FXUS63 KIWX 231146
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
746 AM EDT Sun Aug 23 2026

.KEY MESSAGES...

- Hazardous swimming conditions are expected on Lake MI beaches
  along Berrien Co, MI and La Porte County, IN today. Dangerous
  waves and currents are expected. Monitor the beach forecast 
  for updates. 

- Chances (20-30%) for rain showers today, with partly cloudy 
  skies and gusty northwest winds. Highs in the low-mid 70s.

- Dry tonight into Wednesday morning. Chances for showers and 
  thunderstorms (30-60%) return Wednesday afternoon and persist 
  into Thursday. Highs in the 70s, low 80s.

&&

.DISCUSSION...
Issued at 306 AM EDT Sun Aug 23 2026

The 500mb low hovering over northern Ontario will deepen and shift 
southward into the Lake Huron/Southern Ontario/Quebec area by late 
tonight, then lift slowly northeastward through Wednesday along with 
the corresponding surface low. Our area lingers under cyclonic flow 
aloft/at the surface through later tonight when surface high 
pressure builds in beneath an expanding ridge to our west. The upper 
level ridge builds in more broadly on Tuesday. A shortwave 
pinwheeling around the closed low moves through this afternoon/eve 
along with a surface trough, which will re-invigorate the stronger 
northwest wind gusts and wave activity on Lake MI (thus beach 
hazards statement/small craft remain in place until this evening 
despite the lull overnight/early AM). It will also bring us the 
potential for rain showers where deeper moisture remains and we get 
some afternoon instability (perhaps a little enhancement from cooler 
air over Lake MI). Have chances around 20-30 percent. With cooler 
850mb temps (7-10C) high temps this afternoon will primarily be in 
the low to mid 70s, warmest east of I 69. Lows tonight will be in 
the low to mid 50s. 

Dry conditions persist from tonight into Wednesday morning as a 
dampening upper level ridge moves in over the Great Lakes. Highs 
will be in the 70s, low 80s. Lows will be in the 50s. 

Another upper level trough moves through the Great Lakes Wednesday 
afternoon into Thursday night, bringing a surface low through 
northern Ontario into Hudson/James Bay. A cold front will move west 
to east across our CWA Wed afternoon into Thu, bringing us chances 
(30-60%) for showers and thunderstorms. Beyond that period, the 
upper low lingers over Hudson Bay into Saturday, eventually moving 
northeast through the weekend. Flow over our area becomes more zonal 
in this time, with potential precipitation chances with each 
shortwave rippling through. Confidence wasn't high enough to have 
any pops for Friday/Saturday, but on Sunday we see a stronger wave 
move in so have 20-30 percent chances added in. Temperatures remain 
in the mid-upper 70s, low 80s through the period.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 743 AM EDT Sun Aug 23 2026

Predominantly VFR conditions outside of any potential
shower activity this morning or afternoon. A few showers have
developed over SW Lower MI/NW IN as of this writing, likely to
impact KSBN (or be very close) within the next couple hours.
Have a tempo to account for any MVFR potential. Otherwise, NW
winds pick up this afternoon again, with potential for shower
development closer to KFWA. As mentioned in previous discussion,
models are pretty inconsistent as to where these showers pop, so
persisted with the PROB30 for now. 

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Beach Hazards Statement through this evening for INZ103.
OH...None.
MI...Beach Hazards Statement through this evening for MIZ177-277.
MARINE...Small Craft Advisory until 11 PM EDT this evening for LMZ043-
     046.

&&

$$

DISCUSSION...MCD
AVIATION...MCD