499 
FXUS63 KIWX 201105
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
705 AM EDT Mon Oct 20 2025

.KEY MESSAGES...

- Showers at times through Saturday, mainly north of Highway  
  30.

- Cold Wednesday through Friday with early morning frost likely.

- Freezing temperatures possible, especially Thursday night.

&&

.DISCUSSION...
Issued at 1220 AM EDT Mon Oct 20 2025

An upper level low will move into the Great Lakes region and bring 
active weather including clouds and showers through Thursday. 
Much colder air will be accompany this system. 850 temperatures 
will drop to as low as -3C over Lake Michigan into northwest 
Indiana and far southwest Lower Michigan. Chances for lake 
enhanced showers are less favorable with a short lake fetch. 
However, very large delta T values are expected given the 
latest GLERL Lake Michigan water analysis with surface water 
incredibly warm for late October. Lake Michigan water temps were
usually only around 13C for this time of year. Delta T values 
should exceed 20C and be favorable for instability showers. 

The upper low will bring very chilly Canadian air into the
region. Low temperatures are expected to fall into the 30s
Wednesday and Thursday night when there will be a good chance 
for frost. Will continue to highlight frost and freezing 
concerns for this time in the Hazardous Weather Outlook 
product. The growing season remains active south of the 
Michigan border where frost and/or freeze headlines will likely 
be issued later this week as the cold weather draws near.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 648 AM EDT Mon Oct 20 2025

VFR conditions expected through the TAF period. Clear skies will
give way to lowering cigs after 00z Tue with a disturbance
moving across the region. Cigs down to around 5 kft for KSBN 
and down to around 8 kft for KFWA after 06z Tue. Light rain 
showers will accompany this disturbance but current thinking is
the better chance for the showers will be for KSBN. Did mention
showers in vicinity for KFWA and a few sprinkles would not be
out of the question but the drier air further south looks to
minimize showers being realized at surface. Southerly to
southwest winds will pick up through the period with gusts up to
around 20kts.  

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...Small Craft Advisory until 8 AM EDT this morning for LMZ043-
     046.

&&

$$

DISCUSSION...Skipper
AVIATION...Andersen