940
FXUS63 KIWX 022304
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
704 PM EDT Sun Jun 2 2024

.KEY MESSAGES...

- Dry and slightly less humid through Monday.

- Low confidence chances for showers and thunderstorms Monday
  night into Tuesday.

- More widespread showers and thunderstorms Tuesday night into
  Wednesday.

- Cooler with lingering showers Thursday into the weekend.

&&

.DISCUSSION...
Issued at 300 PM EDT Sun Jun 2 2024

An overall active pattern is expected through the forecast period
with brief lulls in between each key feature.

A "cool" front has nearly cleared the forecast area with
dewpoints in the upper 50s to around 60 in its wake and low to
mid 60s ahead of it. Cloud cover has been stubborn to depart
even with increasing subsidence. Sufficient convergence and
modest instability has allowed for a few showers to develop in
far southeast area which will quickly exit by 4 pm. The cloud
cover sticking around leads to a more uncertain forecast in
whether fog will develop across the area. Considered adding a
patchy fog mention given cross-over temps should be exceeded and
plenty of low level moisture remains. Will defer to the evening
shift to monitor trends.

A northern stream closed low, currently located off the NW US coast,
will move east through the first half of the week, brining an
eventual shift in our pattern. Prior to that, shower/storm chances
will be modulated by poorly modeled, subtle disturbances that may
largely be convectively induced (MCVs). Greatest plume of higher
theta-e air will reside just to our west with the nose of it
intruding on far NW areas Monday evening before spreading slowly
east Tuesday. Models handle convective chances in multiple ways,
none of which seem to suggest more than chc pops Mon night into
Tuesday with no threat for severe weather.

Models are in agreement on the aforementioned upper level low moving
to northern ND by 00Z Wed with the longwave trough digging further
into Great Lakes by 18Z Wed. The closed low itself will actual
shift northward somewhat, keeping the strongest dynamics well
removed from the area. A cold front is still expected to sweep
through Tuesday night into Wednesday with good chances for what
should be non-severe showers and thunderstorms. Abundant
moisture will lead to pockets of heavy rainfall with hydro
trends needing to be monitored.

Beyond Wednesday, medium range models then diverge on handling of
the southward shift of the upper low over the Great Lakes through
the remainder of the period. These discrepancies are posing
challenges in not only forecasted temperatures but timing of
periodic shower chances. The result is a splattering of slgt chc to
chc pops through the end of the forecast with highs near or below
normal.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 655 PM EDT Sun Jun 2 2024

With both TAF sites now behind the cool frontal passage, winds
have trended lower and cigs have begun to lift and KSBN already
has clearing skies. With better radiational cooling conditions
and still fairly moist low levels, dew points in upper 50s
currently, overnight even with some drier air moving into the
region dew point depressions will be small. Some patchy ground fog
will be possible overnight and did continue to message vsbys
down to around 3SM in mist. However, confidence in coverage is
lacking. VFR conditions expected after 13-14z Mon for both TAF
sites.

&&

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

&&

$$

DISCUSSION...Fisher
AVIATION...Andersen