601
FXUS63 KIND 050754
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
254 AM EST Fri Dec 5 2025

.KEY MESSAGES...

- Patchy freezing fog possible across far northwest portions of
  central Indiana towards daybreak today

- Wind chills a few degrees on either side of zero expected across
  northern areas this morning

- Chances for snow late Saturday night and Sunday.

&&

.SHORT TERM (Today and tonight)...
Issued at 254 AM EST Fri Dec 5 2025

Current satellite and surface observations depict mostly clear skies
across the north. This combined with light winds from surface high
pressure and a deeper snowpack has allowed temperatures to drop well
into the single digits. Additional slight cooling through daybreak
may allow for a few spots to drop to near zero. Patchy freezing fog
is possible over northwest portions of the area as additional
radiational cooling occurs. An extensive stratus deck over the south
extending up to the I-70 corridor has kept temperatures warmer,
generally in the teens to mid 20s. These locations are only expected
to cool slightly through daybreak as the stratus deck persist.

Expect quiet weather conditions today with weak surface high
pressure in place. The aforementioned stratus deck may persist into
the afternoon for parts of central Indiana, but clouds are expected
to gradually clear out through the day. Increasing southwesterly
flow will help to warm temperatures into the upper 20s to mid 30s by
the afternoon.

Mostly quiet weather should continue through tonight, but a weak
front is expected to approach towards daybreak Saturday. Clouds will
increase in coverage during the overnight limiting diurnal cooling.
Precipitation appears unlikely due to a lack of deeper moisture and
weak forcing. However, forecast soundings depict slight near surface
saturation with weak forcing which could promote scattered flurries
or patchy freezing drizzle towards daybreak depending on if there is
ice nuclei. The shallow nature of the saturated layer near the
surface layer limits confidence in patchy freezing drizzle or
flurries occurring though so will stick with a dry forecast late
tonight. Lows will range from the low-mid 20s.

&&

.LONG TERM (Saturday through Thursday)...
Issued at 254 AM EST Fri Dec 5 2025

To begin the weekend, there will be a weak frontal passage during
the day on Saturday. This is expected to move through an already
saturated PBL, of which could produce flurries with isolated snow
showers. Confidence is low on any accumulation, but a quick
dusting cannot be ruled out.

A majority of the long term will feature a fairly stagnant upper
pattern, with strong ridging over the eastern Pacific and a robust
subtropical jet over the SE CONUS. This synoptic set up typically
leads to quickly developing shortwaves in the divergent region of
the supergeostrophic jet streaks of which will likely lead to a
succession of wave passages across the Great Lakes region Saturday
night through Wednesday. Past Wednesday, a more amplified western
ridge and East Coast trough will likely lead to surges of cold air
later in the week, but with increasing uncertainty on the location
of any low level disturbances.

The first of these waves is expected to reach central Indiana late
Saturday night into Sunday morning. This wave will begin to weaken
some as it encounters upper level convergence near the
aforementioned subtropical jet, but will still have enough lift for
widespread precipitation across Indiana; albeit lighter overall QPF
than areas upstream. The bigger uncertainty lies within
precipitation type as a modest baroclinic zone resides over the
region. Initially precipitation should remain as snowfall, but as
daytime heating occurs, a transition to rain is likely across
southern portions of the state. As stated, QPF totals will be
subdued some as the wave weakens, but this still could produce some
impactful snow across the area with potential snow fall totals
ranging from T to 2 inches Sunday morning into the afternoon.

The mid week clippers are expected to pass to the north with 80-905
of the ensemble solutions favoring this northern track. This
northern track would put central Indiana mostly in the "warm"
sector. Generally, this would keep any precipitation during the day
on Tuesday and Wednesday as rain, but light snow cannot be ruled out
overnight Monday and Tuesday when diurnal cooling helps keep surface
temperatures near to below freezing. The best chances for
precipitation next week are currently expected to be attached with
the second of the two waves; late Tuesday night through Wednesday
evening.

Temperatures: Each of these clippers will have a positive tilt but
should have enough frontogenetic forcing along the baroclinic zone
for modest temperature swings as they pass. This should lead to
pendulum of highs in the in low to upper 30s Sunday, Tuesday and
Wednesday; Whereas highs are likely to remain below freezing Monday,
Thursday and Friday in the wakes of these clippers. During the
colder stretches of Monday, Thursday, and Friday, lows in the single
digits along with a light breeze will likely lead to near zero wind
chills each morning.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 1228 AM EST Fri Dec 5 2025

Impacts:

- Patchy fog possible overnight, mainly near LAF
- MVFR ceilings expected to continue at BMG/IND through at least
  daybreak before improving during the day today

Discussion:

VFR conditions expected through much of the TAF period for HUF/LAF
outside of patchy freezing fog towards LAF. Freezing fog is possible
near HUF, but confidence is lower. This fog may settle in as early
as 06Z near LAF though it is more likely in the 10z to 14Z
timeframe.

MVFR cigs are ongoing at BMG/IND and are expected to persist through
at least daybreak before improving to VFR during the day. There is
some uncertainty on how quickly this improvement occurs later today.
MVFR cigs cannot be ruled out near HUF as well after 06Z. Winds
will be variable through daybreak at 0-5kts with a predominately
southeasterly direction. Expect winds to then veer more southerly
during the day.


&&

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

$$

SHORT TERM...Melo
LONG TERM...Updike
AVIATION...Melo