421
FXUS63 KIND 310515
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
115 AM EDT Sat Oct 31 2026

.KEY MESSAGES...

- Mostly Sunny and Cooler today.

- Best rain chances return Saturday Night into Sunday.

- Mild and wet pattern likely Monday through Thursday.

&&

.FORECAST UPDATE...
Issued at 952 PM EDT Fri Oct 30 2026

The forecast remains in good shape with only minor adjustments made
in the latest update. Latest satellite imagery depicts extensive mid-
high clouds pushing into central Indiana from the west as a system
over the Plains continues to approach. Residual dry air in the
lower levels should mostly limit precipitation chances through
the overnight, but a few light showers cannot be completely ruled
out across northwestern counties, where there is slightly greater
moisture and marginal forcing. Increasing clouds will keep
temperatures slightly warmer compared to last night, generally in
the upper 40s to mid 50s.

&&

.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 (06Z TAF Issuance)...
Issued at 114 AM EDT Sat Oct 31 2026

Impacts:

- None

Discussion:

Widespread mid and high cloud will gradually continue to overspread
the area with ceilings slowly dropping to near 8-12KFT through the
period as a modest upper level disturbance moves toward the area.

A sprinkle or shower cannot be ruled out at times during the period,
but low level dry air is likely to severely limit this potential,
with virga the most likely outcome. Any precip would be light and
unlikely to cause impacts.

Winds will generally be easterly through the period, between 080-110
degrees, strengthening to 8-10KT during the daytime and dropping to
4-8KT or less overnight.

&&

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

&&

$$

UPDATE...Melo
AVIATION...Nield
DISCUSSION...Eckhoff/SM