426
FXUS63 KLOT 120536
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
1236 AM CDT Mon Aug 12 2024

.KEY MESSAGES...

- Mainly dry conditions and warming temperatures through the
  first half of the week.

- Multiple waves, and a large-scale low pressure system impact
  the Midwest during the second half of the week, lingering into
  next weekend.

&&

.DISCUSSION...
Issued at 326 PM CDT Sun Aug 11 2024

Sunshine across the region this afternoon, along with mixed
diurnal cu fields have allowed temperatures around the area to
climb into the mid and upper 70s. Sfc high pressure will
continue to shift across the Midwest, continuing the dry
conditions across much of northeast Illinois into far northwest
Indiana to start the new work week. One item to note, another
weak upper level shortwave trof will drift across the southern
Great Lakes Monday. This will bring a chance of showers to
portions of central Illinois, as the sfc high pressure tries to
hold position in southern Wisconsin. Best chances for
precipitation late Monday morning through the afternoon appear
to be south of the I-80 corridor (20-30%), however cannot rule
out light shower activity between the I-80/I-88 corridor
(10-20%). With the low Td values, and 20-25 degree spread
between T/Td, this could limit precipitation chances as
saturation of the lower air column will take time.

Behind the passage of this shortwave, an upper-level ridge
builds across the central CONUS. With the ridge building,
temperatures closer to normal for this time of year will be
ushered into the Midwest on Tuesday. The brief "warmer"
temperatures get pushed off to the east mid-week, as the next
weather system begins tracking eastward from the southwest
corridor of Canada.

A large-scale low pressure system will begin developing across
far southwest Canada heading into the start of the new work
week. This will slowly evolve across the Pacific NW through
Tuesday, before beginning the eastward journey...reaching our
area during the second half of the week. The upper level ridge
will limit progress through mid-week, but break down during the
second half of the week. Current model camps have 2 separate
tracks of this low core, one through the north central Plains
and the other across the US/Canadian border. With the southerly
track, this would bring the core (upper-level and sfc system)
across the mid/upper Mississippi River Valley into the lower
Great Lakes region. This would bring more potential for
widespread continual storm activity near the low center. In
contrast, the northern track along the border would bring more
sporadic waves of showers and storms to the region. This system
will continue to track through the area next weekend, bringing
the potential of wrap-around activity on the backside through
next Sunday.

Baker

&&

.AVIATION /06Z TAFS THROUGH 12Z TUESDAY/...
Issued at 1236 AM CDT Mon Aug 12 2024

Cloudiness will be on the increase with BKN-OVC VFR deck
expected today. Can`t completely rule out a brief light shower
or sprinkle, but more likely to be just virga, if anything,
around the terminals. A lake breeze will result in a 5-10kt east
to northeast wind later this afternoon, otherwise expect calm or
light winds through the TAF cycle.

- Izzi

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.

&&

$$

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