213
FXUS63 KIND 221848
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
248 PM EDT Thu Oct 22 2026

.KEY MESSAGES...

- Dry yet pleasant fall weather continues through early next week
  seasonably cool early mornings, above normal afternoon highs.

- Patchy fog will occur in low lying areas late night/early mornings
  through Sunday morning.

- A wetter pattern may take shape late next week/Halloween weekend.

&&

.DISCUSSION (This evening through Thursday)...
Issued at 248 PM EDT Thu Oct 22 2026

Tonight through Sunday...

A broad area of surface high pressure remains centered over Ontario
Canada. A surface ridge axis extends southward into the Gulf
shunting deep moisture well south of central Indiana. Meanwhile,
widespread sinking motion on the eastern edge of upper ridging over
the plains will continue to support mostly clear skies.
Reinforcements to the ridge of surface high pressure will occur as
additional shortwave energy dives southward into the eastern
seaboard through Sunday. As a result several more days of very
quiescent weather is expected for central Indiana, with highs in the
low to mid 70s and light winds. Clear skies, a dry airmass and
fairly long nights will continue the stretch of large diurnal temp
swings with lows in the low-mid 40s. More late night/early morning
patchy fog is also expected in low-lying and traditionally colder
spots thanks to ideal radiational cooling conditions.

Monday through Wednesday...

Upper ridging will breakdown over the MS valley as shortwave energy
from the western CONUS trough moves eastward into the plains on
Monday. Despite increasing high cloud cover, guidance may be
underdoing high temps on Monday, given max thickness values in the
mid 560s. Although some increasing ascent will occur as the
deamplifying shortwave trough approaches the MS valley and central
Indiana on Tue/Wed, only an increase in mid level clouds is
expected. The surface ridge axis will remain well entrenched over
the Gulf, effectively cutting off any moisture return despite
southerly BL flow developing. The biggest change to the weather
besides the increase in cloud cover will be increase in overnight
lows to upper 40s/low 50s Tuesday and Wednesday mornings.

Thursday and Beyond...

Medium range models are in less agreement with the extended period
with main differences centered on phasing between shortwave
energy moving southeastward through Canada and an upper low/trough
over the PAC NW moving eastward towards the northern plains. As a
result, the timing of precip is in question. In line with the
GFS/GEFS members, the NBM has negligible PoPs through Friday but
then opens up the gates for the weekend. While the Op Euro/Euro-
AIFS and the GFS-AI have a frontal boundary generating precip
across the area on Thursday. Beyond the forecast time period
uncertainty grows but there is an increasing composite signal for
wetter than normal weather beginning around Halloween into early
November.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1226 PM EDT Thu Oct 22 2026

Impacts:

- IFR visibility in patchy fog outside of KIND early Fri morning

Discussion:

Another perfect flying day across central Indiana with light winds
of 5 kts of less, generally from the NE, and clear skies. High
pressure remains the dominant feature both at the surface and
aloft.

With clear skies and light winds, another night of patchy fog is
expected. Given occurrences of IFR conditions this morning, see no
reason to deviate for a similar occurrence to happen at KBMG, KHUF
and KLAF Friday morning before 12Z.


&&

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

$$

AVIATION...Crosbie
DISCUSSION...Crosbie