549
FXUS63 KIND 261703
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
103 PM EDT Sat Sep 26 2026

.KEY MESSAGES...

- Mostly sunny skies this weekend with seasonable temperatures.

- Patchy fog possible each morning through Tuesday morning.

- Dry conditions persist through Tuesday, with the next chance for
  rain arriving late Wednesday into Thursday

&&

.FORECAST UPDATE...
Issued at 951 AM EDT Sat Sep 26 2026

Fog and stratus continue across the extreme northeast forecast area
this morning, impacting mainly the Muncie, Winchester, and Anderson
areas. The fog/stratus are trying to advect west. However,
satellite shows that heating is already beginning to slow or stop
the advection with mixing on the western edge.

Otherwise, mid and high clouds continue across the southwest
forecast area. Some of the mid clouds are diminishing.

Have upped sky cover in the far northeast and extended the patchy
fog mention. These will continue to mix out this morning. Left the
southwest as partly cloudy with mostly sunny elsewhere.

Made no changes to high temperatures at the moment, but will
continue to monitor in case changes need to be made from the impacts
of the aforementioned cloud cover.

&&

.DISCUSSION (Today through Friday)...
Issued at 254 AM EDT Sat Sep 26 2026

Overview.

High pressure will dominate central Indiana weather into early next
week, driving a trend toward clearer skies and warmer temperatures.
Low clouds will erode through Saturday morning, giving way to
abundant sunshine and daytime highs reaching the lower 80s by
Monday. A cold front will approach from the northwest late Tuesday,
bringing the next likelihood of showers and thunderstorms before
temperatures cool back toward seasonal averages late in the week.

Rest of Today through Sunday

Surface high pressure is building southwestward with lingering mid-
level cloud cover dissipating as of 3am Saturday. Continued clearing
is expected as large-scale subsidence from the high takes hold. A
subsident patter continues through the weekend as Indiana is between
two systems...one just to our west over the Plains and a nor`easter
over the Mid Atlantic.

Overall, clear skies will allow daytime temperatures to trend above
guidance with highs in the 70s. Lows on the other hand will be a bit
below guidance due to efficient radiational cooling conditions. Low
temperatures in the 40s to near 50 are expected each night.
Additionally, these conditions are good for fog formation and patchy
fog is possible both Saturday, Sunday, and Monday nights.

Monday Through Friday.

The extended period opens with weak upper-level ridge amplification
across the eastern CONUS as surface high pressure shifts toward the
Mid-Atlantic coast. Both deterministic GFS and ECMWF along with
their respective ensemble suites depict strong low-level warm air
advection developing across the Mississippi and Ohio Valleys as the
low off the East Coast finally begins to push off to the northeast.

Southerly flow early next week doesn`t look quite as robust as it
did in recent model runs which will keep highs more towards the mid
70s vs lower 80s. This begins to shift towards Wednesday as the
synoptic pattern begins to shift. Late Wednesday into Thursday a
progressive upper-level trough traverses the Northern Plains and
Great Lakes. Deterministic guidance indicates a surface cyclone
tracking northeast into the Upper Midwest, pulling a trailing cold
front toward central Indiana late Wednesday into Thursday which is
about 12-18 hours slower than previous model runs.

Strong synoptic-scale forcing via PVA and a developing 35-45 kt low-
level jet will foster moisture transport, elevating PWAT values
toward 1.50 inches. Ensemble consensus supports increasing PoPs
beginning late Wednesday for showers and scattered thunderstorms
along with a lower-end potential for a few strong to severe storms.
Post-frontal cold air advection behind the frontal passage will
break the warm trend, returning temperatures to near seasonal
normals in the upper 60s and lower 70s going into Friday.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 103 PM EDT Sat Sep 26 2026

Impacts:

- Patchy fog possible overnight into Sunday morning.

Discussion:

Some passing high and mid clouds will be around through the period,
especially at KHUF. Winds will remain east/northeast at 10kt or less.

During the night, winds will diminish. Expect patchy fog to form.
Other than the usual uncertainty with patchy fog, questions about
how much cirrus will be around increases uncertainty for at least
KHUF. The urban heat island should keep KIND VFR regardless.

Will continue to use a TEMPO for MVFR fog at all but KIND. Cannot
rule out IFR but am not confident enough to include.

&&

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

$$

UPDATE...50
AVIATION...50
DISCUSSION...White/Eckhoff