483
FXUS63 KIWX 231827
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
227 PM EDT Sun Jun 23 2024

.KEY MESSAGES...

* Cooler and less humid into tonight and Monday.

* A couple rounds of convection possible Tuesday into Wednesday,
  best chances Tuesday afternoon into Tuesday night when there is
  the potential for severe weather. Confidence is low.

* Hot and humid conditions may briefly return on Tuesday, dependent
  on clouds and storm coverage.

&&

.DISCUSSION...
Issued at 227 PM EDT Sun Jun 23 2024

Drier and cooler air will continue to advect into the area this
afternoon into this evening behind a cold front, with Monday looking
spectacular with low humidity and ample sunshine. A compact, potent
shortwave will drop southeast through the central and eastern Great
Lakes late this afternoon into this evening, possibly bringing a few
light showers or sprinkles to northern portions of the area during
this time.

The forecast late Monday night through Tuesday night becomes less
clear as a theta-e ridge folds into the southern Great Lakes on the
southern fringe of perturbed westerlies. For later Monday night and
Tuesday morning, will have to monitor the track of a potential
upscale growing MCS across northern WI. Layout of instability axis
advecting east into IL and western IN, and the orientation of the
LLJ into the developing convective system, does suggest a more
southeast trajectory of a weakening MCS into the local area (1). On
the other hand, later development of the MCS, or less organization,
could lead to a miss north during the Tue AM hours (2). Which
solution verifies will dictate what occurs Tuesday afternoon into
Tuesday night. (1) would feature more cloud cover and cooler temps
with the potential for renewed convection along the leftover
composite outflow, which could be positioned south of the area by
peak heating Tue. (2) would lead to a mainly dry/hot Tuesday (heat
indices 95-100F) with a separate convective system (potentially
severe, locally heavy rain) dropping through near a sfc cold front
late Tuesday afternoon into Tuesday night. Lots of bust potential
regarding PoPs/temps/sky/etc in the grids given the dependence of
where and when convection occurs. Stay tuned to future forecasts
with severe storms and dangerous heat both in play.

Wednesday into Thursday does appear to be a little more straight
forward. A more pronounced shortwave tracking through the Great Lakes
will give a synoptic push of any cold front or composite outflow to
the south Wednesday afternoon/night. Did retain a chance PoP for
convection along this front on Wednesday, with Thursday looking
similar to Monday with high pressure in control. The pattern Friday
into Saturday could once again become periodically active given the
progressive flow pattern and next surge of moisture into a
developing frontal system.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 120 PM EDT Sun Jun 23 2024

The weak cold front has moved southeast of FWA with ample post-
frontal low clouds and lingering light precipitation well behind
the cold front over northern Indiana. Made some adjustments for
more persistent clouds and light precipitation based on
satellite, surface & radar obs & trends. It looks like the HRRR
and RAP have initialized this activity reasonably well. Clouds
should decrease and winds should become light by late evening.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Beach Hazards Statement until 5 PM CDT this afternoon for
     INZ103.
OH...None.
MI...Beach Hazards Statement until 6 PM EDT this evening for MIZ177-
     277.
MARINE...Small Craft Advisory until 6 PM EDT this evening for LMZ043-
     046.

&&

$$

DISCUSSION...Steinwedel
AVIATION...Skipper