204
FXUS63 KIND 301854
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
254 PM EDT Fri Oct 30 2026

.KEY MESSAGES...

- Mostly Sunny and Cooler today.

- Best rain chances return Saturday Night into Sunday.

- Mild and wet pattern likely Monday through Thursday.

&&

.DISCUSSION (This evening through Friday)...
Issued at 253 PM EDT Fri Oct 30 2026

This afternoon...

Skies remain mainly clear after last night`s cold front with
temperatures suppressed by about 10 degrees. Highs so far have
been in the low to mid 60s with expected temps near 70 later this
afternoon. Overall, winds out of the northeast should keep weak
cold air advection in place through the day today. Additionally,
dry air advection continues with dew points a few degrees lower
than guidance due to efficient boundary layer mixing.

Clouds increase and thicken overnight keeping temperatures warmer
than previous nights. Most locations should expect to see lows in
the 50s but portions of our northeast may dip into the 40s. A few
showers may even creep into our northwestern counties late in the
night. Overall, precipitation chances should remain low and amounts
light if any.

The culprit is a weak trough ejecting into the Plains this
afternoon. This feature is interacting with a tropical moisture
plume associated with the remnants of Hurricane Vance. Guidance
shows the trough weakening as it lifts northeastward towards
Indiana. Trends within guidance have been towards a drier solution
over the past few days. Our best chances of rainfall are late
Saturday into Sunday with the primary trough axis swinging through.

Monday through Friday...

An active pattern with repeated rounds of precipitation is likely
through next week. The upper level trough associated with the
expected rainfall this weekend will be exiting the region early
Monday morning. A few lingering showers are possible Monday with
PWATs around 1.3 inches and dew points in the mid-to-upper 50s
across Indiana in the wake of the trough.

At the same time, models suggest a secondary upper level trough will
start to evolve over the Great Plains. An associated strong surface
low within the broader cyclonic flow regime will advect unseasonably
moist air into the region from the Gulf, with PWATs around 1.5
inches and dew points potentially in the lower 60s. Coupled with 50-
55 kt SW flow at 500mb and strong isentropic ascent, sufficient
moisture and lift exists for rain and a thunderstorm or two across
the region starting on Tuesday and lasting through Wednesday.

However, there is model uncertainty of the evolution of the trough
as Thursday approaches. While the GEFS and EPS ensembles show the
surface low exiting Indiana into Thursday morning, bringing cooler
and drier air behind it, the GFS indicates the potential of a split
flow regime may develop. In tangent to the split flow regime, a
secondary surface low may form in portions of the mid MS valley
bringing another wave of broad cyclonic flow across indiana. The new
surface low could bring another wave of unseasonably moist air and
more isentropic ascent. If this scenario were to happen, expect
additional rainfall and isolated thunderstorms for Thursday.
Rainfall totals through Thursday will range from 0.75-1.75 in
depending on the evolution and speed of the upper level through.

By Friday, any precipitation will move out of Indiana bringing quiet
and calm conditions. Temperatures Friday should remain in the mid to
upper 60s.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1254 PM EDT Fri Oct 30 2026

Impacts:

- None

Discussion:

Broad area of high pressure over the Great Lakes with an attendant
ridge axis extending southward through the eastern Ohio valley will
move SE into the eastern seaboard through Saturday. VFR conditions
will be prevalent at all terminals owing to dry low level E-NE flow
gradually becoming E-SE, with wind speeds less than 10 kts.

A weak area of showers over central IL will develop slowly eastward
this afternoon and may survive and reach KLAF before dissipating
overnight. For now the potential appears to be low enough to not
warrant inclusion in the TAF.

Meanwhile, copious mid-high level clouds associated with an
approaching weak storm system moving up from the southern Plains
will overspread the region tonight through Saturday with OVC
conditions expected at all terminals by 12Z Saturday. Forecast
soundings show cloud ceilings will lower to as low as 080 briefly in
the morning but will average between 100-150 through remainder of
the day. A few virga showers are possible Saturday, but given the
degree of dry air in the sub-cloud layer, no precip is expected at
the terminals.


&&

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

$$

AVIATION...Crosbie
DISCUSSION...Eckhoff/SM