650
FXUS63 KIND 020150
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
850 PM EST Sun Nov 1 2026

.KEY MESSAGES...

- Light rain and drizzle to continue at times through tomorrow

- Warmer than normal temperatures continue through Tuesday

- Rain chances return Tuesday night with a few rumbles of thunder possible

- Cooler but still near seasonal normals late week into the weekend

&&

.FORECAST UPDATE...
Issued at 850 PM EST Sun Nov 1 2026

Moisture will continue to advect into central Indian over the next
12-24 hours slowly saturating the lower levels of the troposphere.
Saturation has already starting over SW portions of the area where
weak confluence has allowed for slightly greater upward motion with
mid level rainfall processes leading to lower level saturation. This
will be the primary area of concern for fog and drizzle development
tonight as an already saturated layer becomese condensed beneath
weak subsidence.

For the remainder of the area, patchy drizzle and decreasing cloud
depth is expected. Drizzle may become heavy enough at times Monday
morning for slight reductions is visibility (4-6SM), but otherwise
not impacts are expected.

&&

.DISCUSSION (This evening through Sunday)...
Issued at 130 PM EST Sun Nov 1 2026

Overview.

A quiet start to the week will give way to an active and
significantly warmer pattern by Tuesday. Sprinkles and light rain
showers will continue intermittently through tomorrow. As high
pressure shifts eastward, much warmer air will surge north into the
region Tuesday. A strong low pressure system will track across the
Midwest on Tuesday night, bringing widespread rain, gusty winds, and
the potential for a few thunderstorms. Behind this system, much
colder and drier air will sweep in for Thursday with temperatures
closer to normal through the weekend.

Tonight through Monday Night.

Surface high pressure centered across the upper Ohio Valley and
central Appalachians will continue shifting east off the Mid-
Atlantic coast tonight. Aloft, quasi-zonal flow transitions to weak
southwesterly flow downstream of an upper-level shortwave crossing
the Upper Mississippi Valley. Warm air advection intensifies across
the lower Ohio Valley after midnight as an 850mb low-level jet ramps
up to 25 to 35 kt. Additional saturation in the lower levels is
expected to continue through the overnight with saturation currently
at around 700mb which should then saturate to near the surface by
Monday morning. The cloud deck should be shallow by Monday morning
which will increase the chance that the weak isentropic lift could
bring precipitation to the surface.

Scattered showers will continue across the forecast area through
Monday morning before large-scale isentropic ascent shifts eastward
into Ohio by early afternoon. A weak, diffuse surface warm front
will attempt to advance northward toward the Ohio River, but
persistent overcast conditions, weak low-level easterly to
southeasterly flow, and rain-cooled air will reinforce a wedge of
cooler air across central Indiana. This will limit daytime
insolation, keeping afternoon temperatures capped in the mid-50s
north to lower 60s south.  For Monday night, mid-level forcing
diminishes behind the departing northern-stream impulse. However,
residual boundary-layer moisture beneath a low-level inversion
around 900mb will maintain widespread stratus and the potential for
some drizzle. Weak warm advection continues just above the surface,
keeping overnight lows mild and well above seasonal normals,
generally settling in the upper 40s to lower 50s.

Tuesday through Sunday.

Tuesday will initially feature a brief synoptic lull as an expansive
upper-level ridge axis temporarily builds over the eastern third of
the CONUS in response to a deep, amplifying longwave trough over the
western United States. Central Indiana will reside firmly within the
warm sector as the surface warm front lifts north into the lower
Great Lakes. Southerly boundary-layer flow will transport 850mb
temperatures of +10C to +12C into the region, pushing surface highs
into the mid to upper 70s. Aside from isolated showers driven by
weak warm advection, large-scale subsidence should keep the majority
of the daylight hours dry beneath broken cloud cover.

The primary focus centers on the evening and overnight hours as
the western trough rounds its base, acquires a neutral to slightly
negative tilt, and ejects into the Mid- Mississippi Valley.
Deterministic solutions from the GFS, ECMWF, along with their
respective ensembles, remain in good agreement regarding a rapidly
deepening surface cyclone tracking from northern Missouri
northeastward across Illinois into the western Great Lakes.
Kinematic fields associated with this system are exceptionally
potent. An intense 850mb LLJ of 55 to 65 kt will overspread
Indiana Wednesday afternoon and evening, accompanied by a 90 to
100 kt mid- level jet streak overhead. Bulk shear vectors in the
0-6 km layer will exceed 60 to 70 kt, oriented largely parallel to
the advancing surface cold front, while 0-1 km bulk shear climbs
to 35 to 45 kt.

All these favorable dynamics will be countered by an increasingly
hostile thermodynamic field with very poor lapse rates and little to
no instability. Model soundings show little to no instability except
for the far southwestern counties and with the poor timing of an
overnight passage of the front, severe weather looks increasingly
unlikely with a HSLC event not really in play anymore. Models have a
much better handle on the timing with little difference in the
ensembles which boosts confidence in the decreased severe threat.
Outside of the rain chances, the strong low level wind fields will
help to bring breezy conditions with a few gusts up to 30 mph at
times. There may be a few showers that linger into Wednesday, but
expect chances to fall off quickly as slightly cooler air works into
the area.

For Friday through Sunday, broad cyclonic flow aloft will encompass
the Great Lakes and Northeast. Several weak vorticity filaments
rotating through the base of the longwave trough will sustain
intervals of cloudiness and isolated rain Friday and early Saturday,
particularly across north-central and northeast portions of the
area. A sprawling Canadian surface high  will build southeastward
across the mid-Mississippi and Ohio Valleys late Saturday into
Sunday, allowing winds to diminish and skies to clear. Temperatures
will drop to near normal with highs in the upper 50s to low 60s and
overnight lows in the upper 30s.

&&

.AVIATION (00Z TAF Issuance)...
Issued at 635 PM EST Sun Nov 1 2026

Impacts:

- Occasional light rain and drizzle tonight and Monday morning

- Cigs dropping to MVFR tonight and towards IFR Monday morning

Discussion:

Cloudy skies expected through the TAF period with cigs gradually
falling to MVFR after 06Z and eventually IFR towards daybreak. These
IFR conditions should persist into the early afternoon before
lifting back to MVFR. Isolated light rain showers are possible
through 08Z, but coverage is too low to include at this time.
Drizzle is expected to develop primarily at the southern 3 sites
after 08Z, with VIS impacts at KBMG. Drizzle should begin to clear
up after 14Z tomorrow. Winds will remain generally easterly to
northeasterly at 5-10 kt through the TAF period.


&&

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

$$

UPDATE...Updike
AVIATION...Updike
DISCUSSION...White