595
FXUS63 KIND 230541
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
141 AM EDT Wed Sep 23 2026

.KEY MESSAGES...

- Cooler weather will continue through the upcoming week, with
  afternoon temperatures staying below seasonal averages

- A few light showers tonight into tomorrow, mainly across eastern
  Indiana

- Persistent mostly cloudy skies will begin to break towards Friday

&&

.FORECAST UPDATE...
Issued at 958 PM EDT Tue Sep 22 2026

Only minor adjustments to hourly temperatures were needed, otherwise
forecast is in good shape.

Low clouds and somewhat breezy conditions persist across central
Indiana and is expected to continue into tomorrow. Light drizzle
will be possible through the night, given how low clouds are, but
thus far any drizzle that has been reported by people has been light
enough to not be picked up by observation instruments other than
visibility reductions.

&&

.DISCUSSION (This evening through Tuesday)...
Issued at 202 PM EDT Tue Sep 22 2026

Overview.

Central Indiana is set for a prolonged stretch of cool,
dry autumn weather. High pressure anchored to the north and
northeast will keep a continuous supply of cool air moving into the
region on northeasterly winds. Persistent low level moisture
combined with cooler air will keep skies mostly cloudy to cloudy
through Thursday. Skies will then clear Friday into the weekend with
a slight warming trend going into next week.

Tonight Through Thursday.

Broad high pressure continues to remain locked in place across the
Great Lakes region along with low pressure to the southeast allowing
for persistent northeasterly flow both at the surface and near
surface. This is helping to keep widespread cloud cover in place
across much of central Indiana along with keeping temperatures
slightly below normal. A weak shortwave will push southeast across
Iowa tonight into tomorrow which will interact with a remnant vort
max across Ohio during the daytime hours to bring few light rain
showers to central Indiana, mainly across the eastern counties.
Beyond those low chances, dry weather is expected through the
remainder of the 7 day forecast with a fairly steady-state weather
pattern continuing into Thursday.

Friday Through Tuesday.

Increasing subsidence aloft along with weak upper level flow will
begin to break down the cloud cover Friday into the weekend will
help to bring temperatures closer to normal for this time of the
year. Min RH values will drop below 40 percent across south central
Indiana which combined with the drier conditions of late, may need
to be monitored for a low-end fire danger. Near calm winds will help
to limit that threat.

Looking further into early next week, temperatures in the lower 80s
look to return as the surface flow gradually gains a more southerly
component along with gradually increasing rain chances towards late
Tuesday ahead of the next system.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 141 AM EDT Wed Sep 23 2026

Impacts:

- MVFR/IFR ceilings through the forecast period.
- Patchy drizzle this morning, light rain showers and drizzle into
  Wednesday night.

Discussion:

Strong surface high pressure remains in place over southeastern
Canada, providing northeasterly winds between 8-12kt across central
Indiana. Moisture advection from the east has allowed extensive
cloud cover to develop and persist since Tuesday.

An upper-level low is arriving from the west and this has allowed
the surface wind field to gain cyclonic curvature. The primary
effect this will have is to cause the stratus layer to thicken and
for patchy drizzle to develop. We have already seen drizzle over
most of the region since midnight. Patchy drizzle should continue
into the morning hours Wednesday.

Drizzle diminishes later this morning as diurnal mixing intensifies.
However, this may allow for light rain showers to develop during the
afternoon. Showers and renewed drizzle then continue into tonight,
potentially through 12z Thursday.

Winds remain out of the northeast through the TAF period around
10kt, decreasing a bit after 00z.

&&

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

$$

UPDATE...KF
AVIATION...Eckhoff
DISCUSSION...White