675
FXUS63 KIND 041959
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
259 PM EST Thu Dec 4 2025

.KEY MESSAGES...

- Patchy freezing fog overnight, especially northwestern portions of
  central Indiana.

- Wind chills of few degrees either side of zero will be possible
  across northern areas early tonight into Friday morning.

- Low chances for snow will be around Sunday and again Tuesday.

&&

.SHORT TERM (This evening through Friday)...
Issued at 258 PM EST Thu Dec 4 2025

A cold front has passed through Indiana this morning, but is most
noticeable across our northwest where temperatures dropped into the
low teens. Further south, the advancing cold air mass has slowed and
made little progress. In fact, surface winds are now veering as
surface high pressure skirts eastward across northern Indiana. This
will allow winds to go light and variable overnight before switching
to southwesterly tomorrow.

As mentioned above, winds become light and variable under the high
along with clearing skies. This should promote ideal radiative
cooling potential especially where a deeper snowpack exists. The
deeper snowpack is generally across our northwest, which is
coincidentally also deeper into the colder air mass which dropped
south last night. As such, we`re expecting our coldest reading
overnight to be over our northwestern counties. Lows in the single
digits will be common, along with the potential for some negative
temperatures here and there. Further south, lows in the single
digits are possible but teens should be more common.

High resolution guidance is hinting at patchy fog potential
overnight, especially further north and west where the best cooling
potential exists. The air mass that moved south was dry, not overly
so, but dry enough to make the idea of widespread fog seem
unlikely. We`ll introduce the mention of patchy fog for western
and northern portions of our CWA. Should fog occur, it will
coincide with the very cold temperatures expected overnight.
Therefore, we`ll mention it as freezing fog which carries the
potential for light icing on cold surfaces.

As high pressure lift northeastward on Friday, winds will turn
southwesterly and increase ahead of a trough approaching from the
northwest. Low stratus is possible Friday morning into the afternoon
but is conditional on fog development. Regardless, enough sunshine
looks to be present, along with warm air advection from the
southwest, to allow temps to rebound into the upper 20s / low 30s.

&&

.LONG TERM (Friday night through Thursday)...
Issued at 258 PM EST Thu Dec 4 2025

Ridging aloft will remain confined to the Pacific coast through much
of the extended before gradually shifting east into the Plains by
late next week. This will maintain an eastern upper level trough and
broad northwest flow across the region keeping temperatures largely
colder than normal with a few clipper like systems offering the
opportunity for light snow as well.

Friday Night through Sunday

Clouds will thicken Friday night into Saturday as a weak frontal
boundary drifts into the Ohio Valley before washing out. Moisture
will be lacking with the front and expect dry conditions for central
Indiana through Saturday night with seasonably cool temperatures.
Highs will rise above freezing into the mid and upper 30s over most
of the forecast area Saturday afternoon as light southerly flow
develops.

Extended model guidance over the last few runs has trended back in
the direction of the potential for a period with more widespread
light precipitation associated with a clipper system set to track
from the northern Rockies on Saturday into the region by Sunday
afternoon. Moisture will be more plentiful along and ahead of this
feature with growing confidence of a 6 to 8 hour period on Sunday
with precipitation impacting the region. Low level thermals will be
critical with a potential for rain to mix with snow across southern
portions of central Indiana while the airmass remains cold enough
for just snow further north.

The track of the system will be the determining factor on precip
type as a further shift south would support more snow over the area
while a northerly track would favor an increased risk for mixed
precipitation or even a period with primarily light rain. Ensembles
continue to align but there is potential for a light snow
accumulation focused especially across the northern half of the
forecast area on Sunday. At this point...impacts would likely be
minor and certainly lower than both of the recent storms last
weekend and on Monday afternoon and night.

Sunday Night through Thursday

In the wake of the clipper on Sunday...a reinforcing shot of Arctic
air will follow in tandem with strong high pressure to begin next
week with highs reverting back into the 20s over a large portion of
the forecast area on Monday. The high will be east of the region by
Tuesday with return flow enabling temperatures to rise into the 30s
on Tuesday with mid 30s to mid 40s Wednesday. Uncertainty increases
in regards to precip chances but the overall pattern aloft supports
one or two systems dropping southeast through the Great Lakes and
bringing at least the potential for light precipitation including
snow for the middle and latter part of next week.

An amplification of the upper trough will bring another surge
of colder Arctic air by next Thursday and Friday but that will be
temporary as the aforementioned western ridge is expected to move
into the eastern half of the country by next weekend with warmer
temperatures and a brief break from the early winter conditions.
Long range trends do support a return to colder and more unsettled
conditions as we approach the weekend prior to Christmas.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1227 PM EST Thu Dec 4 2025

Impacts:

- Patchy fog possible overnight, mainly HUF and LAF
- MVFR stratus possible Friday morning/afternoon

Discussion:

Skies have cleared today behind a cold front that passed through
this morning. Northerly winds have diminished and gradually become
northeasterly. This trend will continue, becoming easterly and then
southeasterly. A period of light and variable winds are possible as
well. Winds pick up again Friday morning becoming south-
southwesterly.

Though a drier air mass has moved southward, enough moisture remains
for some patchy fog potential tonight. The best chances are with
westward extent, so HUF to LAF. We`ll include a TEMPO group in the
TAFs for each of these sites. Should fog develop, it may lift into a
stratus deck and drift northeastward. We`ll mention SCT015 to
account for this possibility.

VFR ceilings are possible during the day Friday as a system passes
by to our north.


&&

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

$$

SHORT TERM...Eckhoff
LONG TERM...Ryan
AVIATION...Eckhoff