629
FXUS63 KIND 241040
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
540 AM EST Mon Nov 24 2025

.KEY MESSAGES...

- Areas of fog this morning with dense fog focused across the
  southwest half of central Indiana

- Rain expected tonight through Tuesday night

- Turning colder beginning Wednesday into next weekend

- Watching Saturday into the following week for strong storm systems
to bring rain, snow, and large temperature swings to Indiana

&&

.SHORT TERM (Today and Tonight)...
Issued at 257 AM EST Mon Nov 24 2025

A shallow stratus deck with dense fog continues a slow northward
expansion across south central and southwest Indiana while skies
were mainly clear elsewhere with pockets of fog. 07Z temperatures
ranged from the upper 20s over the north to near 40 in the lower
Wabash Valley.

High pressure remains over the area early this morning but will move
off the Mid Atlantic coast by this evening as developing low
pressure ejects out of the Rockies and kicks east into the southern
Plains. The low will pivot northeast into the Ohio Valley by Tuesday
morning with rain becoming widespread tonight.

The first issue for the short term focuses on the fog and stratus
ongoing across the southwest part of the forecast area. The
northward expansion has been slow to this point but RH progs in the
975-950mb layer suggest deeper moisture gradually encompassing the
southwest half of the forecast area after daybreak underneath a
shallow but very strong inversion. With this in mind...expect lower
ceilings and areas of fog to lift north slowly as well over the next
few hours. At this point...the Dense Fog Advisory covers the
situation nicely with no plans to expand with the morning forecast
package. Would prefer instead to monitor trends through the predawn
hours and add counties as needed based on observations and webcams.
Visibilities should improve through mid morning as winds increase
within the near surface layer and the inversion weakens.

Thin high level clouds are already moving into the forecast area
from the west early this morning and will continue to overspread and
thicken through midday. The weakening of the inversion and
increasing mixing through the boundary layer should lead to a
gradual decrease of the low stratus deck over the lower Wabash
Valley but it may take the first half of the day to largely
diminish. Continued influx of moisture aloft into the region will
lead to a gradual thickening and lowering of clouds through late day
with minimal sunshine largely confined to the morning across the
northeast half of the forecast area.

The arrival of broader isentropic lift this evening in advance of a
strengthening low level jet will lead to top down saturation and the
onset of rain from southwest to northeast through the evening. Rain
will become widespread overnight as the low level jet noses into the
Ohio Valley with the potential for up to a half inch of rain along
and south of I-70 by daybreak Tuesday. Lighter amounts are expected
over northern portions of the forecast area further away from the
stronger low level jet.

Temps...temperatures remain a bit tricky for today and are dependent
on how quickly the low clouds erode. Nudged highs down over the
lower Wabash Valley especially into the lower 50s with mid 50s
expected elsewhere. Lows tonight will drop little with the clouds
and rain as most locations hold in the upper 40s.

&&

.LONG TERM (Tuesday through Sunday)...
Issued at 257 AM EST Mon Nov 24 2025

An active weather pattern continues next week with numerous systems
bringing large temperature swings, rain, and windy conditions to the
state.

Tuesday...

Weak troughing lifts northeastward into the Great Lakes Monday night
while a jet streak overhead and an increasing low and mid level jet
bring moisture northward into the state. The best moisture
convergence is currently expected to remain south of central
Indiana, however, modest isentropic lift within the strengthening
LLJ support widespread rainfall early Tuesday morning with lingering
showers through the day. Mid-level moisture will be minimal
throughout, but strong upper level support and saturation above
500mb could lead to high rain rates at times. Generally, QPF totals
for this event are likely to remain below 1 inch with most areas
below 0.5 inches, highest rainfall amounts likely south of I-70.

Southwesterly flow persists behind this initial system as a much
stronger trough and associated low develop over the Northern Plains
and Upper Great Lakes. With the cold air locked up north behind the
next system and a warmer airmass still overhead, high temperatures in
the mid 50s to low 60s are expected despite clouds and showers.

Wednesday through Friday...

A significant pattern shift arrives the day before Thanksgiving as a
strong trough to the north and associated front usher in an arctic
airmass over the entire region. The front pushes through the state
early Wednesday morning, but the lack of moisture behind the
pressure trough passage earlier on Tuesday will limit rain shower
coverage along the boundary. Despite only isolated to scattered
showers signifying the front, the temperatures disparity along this
frontal axis will be large, with temperatures quickly falling 10-15
degrees within a few hours from the low 50s to upper 30s early
Wednesday morning.

