Des Plaines, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

029
FXUS63 KLOT 132334
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
634 PM CDT Sun Apr 13 2025

.KEY MESSAGES...

- Breezy/windy conditions each afternoon through Tuesday, with a
  locally elevated risk of brush fire spread (mainly south of
  Interstate 80) tomorrow afternoon.

- A wetter/stormier weather pattern is expected to become
  established over the Midwest late this week.

&&

.DISCUSSION...
Issued at 219 PM CDT Sun Apr 13 2025

Through Monday Night:

A surface low currently over southwestern Iowa on latest
mesoanalysis will gradually weaken over the course of the
evening. There have been showers and a few storms embedded
along a short wave trough axis in northeastern Iowa and western
Wisconsin. Luckily that trough axis is projected to remain north
of the area. While a few showers may develop this afternoon, for
areas closer to the Wisconsin border, the risk for thunder is
fairly small at this point. There is another slight chance later
this evening for showers as isentropic upglide increases as the
low-level jet ramps up. But both this afternoon`s and evening`s
slight chance for showers will struggle for any appreciable
accumulations as soundings are keeping a layer of dry air close
to the surface.

The previously mentioned weakening of the surface low will be a
result of an upper level trough moving east out of the Dakotas
toward Lake Superior where a new surface low will develop and
strengthen into Monday morning. A cold front will pass through
the region through the day on Monday with two impacts: 1.)
shower chances in the southeast and 2.) strong wind gusts. As
the front arrives in the morning, models do show a saturated
layer in the mid levels. The dry air at the surface is projected
to win out and keep most of the western portions of the
forecast area dry. However, as the morning progresses, top down
saturation should occur with the front being the main forcing
mechanism to develop showers in the afternoon. There could be
some adjustments still made to timing and location, but models
have consistently kept the shower chances south and east of
Interstate 57 with only light accumulations. As for the winds,
the breezy winds out of the south today will sharply turn to
west and strengthen behind the front. Wind gusts of 35 to 40 mph
are expected. And while a localized stronger gust is possible,
it is not expected to meet Wind Advisory criteria. Winds will
diminish slightly overnight into Tuesday morning, but remain
breezy as drier conditions are expected behind the front.

DK

Tuesday through Sunday:

A secondary upper-level impulse is slated to dig southeastward
into the Midwest late Monday night. This will set the stage for
a stronger push of cooler air over the area on continued gusty
northwesterly winds for Tuesday. A small chance (~20%) exists
for a few lingering showers early Tuesday morning with the
passage of the upper impulse. However, this threat will quickly
come to an end area-wide by mid to late morning. A dry but cool
and breezy afternoon is expected for the area as temperatures
top out in the low to mid 50s.

Cloud cover is expected to diminish Tuesday afternoon and evening.
This in combination with abating winds associated with an
approaching surface high will set up a cold night Tuesday night.
In fact, we could see several locations fall near, or even a bit
below freezing, particularly outside the Chicago urban heat
island.

Wednesday is looking to be a quiet day, with slightly warmer
inland afternoon temperatures following the chilly start to the
day. Inland highs should rebound back into the upper 50s to
around 60 degrees. Light winds during the day will favor the
development of a lake breeze and more persistent onshore flow
along the lakeshore areas. Accordingly, conditions will be
several degrees cooler (highs in the mid to upper 40s) near the
lake Wednesday afternoon.

The forecast for the latter half of the week will largely be
dictated by how a cluster of multiple interacting upper-level
disturbances over the western portion of the continent evolves
during the mid-late week time frame. While uncertainty in finer-
scale forecast details remains high owing to the myriad of
possible outcomes for exactly how these complex interactions
will play out, there is reasonable ensemble agreement on the
general idea that an upper-level ridge will set up across the
eastern half of the CONUS late in the week and that at least one
of these disturbances will navigate around this ridge into the
Midwest during this time frame. This would likely entail
temperatures here warming to above to well above normal readings
on Friday and a generally rainier/stormier weather pattern
setting up across the Midwest in the Thursday through Saturday
time frame. It`s difficult to say much more than that at this
point given the complexity of the synoptic pattern evolution.

KJB/Ogorek

&&

.AVIATION /00Z TAFS THROUGH 06Z TUESDAY/...
Issued at 634 PM CDT Sun Apr 13 2025

- Rather strong and gusty west winds expected Monday

VFR conditions are expected through the TAF cycle. Winds will
become west during the pre-dawn hours Monday, then likely begin
to ramp up considerably by mid-morning with frequent gusts of
25-30kt which should continue through the day and even into the
evening hours. There could be a couple/few hours of gusts of
30-35kt Monday afternoon.

- Izzi

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...Small Craft Advisory from 8 AM Monday to 7 PM CDT Tuesday for
     Winthrop Harbor IL to Gary IN.

     Small Craft Advisory from noon Monday to 7 PM CDT Tuesday for
     Gary to Burns Harbor IN-Burns Harbor to Michigan City IN.

&&

$$

Visit us at weather.gov/chicago