873
FXUS63 KIND 270444
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1144 PM EST Fri Dec 26 2025

.KEY MESSAGES...

- Pockets of drizzle,fog and light rain through the first half of
  today

- Warm through the weekend with near record highs Sunday

- Rain with a few thunderstorms Sunday afternoon and evening,
  possibly ending as a brief period of light snow early Monday

- Much colder next week

&&

.FORECAST UPDATE...
Issued at 806 PM EST Fri Dec 26 2025

Low stratus behind a weak wave passage tonight will lead to
widespread low cloud cover. Given high near surface latent heat
fluxes along with calming winds, and weak CAA, patchy fog is likely
to develop despite the ongoing cloud cover keeping temperatures
fairly mild. This is likely not going to be widespread dense fog,
but some scattered pockets of dense fog is possible.

&&

.SHORT TERM (This evening through Saturday)...
Issued at 224 PM EST Fri Dec 26 2025

Rest of Today and Tonight.

Main focus for the short term period will be tracking the potential
return of fog tonight in the aftermath of this afternoon`s frontal
passage. Synoptically an upper level low is exiting the Great Lakes
with a surface cold front stretching to the southwest. As of early
this afternoon it had mostly passed through central Indiana with
surface flow now generally now westerly to northwesterly. Occasional
gusts of 20-25 mph will continue over the next few hours before the
stronger pressure gradients associated with the exiting system begin
to relax. Breaks in the clouds have been few and far between with
expectations that these conditions will continue through the
overnight with a strong inversion above the cloud layer.

Heading into tonight, cloud bases will begin to fall again with the
potential for fog across central Indiana. Models aren`t too bullish
on the potential compared to previous nights, but as winds drop to
near calm in the aftermath of the frontal passage, there will be
plenty of residual near surface moisture which should allow for at
least patchy fog with areas of fog likely. Confidence in coverage of
dense fog isn`t quite as high with the uncertainty in the drop in
dew point depressions, but trends will need to be monitored through
the evening.

Saturday.

Another pattern shift is expected going into Saturday as the surface
flow once again becomes more southeasterly ahead of a stronger upper
level system that will impact central Indiana during the late weekend
into early next week. The persistent low clouds will stick around
through much of the day again tomorrow with little signs of breaking
even moving into the long term period. When it comes to
temperatures, there is a larger than normal model spread for 24
hours out with the uncertainty as to how much the southeasterly flow
will be able to help bring warmer air into the area. Currently
thinking temperatures will be on the lower end of model guidance
with the expected cloud cover, but there could be at  some locations
that reach into the mid to upper 50s in the far south.

&&

.LONG TERM (Saturday night through Friday)...
Issued at 224 PM EST Fri Dec 26 2025

Saturday Night... Broad upper level ridging remain the dominant
feature across the Eastern CONUS, with high pressure sliding through
the Great Lakes. Despite the ridging positioned to the north, the
stratus layer is likely to remain parked across the Ohio Valley with
the low-level flow holding tight across the region Sat ngt into Sun.
This is common to see stratus deck locked in when you have a
stubborn subsidence inversion and keeps low-level moisture trapped.
But the low-level warm air advection advecting north should slowly
lift or erode some clouds. Not entirely though, but some pockets of
blue sky could occur. Temps will still be in the mid 50s to perhaps
low 60s.

Sunday through Sunday Night... the main feature change here has been
the delay of the frontal passage. Synoptic evolution by a deep,
positively tilted 500mb trough digging into the Central Plains. A
positive tilt often delays the eastward progression of a surface
cold front as the primary forcing remains displaced to the west.

Consensus amongst ensemble members continues to increase with
minimal spread, indicating that the frontal passage likely will not
occur until late Sunday or perhaps early Mon morning. This keeps the
region in an unseasonably warm, moist air mass through the duration
of Sunday. Moisture instability will be present, as a stout 50-60kt
llvl jet will advect a plume of moisture with PWAT values nearing
1.25 inches, which is abnormal for this time of year. There does
appear to be a convective risk for late Sun, as dewpoints climb to
near the upper 50s to perhaps even 60 in some spots. Despite
guidance hinting at low MLCAPE values, the presence of strong low-
level shear all suggests that some low-topped convection could
efficiently transport higher energy to the surface and result in
some thunderstorm activity. Highs Sun could also touch record
values, cloud cover will be the main item to monitor. Any breaks
in clouds and temps could easily push to near 70 degrees.

Monday will be a return to winter, in an abrupt way. 850mb thermal
trough makes a quick return and will cause temps to crash quickly,
which could introduce a concern for rapid freezing; however, most
guidance indicates that frontal passage will also have a narrow dry
slug quickly approach and this should be enough to cause subsidence
at the surface drying the environment out quickly before any
freezing issues develop. The arctic airmass pushes the cold air back
into the Ohio Valley by Tuesday, with the high pressure dominating
the atmosphere through much of the upcoming week. This will keep a
more continental polar airmass for Indiana, as temps generally will
be in the 20s and overnight lows in the single digits to teens.
Perhaps some flurries a few days, but at the current setup suggests
there isn`t any large scale system progged to impact Indiana next
week, other than a couple weak clipper systems.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 1144 PM EST Fri Dec 26 2025

Impacts:

- IFR and lower ceilings developing through Saturday morning with
  fog as well
- VFR conditions return Saturday afternoon

Discussion:

Stratus continues to hover between 1000 and 1500ft but as the night
progresses...expect ceilings to slide back to IFR levels. Fog will
develop as well during the predawn hours but should not be as
widespread as this morning. Could still see visibilities briefly
drop below a mile at times near daybreak at the outlying terminals.

Visibilities will recover to VFR levels by mid to late morning but
stratus will be stubborn to mix out with the shallow inversion
persisting. It appears enough dry air will filter down into the near
surface layer by the afternoon to at least mix out some of the lower
stratus with a opportunity for VFR conditions to finally return
into the evening. Stratus will return Saturday night in advance of
the low pressure and frontal boundary that will bring rain to the
region on Sunday. Southeast winds at 10kts or less are expected
Saturday.

&&

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

&&

$$

UPDATE...Updike
SHORT TERM...White
LONG TERM...Beach
AVIATION...Ryan