148
FXUS63 KIND 141637
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1237 PM EDT Wed Oct 14 2026

.KEY MESSAGES...

- Multiple rounds of showers and scattered thunderstorms today
  through Thursday night

- Isolated strong to severe storms are possible this afternoon and
  Thursday, damaging winds and heavy rain the main threats

- Sharply colder conditions arrive Friday, accompanied by northwest
  wind gusts of 30 to 40 mph

- Widespread frost is likely late Saturday night into early Sunday
  morning

&&

.FORECAST UPDATE...
Issued at 1000 AM EDT Wed Oct 14 2026

Clouds continue to thicken from the west this morning with a
convective cluster about to move into the lower Wabash Valley. It
was a muggy morning with 14Z temperatures ranging from the upper 60s
to mid 70s.

The forecast remains on track for the rest of the day. The frontal
boundary has moved into the northern half of the forecast area this
morning and will keep the initial convective cluster confined to
far southern portions of the forecast area and points south through
early afternoon. Additional convection will develop this afternoon
along the southward moving frontal boundary with lighter showers
further north. There remains a low threat for a few cells to produce
isolated damaging winds later this afternoon as CAPE values climb
above 1000j/kg...focused across far southeast counties. COnvection
will shift east of the area this evening.

Highs in the upper 70s and lower 80s are expected this afternoon.
Zone and grid updates out.

&&

.DISCUSSION (Today through Tuesday)...
Issued at 131 AM EDT Wed Oct 14 2026

Today Through Thursday.

An approaching upper-level shortwave trough over the northern Plains
will flatten the downstream ridge, forcing a surface cold front to
sag southward into central Indiana through the day. Gulf moisture
will pool along and ahead of this boundary, driving PWAT values
upward into the 1.4 to 1.7 inch range, which sits well above the
90th percentile for mid-October.

As of early this morning, elevated showers associated with the
aforementioned moisture advection continues to move across northern
Indiana and portions of Illinois. These showers may impact the
northwestern counties, but otherwise expect convection to hold off
until later in the day. Modest mid-level lapse rates will limit
buoyancy with model soundings showing a skinny CAPE profile, but
with SBCAPE values of 500 to 1200 J/kg updrafts will be strong
enough to allow for thunderstorm development. Effective bulk shear
around 35 to 45 kt will provide sufficient organization for
multicell clusters and isolated transient supercell structures. The
primary convective threats will be localized damaging wind gusts and
brief torrential rainfall, though widespread severe weather is not
expected given extensive cloud debris limiting stronger diurnal
heating.

The frontal boundary will decelerate and oscillate across the region
tonight as an open shortwave ejects northeastward from the middle
Mississippi Valley. This will at least some convection through the
overnight, but much less than during the daytime hours.

On Thursday, a deeper, amplifying mid-latitude trough over the Upper
Midwest will induce surface cyclogenesis along the frontal wave,
dragging a secondary, stronger cold front across central Indiana
Thursday afternoon and evening. Pre-frontal warm sector recovery
will support renewed thunderstorm development. While shear profiles
remain strong with 0-6 km bulk shear exceeding 50 kt, thermodynamic
profiles will be conditionally dependent on morning cloud clearance.
Any pockets of surface heating will enhance low-level lapse rates,
maintaining an isolated strong-to-severe risk along and ahead of the
frontal line before dry slotting and strong cold advection scour out
precipitation from west to east Thursday night.

Friday Through Tuesday.

A sharp pattern transition will occur Friday in the wake of the cold
frontal passage as a broad, amplified longwave trough settles over
the eastern half of the CONUS. Robust low-level cold air advection
will cause 850mb temperatures to tumble from near +10C Thursday
evening to between -2C and -4C by Friday afternoon. Efficient
boundary layer mixing in steep low-level lapse rates, combined with
a tight surface pressure gradient behind the departing surface low,
will generate sustained northwest winds of 20 to 25 mph with
frequent gusts of 30 to 40 mph Friday afternoon. Lingering
stratocumulus under the cyclonic upper flow will keep daytime highs
capped in the upper 50s.

A 1028-1030mb surface high pressure will build from the northern
Plains into the lower Ohio Valley over the weekend. Diminishing
winds and clearing skies Friday night will yield lows in the upper
30s but winds should remain just elevated enough through the
night to avoid frost formation outside of very sheltered areas.

The primary frost and freeze concern arrives Saturday night into
early Sunday morning. The surface ridge axis will center directly
across central Indiana, setting up optimal conditions for
radiational cooling with calm winds, a clear sky, and surface
dewpoints dropping into the low 30s. Both deterministic GFS/ECMWF
runs and the EPS/GEFS ensembles indicate high confidence in
overnight lows dropping into the lower 30s across most of the area,
with subfreezing minimums possible likely in traditional cold
drainage areas. Frost headlines will likely be required for this
period.

By Monday and Tuesday, the upper-level trough will lift into the
Canadian Maritimes as low-amplitude ridging and quasi-zonal flow
overspread the mid-Mississippi and Ohio Valleys. The surface high
will shift toward the mid-Atlantic coast, establishing southerly
return flow. Low-level warm air advection will drive 850mb
temperatures back toward +8C to +10C, allowing daytime temperatures
to moderate into the upper 60s and lower 70s. Subsidence under the
surface ridge will ensure dry conditions across central Indiana
through Tuesday ahead of the next upstream disturbance.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1237 PM EDT Wed Oct 14 2026

Impacts:

- Scattered convection this afternoon
- Winds shifting to N/NE by early evening
- Ceilings will fall late tonight into Thursday to MVFR with pockets
  of IFR

Discussion:

An area of showers with embedded thunderstorms continues to move
east across the southern half of Indiana early this afternoon as a
frontal boundary pushes through the area. Additional scattered
convection will likely develop along the front in the immediate wake
of the area of rain and storms but expect all rain will be east of
the terminals by 22-23Z. Wind direction will be chaotic through the
afternoon...especially at KBMG and KHUF...but as the boundary
continues south winds will become prevailing from the N/NE by this
evening.

Ceilings will slowly lower overnight to MVFR levels as moisture
becomes trapped beneath a boundary layer inversion. IFR ceilings are
possible primarily at KBMG by Thursday morning. Winds will begin to
veer back around to the E/SE on Thursday as the front lifts back
north. Rain may impact KHUF and KLAF towards the end of the forecast
period with more substantial convective impacts accompanying a cold
front set to move through the area Thursday evening.

&&

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

&&

$$

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