660
FXUS63 KIND 180647
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
247 AM EDT Fri Sep 18 2026

.KEY MESSAGES...

- Hot temperatures will continue at times into the weekend
  especially south. Heat indices around 100 again today southwest.

- Scattered showers and storms, with locally heavy rain possible,
  will diminish this morning

- Shower and storm chances persist for much of the time into
  early next week, with temperatures turning cooler next week

&&

.DISCUSSION (Today through Thursday)...
Issued at 247 AM EDT Fri Sep 18 2026

Early This Morning...

Thunderstorms from late evening Thursday sent another outflow
boundary into the far southern forecast area. So far early this
morning, only isolated to widely scattered showers and thunderstorms
have developed in the wake of this boundary.

Given the latest trends in radar and in short term guidance, will
keep PoPs no higher than the chance category. As the main surface
boundary continues to sink south, the highest PoPs will gradually
shift south. CAPE has been diminished, so not expecting any severe
storms. Gusty winds will remain possible, especially south where
what CAPE is left is highest.

Advected Layered Precipitable Water data from satellite shows
moisture being brought into the area from the Gulf as usual but also
from both the southwestern USA in the monsoon areas. Values near 2
inches are across the area currently. Thus, the threat for locally
heavy rain continues. With this threat, am hesitant to cancel the
Flood Watch, even though training of heavy rain looks less likely.

Today and Tonight...

The main surface boundary will continue to sink south across the
area. Little upper support will be around to work with the boundary.
Thus odds of convection are low. Will only have some patchy slight
chance PoPs around in the south for most of the day, but can`t rule
out an isolated shower elsewhere. The Flood Watch will likely be
canceled early.

A good temperature gradient will exist today, with highs in the 70s
northeast to around 90 in the far southwest. Heat indices in the far
south will be near 100 again today.

Much of tonight looks dry with forcing remaining away from the area.

Saturday into Tuesday...

An unsettled pattern will continue for much of this period as
various upper and surface waves move through, causing the front to
meander north and south across central Indiana. Moisture still looks
to be plentiful, so locally heavy rain will remain a threat for all
or parts of the area through Monday.

On Saturday, there looks to be a low end severe threat where
isolated severe storms could produce damaging winds.

Highs this weekend will vary from around 80 far north to around 90
far south.

Cooler air will work in for Monday and Tuesday with highs falling to
around 70 to the lower 70s by Tuesday.

Wednesday and beyond...

Surface high pressure will nudge into the area mid to late week next
week and may keep this period dry. Will have to watch for an
inverted trough just to the east, which could bring a few showers if
it ends up being farther west than expected. Temperatures will be
much closer to normal with highs in the 70s and lows in the 50s.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 128 AM EDT Fri Sep 18 2026

Impacts:

- Scattered convection overnight
- MVFR ceilings moving south to at least KIND overnight, with
  IFR developing at KLAF

Discussion:

Confidence continues to lower in numerous to widespread convection
overnight. Radar shows isolated to widely scattered convection
continuing, so will use VCSH and PROB30s as needed overnight. Can`t
rule out additional showers or isolated storms during Friday, but
confidence is too low to include at this time.

An area of MVFR/IFR ceilings will push south overnight as the
surface front moves south. MVFR should at least reach KIND by 12Z,
but there remains a lot of uncertainty on whether it makes it to the
southern sites. IFR will likely move into KLAF.

Ceilings will lift to VFR during Friday afternoon.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 10 AM EDT this morning for INZ030-036>042-
045>049-054>057-063>065-072.

&&

$$

AVIATION...50
DISCUSSION...50