213
FXUS63 KIND 210801
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
301 AM EST Fri Nov 21 2025

.KEY MESSAGES...

- Dense fog through mid morning focused mainly across the northern
  half of central Indiana

- Rain will expand across the area from the southwest today

- Additional rainfall early next week with much cooler weather
  likely post-Thanksgiving

&&

.SHORT TERM (Today and Tonight)...
Issued at 300 AM EST Fri Nov 21 2025

Continued dreary conditions can be expected through the period as a
persistent subsidence inversion aloft and warm air advection beneath
it allows a low-level stratus deck to remain in place. Latest
observations show ceilings and visibilities have improved gradually
through the day as temperatures have slowly warmed. Unfortunately,
this improvement will only be short-lived as ceilings and
visibilities drop again overnight.

Latest guidance has trended drier overnight especially across the
northern half of the area. Forecast soundings show the subsidence
inversion strengthening over the north slightly with winds becoming
very light or even calm at times. This and very small dewpoint
depressions will quickly promote fog development into the overnight,
potentially dense. Patchy drizzle is also possible thanks to
marginal forcing. Guidance shows subsidence slowly increasing aloft
overnight across the south as well. However, greater PBL moisture
and slightly stronger forcing supports better chances for drizzle
and the development of light showers. The higher chances for light
precipitation over southern counties leads to lower confidence in
coverage or duration of fog overnight.

Model guidance depicts the aforementioned subsidence inversion
weakening with increasing isentropic ascent during the day Friday.
This will lead to greater coverage of showers as the day goes on.
Showers should help clear out fog through the morning. Cannot rule
out fog lingering through midday across the north if showers move in
later than expected. Blended guidance has been far too warm with the
stratus deck overhead which has limited the diurnal temperature
swing significantly. High temperatures today and tomorrow were
trended lower than the NBM. Look for lows to generally range from
the mid 40s to near 50F tonight while highs Friday mostly remain in
the low 50s.

&&

.LONG TERM (Saturday through Thursday)...
Issued at 300 AM EST Fri Nov 21 2025

Seasonably mild and dry weather is expected over the weekend as the
recent quasistationary front is finally moved out of the region by
the system expected to bring rain to the area today.

The next rainmaker for the area is the closed low currently over the
West Coast, which will gradually shift northeastward and may phase
with a northern stream upper level disturbance as both promote lee
cyclogenesis over the central Plains, with the resultant surface low
moving quickly into the Great Lakes early to mid next week. This
system will bring another round of rain to the area as late Monday,
with the most significant rain chances Monday night into early
Tuesday.

Depending upon the intensity of the upper low/trough, there will be
some low potential for lingering rain as late as Tuesday night into
Wednesday, but these chances are far more uncertain at this point.

What is more certain is that a fairly substantial cooldown is likely
for Thanksgiving and beyond, though the exact magnitude of the
colder conditions remains to be seen. At the moment, highs in the
30s and lows in the 20s and perhaps upper teens appear likely.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 1216 AM EST Fri Nov 21 2025

Impacts:

- Widespread IFR/LIFR conditions through tonight
- Rain overspreading the terminals predawn hours through the morning

Discussion:

Very poor flying conditions will continue through the duration of
the forecast period as moisture remain trapped in the near surface
layer beneath an inversion. Ceilings hovering early this morning at
or below 500ft and expect that to continue along with the expansion
of dense fog at times through and beyond daybreak. Rain will expand
into the region first reaching KHUF and KBMG in the predawn hours
then the other terminals through the morning.

Widespread rain is expected to last into tonight with the potential
for the heaviest rainfall at KBMG. The onset of rain should flush
out the dense fog and may help bump up ceilings slightly during the
day...but IFR and lower conditions will persist. Near calm winds
through daybreak will shift to E/NE at 5-7kts this afternoon.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory until 10 AM EST this morning for INZ021-
028>031-035>049-054>057.

&&

$$

SHORT TERM...Ryan
LONG TERM...Nield
AVIATION...Ryan