420
FXUS63 KIND 280541
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
141 AM EDT Thu Aug 28 2025

.KEY MESSAGES...

- Scattered showers Thursday over northern counties with lower
  chances to the south and west

- Dry and quiet weather for the weekend into early next week

- Potential for another system mid-week with another shot of cooler
  afterwards

&&

.FORECAST UPDATE...
Issued at 933 PM EDT Wed Aug 27 2025

Areas of mid level clouds were drifting across the northwest half of
the forecast area this evening with mainly clear skies elsewhere.
Showers over central and northern Illinois earlier had largely
diminished. 01Z temperatures ranged from the upper 50s to the mid
60s.

The region remains under the influence of a persistent longwave
upper level trough anchored near James Bay and impacting much of the
country east of the Mississippi River. A stronger wave traversing
down the back side of the upper trough over the upper Midwest will
approach the area from the northwest by daybreak Thursday. Models
appear to be struggling a bit in handling the overall intensity of
the wave aloft evidenced by the convective cluster over southern
Minnesota which is more developed than most short range guidance has
shown. The expectation overnight is that the ongoing activity will
track southeast while gradually weakening...but will make it into
northwest Indiana during the predawn hours and potentially into the
northern Wabash Valley and far northern portions of the forecast
area near or just after daybreak Thursday. Sped up the arrival of
showers by a couple hours in northwest counties as a result and may
eventually need to expand precip chances further south into the
forecast area on Thursday morning.

Bumped up cloud cover overnight and nudged low temperatures up a
degree or two in the northern Wabash Valley. Zone and grid updates
out.

&&

.SHORT TERM (This evening through Thursday)...
Issued at 205 PM EDT Wed Aug 27 2025

Rest of Today and Tonight.

As of early this afternoon coverage of diurnal cu continues to
increase as surface temperatures are warming into the upper 60s to
low 70s with saturation at the top of the boundary layer. With the
surface high centered over the southwestern counties the winds at
the top of the boundary layer are much weaker than yesterday which
is keeping surface winds to the 4-8 mph range. Expect diurnal cu to
maximize towards 20Z with a gradual decrease afterwards and towards
sunset. A weak upper level wave aloft will advect additional mid and
high level clouds through the overnight hours tonight which will
help to insulate temperatures more than the last few mornings with
overnight lows only in the low to mid 50s.
Wednesday.

Thursday.

The most active day of weather for the period will be tomorrow
afternoon as another upper level wave pushes through the Great Lakes
region with portions of central Indiana on the southwestern
periphery of the better forcing aloft. Confidence continues to
increase in at least some precipitation from near Lafayette east and
portions to the north and east of Indianapolis with highest
confidence towards Muncie. There will be at least some instability
due to the steep lapse rates aloft but surface moisture will be
minimal and help to limit the higher-end CAPE values. There remains
some timing differences in the passage of the better forcing between
the different CAMs but the early afternoon currently looks to be the
most favorable time.

&&

.LONG TERM (Thursday night through Wednesday)...
Issued at 205 PM EDT Wed Aug 27 2025

Thursday Night Through Sunday.

Another surge of cooler air will move in behind the exiting upper
level trough with precipitation expected to be well out of the
forecast area by 00Z. This surge won`t be quite as potent as the
earlier weak cool air but expect most areas to fall into the low to
mid 50s with gradually clearing skies. Upper level northwesterly
flow and northerly surface flow will continue into the early weekend
with mostly clear skies and quiet weather. Little to no flow aloft
will keep a fairly persistent pattern even into early next week.

Monday Through Wednesday.

Surface flow will gradually become more easterly early next week as
a low pressure system forms across the Upper Plains and gradually
moves eastward. Confidence in the forecast lessens going towards the
middle of the week as models struggle to resolve how this weak
system interacts with a much stronger upper level trough moving
south out of Canada but it looks likely that at least by mid to late
week rain chances will begin to increase with another strong surge of
cold air behind the system helping to keep temperatures below normal.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 141 AM EDT Thu Aug 28 2025

Impacts:

- Low chance for rain showers/storms mainly at KIND and KLAF

Discussion:

A atmospheric disturbance currently approaching Indiana from the
northwest will bring a BKN to OVC layer of mid-level clouds through
Thursday morning. Guidance shows the possibility of scattered rain
showers (isolated thunder possible too) this morning into the
afternoon, mainly from LAF to IND. Rainfall probability decreases
with southward extent but an isolated shower may still be possible
from HUF to BMG. Probabilities are low enough to preclude from the
TAFs for now.

The aforementioned disturbance will push a cold front south late this
evening into tonight. A wind shift from WSW to NE will occur with
speeds generally under 10kt.

Low clouds may also be present behind the cold front, especially
northeast of IND. Whether these clouds make it to any of the
terminals is up in the air, but will include a SCT030 group to
account for the possibility.

&&

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

$$

UPDATE...Ryan
SHORT TERM...White
LONG TERM...White
AVIATION...Eckhoff