798
FXUS63 KIWX 200923
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
523 AM EDT Wed Aug 20 2025

.KEY MESSAGES...

-  There is a High Swim Risk for southeast Lake Michigan beaches
   today. A Beach Hazards Statement remains in effect through
   this morning for northern Berrien County and through early
   Thursday morning for southern Berrien County and La Porte
   County.

- Expect much less humid conditions and seasonable conditions
  for the remainder of the week. Dry aside from a slight chance
  (20% or less) for rain on Saturday.

- Cooler conditions arrive for late weekend into early next
  week. Highs in the low 70s and lows in the 40s are possible.

&&

.DISCUSSION...
Issued at 242 AM EDT Wed Aug 20 2025

After several weeks of above normal temperatures and very humid
conditions, we are finally getting a break! Hot and humid days are
behind us, at least for the next 1-2 weeks. A few sprinkles will be
possible early this morning before daybreak as a trough pivots
through but much of the day will be dry. In fact, surface high
pressure over the upper Great Lakes region will allow for seasonable
temperatures and dry conditions to persist across the area this
week. Northerly flow will usher in a much more comfortable airmass;
expect dewpoints in the low to mid 60s (so still a bit humid but
definitely nowhere near as uncomfortable as it has been in recent
weeks) and highs only in the upper 70s to low 80s over the next
several days. Diurnally-driven northeast winds will gust to 15 to 20
mph this afternoons and evening before subsiding after sunset.

In the wake of yesterday`s cold front, hazardous swimming
conditions have developed on Lake Michigan. A Beach Hazards
Statement is in effect until 11 AM ET today for northern Berrien
County and until 5 AM ET/4 AM CT Thursday, August 21st for
southern Berrien County and La Porte County. As winds become
more northeasterly today, the highest waves and dangerous
swimming conditions will shift towards the southern end of Lake
Michigan, which is why the Beach Hazards Statement will end
sooner for northern Berrien County. Waves of 3 to 5 feet are
expected today alongside strong rip and structural currents near
New Buffalo, MI and Michigan City, IN. A strong north to south
longshore current is also expected. With lifeguards at many
southeastern Lake Michigan beaches done for the season, use
extreme caution around the water and on piers! Stay out of the
water and heed beach flags and warning signs!

Our only chance for rain in the next 7 days is a very low chance
(20% or less) during the day on Saturday. Uncertainties remain but
it is possible that the forecast area remains dry on Saturday
dependent on how much (if any) forcing and moisture accompanies this
front. There does appear to be (per RAP and GFS soundings),
decent instability and speed shear on Saturday with the front.
Given that cold air behind the front will be moving over the
warm waters of Lake Michigan, there could be some waterspout
potential later Sunday into early Monday as a trough pivots
through. 850 mb temps look to be around 0C during this timeframe and
lake temperatures are still in the low 60s.

Grab your pumpkin spiced lattes, sweaters, and get ready to open up
some windows as big changes are ahead by early next week! After the
cold front comes through Saturday, much cooler air filters in behind
it to end the weekend and begin the new work week. There is high
confidence that this will be a taste of true fall-like weather;
temperatures will be 10+ degrees below normal. Highs in the low 70s
and lows in the 40s are possible for several days next week!

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 149 AM EDT Wed Aug 20 2025

MVFR cloud decks abound over MI, IN, and NW OH which should
improve by later Wed afternoon/evening. Outside of a clearer
patch just west of KFWA, ceilings are generally 1000-3000 ft,
with a few sporadic BKN005-BKN009 reports (more of them over
central Lower MI). For now think KSBN will linger around
1500-2500 ft through the period, and then KFWA as well but with
the potential for a brief IFR stint if the lower patch sinking
southward stays at present levels. As of this writing, K62/KANG
are reporting 1000ft, and KIRS/KJYM/KDTL/KRMY are all between
700-900. Have a tempo for around 1000 until 9z, when I have bkn
1000. It`s possible we see 700 feet, but held off. Will amend if
I suspect they make it south (Only the NAM in guidance has this
low). N-NW Winds shift to the N-NE overnight into Wed.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Beach Hazards Statement through late tonight for INZ103.
OH...None.
MI...Beach Hazards Statement through late tonight for MIZ277.
     Beach Hazards Statement until 11 AM EDT this morning for
     MIZ177.
MARINE...Small Craft Advisory until 2 AM EDT Thursday for LMZ043.
     Small Craft Advisory until 5 AM EDT Thursday for LMZ046.

&&

$$

DISCUSSION...Johnson
AVIATION...MCD