333
FXUS63 KIND 191019
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
619 AM EDT Wed Aug 19 2026

.KEY MESSAGES...

- Flood Watch in effect from 2PM Today through 8AM Thursday across
  the northern half of central IN with localized flash flooding
  possible

- Scattered to numerous showers and storms are expected this
  afternoon into tonight, isolated severe storms are possible

- Generally drier late this week through early next week, but there
  is a chance for showers and storms late Friday into Saturday

&&

.DISCUSSION (This afternoon through Tuesday)...
Issued at 618 AM EDT Wed Aug 19 2026

Today through tonight...

Patchy fog will be possible through daybreak as winds remain very
light across central Indiana. Any fog that develops should quickly
mix out in typical diurnal fashion. Regional radar mosaic depicts an
MCS currently moving across eastern MO and western IL. This system
will continue to propagate southeastward along an instability
gradient, keeping precipitation mostly confined to southwest
portions of the forecast area through the morning. Isolated
thunderstorms cannot be ruled out given weak elevated instability.

Greater chances for convection are expected this afternoon into
tonight as a mid-upper level wave pushes across the region. At the
surface, a weak west to east oriented cold front should gradually
push south providing low-level convergence. These features along
with daytime heating over an abundantly moist environment supports
the potential for scattered to numerous showers and thunderstorms.
Convection could continue well into the overnight, but expect
generally decreasing coverage late tonight as the the strongest
forcing shifts east

Deep-layer wind shear is supportive for organized convection, but
there remains some uncertainty on the degree of destabilization
later today which limits confidence on the overall severe threat.
Isolated damaging wind gusts or severe hail appear possible if
sufficient destabilization occurs as favorable deep-layer wind shear
supports the potential for multicell line segments and possibly even
a few transient supercells.

The greater concern will be localized flash flooding given soils
remain very saturated from recent rainfall. Model guidance continues
to suggest the potential for training storms with the west to east
oriented cold front slowly pushing south. Warm rain processes and
PWATs around or over 2 inches will also promote efficient rainfall
rates. Latest CAMs generally suggest the potential for 1 to 3 inches
of rain where training occurs. A Flood Watch is in effect from 2 PM
today through 8 AM Thursday across the northern half of central
Indiana where training storms over saturated soils appears most
likely. Additional fog development is possible late tonight once
convection dissipates.

Thursday through early next week...

Surface high pressure building in will provide mostly quiet weather
conditions Thursday and Friday. A few upper level disturbance will
move in late Friday into Saturday supporting at least low rain
chances with sufficient moisture advecting into central Indiana.
Long range guidance generally depicts surface high pressure building
in once again late weekend into early next week providing mundane
weather conditions. Expect temperatures to remain slightly below
normal during the period.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 618 AM EDT Wed Aug 19 2026

Impacts:

- Scattered to numerous showers and thunderstorms possible today,
  mostly after 18Z through tonight.

- Fog development possible tonight

Discussion:

Patchy fog cannot be ruled out through 12Z today, mainly at the
outlying TAF sites. A shortwave trough approaching from the
northwest is expected to bring scattered to numerous showers and
thunderstorms to central Indiana this afternoon through tonight.
Some uncertainty remains regarding timing, and thus a Prob30 group
was included to cover this potential initially after 18Z.

A TEMPO was included for some sites during the evening when greater
coverage can be expected. Convection could linger during much of the
overnight, but uncertainty remains. Fog development also appears
possible late overnight if convection and clouds clear out. Winds
should increase slightly from the WSW as the shortwave approaches
later today with speeds remaining under 10kt. Look for winds to
become northeasterly tonight.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
Flood Watch from 2 PM EDT this afternoon through Thursday
morning for INZ021-028>031-035>049-054>057.

&&

$$

AVIATION...Melo
DISCUSSION...Melo