938
FXUS63 KLOT 272016
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
316 PM CDT Thu Jun 27 2024

.KEY MESSAGES...

- Quiet conditions will persist into the overnight hours.

- After the high swim risk ends this afternoon, a moderate swim
  risk may linger at beaches located at the southern end of
  Lake Michigan until the early evening hours.

- A Marginal Risk for severe weather exists Friday over most of
  the area and southeast of Chicagoland on Saturday. While the
  threat isn`t particularly high-end, some gusty winds can`t be
  ruled out with any of the stronger storms.

&&

.DISCUSSION...
Issued at 244 PM CDT Thu Jun 27 2024

Through Friday Night:

Quiet conditions will persist into the overnight hours as a
moderately strong high pressure lingers over Lake
Ontario/Upstate New York. Warm advection will increase over the
Western Corn Belt tonight and isentropic upglide over an
approaching warm front will lead to showery precipitation over
Iowa tonight. Going into tomorrow, this rain will have to fight
some lingering low level dry air from the high pressure system,
but with time, the low levels will saturate and light rain
should spread in from the east and northeast with time, mainly
in the afternoon. CAPE with this activity is projecting to be
weak so widespread thunderstorms are not expected, but a few
rumbles of thunder may move through especially in the late
afternoon/early evening when models project a weak shortwave
moving through. There may be a bit of a lull around midnight,
before more showers and rumbles of thunder occur overnight as a
sfc front approaches from the northwest. There may be a bit
more elevated CAPE along the front. Any strong storms that occur
during this time period may have some gusty winds, but severe
weather chances attached the Marginal Risk look low.

NWS Chicago


Saturday through Thursday:

The sfc cold front is expected to slide southeast with time late
Saturday morning into the afternoon hours. As the front moves
through, dew points and temperatures should ease with time
leading to comfortable and cool conditions Saturday night into
Sunday. Comfortable and seasonable conditions are then expected
Sunday and Monday as high pressure exerts it`s influence over
the Upper Midwest.

An unsettled pattern is then projected to return Tuesday into
the rest of the extended as long-range models depict multiple
shortwaves and boughts of warm advection into late next week,
spurring daily chances for showers and thunderstorms.

NWS Chicago

&&

.AVIATION /18Z TAFS THROUGH 00Z SATURDAY/...
Issued at 1255 PM CDT Thu Jun 27 2024

VFR conditions are expected to continue into tonight as clear
skies give way to BKN250 cloud cover generally after 00z this
evening. High cloud cover should remain into tomorrow morning,
slightly decreasing in height to around BKN090 to BKN100 by the
morning hours on Friday. Toward the afternoon hours, 30% chances
for showers and perhaps a rumble of thunder or two will spread
in from west to east, generally reaching the Chicagoland area in
the late afternoon to early evening tomorrow.

Winds will generally be northeasterly this afternoon and will
gradually come around to southeast by dawn Friday morning, then
south southwest by Friday afternoon. Winds will increase in the
late morning and remain elevated into the evening with gusts to
around 20 knots.

NWS Chicago

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement until 4 PM CDT this afternoon for
     ILZ006-ILZ103-ILZ104.

IN...Beach Hazards Statement until 4 PM CDT this afternoon for
     INZ001-INZ002.

LM...Small Craft Advisory until 3 PM CDT this afternoon for the IL
     and IN nearshore waters.

&&

$$

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