461
FXUS63 KIWX 050606
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
206 AM EDT Fri Jul 5 2024

.KEY MESSAGES...

- Chances for showers and thunderstorms persist into Friday,
  with locally heavy rain the main concern.

- More comfortable humidity levels this weekend, with only
  limited chances for showers Saturday.

- Somewhat better shower and thunderstorm chances return Monday
  into Tuesday.

&&

.DISCUSSION...
Issued at 238 PM EDT Thu Jul 4 2024

While high confidence exists on a relatively active pattern, finer
details continue to have much lower confidence due to difficulty in
timing and location of key features. Forecast emphasis will be
on the next couple of days with few overall changes expected for
the later periods.

Diffuse frontal boundary was located from southern IL to north of
IND and then towards NW Ohio. Area of light to occasionally moderate
rainfall worked north across much of the area, but a slow weakening
trend occurred as it moves away from the front and best LLJ
position. Heavier rain and thunderstorms remained south of the area
across central/southern Indiana associated with a weak disturbance.
Although earlier CAMs suggested a bit more robust development
possible late this afternoon into early evening, they seem to have
backed off, maybe as a result of the more extensive coverage of the
precip the first part of the day. MCV was working into southern IL
and will continue east, likely being the main focus for
additional development later today south of our area. With the
front in the area and pockets of heating, mainly SE, can`t rule
out some additional showers/storms popping that would produce
mainly locally heavy rain. Pockets of clearing upstream across
central IL are allowing for some new shower development. Models
seem to suggest after 3Z little or no chance for development
until maybe closer to Fri morning as the main trough begins to
edge in to western areas. Pops also adjusted accordingly with
any likely mention overnight removed. Lift from the front and
plenty of moisture around should allow for isolated to maybe
scattered showers/storms through late Friday afternoon along and
ahead of the front. Shear parameters aren`t bad as is some
cooler air aloft. However, better severe chances should remain
east of the area.

Bulk of the weekend could end up dry with maybe just a few light
showers Saturday as the main trough pushes NE and heights increase
somewhat before the next trough early next week. Some models show a
weak disturbance Saturday that could still bring a few showers, but
CAMs don`t seem overly impressed at this point. Typical early July
temps can be expected with highs in the low to mid 60s with
dewpoints remaining in the mid to upper 50s, making for a
comfortable holiday weekend.

Next deeper trough edges toward the region late Monday into Tuesday
with chances for showers and storms increasing with this feature.
Moisture return will occur ahead of the trough, but conservative chc
pops will be maintained at this point.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 155 AM EDT Fri Jul 5 2024

Quite a pot-pourri of conditions this forecast period, starting
with BR/FG troubles for the first half (MVFR to IFR likely,
possibly LIFR at KFWA), and then showers/storms this morning
and afternoon.

Visibilities around the area as of this writing range from 1/4
mile all the way up to 10 miles, likely thanks to firework
smoke and low level moisture trapped beneath the inversion.
Skies are clear in many locations as well, helping to radiate
better with the calm winds. However, a majority of the sites as
of the latest observations have 1/4 to 4SM visibility. KSBN and
KFWA have fluctuated between around 2 miles and 6 miles, and
suspect it will bounce around until sunrise. At KFWA I suspect
we have the better potential to drop to around 1 mile or even
less towards 12z, so have tempos in for that.

Otherwise our first round of possible showers would be this
morning as a decaying line of showers and storms moves into the
area. All but one of the models suggest the showers will die
before reaching KFWA, but most have it reaching KSBN (albeit
much weaker). Left thunder out for now as we`ll really be
struggling for instability-will monitor lightning trends and
adjust as needed. Later in the afternoon showers and storms are
possible, but most of the guidance keeps the better potential
east of KSBN, but KFWA looks to see showers and storms in the
18-00z window. MVFR to VFR conditions are most likely in
thunderstorms, with the occasional drops to 2SM (IFR) possible
in heaviest showers/storms.

&&

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

&&

$$

DISCUSSION...Fisher
AVIATION...MCD