517
FXUS63 KIND 091947
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
247 PM EST Sun Nov 9 2025

.KEY MESSAGES...

- Snow continues into tonight, accumulations around an inch south of
  I-70 and between 1-2 inches north of I-70.

- Wind gusts of 20-30 mph today and again Monday.

- Lows in the 20s Sunday night and Monday night, with wind chills
  in the teens at times Sunday night into Monday night.

&&

.SHORT TERM (This evening through Monday)...
Issued at 247 PM EST Sun Nov 9 2025

Upper-level analysis shows deep troughing over the northern Plains
and into the Great Lakes. A more concentrated area of vorticity
within the trough is located over Lake Superior. Guidance shows the
trough digging southward with the vort max reaching Indiana around
sunrise Monday.

At the surface, a low pressure system which passed through Indiana
last night is deepening over the Mid-Atlantic states. Strong
northwest flow behind the departing low has allowed cold air to
quickly move southward. Temperatures, which peaked before sunrise,
have been steadily dropping through the 30s today. Continued cold
air advection is expected as the upper-level troughing moves
southward.

Temperatures...

Guidance is in very good agreement showing a continued drop into the
mid 20s tonight. Combined with brisk northwesterly winds between 10-
20 gusting to 30mph, wind chills as low as 10 degrees F are likely
tomorrow morning and again Tuesday morning. Highs on Monday are
expected to remain in the 30s, especially if there`s a layer of snow
on the ground (higher surface albedo will help offset increasing
sunshine Monday afternoon). Above-freezing temperatures are still
anticipated, which will help any accumulated snow melt through the
day Monday.

Snowfall...

Snow showers are now being reported across the western half of
central Indiana. These snow showers are lake-enhanced to an extent,
as the aforementioned northwesterly winds have a long fetch off Lake
Michigan. This band of snow should pivot eastward today as winds
slowly become more west-northwesterly. Snow amounts will be light
through the afternoon, and confined mainly to grassy/elevated
surfaces.

That changes tonight, however, as the air and ground continue to
cool. An inverted surface trough (induced by lake-warmed boundary
layer and enhanced by the vort max aloft) will allow for a heavier
batch of snow tonight into Monday morning. Combined with large-scale
lift from the vort max itself, snowfall rates could be enough to
overcome residual ground warmth to allow for accumulations on paved
surfaces. High-resolution guidance shows snowfall rapidly ending
with the passage of the upper-level vort max late morning Monday.

Some high-res guidance hints at a second, but weaker, vort max
dropping southward Monday night. This could end up clipping our
northeastern counties, leading to increased snow totals up there.

Our northern counties are favored for accumulating snowfall through
Monday morning. Snowfall rates and duration will decrease with
southward extent, given the partial dependence on lake generated
instability. Amounts around an inch will be the most common
scenario, with areas of 1-2 inches north of I-70. An isolated 3 inch
amount cannot be ruled out either. Further south, amounts between a
trace and an inch can be expected.

&&

.LONG TERM (Monday night through Sunday)...
Issued at 247 PM EST Sun Nov 9 2025

Monday Night Through Thursday.

There may be a few lingering flurries/light snow showers across the
northern and northeastern portions of the forecast area, but as the
surface and near surface winds gain a more westerly vs northerly
component, expect to see the lake enhanced snow shift north out of
the forecast area. The air advecting into the area aloft will be
much drier which should allow for skies to clear through the night
with another night of lows in the low to mid 20s likely. As the
pressure gradients relax, wind speeds will decrease but with
temperatures slightly cooler compared to Sunday night, minimum wind
chills are likely to be as cold if not slightly colder than compared
with Sunday night

Southerly flow will quickly return Tuesday with broad ridging across
all but the eastern portions of the US which will bring a return of
near to above normal temperatures by Wednesday. Deep mixing
Wednesday will help to drop dew points and bring RH values below 40
percent along with occasional wind gusts of 20 to 30 mph. Surface
flow will be more westerly on Thursday with lighter winds as another
upper level low moves across Southeastern Canada.

Friday Through Sunday.

The ridge is expected to become more amplified Friday into the
weekend with a trough to the west of the Rockies and along the East
coast along with the low end threat for some light rain across the
Ohio Valley where a weak shortwave will move southeast along the
ridge. The warming trend is expected to continue into Saturday with
the potential for highs in the mid to upper 60s. Looking into early
next week, another low pressure system looks likely early in the
week which could bring widespread rain.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1230 PM EST Sun Nov 9 2025

Impacts:

- MVFR ceilings through the afternoon and into tonight.
- Light snow at times, MVFR/IFR visibilities in snow.
- Winds between 10-20kt with gust to 25-30kt.

Discussion:

Lake-enhanced snow showers are moving southward through Indiana as
of 17z. Snow is expected at all terminals with minor visibility
reductions. A break in the snow is likely this evening and into
tonight before a more substantial round of snow moves southward.
MVFR/IFR conditions are possible late tonight into Monday morning
before snow tapers off around 16z Monday. Quick improvement to VFR
conditions is expected after the snowfall ends.

Winds will primarily be out of the northwest today between 10-20kt
gusting to 25-30kt. Winds may decrease overnight ahead of the second
round of snowfall, before increasing again late Monday morning into
Monday afternoon.


&&

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

$$

SHORT TERM...Eckhoff
LONG TERM...White
AVIATION...Eckhoff