300
FXUS63 KIWX 290748
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
348 AM EDT Sat Jun 29 2024

.KEY MESSAGES...

- Showers with scattered storms today; some storms may be
  marginally severe with strong to locally damaging winds and
  heavy rainfall.

- Dry, cooler & less humid Sunday and Monday. Highs in the 70s.

- Very warm Tuesday through Thursday (July 4th) with highs in the
80s to around 90. Chances for showers and storms each day.


&&

.DISCUSSION...
Issued at 313 AM EDT Sat Jun 29 2024

A very moist airmass was over the area with precipitable water
values topping 2.0" per SPC mesoanalysis. These values are also at
or above the climate maxes for this time of year per SPC upper air
climatology and the GEFS ensemble situational awareness table. With
deep saturation up to 300 mb per HRRR BUFKIT, this airmass will
favor very efficient rain-producer. So far since last night, rainfall
amounts have been almost exclusively under 0.60" given the fast
northeast movement of the showers (northeast at 35 mph). Weak
upper level support and a cold front will bring additional
chances for showers and storms later today into early tonight.
Surface based CAPEs will become substantial per HRRR topping
4000 J/Kg. Given a lot of instability, high precipitable water
values but more meager 0-6 Km shear, storms are expected to
become marginally severe to possibly severe from about 1 pm EDT
through the afternoon with the arrival of the upper level
support and occurrence of daytime heating. It looks like the
greatest severe weather threat will be from damaging winds. Wet
bulb zero heights appears to be too high to favor a large hail
threat.

Much cooler and less humid air will spread over the region
behind a cool front tonight. Highs Sunday will only be around
70 to 75 with lows Sunday night dipping into the 40s near the
Michigan border. Very warm air will quickly return with highs
well into the 80s by Tuesday. Energy in the form of short waves
in the northern stream will bring chances for showers and storms
from Wednesday through the end of the week. Temperatures should
be near normal during this time.


&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 137 AM EDT Sat Jun 29 2024

Broad warm/moist air advection ahead of a weak and disjointed
trough will support periodic showers through the morning.
Isolated thunderstorms are possible with the best chances at
KSBN where slightly higher MUCAPE resides but coverage will
remain low. Models continue to suggest some brief MVFR ceilings
during the late morning as low level moisture continues to pool
ahead of the approaching cold front. Confidence is not high but
will hold with brief MVFR mention. There is potential for a
second round of showers and isolated storms late Saturday
afternoon, mainly at KFWA, as the cold front approaches. Forcing
remains weak though and CAM`s remain very inconsistent on when
and if storms actually occur. Will therefore keep the afternoon
dry for now.

&&

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

&&

$$

DISCUSSION...Skipper
AVIATION...AGD