218
FXUS63 KIWX 050640 CCA
AFDIWX

Area Forecast Discussion National Weather Service Northern Indiana
235 AM EDT Wed Jun 5 2024

.KEY MESSAGES...

- There is a marginal risk of severe thunderstorms this  afternoon
and evening, primarily along and east of I-69.

- Warm and humid conditions today give way to cooler than-normal
temperatures for much of the next seven days.

&&

.DISCUSSION...
Issued at 232 AM EDT Wed Jun 5 2024

A cold front approaching the Mississippi River this morning will
bring a marginal risk of severe thunderstorms in the afternoon and
evening along and east of I-69 (generally speaking). Damaging wind
gusts are the primary concern, followed by heavy rainfall and hail.
The timing of these storms remains about 2pm to 8pm EDT.

Showers and thunderstorms are ongoing over northwest Indiana early
this morning, associated with a MCV lifting in from Illinois, aided
further by a strengthening 850-mb jet. Heavy rainfall and perhaps
strong wind gusts near 40 mph are possible (as reported over
northeast IL). Elsewhere in the forecast area will be untouched by
the time the cold front arrives in the afternoon. Temperatures
rising in the 80s with dew points near 70 degrees will permit
impressive CAPE ahead of the cold front while shear and lapse rates
are lacking (25 knots 0-6km and 6C/KM mid-level, respectively).
Coverage of storms along the cold front varies among model guidance,
likely due to the marginal environment, but guidance favors discrete
cells in our area perhaps congealing into a line across central Ohio.

Drying out for a time early in the night behind the cold front but a
a few showers may arrive later on associated with a screaming, 85-
knot jet at 500mb. Moisture transport from the Pacific is somewhat
poor, navigating significantly poleward atop a towering ridge over
the Four Corners before spilling over the Great Lakes. However, RH
remains elevated in the column through Friday, warranting at least
slight chance POPs at times as various embedded vorticity maximums
rotated around the closed low aloft. Temperature-wise, Friday looks
to be the coolest of the next seven with highs right near 70
following two distinct waves of CAA.

This upper-level low lingers over the (eastern) Great Lakes into at
least the start of next week, if not longer. This complicates the
forecast as models do not handle cut-off lows very well. Overall,
showers at times are probable paired with cooler-than-normal
temperatures for June.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1241 AM EDT Wed Jun 5 2024

Scattered convection, associated with an upper level
disturbance, will lift through the KSBN vicinity later tonight
with brief vis/cig restrictions possible. A few showers could
clip KFWA toward daybreak, though chances remain on the low
side. A cold front then swings through KSBN midday, and KFWA
this afternoon, with additional rounds of showers/storms
anticipated along it. Mainly VFR, though MVFR ceilings may
settle in for a time later this morning, mainly at KSBN.
VFR/dry otherwise post frontal into Wednesday night.

&&

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

&&

$$

DISCUSSION...Brown
AVIATION...Steinwedel