165
FXUS63 KIWX 111058
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
658 AM EDT Thu Jul 11 2024

.KEY MESSAGES...

- Morning fog dissipates and may allow for a few afternoon
  showers and thunderstorms that have a chance to linger
  overnight.

- Periodic chances for showers and thunderstorms between Friday
  and the middle of next week with the best chance for storms
  occurring during the afternoons.

- 90 degree high temperatures are most possible Sunday through
  Tuesday of next week, dependent on thunderstorm chances.

&&

.DISCUSSION...
Issued at 300 AM EDT Thu Jul 11 2024

A relatively dry airmass is in place today with low to mid 60s dew
points, but 850 mb dew points around 10C. This still allows for some
instability to build in after the morning fog dissipates with 500 to
1500 J/kg of MUCAPE. The kicker shortwave that helped to push the
remnants of Beryl eastward only slowly saunters through the Great
Lakes region between today and Friday. A lack of upper and low level
kinematic support exists limiting shear and this also limits
severity to just general thunder mainly south of US-30 this
afternoon. Locally heavy rain would be the main threat, which could
be exacerbated by the already saturated ground. It is interesting to
see models continue the convection tonight without shear and with
waning instability perhaps along an outflow boundary and perhaps
sustained with the antecedent low level moisture. The ECMWF has an
area of warm advection and large scale ascent coupling at times
tonight that may be able to sustain it. With the shortwave
continuing to saunter through and ongoing showers and storms,
Friday, will have to see if sunshine can peak through, but
GFS/NAM/ECMWF all create 1500 to 2000 J/kg of MUCAPE, which will
allow for more showers and thunderstorms Friday afternoon.
DCAPE is still up between 800 and 1200 J/kg indicating wet
microbursts could be observed in these storms. There is some
signal of more of a moisture axis east of US- 31 on Friday and
that seems to be where models are keying into providing PoPs.
Highs Wednesday generally spanned the 70s, but with some
increased sunshine and some warming in the low levels,
temperatures will be able to reach around 80 degrees with a few
spots south of US-24 able to reach into the low 80s. This is
thunderstorm dependent though. Friday`s highs will also be
thunderstorm dependent, but additional warm advection may allow
for highs in the low to mid 80s.

For Saturday into next week, a ridge over the southwestern CONUS
slowly edges eastward into the Central Plains. This pattern will
allow Pacific shortwaves to pass near the region through mid week.
The first such wave arrives Saturday morning, continues into the day
time, and will have some instability to work with, but shear and
columnar moisture appear to lacking likely limiting the hazards as a
result. A few more of these waves are expected to move through
between Sunday and mid week next week providing opportunities for
showers and thunderstorms. Through that time frame, an upper low
forms across Central Canada and pushes a cold front through by
Tuesday or Wednesday of next week. Friday night and Saturday,
especially for areas east of IN-15 and north of US-6 have the best
chance for a dry period. As mentioned previously, thunderstorms
may be around the around area and that could cut into how warm
temperatures could get, but Sunday through Tuesday still has the
best chance to achieve 90 degrees before temperatures cool off
behind the cold front.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 658 AM EDT Thu Jul 11 2024

Dense fog is expected to mix out quickly as the sun comes up
with return to VFR by 13-14Z (though exact timing is somewhat
uncertain). VFR conditions then expected the rest of the period.
There is a low chance for storms this afternoon but better
forcing and moisture appear to remain southwest of the terminals
so will hold dry for now.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Dense Fog Advisory until 9 AM EDT this morning for INZ005>009-
     017-018-025>027-116-216.
OH...Dense Fog Advisory until 9 AM EDT this morning for OHZ001-004-
     015.
MI...Dense Fog Advisory until 9 AM EDT this morning for MIZ078>081.
MARINE...None.

&&

$$

DISCUSSION...Roller
AVIATION...AGD