634
FXUS63 KIWX 290608
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
208 AM EDT Wed May 29 2024

.KEY MESSAGES...

- Cool conditions with periodic showers and thunderstorms will
  continue tonight into Wednesday, best chances in the morning.

- Dry weather is expected Thursday and Friday but more rain
  chances increase this weekend into next week.

&&

.UPDATE...
Issued at 1038 PM EDT Tue May 28 2024

Line of mainly sub-severe convection (winds to 40 mph and small
hail) along a low level trough is finally beginning to weaken as
it nears the IN/OH border. One cell in northeast Jay Ct IN did
briefly take off with accumulating quarter size hail and a
reported wall cloud. Otherwise showers and embedded thunder
will focus more into north/northeast zones overnight before
shifting back to the southeast Wednesday morning as the system
deformation/fgen axis pivots south. Forecast in good shape
otherwise with minor tweaks to hourly temps/PoP.

&&

.DISCUSSION...
Issued at 229 PM EDT Tue May 28 2024

A broad trough and collocated cold temperature anomalies over the
Great Lakes shifts eastward between this evening and Thursday
bringing times of showers and storms as various areas of vorticity
pinwheel through the area. After this morning`s vort max shifted
eastward, the break allowed for additional sunshine and surface
heating ahead of a second vort max for this evening between 6pm and
10pm. There is a 25 to 30 kt low level jet that passes by to our
southeast, but that`s fairly weak for shear for storms to tap into.
Given windows of mid level lapse rates between 6 and 7 C/km can see
hail as a possible storm hazard as well as wind with moisture loaded
microbursts. SPC`s marginal appears warranted as despite the weak
shear, perhaps a storm or two could put out outflow boundaries that
could aid downstream storms. These showers and storms are expected
to linger into tonight, but the severity of such storms is expected
to die off. Showers and storms are also expected to continue into
Wednesday as the main vort max shifts slowly eastward around the
base of the trough. Negative theta-e pushes into the area behind an
instability trough during the afternoon Wednesday, but shear is
expected to be lacking. Instability driven thunderstorms will be
capable of gusty winds and locally heavy rain during this time.
Finally, one last vort max slides through east of I-69 on Thursday.
At this point, expect much drier conditions with dew points back in
the 30s and 40s. Surface high pressure is quick to follow allowing
for drier conditions across a good chunk of the forecast area.

Friday comes with the greatest confidence of an all clear call with
surface high pressure overhead and sliding eastward through the day.
With the high pressure center just east of the forecast area later
Friday, expect warm air advection to ensue and bring us back up to
the mid 70s for highs after being in the upper 60s and low 70s in
the days prior.

A couple of days ago, this ridge was much broader, but an area of
low pressure is expected to eject into the Southern Plains Friday
and infringe on its western periphery. A strung out area of
vorticity is located on the western periphery of the mid level ridge
and this is expected to slowly trek towards the area somewhere
between very early Saturday (ECMWF camp) and Saturday afternoon (GFS
camp) bringing a renewed chance for showers and potential
thunderstorms.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 201 AM EDT Wed May 29 2024

Predominantly MVFR to VFR conditions expected at the TAF sites
this period. The only exception will be this morning where we
have some IFR ceilings/visibilities associated with the cold
front. Expect we could see some 700 ft ceilings (as there are
upstream) and visibilities around 2-3 miles at times. Once the
front passes, expect improvement to VFR (11/12z KSBN, then more
like 15z at KFWA).


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Beach Hazards Statement through this evening for INZ103.
OH...None.
MI...Beach Hazards Statement through this evening for MIZ177-277.
MARINE...Small Craft Advisory from 8 AM this morning to 11 PM EDT this
     evening for LMZ043-046.

&&

$$

UPDATE...Steinwedel
DISCUSSION...Roller
AVIATION...MCD