637
FXUS63 KIND 011036
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
636 AM EDT Thu Oct 1 2026

.KEY MESSAGES...

- One more warm day today

- Widespread rain expected tonight into Friday morning, with amounts
  of one half to one inch

- Dry and much cooler weather expected over the weekend into next
  week; potential for first lows to drop into the 30s across portions
  of central Indiana Tuesday morning

&&

.DISCUSSION (Today through Wednesday)...
Issued at 327 AM EDT Thu Oct 1 2026

Main focus remains on the cold front expected to slowly sag through
the area late today into Friday, which will serve as focus for
widespread rainfall, particularly this evening into Friday morning.

Limited instability will be present in a fairly pseudotropical
airmass owing largely to the tropical moisture brought into the
system by the remnants of Hurricane Polo in recent days, which will
instead present deeply saturated, near moist adiabatic profiles,
promoting locally heavy downpours as the primary concern.

Precipitable water values may approach 2 inches at their peak, which
is near climatological maximum for the time of year, but without a
more substantial convective component or stronger forcing, expect
QPF amounts to be limited to a widespread one half to one inch
through the event, which is well within the capacity of the current
hydrologic situation per river ensembles and flash flood guidance.

HREF Local Probability Matched Means do indicate an outside chance
for isolated areas to approach two inches, but this would be over a
24 hour period, which again would be of limited impact.

Two strong areas of cool Canadian high pressure are expected to
traverse the Great Lakes in the wake of the cold front this weekend
into next week, bringing the coolest air of the Autumn season thus
far to central Indiana, along with another prolonged dry spell.

Highs today will again rise well into the 80s across most areas,
with lows tonight in the upper 50s to mid 60s, largely modulated by
low level humidity, with much cooler conditions thereafter once the
front has fully exited the area. Highs from Friday onward will
largely fall in the mid 60s to mid 70s, with lows generally in the
40s to around 50, though early next week the first lows in the 30s
will be possible Monday night, mainly northeast.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 636 AM EDT Thu Oct 1 2026

Impacts:

- Non-convective LLWS early in the period

- Southwesterly wind gusts between 20-25 KT Thursday midday -
  afternoon

- Rain expected tonight, storms possible

- IFR conditions possible very late in the period

Discussion:

Modest LLWS will continue for the first few hours of the period
until wind gusts ramp up around midday as mixing increases.
Increasing mid and high clouds can be expected today as moisture
increases ahead of an approaching low pressure system.

Sustained winds of 10-15KT with gusts 20-25KT can be expected from
midday into the afternoon, from around 220-230 degrees. Gusts will
subside in the evening and winds will begin to veer westerly and
then northerly as the front slowly sags into the area. Widespread
rain will accompany this front, and a few rumbles of thunder cannot
be ruled out, but now think the PROB30 groups are a bit too
aggressive given the minimal instability.

Conditions will likely deteriorate as the front passes, with low
clouds likely to develop. Guidance suggests widespread IFR late
tonight into Friday.

&&

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

&&

$$

AVIATION...Nield
DISCUSSION...Nield