182
FXUS63 KIWX 182356
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
756 PM EDT Sat Jul 18 2026

.KEY MESSAGES...

- Smoke from Canadian wildfires will continue to bring periods
  of poor air quality and reduced visibility through at least
  Monday.

- High swim risk conditions are expected along Lake MI beaches
  in Berrien County, MI and La Porte County, IN this evening
  into late tonight. Dangerous waves and currents are expected.

- Additional chances for showers and thunderstorms return Monday
  night into Tuesday.

&&

.DISCUSSION...
Issued at 1241 PM EDT Sat Jul 18 2026

Main focus of forecast remains on arrival of a cold front, set to
bring a round of strong to severe storms this afternoon and early
evening. In the wake of the front, northerly winds which will bring
cooler and less humid air as well a High swim risk for the SE Lake
Michigan beaches.

Initiation has occurred a few hours ahead of schedule with a broken
line of non-severe showers and storms from Cass county, MI west to
Chicago. SPC recently issued a mesoscale discussion highlighting
the concerns and trends for the next several hours. To sum it
up, sufficient instability (over 2000 J/KG of SBCAPE and a
narrow band of around 1000 J/KG of DCAPE) is already in place to
allow continued organization over the next several hours as
they move SSE with primarily a damaging wind threat with the
stronger storms. Sufficient low and mid level lapse rates will
allow for hail production, but freezing levels AOA 15,000 ft may
lead to increased wet microburst potential with embedded
smaller hail. Movement will be somewhat faster than yesterday,
but PWATs above 1.75" will allow for some isolated hydro
concerns, especially in isolated areas that received 2 to 7
inches of rain over the past 24 hours. Maintaining a period of
high likely pops along and ahead of the front.

The front will clear the area this evening with increasing NW winds
to bring a peak to dangerous swim conditions for all beaches along
SE Lake Michigan. Beach Hazard Statements remain in effect into
Sunday. Winds will shift more NE with time and slowly reduce the
risk Sunday night.

Cooler and slightly less humid conditions arrive behind the front as
the heat dome shifts west and we end up in a NW flow aloft which
persists through the remainder of the period. As is often the case
with these NW flow setups, one or more convective complexes are
likely to develop upstream and may move across portions of the
region. The main potential right now look to reside with a stronger
trough arriving later Monday into Tuesday which will likely bring
some showers and storms and maybe a risk of severe weather,
depending on the timing of the feature.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 752 PM EDT Sat Jul 18 2026

Predominantly VFR conditions outside of HZ/FU from Wildfires
filtering back in. Uncertain as to how low the visibility will
drop later at night, guidance suggests an initial drop to 4-6SM
(currently happening at KSBN) and then improvement back to 6SM
or greater later tonight. Expect KFWA to drop to 5-6SM at some
point (closer to 3z), based on the immediate upstream obs from
the N-NW. Otherwise, decreasing lower-mid level cloud cover
tonight, then high clouds return later on (SCT-BKN).

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Air Quality Alert until midnight EDT /11 PM CDT/ Sunday night
     for INZ005>009-012>015-017-018-020-022>027-032>034-103-
     104-116-203-204-216.
     Beach Hazards Statement until 4 AM CDT Sunday for INZ103.
OH...None.
MI...Air Quality Alert from midnight tonight to midnight EDT Sunday
     night for MIZ078>081-177-277.
     Beach Hazards Statement until 5 AM EDT Sunday for MIZ177-277.
MARINE...Small Craft Advisory until 5 AM EDT Sunday for LMZ043-046.

&&

$$

DISCUSSION...Fisher
AVIATION...MCD