867
FXUS63 KIWX 310637
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
237 AM EDT Sun Aug 31 2025

.KEY MESSAGES...

- Seasonable and dry today through Tuesday. Highs near 80 degrees.

- Big changes are ahead by midweek! A strong cold front will
  sweep through Wednesday afternoon through early Thursday,
  bringing chances for rain/storms and much cooler temperatures.

- Highs only in the 60s Thursday and Friday with near record lows
  well into the 40s.

- There is a Moderate Swim Risk for Lake Michigan Beaches in
  Berrien County, MI on Wednesday. There is a High Swim Risk for
  both La Porte County, IN and Berrien County, MI on Thursday.

&&

.DISCUSSION...
Issued at 236 AM EDT Sun Aug 31 2025

With surface high pressure overhead, expect dry conditions to
persist over the next several days. Mostly clear skies will allow
for increased insolation today, which will boost temperatures up
into the upper 70s to near 80 degrees. Given antecedent dry
conditions, diurnal temperature spreads will be around 30-35 degrees
with lows falling back into the mid to upper 40s tonight into early
Monday morning under clear skies. To usher in the unofficial end of
summer and begin meteorological fall, Labor Day will be very similar
to today. Highs will be near 80 degrees area-wide on Monday with
comfortable humidity and mostly clear skies. Enjoy the holiday
weekend!

Big changes are ahead by midweek! For those awaiting another taste
of fall, get your sweaters, flannels, and pumpkin spice lattes ready
for Thursday! High temperatures will drop over 20 degrees between
Wednesday and Thursday. An area of low pressure will drop into the
Upper Great Lakes on Wednesday from western Ontario, with the
system`s attendant surface cold front and upper level trough
extending throughout the Midwest. The strong cold front will sweep
through the forecast area Wednesday afternoon through daybreak
Thursday morning, bringing chances for showers and maybe even a
rumble of thunder or two. Increased moisture out ahead of the front
(dewpoints in the low 60s) may allow for a few prefrontal showers
during the day Wednesday before the highest precipitation
chances arrive with the front on Wednesday evening. As the upper
level trough pivots through on Thursday and with a tight
pressure gradient along and behind the front, expect gusty winds
to accompany the sharp temperature drop late Wednesday into
Thursday. With persistent northwest flow on Thursday and Friday,
temperatures will only make it to the low to mid 60s for highs!
Lows will be well into the 40s (with maybe a few low lying,
rural locations making it into the upper 30s Friday morning?
Very low confidence but something we`ll have to keep an eye on.)
It is worth noting that the GFS is much stronger than the ECMWF
as to how cold it is on Thursday and Friday and how much
temperatures can rebound by the weekend. The GFS suggests highs
could be in the 60s until early next week with the Euro
depicting a gradual return to the 70s over the weekend and into
early next week. Have stuck with the NBM for now as it seems to
be a good middle ground between the two.

Behind the strong cold front, breezy northwest winds and high waves
will develop over Lake Michigan. There is a Moderate Swim Risk for
Berrien County, MI beaches on Wednesday and a High Swim Risk for
both Berrien County, MI and La Porte County, IN beaches on Thursday.
Stay out of the water and stay off of piers/breakwalls! Strong rip
and structural currents are expected in addition to the high wave
action.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 128 AM EDT Sun Aug 31 2025

A strong ridge of high pressure remains anchored over the Great
Lakes through the period resulting in light winds. A very dry
and stable airmass will also ensure VFR conditions with just a
few diurnal 4-5kft cu expected.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...None.

&&

$$

DISCUSSION...Johnson
AVIATION...AGD