-- Discussion containing changed information from previous version are highlighted. --
697
FXUS63 KIND 131804
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
204 PM EDT Sun Jul 13 2025

.KEY MESSAGES...

- Areas of fog early this morning, potentially dense in some
  locations

- Localized flooding and isolated strong to severe wind gusts
  possible through the evening

- Not quite as warm/humid through Monday...with otherwise humid and
very warm/marginally hot conditions returning Tuesday

- Daily chances of showers/t-storms next week for mainly Tuesday and
onward with isolated downpours/localized flooding possible

&&

.FORECAST UPDATE...
Issued at 1011 AM EDT Sun Jul 13 2025

Forecast is largely on track and only minor updates were needed to
match to current obs. Chances for showers and storms decent for
early evening and beyond as the old frontal boundary remains across
the southern portion of the forecast area, along which another short
wave will interact. Can`t rule out a few storms becoming strong to
possibly severe, with the main threat being severe, mainly across
the south the boundary already exists.

Highs today should be slightly cooler than yesterday, with highs
staying below 90 across all of central Indiana while max HI near 95
is expected.

&&

.SHORT TERM (Today and tonight)...
Issued at 244 AM EDT Sun Jul 13 2025

Early This Morning...

Light winds and a moist low level atmosphere will allow some stratus
and fog to continue to develop across central Indiana during the
early morning hours. There is the potential for some dense fog in
some areas, and latest short term hi-res guidance gives confidence
to this potential.

Will continue to mention patchy to areas of fog. May need a Special
Weather Statement for fog. Will continue to watch closely.

This Morning through Mid-Afternoon Today...

Fog and stratus will mix out early in the period, and the moisture
will end up in a cumulus field. Will have partly cloudy skies
overall today.

The morning will remain quiet, but as an upper level wave approaches
during the afternoon, some convection will pop up given the
instability that will have built up by then. Will have some mainly
chance category PoPs into mid afternoon.

Mid-Afternoon Today into This Evening...

The old front will remain across southern portions of the forecast
area today. As the upper wave gets closer late this afternoon,
forcing from it will interact with the front and produce more
coverage of convection near the front.

Will have likely PoPs late this afternoon across portions of the
southern forecast area. As the upper wave moves in this evening,
will have likely PoPs over the remainder of the southern forecast
area, with chance PoPs continuing elsewhere.

The best instability will be across the southern forecast area,
closer to and south of the old front. The expected instability might
be enough for some isolated strong to low end severe storms.

Of more concern will be the high moisture content of the atmosphere,
with precipitable water values returning to over 2 inches. Forcing
may be enhanced in some areas as guidance is showing the potential
for deformation across central and southern portions of the forecast
area. Heavy rain and localized flooding will remain a threat.

Highs today will be cooler and in the mid to upper 80s most areas
thanks to increased cloud cover. However, heat indices will reach
the mid 90s for mainly southern portions of the area.

Overnight...

Forcing from the upper wave will diminish as it moves east, so PoPs
will lower during the night. Lows will be in the upper 60s to lower
70s.

&&

.LONG TERM (Monday through Saturday)...
Issued at 244 AM EDT Sun Jul 13 2025

Stagnant mid-summer synoptic pattern to continue over the Midwest
this week, as the H500 588 dm height contour to remain generally in
a zonal west-to-east alignment just north of central Indiana through
at least mid-week.  Weak surface ridging through Monday night will
suppress better deep moisture to the south, with precipitable water
values closer to only 1.50 inches over the local region.
Corresponding surface dewpoint reductions will be minor, but should
be enough to get lows Monday night into the upper 60s for much of
the region.  Improvement also expected to heat parameters Monday
afternoon, with high temperatures in the mid to upper 80s supporting
maximum heat indices in only the upper 80s to mid-90s.

Light southerly breezes Tuesday afternoon will then return several
marginally hot and humid days through the mid-week.  Highs in the
upper 80s to around 90F...will combine with dewpoints in the low to
mid-70s...to yield afternoon maximum heat indices into the mid-90s
to low 100s.  The return of organized diurnally-driven convection
Tuesday should increase on to numerous showers/scattered TRWs for
both Wednesday and Thursday...which should at least provide late-day
heat relief for some locations.

An increasingly-active northern jet should send several short waves
eastward along the Canadian border through the mid- to late week.
While there is so far low confidence in any of these weaknesses
plunging cooler air into the local region by the end of the long
term, they will at least encourage surface low pressure to take form
across the central Plains, with associated gradient and weak
convergence over the local CWA fueling convection with oppressive
humidity, lift...and just enough wind shear to present the potential
for stronger storms by the late workweek.  Greatest threats in any
stronger mid/late week thunderstorms will be isolated flooding
from downpours and possibly strong to severe winds. Chances for a
cold frontal passage will be highest by the end of the long term,
with the periods` lowest temperatures possible as the workweek
ends. Indianapolis` normal max/min will maintain the year`s peak
values through July 22...85/67.

&&

.AVIATION (18Z TAF Issuance)...
-- Changed Discussion --
Issued at 203 PM EDT Sun Jul 13 2025

Impacts:

- Convection after 20Z today, stronger gusts possible near KHUF/KBMG
through 02Z this evening with SHRA/TSRA possible at all sites
- MVFR conditions possible within storms
- Patchy fog will be possible again late tonight into tomorrow
morning with MVFR or isolated IFR conditions

Discussion:

Scattered to broken VFR cumulus field developing this afternoon.
Weak cool frontal zone slowly crossing central Indiana will promote
convection starting in the west around 20Z continuing into the
night. Showers may even continue into tomorrow morning, mainly for
IND and BMG. Some stronger cells could produce brief higher wind
gusts, possibly 40 kts or higher. Within storms heavy rain and
lightning will be a threat as well, in addition to MVFR conditions.
...with greatest coverage along/south of I-70 corridor.

Starting off with SW winds of about 10 kts or less. Stronger winds
within storms possible later today. Then overnight into tomorrow,
winds will be light and variable and with moisture and low clouds in
place, patchy fog will again be possible with MVFR to IFR
conditions.
-- End Changed Discussion --

&&

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

$$

UPDATE...KF
SHORT TERM...50
LONG TERM...AGM
AVIATION...KF