341
FXUS63 KIND 291853
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
253 PM EDT Sun Jun 29 2025

.KEY MESSAGES...

- Rain/storm chances persist through Monday night with the
  greatest coverage during the afternoon and evening hours

- Localized flooding is the primary threat through Monday night,
  but isolated strong wind gusts are also possible Monday
  afternoon and evening

- Drier and slightly cooler weather expected towards the middle of this
  week before more humid conditions return Friday into next weekend

&&

.SHORT TERM (This Evening through Monday Night)...
Issued at 253 PM EDT Sun Jun 29 2025

Yet another afternoon with scattered convection over the region with
a moist and unstable airmass in place. 18Z temperatures are lower
than the last several days courtesy of the convection and plentiful
cloud coverage...running generally in the low to mid 80s.

Unsettled weather will continue through Monday as a series of upper
level waves track through the Ohio Valley followed by a cold front
Monday night. Periodic showers and thunderstorms will persist as a
result...with highest coverage expected Monday afternoon and
evening.

Showers and storms are pockmarked across the forecast area this
afternoon and will likely increase in coverage over the next few
hours as instability levels peak. The KIND ACARS sounding shows poor
lapse rates present through the column...meaning stronger winds from
collapsing downdrafts are likely to be less of a concern into the
evening. The greatest impact remains the potential for localized
flooding from slow moving convection producing torrential downpours.
PWATs are already near 2 inches and are likely to tick up further
into the evening. Best potential for storms remains across the
southern half of the forecast area where deepest moisture resides
but convection really could pop up anywhere across central Indiana.

The loss of diurnal heating this evening should lead to convective
coverage diminishing but that respite is expected to be brief and
last only into the early overnight. The first of the series of upper
level waves associated with a broader trough aloft will arrive
during the predawn hours with scattered convection increasing yet
again prior to daybreak. This will parlay into Monday as the
combination of the forcing aloft with an approaching cold front will
interact with the moist unstable airmass across the Ohio Valley for
numerous to widespread convection peaking during the afternoon and
evening.

The risk for a few storms producing damaging winds is greater by
late day with the infusion of slightly better BL shear present
immediately ahead of the upper trough axis but an overall skinny and
elongated CAPE profile with unidirectional shear profiles is
supportive of a generally messy multicellular convective mode for
the afternoon and evening. Heavy rain and localized flooding will
remain primary concerns as well. Showers and storms will continue
into Monday night ahead of the frontal boundary with rain ending
from west to east overnight as the front sweeps off to the east.

Temps...lows tonight will fall mainly into the lower 70s. Highs are
expected in the mid 80s on Monday. As cooler air advects into the
region behind the frontal passage Monday night...lows will drop into
the mid and upper 60s.

&&

.LONG TERM (Tuesday through Sunday)...
Issued at 253 PM EDT Sun Jun 29 2025

Unsettled weather for the early part of this week will shift
east Tuesday morning as a drier and slightly cooler airmass builds
in courtesy of broad surface high pressure and drier northwest flow
aloft. Upper level ridging will return by late next week with a
likely return to isolated to scattered diurnal convection Friday
into the weekend as a hotter and more humid airmass reestablishes
across the Ohio Valley.

Tuesday through Thursday..

Other than a few lingering showers Tuesday morning...mostly quiet
weather conditions are expected Tuesday through Thursday as high
pressure settles across the region. Dewpoints will finally fall back
into the lower and middle 60s and perhaps even down into the upper
50s in northern portions of the forecast area for midweek...a
refreshing respite from the oppressive air of the last week or so.
While largely dry conditions are expected...a few showers and storms
are possible focused mainly across northern counties by Thursday
afternoon as a weak front drifts into the lower Great Lakes. Highs
will mainly reside in the low to mid 80s Tuesday and Wednesday
before beginning to rise on Thursday.

Friday through Sunday...

The arrival of ridging aloft coinciding with a weakening of the
surface high will enable deeper moisture to advect back into the
Ohio Valley for late week with growing confidence in higher dewpoint
air at or above 70 degrees making a return for Independence Day into
next weekend. Instability will increase in response with isolated to
scattered pulse intensity...short lived and slow moving convection
developing during the afternoon and evening ...mainly Saturday and
Sunday. May see an increase in overall convective coverage late next
weekend into early next week with signals in the ensembles for a
cold front to approach the region from the northwest. Highs will
rise back into the lower 90s for next weekend with heat indices
again approaching 100 degrees.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1245 PM EDT Sun Jun 29 2025

Impacts:

- Scattered showers and storms through the afternoon, then more
  numerous coverage late tonight into Monday
- Patchy fog possible near daybreak Monday
- MVFR ceilings at times early this afternoon then again on Monday

Discussion:

Moist and unstable airmass across the region will again aid in
scattered convective development through the afternoon...especially
across the southern half of central Indiana. Brief restrictions will
be possible with any heavier shower or storm. Ongoing pockets of
MVFR stratocu will lift to VFR levels over the next few hours as
well.

There may be a brief lull in convection this evening as diurnal
heating is lost but a series of weak upper level waves set to move
through the Ohio Valley overnight and into Monday will bring
additional convection to central Indiana likely to be more
widespread in coverage on Monday.

MVFR ceilings are again a possibility in the predawn hours through
the first half of Monday. Winds will generally be light and
southerly through much of the forecast period...veering to southwest
on Monday and increasing closer to 10kts.

&&

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

&&

$$

SHORT TERM...Ryan
LONG TERM...Ryan
AVIATION...Ryan