8753 3894 8752 3898 8727
      3872 8729 3871 8752 3874 8750 3877 8750
      3877 8751 3878 8749 3882 8753 3885 8753
      3886 8755
TIME...MOT...LOC 2024Z 258DEG 21KT 3881 8762

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

Crosbie

Special Weather Statement
National Weather Service Indianapolis IN
449 PM EDT Wed Sep 16 2026

INZ051-060-162115-
Vigo IN-Sullivan IN-
449 PM EDT Wed Sep 16 2026

...A strong thunderstorm will impact portions of southern Vigo and
northern Sullivan Counties through 515 PM EDT...

At 449 PM EDT, Doppler radar was tracking a strong thunderstorm 11
miles southeast of Marshall, moving east at 25 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Prairieton, Prairie Creek, Farmersburg, Fairbanks, Riley, and
Pimento.

This includes Interstate 70 between mile markers 12 and 15.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3931 8760 3934 8758 3934 8756 3935 8754
      3935 8753 3938 8753 3945 8725 3920 8725
      3920 8759 3922 8757 3924 8758 3925 8757
      3925 8760 3928 8761 3930 8760 3931 8762
TIME...MOT...LOC 2049Z 258DEG 21KT 3928 8754

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

Crosbie

Special Weather Statement
National Weather Service Indianapolis IN
513 PM EDT Wed Sep 16 2026

INZ051-052-060-162200-
Clay IN-Vigo IN-Sullivan IN-
513 PM EDT Wed Sep 16 2026

...A strong thunderstorm will impact portions of southeastern Vigo,
northeastern Sullivan and southwestern Clay Counties through 600 PM
EDT...

At 512 PM EDT, Doppler radar was tracking a strong thunderstorm 10
miles south of Terre Haute, moving east at 25 mph.

HAZARD...Wind gusts of 50 to 55 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Shelburn, Prairieton, Farmersburg, Clay City, Riley, Cory, Saline
City, and Pimento.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3918 8744 3937 8749 3944 8711 3924 8707
TIME...MOT...LOC 2112Z 258DEG 21KT 3931 8737

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...55 MPH

Crosbie

Special Weather Statement
National Weather Service Indianapolis IN
543 PM EDT Wed Sep 16 2026

INZ047-054-055-162215-
Johnson IN-Morgan IN-Marion IN-
543 PM EDT Wed Sep 16 2026

...A strong thunderstorm will impact portions of northeastern Morgan,
northwestern Johnson and southwestern Marion Counties through 615 PM
EDT...

At 543 PM EDT, Doppler radar was tracking a strong thunderstorm near
Mooresville, or 12 miles southwest of Indianapolis, moving east at 10
mph.

HAZARD...Wind gusts of 50 to 55 mph and half inch 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...
Indianapolis, Greenwood, and Camby.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3955 8615 3959 8634 3963 8633 3967 8633
      3970 8614
TIME...MOT...LOC 2143Z 269DEG 10KT 3963 8627

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...55 MPH

AGM