177
FXUS63 KIND 162124
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
524 PM EDT Fri Oct 16 2026

.KEY MESSAGES...

- Winds gusting to between 25 and 35 mph this afternoon into tonight.

- Scattered showers mainly late this afternoon into early tonight.

- Patchy frost possible tonight, mainly sheltered locations north of
  Indy.

- Widespread frost Saturday night with sub-freezing temps possible.

- Freeze Watch issues for northeastern counties Saturday night into
  Sunday morning.

&&

.DISCUSSION (This evening through Friday)...
Issued at 301 PM EDT Fri Oct 16 2026

Cold air advection is ongoing following a cold frontal passage last
night. Temperatures have been falling through the daylight hours as
northwesterly winds gust to between 20-30 mph. Little additional
temperature recovery is anticipated and our highs for the day are
likely to have already occurred. Persistent low cloud cover will
help today feel quite miserable after the prolonged stretch of warm
weather we have seen.

Aloft, a potent but positively-tilted trough is diving in from the
north. This feature will steepen lapse rates while propelling a
secondary front southward. Lapse rates could steepen even more
immediately down wind of Lake Michigan as flow passes over the
warmer water, increasing boundary layer temps by a few degrees. A
band of scattered showers is likely this evening in conjunction with
these features. Best timing brings showers to the Lafayette area
around 5-6pm with activity reaching Indy by 7-8pm, and eventually
Bloomington by 9-10pm. Shower activity could be briefly heavy, but
overall rainfall amounts will be under a tenth of an inch.

Winds are expected to become northerly behind the secondary front.
Speeds and gusts are also expected to increase, with gusts this
evening between 25 to 35 mph possible. The upper trough departs
overnight and a quick reduction in winds appears likely tonight.
Guidance is in good agreement showing speeds dropping to under 15
mph by sunrise.

Combined with clearing skies, winds may become calm enough to allow
for patchy frost north of Indy overnight mainly in sheltered areas.
Overall, our current thinking is winds remain elevated just enough
to prevent widespread frost. As such, a Frost Advisory was not
issued for tonight. Nevertheless, we introduced the mention of
patchy frost in rural areas over the northern parts of our CWA.

As surface high pressure builds in on Saturday, the clearing trend
continues with winds becoming calm by sunset. Temperatures likely
remain suppressed somewhat due to waning cold air advection. Highs
only in the 50s are probable despite a return to sunshine. By
Saturday night, ideal radiative cooling conditions will be in place.
Temperatures in the 30s are very likely with widespread frost.
Northeastern portions of our CWA may even dip into the low 30s or
upper 20s. We have issued a Freeze Watch for these northeastern
areas Saturday night into Sunday morning. Depending on how the
surface high sets up, the Freeze Watch may need to be expanded in
further updates.

Similar conditions are likely Sunday night with areas of frost
likely, especially in rural locations.

NEXT WEEK

Ensemble guidance is in good agreement showing surface high pressure
remaining in place through at least mid next week...possibly even
the entire week. Aloft, troughing is replaced by ridging. These two
factors point towards a warming trend through next week. The warming
should be gradual, as the advective component is not there. Highs
rebound into the 70s which is a far cry from the near 90 readings we
saw a few days ago.

&&

.AVIATION (00Z TAF Issuance)...
Issued at 524 PM EDT Fri Oct 16 2026

Impacts:

- MVFR ceilings through tonight.
- Wind gusts 20 to 30 knots through 04Z.
- Rain showers possible this evening with minimal VIS impacts.

Discussion:

GOES19 imagery shows abundant cold air advection strato CU streaming
across Indiana. Radar showing some rain showers within the cyclonic
flow streaming toward IND and BMG. A moderate pressure gradient
across the area was continuing to allow gusts to 20-25 knts.

As daytime heating is lost this evening and the cyclonic flow
lessens,  winds will slowly subside and clouds should begin to show
some breaks, as seen on upstream on GOES19 over NRN IL and WI. Thus
have included some VCSH for the first few hours to account for the
approaching showers. Overnight skies will be trended to VFR as
strato cu is expected to dissipate as high pressure arrives from the
west.

Forecast soundings on Saturday continue to show a dry column as the
high pressure system arrives, leading to VFR conditions and lighter
winds.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
Freeze Watch from late Saturday night through Sunday morning for
INZ030-031-037>042-048-049-056-057-065.

&&

$$

AVIATION...Puma
DISCUSSION...Eckhoff