359
FXUS63 KIND 152338
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
738 PM EDT Mon Jun 15 2026

.KEY MESSAGES...

- Cooler temperatures through Tuesday night with highs in the low-
  mid 70s and lows in the 50s

- Showers and thunderstorms possible Tuesday, marginal risk of
  severe weather.

- Showers and thunderstorms likely on Wednesday with a much greater
  risk of severe weather.

&&

.DISCUSSION (This evening through Monday)...
Issued at 159 PM EDT Mon Jun 15 2026

Surface analysis early this afternoon shows a surface ridge of high
pressure stretching across the Central Plains into Indiana and Ohio.
Light winds and pleasant dew points in the 50s and upper 40s were
present. GOES19 shows SCT-BKN CU across the area. Aloft, water vapor
showed a deep and broad area of low pressure over Hudson Bay. This
feature was providing cyclonic flow across most of Canada, the Great
Lakes and Indiana. Furthermore, this strong flow was keeping
intrusions of hot and humid tropical air out of the Ohio valley.
Within the upper flow, a short wave was found over the Dakotas,
pushing SE.

Tonight...Quiet and cool weather is expected once again tonight as
the surface high pressure system pushes toward KY and TN before
reorganizing over the Virginias. Forecast soundings overnight show a
dry column while under the influence of the high pressure system
with subsidence in place aloft. Slight warm air advection will be in
place, so lows overnight should be a tad warmer than persistence.

Tuesday...Southerly surface flow will resume on Tuesday, allowing a
bit more warmth and humidity to arrive across the area. Aloft, the
first of two subtle waves is expected to arrive across Indiana
during the late morning and early afternoon hours. Forecast
soundings suggest some CAPE available as convective temperatures are
reached. Shear also appears favorable for at least some storm
development. HRRR continues to suggest mid day through early
afternoon showers and storms to push across our area. Although
widespread severe weather appears unlikely, a few severe storms,
with the main threat being damaging straight line winds, will be
possible. Highs will once again reach the upper middle and upper 70s.

Tuesday Night...Dry weather will be expected on Tuesday night as
models suggest weak ridging in place aloft along with surface high
pressure in place over the Carolinas. These two features will keep
quiet but more mild weather across Central Indiana through
early Wednesday Morning.

Wednesday...

...ENHANCED SEVERE WEATHER THREAT ON WEDNESDAY...

As of this writing, SPC has placed much of central Indiana within an
Enhanced area for severe weather on Wednesday. This is due to the
models suggesting a second and stronger upper wave passing within
the flow aloft. The wave is expected to trigger a deepening surface
low, expected to track across IL and into the Great Lakes. This will
place Indiana within the warm sector as the forcing passes along
with an associated cold front late Wednesday night. An unusual
feature for this time of year is the strong surface low allows for
the development of a very strong LLJ across northern Indiana on
Wednesday night, in excess of 60 knts. Forecast soundings show
favorable CAPE in excess of 1700 J/KG in a highly sheared
environment. Supercell Composites appear to be high during the mid
to late afternoon and helicity appears to be favorable for
tornadoes. Should all these signals remain in the next few days,
Wednesday will be a significant weather day with tornadoes quite
possible, especially in western Central Indiana. A
caveat...convective remnants of an MCS over WI could impact cloud
cover, particularly across northern parts of Indiana during the
morning hours. This could impact afternoon instability. Nonetheless,
the day looks like morning clouds, possible precipitation across
northern Indiana, followed by convective initiation after 600PM in
IL with propagation across Central Indiana through 200 AM. It is
this evening window that will be most concerning for severe weather
potential. Continue to stay weather aware in the coming days and be
ready to activate your preparedness plan on Wednesday.

Thursday Through Monday.

By Thursday morning, the convective system and its associated deep-
layer forcing will have advanced well into the upper Ohio Valley,
leaving central Indiana embedded within a regime of strong post-
frontal subsidence. The primary synoptic driver will be an expanding
1022 mb surface high pressure sliding southeastward out of the
northern Plains. This area of high pressure and and dry air
advection aloft will allow for skies to slowly clear. Going into
Friday, continued CAA will help keep highs on Thursday into Friday
in the mid to upper 70s across the northern counties and the lower
80s further south.

Given the substantial rainfall accumulated prior to Thursday
morning, hydrologic impacts will become a greater concern going into
the weekend. MMEFS guidance shows an elevated probability of river
flooding, especially on the Wabash River. The guidance indicate a 60
to 80 percent chance of several crests reaching minor flood stage
with river levels similar to potentially slightly higher than the
flooding that occurred earlier this week.

Ideal radiational cooling and dry surface air on Friday and Saturday
nights will allow overnight minimums to drop into the low to mid-
50s. By Sunday and Monday, the high pressure center will slowly
drift toward the mid-Atlantic, causing low-level winds to shift to a
more southerly component. This will kick off a gradual warming trend
allowing afternoon highs to return to near-seasonal norms in the
lower to mid-80s.  While the operational consensus strongly supports
this prolonged dry spell, a notable alternate scenario is present
within a cluster of the European ensemble members. This subset of
guidance suggests that a weak, secondary shortwave dropping down the
eastern edge of a larger Canadian longwave trough could slide
slightly further west than currently projected around Saturday
night. If this deeper track verifies, rain chances will gradually
begin to increase as early as Sunday night, but confidence remains
low due to the aforementioned model differences.

&&

.AVIATION (00Z TAF Issuance)...
Issued at 735 PM EDT Mon Jun 15 2026

Impacts:

- Chance of thunderstorms Tuesday afternoon after 17z.

- Wind gusts between 18-25 kt are possible on Tuesday

Discussion:

VFR conditions are expected through much of the period. On Tuesday,
a quick moving upper level weather disturbance will push toward
Indiana. HRRR suggests a line of shower and storm development
pushing across the TAF sites within the 16Z-22Z time frame. For now,
have included a tempo group to account for that. Brief MVFR
conditions are possible with any TSRA that strikes a TAF site. A few
lingering showers or storms are possible after 22Z.

Look for predominately southwesterly winds through the period with
winds increasing on Tuesday. Winds gusts between 18-25 kt are
possible on Tuesday.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

AVIATION...Melo
DISCUSSION...Puma/White