182
FXUS63 KLOT 290831
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
331 AM CDT Sat Jun 29 2024

.KEY MESSAGES...

- Dangerous swimming conditions with large waves expected late
  tonight through Sunday night at Lake Michigan beaches.

- Multiple chances for showers & storms late Tuesday through
  Friday, MANY dry hours between any bouts of rain

&&

.DISCUSSION...
Issued at 330 AM CDT Sat Jun 29 2024

Through Sunday:

(coming soon)

Sunday Night through Friday:

Monday`s weather looks gorgeous before we ease back into a
somewhat more active pattern the remainder of the upcoming work
week. Monday will be sunny with comfortable humidity and high
temps in the 70s.

By Tuesday, attention will turn to a positively titled upper
trough over the northern Plains. This trough is progged to track
eastward into Ontario by Wednesday afternoon with associated
surface low likely to track eastward across southern Canada.
Cold front trailing south from this low is progged to settle south
into northern Illinois later Tuesday night, eventually laying out
east-west somewhere in the area Wednesday. Generally speaking,
timing doesn`t look terribly favorable for convection in our area,
with frontal boundary and storms looking to arrive later Tuesday
evening into the overnight hours. Given respectable shear and
stout low level jet, its possible storms could continue well into
the night despite stronger synoptic forcing progged to remain
well north of the area with the upper trough displaced well to our
north.

Uncertainty grows Wednesday with low confidence on where the
surface front, likely augmented by convective outflow/cold pools,
will end up. Better chances of storms Wednesday will probably be
across our southern CWA or even south of the area depending on how
far south the effective boundary ends up.

Another trough is progged to dig into the northern Plains Thursday
afternoon before tracking east into the western Great Lakes
Friday. This could pull the boundary back north with shower/storm
chances increasing again Thursday into Friday. Too far out to get
into specifics on timing the better chances, but certainly can`t
rule out storms posing some challenges for outdoor activities for
the July 4th holiday.

- Izzi

&&

.AVIATION /06Z TAFS THROUGH 12Z SUNDAY/...
Issued at 1245 AM CDT Sat Jun 29 2024

- Period of MVFR CIGS expected this morning
- Westerly winds expected to become gusty this afternoon,
  shifting to gusty northwest this evening

A few ISOLD SHRA possibly during the first couple/few hours of
this TAF cycle, but generally expecting dry conditions at the
terminals. Area of some MVFR CIGS upstream over portions of
northeast IA and southern WI are expected to overspread the
terminals later this morning before scattering out with bases
lifting this afternoon.

As skies partially clear this afternoon, should see westerly
winds begin gusting to around 20kt. Winds may briefly ease early
this evening, but then shift to northwest and pick up by mid-
late evening as a cold front moves across the terminals. Expect
to see at least occasional gusts tonight, particularly at ORD
and MDW.

- Izzi

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement from late tonight through late Sunday
     night for ILZ006-ILZ103-ILZ104.

IN...Beach Hazards Statement from late tonight through late Sunday
     night for INZ001-INZ002.

LM...Small Craft Advisory from midnight tonight to 4 AM CDT Monday
     for the IL and IN nearshore waters.

&&

$$

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