679
FXUS63 KIWX 232333
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
633 PM EST Sun Nov 23 2025

.KEY MESSAGES...

- Continued seasonably mild with highs in the 50s through
  Tuesday.

- Light rain developing Monday night then ending Tuesday except for
  lake effect rain showers.

- Turning much colder for Thanksgiving Day through the end of
  the week with highs in the 30s and wind chills in the teens
  and 20s.

- Additional chances for precipitation exist through the holiday
  weekend, but confidence remains low on specific concerns and
  impacts.

&&

.DISCUSSION...
Issued at 233 PM EST Sun Nov 23 2025

A very energetic pattern will take shape this week, with large
temperature swings, multiple rounds of precipitation, and windy
conditions impacting much of the upcoming Thanksgiving weekend/ Many
finer details remain to be resolved, but at least some signals
already exist to help focus the main time frames of concern.

The forecast period will start dry and seasonably warm temperatures
through Monday as high pressure drifts across the region. A closed
upper low, currently over the Four Corners region, will drift ENE
and slowly deamplify, reaching Missouri by 6Z Tue. Ahead of this
feature, broad sfc low pressure will interact with sufficient
moisture to bring a period of rain to the area Monday evening into
early Tuesday. Not expecting a lot of QPF, nor any sort of wintry
mix as the Gulf remains cut off and thermal profiles remain above
freezing.

As this first wave moves NE and continues to weaken, a northern
stream trough will dig into the Plains and deepen as the left front
quadrant of a 120+ kt jet streak rounds the trough. The
aformentioned sfc low will quickly deepen as the trough approaches,
eventually tracking from western WI at 00Z Wed to NE of Lake
Superior by 00Z Thu. As it does, strong CAA will commence across the
Plains and move rapidly SE and overspread the area Tuesday night
into Wednesday. The timing of the CAA will result in steady or
falling temperatures Wednesday along with a chance for some
scattered rain/snow showers along the front.

Windy and much colder conditions will dominate the start of the
holiday weekend. An overall W to NW flow looks to setup across Lake
Michigan, resulting in chances for lake effect snow showers across
our Michigan counties. It remains too early to determine specific
impacts, but some travel impacts are possible late Wednesday into
Thanksgiving day.

The deep upper low will continue NE into Ontario over the weekend,
with the next wave of interest diving south into the Western US and
linger in the SW states. As it does an increasing SW flow will begin
to establish late this weekend and persist into next week. This will
allow a return of Gulf moisture to the region, which will interact
with one or more disturbances ejecting from the trough. A baroclinic
zone will setup somewhere near or north of the Ohio River with the
first round of precipitation as early as Saturday, followed by 1 or
more additional rounds into early next week. Thermal profiles are
all over the place, dictated by the location of this boundary.
Suffice to say, some travel issues could materialize for the end of
the holiday weekend. It is far too early to discuss what may occur,
but monitoring of later forecasts is certainly recommended.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 633 PM EST Sun Nov 23 2025

Negative theta-e advection allowed for cool and dry conditions for
today and for initial VFR conditions for this TAF period. Previous
runs of the aviation forecast guidance indicated near surface
moisture and even some MVFR CIGs stalled out just west of the IL/IN
border as WAA brings in positive theta-e advection along a warm
front. Latest model runs have moderated those CIGs to VFR instead
within that WAA area. 23.12 ECMWF model sfc dew points also indicate
this wall of dry air holding the low level moisture back. RAP time
sections at SBN show a narrow layer of near surface moisture that
would normally be considered for adverse flight conditions, but the
rest of the guidance seems to be going in the other direction. Will
side with the majority of the guidance at this point and lean VFR,
but will brief the next shift of the RAP time section character so
they can interrogate that again. Expect high CIGs to low to mid
level by the end of the TAF period as the chances for rain become
higher, but rain likely waits until after 00z Monday evening.

Winds, initially out of the NW, back S`erly early in the TAF period
and remain generally out of that direction through the rest of it.
Peak heating midday Monday may allow for a period of 10 kt sustained
winds, but shallow mixing due to a 925 mb inversion restricts gusts
to below 20 kts for the bulk of the period.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...None.

&&

$$

DISCUSSION...Fisher
AVIATION...Roller