094
FXUS63 KIND 111607
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1207 PM EDT Sun Oct 11 2026

.KEY MESSAGES...

- Clouds will dissipate through the afternoon hours with mostly
  clear skies by the evening

- Near record temperatures Monday and Tuesday

- Showers return mid-week

- Coolest air of the season so far next weekend

&&

.FORECAST UPDATE...
Issued at 935 AM EDT Sun Oct 11 2026

Dreary morning as the region remains within the backwash of the
Isaias remnants. Thick low stratus along with patchy drizzle and a
few light showers persisted across the forecast area although the
back edge of the clearing was just west of the Illinois state line.
13Z temperatures were in the upper 50s and lower 60s.

The ongoing drizzle will diminish over the next couple hours as
drier air aloft slowly filters down into the boundary layer. The
back edge of the stratus deck will progress east steadily into the
afternoon as the trailing upper low with Isaias moves into the
central Appalachians. Expect most if not all of the forecast area
will have sunshine by late afternoon.

Temperatures will be heavily dependent on how long it stays
cloudy...with highs ranging from around 70 in the far east to near
80 in the Wabash Valley. Zone and grid updates out.

&&

.DISCUSSION (Today through Saturday)...
Issued at 131 AM EDT Sun Oct 11 2026

Today Through Monday.

The synoptic setup features a weakening mid-level trough associated
with the remnants of Isaias exiting to the east with lingering mid-
level moist advection and weak surface frontogenesis across
southeastern central Indiana. HREF component members including the
HRRR and NAM3km show remnant light rain and low-level cloudiness
ending west to east between 12Z and 16Z as subsidence behind the
trough axis takes hold. Deepening boundary layer mixing under weak
northwest surface flow behind the departing surface boundary will
clear cloud cover by mid-afternoon. Thermal profiles off the GFS and
ECMWF show 850 MB temperatures near 10C to 12C, supporting daytime
highs in the low to mid 70s across the CWA. Surface high pressure
centered over the Ohio Valley will maintain light and variable winds
overnight, allowing radiational cooling to drop surface temperatures
into the mid 50s. Fog looks likely across eastern Indiana tonight
as the clearing reaches the area and winds drop to near calm. The
western extent of the fog remains uncertain and will depend on
the timing of the clearing.

In the aftermath of the exiting low, a surface high will slide east
toward the Mid-Atlantic coast on Monday as a broad trough amplifies
across the Northern Plains. Surface pressure falls across the Upper
Midwest will tighten the regional pressure gradient, strengthening
low-level southerly to southwesterly return flow. Deterministic GFS
and ECMWF soundings display a deep boundary layer with winds at the
top around 20-25kt. Model guidance shows dry mid-level air beneath
deep subsidence, which will allow for RH values to drop to around 40
to 50 percent. With this strong WAA and clouds limited to high
cirrus, much above normal temperatures are expected with some spots
near the Illinois border reaching close to 90 degrees. Gusty
southwesterly winds of 15 to 25 mph are expected during the
afternoon hours before relaxing slightly Monday night as the
boundary layer decouples under mostly clear skies.

Tuesday Through Saturday.

The unseasonably warm thermal ridge will remain positioned across
the Ohio Valley on Tuesday ahead of a potent cold front extending
from an upper-level low moving across Ontario and the Upper Great
Lakes. Models continue to show good agreement in high temperatures
climbing into the upper 80s under mostly sunny skies with another
day of deep boundary layer mixing. Moisture transport will begin to
ramp up late Tuesday night along the pre-frontal trough axis as a 40
kt LLJ advects Gulf moisture, increasing PWATs above 1.3 inches.
Scattered shower activity will enter northwestern counties after 06Z
Wednesday.

Model guidance, including deterministic runs and ensemble clusters
from the GEFS and EPS, shows the surface cold front decelerating and
stalling west-to-east across central Indiana Wednesday and Thursday
as it becomes parallel to the mid-level atmospheric flow. Strong
lower-level baroclinic forcing combined with broad synoptic lift
from an approaching shortwave trough will generate widespread
precipitation along and south of the boundary. Soundings show modest
MUCAPE between 300-800 J/kg along with 0-6 km bulk shear exceeding
40 kt, supporting embedded elevated convection and isolated heavier
rainfall totals. While models have a good idea on the broader
synoptic pattern, there remains quite a bit of uncertainty as to the
phasing of the system and where the stronger forcing sets up which
keeps confidence low on precipitation totals.

The upper trough axis clears the region early Friday, driving the
frontal boundary well south into the Tennessee Valley and opening
the door for strong post-frontal CAA. Surface high pressure of
Canadian origin will build southeastward from the Northern Plains
into the Great Lakes and Ohio Valley. Gusty northwesterly winds
Friday morning will gradually diminish by Saturday as the core of
the high centers over the region. High temperatures on Friday will
reach the upper 60s, cooling further on Saturday to the upper 50s.
Clear skies and light winds Friday night and Saturday night will
promote efficient radiational cooling, dropping overnight lows
into the upper 30s to lower 40s across central Indiana with frost
looking increasingly likely along with a potential freeze in more
rural and typically cooler areas.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1207 PM EDT Sun Oct 11 2026

Impacts:

- Lower stratus diminishing from the west this afternoon
- Patchy fog at KIND early Monday morning

Discussion:

Stratus deck continues to steadily erode from the west early this
afternoon with the expectation that it will be east of all the
terminals within a few hours. Some cu development will develop on
the backside of the stratus deck but the overall trend will be
towards clear skies by late afternoon and early evening. N/NW wind
this afternoon will become light and variable this evening.

Patchy fog is expected to develop across eastern Indiana in the
predawn hours Monday and may spread back towards KIND for a few
hours near daybreak. Otherwise VFR conditions are expected for the
rest of the forecast period with southwest winds around 10kts
developing Monday.

&&

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

&&

$$

UPDATE...Ryan
AVIATION...Ryan
DISCUSSION...White