730
FXUS63 KIWX 090439
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
1239 AM EDT Thu Oct 9 2025

.KEY MESSAGES...

- Areas of frost early this morning and Friday morning.

- Temperatures warm back to near or slightly above normal this
  weekend into next week.

- Rain will remain sparse through the next 7 days.

&&

.DISCUSSION...
Issued at 216 PM EDT Wed Oct 8 2025

High pressure over WI this afternoon shifts east through time,
bringing back-to-back crisp and frosty nights. With low pressure
well off the northeast US coast, confidence is high in light wind
overnight and clear skies. Current forecast lows are on the
colder side of guidance, which, given this pattern change,
placement of the surface high, and 850mb temperatures of 2C to
4C, aiming to the cold side of guidance appears warranted. As a
result, have opted for an area-wide frost advisory. The argument
could be made that some northwest OH counties and Indiana
counties south of US 24 may not have a long enough duration of
36F, but this seems to be splitting hairs in the grand scheme.
Advisories will need to be considered again for Friday morning.

Return, southerly flow, takes place Friday but is at odds with
falling heights aloft ahead of an incoming low. This low deepens and
races across Michigan Saturday. This upper-level low is moisture
starved given its  continental polar source region. However,
guidance has been trending wetter these past couple of days as
solutions have become more amplified. Not a washout for our area,
but at least northern potions of the forecast area have a 20% chance
of showers Friday night and Saturday.

Upper-level ridging resumes in the wake of this low. High
temperatures will return to the 70s. Prospects for rain next week
remain murky and dependent on the placement and magnitude of this
upper-level ridge taking shape. In the meantime, in-house blend has
spurious slight-chance POPs near the lake.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1222 AM EDT Thu Oct 9 2025

A large surface high pressure area with a center near KAPN was
helping to keep a northeast to east flow over northern Indiana.
These winds were reflected in the SBN and FWA TAFs. The observed
and forecast soundings continue to be much too dry to support
precipitation or even clouds. Patchy shallow fog and ground fog
are possible with deep radiational cooling, but any fog is not
expected to be operationally significant at the terminals.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Frost Advisory from 4 AM EDT /3 AM CDT/ to 9 AM EDT /8 AM CDT/
     this morning for INZ005>009-012>015-017-018-020-022>027-
     032>034-103-104-116-203-204-216.
OH...Frost Advisory from 4 AM to 9 AM EDT this morning for OHZ001-
     002-004-005-015-016-024-025.
MI...Frost Advisory from 4 AM to 9 AM EDT this morning for
     MIZ078>081-177-277.
MARINE...None.

&&

$$

DISCUSSION...Brown
AVIATION...Skipper