482
FXUS63 KIWX 291739
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
139 PM EDT Tue Sep 29 2026

.KEY MESSAGES...

- While it is possible spotty showers creep into areas north of
  US-6 on Wednesday, a majority of the area remains dry.

- Rain is expected late Thursday into early Friday. Around an
  inch is anticipated for most locations. No severe weather or
  significant flooding is expected.

- A warming trend takes mid to upper 70 degree high temps today
  into the 80s for areas south of US-30 by Thursday.

- Trends are towards a dry and cooler weekend which looks to
  continue into next week.

&&

.DISCUSSION...
Issued at 125 AM EDT Tue Sep 29 2026

Surface high pressure is shifting east underneath mid level ridging
and this keeps the area dry once again. One thing that does happen,
though, is that warm advection commences bringing a return to upper
cloudiness for this evening and tonight. This warm advection also
helps southern areas get into the upper 70s to around 80 degree
highs for Wednesday. This is especially the case because the
vorticity is more focused to our north and west as opposed to
overhead. The best of the instability (still less than 100
J/kg of MUCAPE) finally arrives around 00z in our northwest, but
surface dew points are still below 60F and the best forcing has
moved more northeastward instead of eastward into southwest Lower
MI. All of this to say that it is possible that rain gets into the
area Wednesday afternoon/evening, but severe weather is expected to
be limited and thunderstorm chances are low, if not non-existent.
This is why we have good chances to see those 80 degree highs on
Wednesday is that, despite cloud cover, we have limited rain chances
down south there. By the time we get to Thursday, the stalled front
to our west slides eastward slowly as a trough moves east-
southeastward across southern Canada. Later Thursday and Thursday
night is our best thunderstorm chance of this rainy period as the
NAM brings through areas of instability up to 1000 J/kg of MUCAPE.

Rain may linger into Friday morning, otherwise, the trend will be to
dry out Friday afternoon as a surface high pressure system moves in.
This dry period also looks to last a while as the later
Saturday/Saturday night rain chance doesn`t have much model
agreement at this point. So, a series of high pressure systems move
through and the area remains underneath an area of subsidence as a
result.

Highs in the 70s to around 80 today through Thursday, trend lower,
behind the cold front Thursday night, allowing for a return to highs
in the 60s and lows in the 40s for Friday through early next
week.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 129 PM EDT Tue Sep 29 2026

A mid level ridge axis maintains its influence across the
southern Great Lakes region this afternoon with weak mid level
subsidence and relatively dry low/mid level air in place. This
ridge axis will shift across the eastern Great Lakes tonight as
a mid level short wave trough ejects northeast out of the South
Dakota into the western Great Lakes. This short wave will allow
a low level front to approach the western Great Lakes
overnight, but the dampening nature of this trough will hang up
this baroclinic zone on Wednesday. Stronger isentropic ascent in
association with this boundary will be the focus for increased
potential of rain showers at KSBN toward end of this forecast
valid period. KFWA still appears to be somewhat southeast
displaced from stronger forcing and overall dampening nature of
the Great Lakes wave still leads to questions at KFWA
experiencing any precip through the day on Wednesday. VFR
conditions are expected to persist through this period with
light south winds continuing.

&&

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

&&

$$

DISCUSSION...Roller
AVIATION...Marsili