445
FXUS63 KIWX 072308
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
708 PM EDT Sat Jun 7 2025

.KEY MESSAGES...

- Showers and a few thunderstorms will develop this evening and last
  into Sunday morning. Locally heavy rainfall possible.

- Scattered showers and storms possible Sunday night (40-50%), and
  again late Monday afternoon into Monday evening (20-30%).

- Seasonable temperatures through Tuesday (highs mid-upper 70s),
  trending warmer Wednesday through Friday (highs low-mid 80s).

&&

.UPDATE...
Issued at 707 PM EDT Sat Jun 7 2025

While confidence remains high on eventual expanding area of
showers and a few storms, onset of light precip in SW counties
is a bit slower with surface obs indicating precip still back
across central IL. CAMs still seem to suggest
arrival/development of light precip in the 00-03Z time frame in
the W/SW and then expand east and north, possibly further north
than highest pops depict. Will watch trends for possible ramp up
of pops for light precip further north. Main MCV may just clip
our southern areas with the greatest focus for heavy rain
residing near this feature.

&&

.DISCUSSION...
Issued at 220 PM EDT Sat Jun 7 2025

A compact, convectively-augmented shortwave, currently over srn
IA/nrn MO, will track east through the area tonight into Sunday
morning bringing rain and chances for thunder, with some semblance
of a diabatically modified low level circulation accompanying this
feature through central IN/OH. Slow cell motion, weak MUCAPE and
respectable moisture (~8 g/kg in the 850-700 mb layer) hint at
efficient rain rates and the potential for localized nuisance
flooding in a small area near the low center. Latest guidance favors
the southern half of the IWX forecast area for higher PoPs/QPF,
though confidence on where heavier totals may materialize remains
low given the compact nature and lingering model details in handling
of low level mass fields.

Low clouds and any lingering showers should exit nw OH by Sunday
afternoon with partly cloudy and mainly dry conditions anticipated
for the afternoon. Cold frontal passage then brings renewed
shower/storm chances in for Sunday night on the leading edge of an
upper level low diving southeast toward the Western Great Lakes.
Continued to cap PoPs in the chance range during this time as the
front likely outpaces better forcing and instability. Dry slot
produces a pleasant/mainly dry Monday, though additional low chances
for widely scattered convection returns late Monday afternoon-
evening as a vort max rotates through the southern periphery of the
large western/northern Great Lakes upper low. The rest of the week
then features a trend toward warmer temperatures.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 707 PM EDT Sat Jun 7 2025

Deteriorating flight conditions still appear most likely to
hold off till near/just before 6Z at both locations with
greatest impacts likely at KFWA closest to the deeper moisture
and lift. Outside of some minor wind adjustments early overall
TAFs left untouched. Did bring in improving conditions after 15Z
at both locations with KSBN the first to likely see a return to
VFR prior to 18Z Sun.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Air Quality Alert until midnight EDT /11 PM CDT/ tonight for
     INZ005>009-012>015-017-018-022>027-032>034-103-104-116-
     203-204-216.
OH...None.
MI...None.
MARINE...None.

&&

$$

UPDATE...Fisher
DISCUSSION...Steinwedel
AVIATION...Frazier