251
FXUS63 KIND 280432
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1232 AM EDT Mon Sep 28 2026

.KEY MESSAGES...

- Mostly sunny early this week with warming temperatures.

- Patchy fog possible Monday and Tuesday mornings.

- Dry conditions persist through Wednesday, with the next chance for
  rain arriving Thursday and then continuing into the weekend.

&&

.FORECAST UPDATE...
Issued at 949 PM EDT Sun Sep 27 2026

The forecast remains in great shape with only minor adjustments
needed. Look for quiet weather conditions through the overnight as
surface high pressure remains in control across the region. Mostly
clear skies combined with very light winds will support patchy fog
development again by late tonight. Very limited cloud cover and
light winds is supporting a rapid drop in temperatures this
evening. Latest observations depict temperatures are in the 50s
across much of central Indiana. Expect continued cooling through
the overnight with lows mostly in the mid-upper 40s.

&&

.DISCUSSION (This evening through Sunday)...
Issued at 215 PM EDT Sun Sep 27 2026

Rest of This Afternoon through Tuesday...

Subsidence on the west side of the upper low on the east coast of
the USA along with surface high pressure will continue to provide
dry and quiet weather for central Indiana.

Mainly some passing high clouds are expected, especially across the
western forecast area. Good radiational cooling will occur tonight
and Monday night, so have cut blended guidance`s temperatures both
nights. These conditions will allow for patchy fog once again late
tonight/early Monday and late Monday night/early Tuesday.

With the dry atmosphere in place and plentiful sunshine expected,
raised Monday`s and Tuesday`s highs from blended guidance.

Wednesday through Next Weekend...

A northern stream upper trough will move through Canada and the
Great Lakes into Friday, and this will bring a surface front into
the area by Friday.

Meanwhile, an upper low across the southwestern USA will gradually
move northeast. This low will have taken in tropical remnants and
will thus have good moisture with it. A surface low pressure system
will accompany the upper system.

The upper low will weaken as it moves north and east, but guidance
continues to differ on its speed and what happens with it. Some
guidance has the northern stream absorb the remnants of the upper
low while others keep the upper low separate and farther southwest.
This also affects the eventual location of the associated surface
low pressure system. Thus, there is higher uncertainty in the
forecast for later this week.

It now appears forcing will arrive later than previously thought, so
Wednesday looks dry during the day. Otherwise, rain chances will be
around Thursday into next weekend. With the uncertainty, confidence
in timing and location of the highest PoPs remains low. With the
weakening upper low still having tropical moisture, locally heavy
rain will be a threat late week.

With the slower arrival of the system, well above normal
temperatures (upper 80s not out of the question for parts of the
area) will continue into Thursday. Afterward, clouds/rain/cooler air
behind a front will lead to below normal temperatures next weekend.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 1232 AM EDT Mon Sep 28 2026

Impacts:

- Patchy fog possible at the outlying TAF sites between 08-12Z today

Discussion:

Outside of patchy fog at the outlying TAF sites this morning, VFR
conditions are expected. Some guidance hints at broken stratus
forming near KLAF late tonight, but not confident enough to include.
Will have to watch though as some stratus formed yesterday morning
well northeast of the area.

Patchy ground fog will likely develop at the outlying TAF sites
between 08-12Z today. Will continue to use a TEMPO for MVFR fog at
all but KIND. Brief IFR conditions cannot be ruled out. Additional
patchy fog may develop into Tuesday morning, but confidence is not
high enough to include at this time.

&&

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

$$

UPDATE...Melo
AVIATION...Melo
DISCUSSION...50