158
FXUS63 KIWX 021046
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
646 AM EDT Sun Jun 2 2024

.KEY MESSAGES...

- Drying out Sunday with slowly decreasing clouds.

- Frequent chances of showers and thunderstorms beginning Monday
  night.

- After a warm start to the week, it will be notably cooler by
  week`s end.

&&

.DISCUSSION...
Issued at 307 AM EDT Sun Jun 2 2024

A weak cold front is working its way through Michiana early this
morning. This feature is most visible on radar as a fine line of
showers. Behind this, dew points are falling to the 50s paired with
a northerly wind. This feature is forecast to track southeast,
likely washing out by the afternoon as ridging resumes aloft.
Otherwise, showers are departing northwest Ohio at this time
thus promising a mainly dry Sunday for the area. I say "mainly"
not only for the aformentioned fine line of showers, but because
we`ve noted intermittent drizzle at the office. This patchy
drizzle is forecast to end in the wake of the cold front.
Lastly, fog is noted in upstream observations, primarily across
the Mississippi River. This airmass arrives overhead tonight
such that fog could be a concern. Guidance is split at this
moment, so, will pass this concern to the incoming shift.

Dry weather prevails through the day Monday, amid weak zonal
flow aloft and high pressure arriving in the wake of Saturday`s
rain- maker. Over the Northern Plains on Monday, thunderstorms
are forecast to develop in the vicinity of a cold front. These
storms drift east into Illinois late in the day. This change in
timing, thanks to lingering high pressure and weak flow aloft,
has allowed me to remove POPs Monday afternoon. The chance for
showers and storms remains in the forecast after sunset,
however, but coverage is questionable. WFO Chicago and I worked
to reduce POPs during that time frame.

Convection amid weak zonal flow offers low confidence in the
coverage of showers and storms Tuesday. In the meantime, I held
close to the inherited forecast which follows a subtle diurnal curve
in POP coverage.

Following this, a deep cut-off low plagues the forecast Wednesday
through the end of the week. This will bring widespread showers and
thunderstorms Wednesday, followed by cooler temperatures. As spokes
of vorticity revolve around the low in the days that follow, off and
on showers are nearly guaranteed. Coverage is uncertain here as
well, thus POPs near 20% litter the late-week forecast.
Observed high temperatures from Monday and Tuesday in the 80s
will give way to highs in the low-70s both Friday and Saturday.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 646 AM EDT Sun Jun 2 2024

Low stratus will slowly lift through the morning with VFR
expected by mid-afternoon however confidence in the exact timing
of transitions to MVFR and VFR is not high. June sun angle will
help mixing but forecast soundings show a very deep moist layer
to erode with limited dry air advection. Fog and stratus will be
possible again Monday morning given light wind, mostly clear
skies, and residual boundary layer moisture but confidence is
too low to include at this time.

&&

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

&&

$$

DISCUSSION...Brown
AVIATION...AGD