842
FXUS63 KIND 250701
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
301 AM EDT Thu Jun 25 2026

.KEY MESSAGES...

- Flood Watch from late this afternoon through Saturday morning for
  southwest portions of central Indiana with 1 to 3 inches of rain
  possible

- Multiple rounds of showers and storms producing torrential
  rainfall and localized flooding later today into the weekend

- Isolated severe storms possible as well this afternoon and evening
  and again on Friday

- Hot and humid conditions expected for much of next week with
  multiple days in the 90s

&&

.DISCUSSION (Today through Wednesday)...
Issued at 301 AM EDT Thu Jun 25 2026

Convection continues to weaken across the northern Wabash Valley
early this morning with a more stable and drier airmass lingering
across the region. With light southerly flow...temperatures ranged
from the mid 60s to the lower 70s at 06Z.

The aforementioned convection is in advance of a diffuse frontal
boundary currently extending from the western Great Lakes back into
the Missouri Valley. Quasi-zonal flow aloft in tandem with the
boundary drifting south and becoming nearly stationary over the Ohio
Valley will reestablish an active regime with multiple opportunities
for showers and storms today through the first half of the weekend.
Storms will carry a renewed concern for flooding focused especially
on Friday and Friday night. The front will be forced north of the
region by late weekend as the upper level pattern transitions to
deep ridging over the Mississippi and Ohio Valleys resulting in an
extended period of hot and humid weather for much of next week.

Today through Saturday Night

The presence of lingering dry air through the column and a capping
inversion near 600mb noted nicely on the KIND ACARS will aid in
further weakening of ongoing convection and decreasing coverage over
the next several hours. There remains subtle instability present
below the cap which combined with an increase in westerly 850mb flow
and gradual moisture advection into the region will be enough to
maintain isolated to scattered convection through daybreak drifting
south to near if not just south of the I-70 corridor. Expect any
leftover showers to largely diminish later this morning as low level
flow weakens.

The presence of the boundary slipping south into the forecast area
interacting with a progressively moist and unstable airmass this
afternoon will support renewed development of scattered convection
focused especially across the southern two-thirds of the forecast
area. A modestly unstable but low shear environment supports more
disorganized pulse intensity convection for the afternoon and early
evening with the potential for localized damaging winds from any
collapsing cells. PWATs will continue to rise throughout the day
with torrential rainfall accompanying convection and bringing the
initial threat for localized flooding that will be present across
the area into the weekend.

Convection will decrease in coverage this evening and remain largely
confined to the vicinity of the frontal boundary likely to be
located across the southern part of the forecast area. A surface
wave developing on the frontal boundary across the High Plains will
eject east this evening and track into the Ohio Valley on Friday. A
feed of rich Gulf moisture will advect into the region in advance of
the surface low and interact with increasing low level convergence
along the boundary to bring the potential for more widespread
heavier rainfall from the predawn hours Friday into Friday night.
Expect an airmass supportive of highly efficient rainfall rates
during the period focused across the southern half of the forecast
area...highlighted by PWAT values climbing to near 2 inches...deep
saturation through the column and a freezing level rising to near
15kft suggestive of warm rain processes.

Considering the recent wet conditions from the active pattern of
late...torrential rainfall producing flash flooding is a growing
concern and have introduced a Flood Watch for the southwest part of
the forecast area west of a Terre Haute to Bedford line where
confidence is highest in potential impacts based on antecedent
conditions and where PWATs are likely to be the highest. 1 to 3
inches of rain with locally higher amounts are expected in the lower
Wabash Valley through Saturday. Anticipate the Watch will need to be
extended further east across the rest of the southern forecast area
at some point later today or tonight but impacts from more
widespread heavy rainfall in these areas are not expected until
during the day Friday at the earliest.

An isolated severe weather risk remains within the scope of
possibilities on Friday afternoon and evening but confidence is
higher in this being a greater concern near or just south of the
front which will be located somewhere across southern Indiana. The
NAMNest is showing as a clear outlier with a slightly deeper surface
low tracking further north across the area and consequently pulling
the boundary back north as well. Should this solution come to
fruition...a concern for damaging winds and a few tornadoes would be
on the table with increasing low level shear and helicity across the
front. The favored output at this time is with a more southern
position to the boundary throughout the day Friday with deepest
instability and shear largely remaining southwest of the forecast
area.

The front will meander over the region through Saturday night...
possibly shifting towards the Ohio River Friday night before
returning north on Saturday. The continued presence of the boundary
over the region will keep the risk for scattered convection across
the forecast area through the first half of the weekend. Will need
to monitor the possibility of a convective cluster impacting the
region Saturday night on the eastern side of an approaching upper
level ridge that will eventually force the frontal boundary back to
the north of the region on Sunday.

Sunday into Next Week

In the wake of convection early Sunday...the upper ridge will expand
into the area with the front lifting away to our north. This will
serve as the transition point towards progressively hotter and more
humid conditions that are likely to last well into next week.
Multiple days with highs in the 90s are anticipated through much of
next week with the highest heat indices of the summer so far rising
into the low 100s during the afternoons. Isolated late afternoon and
evening convection may develop by the second half of next week as
the mid level heights begin to fall back. As the upper ridge will
retrograde back to the southwest by next weekend...will need to
monitor for an increased risk for convective clusters riding along
the periphery of the ridge impacting parts of the region.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 1236 AM EDT Thu Jun 25 2026

Impacts:

- Isolated to scattered showers and possibly a thunderstorm may
  impact terminals through daybreak Thursday

- Additional storms possible Thursday afternoon and evening

Discussion:

Predominantly VFR conditions expected through the period outside of
any possible impacts from convection.

An area of convection continues to drift south into north central
Indiana early this morning...likely impacting KLAF around or shortly
after the 06Z TAFs are issued. Greater uncertainty exists as the
showers and storms press further south overnight and interact with
an increasingly unfavorable airmass. Will continue with PROB30s for
showers at the other terminals for a few hours during the predawn
hours through 12-13Z. A rumble of thunder will be possible but far
too uncertain and low probability for mention.

After a largely quiet morning...renewed convective development is
anticipated during the afternoon as a frontal boundary sags across
the area. Better instability present this afternoon will warrant the
inclusion of thunder in another set of PROB30 groups for the
terminals from mid afternoon into the evening. Showers will linger
in the vicinity of the boundary into tonight in advance of an area
of widespread rainfall that will expand into the region around
daybreak Friday.

Light S/SW winds early this morning will become W/SW up to 10kts
this afternoon before diminishing again this evening.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
Flood Watch from this afternoon through Saturday morning for
INZ051>053-060>062-067>070.

&&

$$

AVIATION...Ryan
DISCUSSION...Ryan