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816
FXUS63 KLOT 091127
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
627 AM CDT Sun Jun 9 2024

.KEY MESSAGES...

- Northwest winds gusting 30-35 mph this afternoon.

- Cold front this evening with gusty northerly winds tonight and
  Monday along with building waves and dangerous swimming
  conditions for Lake Michigan beaches.

- A gradual warming trend is expected Tuesday onward with
  periodic thunderstorm chances mid-to-late week (20-40%).

&&

.DISCUSSION...
Issued at 155 AM CDT Sun Jun 9 2024

Through Monday:

With mainly clear skies and light winds, shallow ground fog has
develop in some areas early this morning. Low level winds are
expected to slowly increase through sunrise and this will likely
limit the fog potential early this morning.

Northwest winds will steadily increase this morning with gusts
into the 30-35 mph range this afternoon. These stronger winds
may begin to diminish some by late afternoon with increasing
clouds expected in the late afternoon and into the evening but
some gusts are likely to persist through sunset. High temps will
likely reach the upper 70s to around 80 most locations today.

A cold front will move south down Lake Michigan this afternoon
and arrive into northeast IL this evening, switching winds to
the north/northeast. Winds may increase into the 30-35 mph range
over southern Lake Michigan and remain at those speeds through
daybreak Monday morning, then only slowly diminish Monday.
These strong northerly winds will allow for high waves at Lake
Michigan beaches and create dangerous swimming conditions.

High temps on Monday will be well below normal, possibly only
reaching the upper 60s for many areas near the lake and perhaps
lower 70s further inland. cms


Monday Night through Saturday:

Short-wave ridging will move overhead heading into Tuesday with
the center of an expansive surface high pressure shifting east
of the area. This will turn winds back out of the southwest
ushering in a stretch of warm advective flow into the region
with high temperatures already warming back into the mid-upper
70s by Tuesday afternoon.

Beyond Tuesday the upper level pattern will feature
predominantly zonal flow across the northern Plains into the
Upper Midwest. This general pattern will continue the trend
toward warmer and more humid conditions along with the potential
for thunderstorms in the region. Confidence in timing and
placement of any potential shower/storm chances remains low
through the end of the week due to continued variability in
model timing of subtle waves moving within the upper flow and
any associated MCSs. At this range the best signal for storms in
our area exists during the Thursday afternoon/night timeframe.
Something to keep an eye on over the coming days!

Petr

&&

.AVIATION /12Z TAFS THROUGH 18Z MONDAY/...
-- Changed Discussion --
Issued at 625 AM CDT Sun Jun 9 2024

Key Messages:

- Breezy WNW winds develop by this afternoon with gusts to 30kt

- Gusty northeast wind shift this evening (between ~1-4Z) followed
  by a period of MVFR CIGS overnight

West northwesterly winds will steadily increase through the
morning with gusts to 30kt expected by this afternoon. Winds
will begin to ease toward sunset; however, a gusty northeast
wind shift is expected behind a lake enhanced cold front this
evening (roughly between 1-4Z). The timing of this wind shift
will need to be refined with later updates. A period of MVFR
stratus may accompany the front for at least part of the
overnight hours before scattering out toward daybreak Monday
with winds returning to a more northerly direction.

Petr
-- End Changed Discussion --

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement from this evening through late Monday
     night for ILZ006-ILZ103-ILZ104.

IN...Beach Hazards Statement from this evening through late Monday
     night for INZ001-INZ002.

LM...Small Craft Advisory from 10 AM this morning to 9 PM CDT
     Monday for the IL nearshore waters.

     Small Craft Advisory from 9 PM this evening to 9 PM CDT Monday
     for the IN nearshore waters.

&&

$$

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