366
FXUS63 KIWX 240954
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
554 AM EDT Sun Aug 24 2025

.KEY MESSAGES...

- Periodic chances (10-40%) for showers late this afternoon
  through Tuesday morning, mainly across far northern IN and
  lower MI.

- Highs in the 70s today followed by highs only in the mid 60s
  to near 70 Monday and Tuesday.

- Beach Hazards Statement in effect through Tuesday evening for
  Lake Michigan beaches.

&&

.DISCUSSION...
Issued at 227 AM EDT Sun Aug 24 2025

A cold front is now east of the forecast area and high pressure is
stationed over the Central Plains, spilling into the Great Lakes.
Dry to begin the day before lake effect rain showers develop.
Showers are activated late this afternoon by a secondary dose of
cold air advection from from an upper-level trough currently racing
into the UP of Michigan. While fairly uniform northwest flow is
underway early this morning, moisture and forcing are weak. Thus,
the arriving trough will provide the extra oomph required for lake
effect showers. Showers will be most numerous for Michiana but could
spread as fear inland as northwest Ohio and far northern Fort Wayne,
especially by Monday.

The synoptic pattern today through at least Tuesday is characterized
by a large upper-level low over James Bay. This pattern is conducive
for not only lake effect rain showers, but waterspouts and dangerous
waves and rip currents at Lake Michigan beaches. A Beach Hazards
Statement is currently in effect and lasts through the daytime hours
Tuesday.

High temperatures bottom out Monday as a secondary Canadian low
rotates through the Great Lakes. Monday morning lows near 50 give
way to highs only in the 60s. Slight improvement by Wednesday as
this troughing pattern shifts east. As a trough arrives to the west
coast late this week, rising heights across the Midwest will allow
for gradually rising temperatures but still below normal. Aside from
lake effect, no rain to speak of this week.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 551 AM EDT Sun Aug 24 2025

Few changes made to the 12Z TAFs. By late morning into the
afternoon, winds increase with sustained speeds around 10-15
kts out of the west-northwest with gusts as high as 25 kts
(especially close to the lakeshore). VFR ceilings are expected
to persist although additional cloud cover will move in by the
afternoon and evening (aided by cooler air moving over the
warmer waters of Lake Michigan). Lake effect rain showers are
expected over much of Lower Michigan and far northern Indiana
after 21Z, although there could be showers as early as 18Z.
Have decided to put prevailing MVFR ceilings and visibilities in
the TAF at KSBN tonight given the high confidence in scattered
lake effect showers in the area tonight. Can`t rule out a stray
storm or two, but have continued to keep that out of the KSBN
TAF for now due to low confidence. KFWA should stay dry for this
TAF forecast period, but may get in on some showers beyond the
TAF forecats period during the day Monday as the lake effect
showers push inland. Expect lake effect clouds to persist
across the area for much of the overnight hours into the day
Monday. Have gone a bit more pessimistic with cloud cover this
evening and overnight with BKN instead of SCT.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Beach Hazards Statement through Tuesday evening for INZ103.
OH...None.
MI...Beach Hazards Statement through Tuesday evening for MIZ177-277.
MARINE...Small Craft Advisory until 8 PM EDT Tuesday for LMZ043-046.

&&

$$

DISCUSSION...Brown
AVIATION...Johnson