341
FXUS63 KLOT 282250
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
550 PM CDT Thu May 28 2026

.KEY MESSAGES...

- A stagnant, predominantly precipitation free pattern will
  prevail through at least mid next week, with seasonably warm
  daytimes inland, and cooler temperatures closer to the lake.

- After swimming conditions improve this evening, hazardous to
  dangerous conditions may redevelop at Lake Michigan beaches on
  Saturday.

&&

.DISCUSSION...
Issued at 150 PM CDT Thu May 28 2026

Persistent western CONUS troughing and northeastern North
America troughing will result in a sharp "omega block" type
ridge extending into central Canada through midweek next week.
Expansive, seasonably strong surface high pressure from Hudson
Bay to the Great Lakes will lock in warm regime, though it will
be cooler by the lake. In addition, synoptic easterly low level
flow will be prone to dew points mixing out daily (and likely
running below much of the guidance), keeping better column and
low level moisture, and any associated precip chances west of
the MS River. This will also result in comfortable overnight-
early morning conditions outside of Chicago.

The backdoor frontal passage that brought dangerous swimming
conditions to the beaches today and lake cooling extending much
farther inland will revert to a classic lake breeze type setup
on Friday. Another backdoor frontal passage early Saturday will
bring a repeat of similar conditions to those of today.
Hazardous to dangerous (moderate to high swim risk) conditions
may redevelop at Lake Michigan beaches, which may necessitate a
Beach Hazards Statement for at least portions of the shoreline
Saturday.

Signs are pointing toward the blocking regime finally breaking
down later next week, which may enable some spotty precip
chances to return as dew points become a bit more early June-like.

Castro

&&

.AVIATION /00Z TAFS THROUGH 06Z SATURDAY/...
Issued at 550 PM CDT Thu May 28 2026

There are no aviation concerns through the TAF period.

A surface high pressure system centered over the Upper
Peninsula of Michigan will drift southward through the next 24
to 30 hours setting the stage for calm winds overnight and
light (5 kt or less) winds tomorrow across the general region.
A lake breeze will push inland from Lake Michigan by early
afternoon, favoring 18-19Z at GYY, and 19-20Z at ORD/MDW. Broken
upper-level clouds based between 30-35kft will continue to
stream overhead through tomorrow.

Finally, cannot rule out an isolated patch or two of shallow fog
with reduced visibility tonight at outlying airports (RFD/DPA).

Borchardt

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement until 8 PM CDT this evening for ILZ006-
     ILZ103-ILZ104.

IN...Beach Hazards Statement until 8 PM CDT this evening for INZ001-
     INZ002.

LM...Small Craft Advisory until 7 PM CDT this evening for the IL
     and IN nearshore waters.

&&

$$

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