811
FXUS63 KIND 290441
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1241 AM EDT Thu Oct 29 2026

.KEY MESSAGES...

- Unseasonably warm temperatures in the 70s to near 80 expected
  through Saturday.

- Slight chances of rain late Thursday northern sections.

- Higher chances of rain Saturday Night into Sunday.

- Mild and wetter pattern likely next week.

&&

.FORECAST UPDATE...
Issued at 857 PM EDT Wed Oct 28 2026

The forecast remains in good shape with only minor adjustments made.
Expect quiet weather through the overnight as surface ridging still
extends back into Indiana from high pressure centered just off the
Northeast coast. Satellite imagery depicts mostly clear skies across
the area, but there more enhanced mid level clouds pushing across
Illinois with a subtle impulse moving through. This may promote
slightly greater cloud cover late tonight across northern counties.
Otherwise enjoy a quiet night. Efficient radiational cooling
conditions will allow for temperatures to drop into the upper 40s
and lower 50s.

&&

.DISCUSSION (This evening through Wednesday)...
Issued at 309 PM EDT Wed Oct 28 2026

Tonight through Thursday night...

A broad area of surface high pressure extending from New England
into the Srn Appalachians will slowly give way to a low pressure
area and cold front moving from the northern Plains into the western
Great Lakes region. Winds will remain light southerly overnight with
lows in the upper 40s to lower 50s area wide. On Thursday, expecting
another day of large diurnal changes in temps, with temperatures
quickly rising into the 70s by noon thanks to a shallow inversion,
increasing SW winds and steep low level lapse rates. Thermal ridge
takes aim at central IN with +13C at 850mb by 18Z. High temperatures
as a result are expected to be 15-20 deg above normal from the upper
70s to near 80. For reference the record high for Indianapolis on
Thursday is 82 set in 1927.

As the cold front pushes south from northern Indiana, sufficient
moistening of the BL combined with frontal ascent suggests the
potential for light rain showers to occur over northern portions of
central Indiana during the late afternoon/evening. NAM is the most
bullish of the suite of model guidance, but inspection of the NAM
forecast soundings suggest this may be due to the normal NAM over
saturation bias in the BL. It does appear prudent to carry slight
chance PoPs given the degree of available moisture (dewpts in the
mid-upper 50s) and fairly strong convergence along the front. Poor
mid level lapse rates owing to mid level subsidence in the wake of
the primary shortwave trough axis moving into the eastern Great
Lakes will preclude any TS chances.

Friday through Friday Night...

The surface frontal boundary is expected to undergo frotolysis
across the Ohio Valley early on Friday. The presence of upper
ridging building in from the west ahead of weak shortwave trough
moving through the southern Plains, combined with surface high
pressure centered over the Great Lakes, will lead to much more
quiescent weather on Friday across central Indiana. By Friday night,
the lead shortwave is expected to approach the MS valley. There is
some signal for enough mid level saturation to occur where the
greatest height falls/weak FGEN forcing occur, that some light
showers will be possible across northern zones Friday night.

Saturday through Sunday...

As the lead shortwave trough moves through the upper ridge, with
limited low level response seen on guidance, the consequent effect
will be widespread mid-high level cloud cover on Saturday with
little to no precip chances expected except early in the far north.
There is a high degree of model uncertainty with regards to the
precip potential for Sat night into Sunday. The GFS has a much
stronger secondary shortwave (current well west of the Baja CA
coast) moving across the MS valley into the Ohio Valley Sat night
into Sunday. In particular the GFS has a much stronger 850 mb jet
that develops over the Gulf Coast, somewhat convectively enhanced,
but also supported by barrier jet processes on the fringes of the
surface ridge in the Carolinas. As a result, more rapid moisture
return by the GFS would support greater QPF across central Indiana.
However, ensemble data and the OP Euro are much weaker with the mass
fields and consequent QPF amounts and coverage through Sunday. In
fact the OP Euro has almost no precip for central Indiana as the
shortwave trough undergoes greater deamplification. For now, will
play the middle ground with moderate PoPs for the entire forecast
area Sat night into Sunday.

Monday through Wednesday...

Not too unsurprising, the differences in guidance becoming amplified
with the upcoming phasing/pattern amplification over the western and
central CONUS early next week. The GFS is much more bullish with a
large closed cyclone developing over the Plains by Monday with
strong phasing of the northern and southern streams/shortwaves.
While the Euro and other ensemble guidance keep the streams slightly
out of phase and pattern more progressive. As a result, the forecast
leans more towards the progressive solutions with rainfall chances
increasing by Tuesday-Wednesday. Moisture return and quality of
instability are the main questions regarding TS coverage and severe
potential this far out. However, kinematics will be favorable for
some potential severe if instability is higher than currently
progged.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 1241 AM EDT Thu Oct 29 2026

Impacts:

- Southerly winds becoming NW to N late in the period.

- Otherwise, mainly VFR conditions are expected.

Discussion:

Southerly winds ahead of an approaching cold front will be in place
across Indiana today. Forecast soundings though the day suggest a
dry column, with perhaps some low VFR cigs with the cold front
passage late in the afternoon and early evening. Winds will shift
from the south to the northwest in the wake of the front.

Forecast soundings quickly return to a dry column after 04Z as a new
high pressure system arrives with northerly winds.

&&

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

$$

UPDATE...Melo
AVIATION...Puma
DISCUSSION...Crosbie