610
FXUS63 KIND 280951
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
551 AM EDT Sun Jun 28 2026

.KEY MESSAGES...

- Warm and humid today

- Hot and humid condition expected for much of the upcoming week
  with multiple days in the 90s and heat indices over 100 degrees

- Heat Advisory in effect Monday afternoon through Thursday

&&

.DISCUSSION (Today through Saturday)...
Issued at 316 AM EDT Sun Jun 28 2026

Showers have diminished across the forecast area early this
morning...leaving a damp and muggy airmass with a thick blanket of
lower stratus. 06Z temperatures were mainly in the lower 70s.

The frontal boundary that has served as a focal point for the storms
and heavy rainfall in the Ohio Valley over the last few days will
begin a northward trek today in response to broad ridging aloft
expanding into the region. The ridge will amplify across much of the
eastern part of the country over the next several days with an
extended stretch of hot and humid conditions lasting into next
weekend. This will be easily the hottest weather of the summer to
date with dangerous heat indices becoming a primary concern
throughout the forecast period.

While it remains quiet early this morning...anticipate an area of
convection developing over the Missouri Valley over the next few
hours expanding into the lower Ohio Valley towards daybreak. This is
courtesy of a subtle wave drifting down the eastern flank of the
approaching ridge. The bulk of the convection will remain southwest
of central Indiana but a few storms may briefly sneak into portions
of the lower Wabash Valley that are waterlogged from repeated rounds
of heavy rain the last few days. Will maintain low pops in the far
southwest counties for a few hours around daybreak.

The primary impacts through mid morning will be low stratus and
areas of fog developing with the near surface layer saturated and
only very light wind flow. As low level mixing develops later this
morning will see ceilings begin to lift but considering the moist
boundary layer conditions...expect a broken cu field to linger over
much of the forecast area all day. Model soundings do show an
increasingly unstable airmass developing this afternoon but also a
gradual strengthening of a mid level cap as heights aloft rise.
Cannot entirely rule out a stray shower or storm as a result but
chances look too low for a mention in the forecast at this time
especially with no appreciable forcing aloft present.

The upper level ridge will continue its expansion in the area
tonight with an extended stretch of days with highs above 90
commencing on Monday. The core of the ridge peaks with heights at
596-597dam by Tuesday and Wednesday before slowly flattening by next
weekend. Daily max heat indices above 100 degrees Monday through
perhaps as far as next Saturday will warrant a Heat Advisory
issuance beginning on Monday. While there are still a few details to
work out...the most efficient way to message this upcoming
significant heat will be with an extended multi-day Advisory out for
much of the upcoming week. The expected length of the upcoming heat
wave with several nights with lows in the 70s could lead to
adjustments in the headlines as the week progresses.

Isolated late afternoon and evening convection may develop as early
as Thursday as the mid level heights begin to slip back in response
upper level waves tracking across the northern tier of the country.
This will become even more prevalent as the ridge flattens into next
weekend with an increasing threat for scattered convection over
parts of the forecast area.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 551 AM EDT Sun Jun 28 2026

Impacts:

- Widespread sub-IFR conditions through mid morning in fog and low
  stratus

- VFR conditions returning for this afternoon and tonight

- Patchy fog possible at KBMG predawn Monday

Discussion:

Widespread IFR and lower conditions were ongoing at the terminals
early this morning due to low stratus and fog. This will persist for
the next few hours before low level mixing commences and enables
ceilings to lift back to VFR levels early this afternoon. Broken cu
will linger through the afternoon with clouds decreasing in coverage
tonight as upper level ridging expands into the Ohio Valley.

Winds will remain below 10kt throughout the forecast period and
occasionally calm to light and variable this morning. Light
southerly flow develops for this afternoon and tonight. Patchy fog
may develop predawn Monday at KBMG.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from noon Monday to 8 PM EDT Thursday for INZ021-
028>031-035>049-051>057-060>065-067>072.

&&

$$

AVIATION...Ryan
DISCUSSION...Ryan