517
FXUS63 KIND 250804
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
304 AM EST Tue Nov 25 2025

.KEY MESSAGES...

- Today: rain showers early, tapering to drizzle midday...noticeable
  humidity and mild with highs 55-60F

- Turning colder beginning Wednesday through this weekend

- Increasing confidence in snow late Friday night into Saturday with
  a mixture of precipitation types persisting into Sunday before
  ending

- Cold and unsettled pattern continues into early December

&&

.SHORT TERM (Today and tonight)...
Issued at 304 AM EST Tue Nov 25 2025

Today...

Rather weak H500 short wave will slowly lift from northern Illinois
to eastern Great Lakes...while corresponding modest surface low
pressure drifts just northwest of local region into southern
Michigan.  Despite overall unimpressive gradients, trough extending
south down Mississippi Valley will focus a broad fetch of Gulf
moisture into Indiana this morning.  A period of steadier pre-dawn
rain that should drop over 0.25 inches on several southern Indiana
counties by 12Z...will trend to more scattered showers for most
areas through the morning hours...although latest CAMs note the
potential for a second round of briefly moderate rain after dawn
over south-central and southeastern zones.

Departure of better forcing to our east will replace showers with
drizzle from west to east through late morning to midday hours.
Total precipitation for this quick/small system should range from
around 0.25 inches for most spots near/north of I-70, with a
gradient across southern counties up to around 0.50 inches for far
southeastern zones.  Humidity will be noticeable as mainly light
breezes veering from southerly to WSW push dewpoints into at least
the mid-50s.  Thick low stratus will not prevent this warm advective
flow from bringing possibly the mildest day since 11/15...and
probably the highest temperatures for the foreseeable future.  Max
temps this afternoon  will range from the mid-50s for Lebanon and
north/west...to around 60F along the US-50 corridor.

Tonight...

This evening will include the remainder of this afternoon`s brief
quasi-lull, between departing weaker system and approaching,
blustery polar invasion.  Conditions will be continued damp for late
November under lingering low stratus, with a few lingering showers
that should not produce any noteworthy precipitation for most areas.

Next, more impressive short wave trough will plunge and tilt through
the Upper Mississippi Valley, inducing impressive surface
cyclogenesis tonight over Wisconsin.  The system`s corresponding
cold front extending southward from the occlusion`s triple point
over Michigan`s Lower Peninsula...will cross the local region during
roughly 05Z-10Z.  Westerly winds will increase amid the post-frontal
zone, with gusts nearing 25-35 mph through pre-dawn hours.  Readings
will plummet after midnight from the low-50s to mid-30s for most
locations.

&&

.LONG TERM (Wednesday through Monday)...
Issued at 300 AM EST Tue Nov 25 2025

The early morning cold frontal passage on Wednesday will be the
initial salvo in the significant pattern change towards colder and
more unsettled conditions that will continue into early December
that we have been discussing for a while now. The initial impact
will be noticeably colder air for the second half of the week
including Thanksgiving but as broad meridional upper level troughing
takes hold over much of the eastern half of the country by this
weekend...a series of storm systems will impact the Ohio Valley into
next week with increasing confidence in multiple opportunities for
wintry precipitation including snow.

Wednesday through Friday

As mentioned above...the cold front will sweep across the forecast
area prior to daybreak Wednesday...with strong cold advection taking
over as upper level heights tumble as the strengthening upper level
low pivots across the Great Lakes. Flurries and a few snow showers
will be possible Wednesday focused mainly across the northeast half
of the forecast area with weak low level instability present within
the cold advection pattern. The lack of substantial moisture will
limit coverage and keep snow very light.

The much greater impact besides the arrival of a much colder airmass
with temperatures likely falling Wednesday afternoon will be the
onset of strong gradient winds as the surface low deepens over the
Great Lakes throughout the day. Combined with the strong cold
advection in the post-frontal airmass...peak gusts near 45mph will
be possible across northern portions of the forecast area Wednesday.
Gave some consideration to introducing a Wind Advisory over northern
counties but will hold off to take advantage of an additional round
of model data and better determine how far south across central
Indiana a potential Advisory would be warranted.

Winds remain breezy though not as strong on Thanksgiving as the
tight pressure gradient persists in the wake of the departing
surface low. Despite increasing sunshine for Thanksgiving Day it
will be cold with highs in the 30s. Temperatures may struggle to
rise above freezing over northern counties and the continued brisk
winds will keep wind chills in the 20s. Friday may end up being the
best day of the extended holiday weekend despite continued well
below normal temperatures in the 30s. Sunny skies are expected
Friday and winds will finally relax as the low pressure moves away
into the Canadian Maritimes.

Friday Night through Monday

The second part of the pattern transition comes over the weekend as
a much more active regime develops and interacts with the broad
upper level trough settling across the eastern part of the country.
A potent short wave will dive out of the Pacific Northwest on
Friday then pivot quickly into the central Plains on Saturday.
Moisture will increase in advance of a surface wave poised to eject
out of the Rockies Friday night then kick E/NE into the Great Lakes
and Ohio Valley by Sunday morning.

Precipitation will arrive across the region as early as late Friday
night and persist into Saturday. Extended model guidance continues
to struggle on the details with a broad range of scenarios in play.
That being said...the overall model suite is trending in the
direction of at a minimum a thump of snow on the front end of the
precipitation shield Saturday with the initial surge of warm
advection. Greater uncertainty in precip type develops as the day
progresses that will largely depend on the orientation...speed and
intensity of the wave aloft and the eventual track of the surface
low into Sunday morning. Trends support rain mixing with snow from
the south by Saturday afternoon with an eventual transition to rain
over most if not all of the area by early Sunday morning as the
surface low moves into the lower Great Lakes. The primary takeaway
message for late Friday night and Saturday is that the potential for
accumulating snow and at least some impacts to travel is increasing
prior to a transition to predominantly rain that would last into
Sunday before ending. Stay tuned for updates.

After a brief break in the unsettled weather...precipitation will
return for early next week as an inverted surface trough lifts into
the Ohio Valley. Even less confidence exists with this system with
respect to precip type but at this early stage all precip types are
on the table with the possibility for another opportunity for snow
for some. Highs will sneak back up into the upper 30s and lower 40s
for Sunday and Monday but there are signs of the coldest daytime
temperatures of the season impacting the region by the middle of
next week.

Looking out further into next week and beyond...additional chances
for wintry precipitation including snow will exist as the active
pattern persists. High confidence remains in a cold and largely
unsettled pattern continuing for the region through the first half
of December.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 1239 AM EST Tue Nov 25 2025

Impacts:

- VFR deteriorating quickly in rain tonight to IFR/LIFR by 09Z

- LIFR/IFR continuing into Tuesday evening...as -SHRA taper to -DZ
  from west to east by midday

- Ceilings most likely improving to MVFR towards end of 24-hr TAF
  period

Discussion:

Upper short wave trough and weak surface low pressure crossing
Midwest through Tuesday evening...will bring poor flying conditions
from pre-dawn hours into at least early this evening.  Low ceilings
will lead IFR/LIFR conditions, with visibility likely falling to IFR
at most TAF sites this morning.  Rain will increase in coverage from
southwest to northeast during overnight hours...then scatter out to
-SHRA from west to east after 10Z...before tapering to -DZ around
late morning to midday hours.

IFR to linger this afternoon, with low-MVFR not expected until at
least late this evening.  Additional showers are expected Tuesday
evening as a cold front approaches the region. Southeast winds
tonight will veer to south and then southwest on Tuesday.

&&

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

$$

SHORT TERM...AGM
LONG TERM...Ryan
AVIATION...AGM