564
FXUS63 KIND 150627
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
227 AM EDT Wed Oct 15 2025

.KEY MESSAGES...

- Dry weather through Friday with warmer than normal temperatures
  continuing

- Active weather this weekend with showers and storms late Saturday
  into Sunday

- Turning cooler Sunday and Monday

&&

.SHORT TERM (Today and tonight)...
Issued at 225 AM EDT Wed Oct 15 2025

Mostly quiet weather conditions are expected through the period with
surface high pressure continuing to build in. Current IR satellite
imagery depicts extensive low-mid level clouds to the northwest of
central Indiana. These clouds are associated with an upper trough
that will push through the region during the period. Look for clouds
to increase through the morning before mixing out some late in the
day. This will limit diurnal heating, but highs in the 70s are still
expected for most locations. Some southwestern counties could
approach 80F due to less cloud cover.

There is a non-zero chance for sprinkles today with the
approaching upper wave. Residual low-level dry air evident in
forecast soundings will make it difficult, but cannot rule out
sprinkles if sufficient top-down saturation occurs. Some low-mid
level clouds are expected to linger over western portions of
central Indiana tonight. This would limit diurnal cooling slightly and
keep temperatures warmer compared to areas further east.
Temperatures are currently expected to range from the mid-upper
40s across the east to low 50s across western counties.

&&

.LONG TERM (Thursday through Tuesday)...
Issued at 225 AM EDT Wed Oct 15 2025

Thursday Through Friday.

A broad ridge of high pressure will remain in place over much of the
Central US Thursday with strong upper level lows to the west and to
the east. Showers and thunderstorms are expected over the upper
Midwest as Gulf air advects over a nearly stationary front, but this
will keep to the northwest of the forecast area. The nose of the
upper level ridge will be overhead during the daytime hours on
Friday with  southerly surface flow gradually increasing ahead of the
arriving low pressure system this weekend.

Saturday Through Tuesday.

The main focus for the long term period will be tracking the
potential for both heavy rain and a few storms late Saturday into
Sunday as the aforementioned low pressure system tracks into Canada
and a secondary low ejects from the Four Corners region and
undergoes cyclogenesis as it tracks through Oklahoma into the
Tennessee Valley. The interaction between these two systems will be
the catalyst for the active weather trough the weekend. The LLJ will
ramp up ahead of the arrival of lift associated with the low
pressure systems on Saturday with a direct connection to Gulf air
bringing copious amounts of moisture to the area. Much of the timing
uncertainty has been resolved with models honing in on Saturday
night into early Sunday as being when the front will pass and when
the heaviest rain is likely.

Both isolated flooding and a few stronger storms will be possible
Saturday night into Sunday for Indiana with highest chances across
the southern and southwestern portions of the state. With the timing
looking more likely to be during the overnight hours vs afternoon
and evening, the instability will generally remain elevated which
lowers the concern for severe weather but increases the threat for
heavy rain as the forcing will be moving over when the LLJ is
maximized. There is still 15-25kts of shear in the lowest 1km, but
without better surface based instability, the severe risk should
remain southwest of the forecast area.

In addition to the very limited severe threat, isolated flooding
will be a concern across the lower Ohio Valley with an axis of 2-4
inches likely somewhere in the area. There is increasing confidence
in this axis being either along or south of the Ohio River, but
amounts of around an inch look likely for much of south central
Indiana with lesser amounts to the north.

Cooler weather is expected in the aftermath of the system late
Sunday into Monday. Another low pressure system looks to quickly
move through aloft Tuesday into Wednesday but models are struggling
on the broader synoptic pattern which keeps confidence low in the
weather through the remainder of the week.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 107 AM EDT Wed Oct 15 2025

Impacts:

- Patchy ground fog possible at outlying TAF sites towards daybreak.

Discussion:

VFR conditions are expected through the TAF period.

Like previous nights, some patchy ground fog is possible at the
outlying TAF sites towards daybreak. Fog potential may be limited
due to cloud cover approaching from the west overnight. Should fog
occur, brief minor reductions in visibility are possible.

Clouds should become thick enough to become a mid-level ceiling
between 5000-10000ft towards daybreak. MVFR ceilings are unlikely,
but cannot rule it out briefly near KLAF along with a stray sprinkle.

Winds should remain light and variable overnight, with a dominant
northeasterly component. Winds pick up a bit during the afternoon
Wednesday but should remain under 10kt maintaining a northeasterly
direction.


&&

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

$$

SHORT TERM...Melo
LONG TERM...White
AVIATION...Melo