Steepening low level lapse rates as much colder air advects in aloft
along with a strong 30-40 kt low level jet will make for a cold and
windy day. West northwesterly winds 15-25 mph with gusts over 35-40
mph are likely...stronger gusts may be possible. Lower confidence in
the temperature forecast for Wednesday as guidance may not be
handling the set up well as temperatures may not follow a typical
diurnal pattern. High temperatures may be reached early in the day
before the front, with steady or falling temperatures in the 30s
during the afternoon and evening. Wind chill values will likely
remain below freezing all day, dropping into the teens by Wednesday
night. Not too concerned with wintry weather at the moment as enough
dry air should be advecting in, limiting snow showers within the
cyclonic northwest flow pattern; however would not be surprised to
see on and off flurries.

Winter-like temperatures and breezy conditions persist Thanksgiving
and Friday as strong northwesterly flow keeps an arctic airmass
entrenched over the region. While conditions will be fairly dry,
high temperatures may struggle to get above the freezing mark while
wind chill values stay in the teens and 20s.

Next Weekend into Early December...

Confidence is increasing in a significant storm system and strong
baroclinic zone developing next weekend and into the first week of
December, setting the stage for an active period with widespread
precipitation and large temperature swings. Long range guidance has
been consistent in showing an active southwesterly subtropical jet
across the Central and Southern CONUS in response to a sharpening SW
to NE temperature gradient setting up from the Plains to the Great
Lakes. This classic winter-time pattern can bring widespread heavy
rain, snow, and storms to a large portion of the CONUS. While
confidence is low on the specifics and exact evolution of mesoscale
and synoptic scale features, confidence is increasing in this
pattern developing with Central Indiana within or near the main
storm track.

The set up for Saturday is fairly complex as longer range guidance
indicates a weak trough approaching from the northwest within the
northern branch of the jet, while the subtropical jet increases
southwesterly flow aloft through the Ohio Valley. Interactions from
both the northern and southern branches of the jet can result in
favorable set up for snow. Flow becomes southerly going into
Saturday as a surface low tracks across the Midwest into the Great
Lakes with sufficient moisture advection northward with a 30 kt LLJ
overhead. Deeper cold air in place from the previous few days may
take a while to retreat northward, setting the stage for a quasi
overrunning event where warmer moist air overruns a cold, denser
airmass at the surface. While confidence is lower in the finer
details of this set up and the overall evolution and track of
synoptic features, this will be a system to watch as any snow this
time of year can cause major travel impacts. Keeping snow in for the
first half of the day Saturday, transitioning to a rain/snow mix
during the afternoon, then all rain by the evening. This is an
initial forecast and details will likely change and be fine tuned
over the next several days.

The active pattern is expected to persist into the following week
with additional waves of precipitation tracking through the state
and large temperature swings. We will be monitoring this timeframe
closely and updating the forecast accordingly as confidence
increases on timing, track, and impacts.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 540 AM EST Mon Nov 24 2025

Impacts:

- LIFR/VLIFR conditions in stratus and fog at KHUF through most of
the morning and potentially at KBMG as well
- Rain developing this evening with deteriorating conditions
to IFR and lower tonight


Discussion:

Dense fog and very low stratus at or below 500ft continue to impact
KHUF early this morning and will continue to do so over the next 3
to 5 hours with only slow improvement into the early afternoon. The
stratus and fog has been just to the south and west of KBMG over the
last couple hours and it remains likely that restrictions will
develop for part of the morning here as well. Ongoing patchy fog at
KLAF will improve shortly after sunrise.

Ceilings will slowly thicken and lower through the course of the day
as progressively deeper moisture in the mid and upper levels advects
into the region from the west. Ceilings will once again lower
this evening and eventually drop to IFR or lower overnight as rain
becomes widespread over central Indiana.

Near calm winds early this morning will become S/SE at near 10kts
this afternoon then weaken slightly tonight.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory until 11 AM EST this morning for INZ051>053-
060>064-067>072.

&&

$$

SHORT TERM...Ryan
LONG TERM...CM
AVIATION...Ryan