979
FXUS63 KIWX 130003
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
803 PM EDT Fri Jul 12 2024

.KEY MESSAGES...

* Periodic chances (20-40%) for thunderstorms Saturday night
  through Tuesday. There is the potential for severe storms,
  especially later Sunday night through Tuesday.

* Hot and humid conditions are expected Sunday and Monday,
  dependent on storm coverage and timing.

&&

.DISCUSSION...
Issued at 133 PM EDT Fri Jul 12 2024

Broad but weakening upper trough axis positioned through wrn MI will
rotate out into se ON by sunset. Residual convergent moist axis
invof the tri-state line and south may yield an isolated shower
or storm this aftn with continued heating/destabilization
otherwise the rest of the area expected to stay dry.

Return flow begins in earnest late day in response to building
thermal ridge out west and developing low pressure across NE. While
most cam solutions are dry tomorrow aftn will hold w/slight chc
mention west and south to account for upticking theta-e ridge.

Thereafter large scale pattern aloft from the nrn plains through the
lakes/OH valley turns quite interesting. Substantial
heating/moisture advection beneath building upper ridge across the
plains portents several episodes of strong to severe convection in
the coming days. How this plays out exactly in regard to timing and
potential severity remains in question given mesoscale system
development upstream over the Dakotas and upper midwest followed by
subsequent downstream evolution and timing which will ultimately
dictate the potential threats here. Suffice it to say a period of
hot and stormy wx looks likely Sun-Tue before a more vigorous cold
front swings through toward Wed and shunts the heat and moisture
south.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 800 PM EDT Fri Jul 12 2024

An upper level vort filament from southern Missouri into west
central Ohio will be a focus for isolated showers for a few more
hours this evening, but remaining well east of the terminals. A
few showers attempted to develop along a lake breeze boundary
east of the KSBN vicinity earlier this evening, but loss of peak
heating should limit this potential for the remainder of the
evening. Northern Indiana should remain between better mid/upper
level forcing areas overnight into early Saturday, with
clear/partly cloudy skies. Broad low level anticyclone providing
light winds, lingering near sfc moisture, and mainly clear skies
should allow some shallow fog to form once again Saturday
morning. IFR/MVFR vsbys are possible, but confidence remains
somewhat low on coverage at the terminals. Fog should dissipate
quickly in the 12Z-13Z timeframe on Saturday. A few isolated
storms are possible across northern Indiana during the day
Saturday but somewhat tempered instability and upstream
positioning of forcing should hold off greater thunder chances
until after this forecast valid period into Saturday night when
richer low level theta-e airmass shifts eastward.

&&

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

&&

$$

DISCUSSION...T
AVIATION...Marsili