Crystal Lake, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

388
FXUS63 KDVN 111725
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1225 PM CDT Fri Apr 11 2025

.KEY MESSAGES...

- Near freezing lows and frost possible for some early Saturday
  morning.

- Above normal temperatures for the weekend.

- Cooler weather toward the middle of next week with the
  potential for more near freezing lows and frost for some next
  Wednesday morning.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 200 AM CDT Fri Apr 11 2025

Latest GOES Nighttime Microphysics imagery shows a large expanse
of stratus from northern MN through eastern IA and northern IL
within a cool advection regime. Regional and local radar has also
shown some spotty returns - mainly sprinkles or isolated very
light rain. There is however, a large area of clearing taking
place into WI aided by dry advection in the low/mid levels on
E/NE flow. Overall, the general consensus of the guidance has
this drier air advecting into our region supporting decreasing
cloudiness for many areas this morning from east to west.
CU rule would then support the potential for some BKN cumulus
developing with surface heating by afternoon, especially along
the Hwy 20 corridor and also across our far western service
area. Thus, anticipate generally partly to mostly sunny skies
for today. With the anticipation of solar insolation we should
get highs back into the mid to upper 50s for most areas, with
lower 50s possible where any period of BKN clouds lingers while
lower 60s are possible with any longer duration of full sunshine.

Tonight, we should see skies become mostly clear as a surface
high pressure ridge traverses the area and sets up shop from
downstate IL into southern MO by 12z Saturday. As we get on
the backside of the ridge late tonight, a developing southerly
puff and weak warm advection may prevent a complete bottoming
out of temperatures for many. Still, a chilly night is on tap
with lows expected to be generally in the low to mid 30s with
patchy frost possible. However, sheltered and low lying areas,
river valleys, etc. will be favored to be on the cold side of
guidance with lows near progged 850 mb temperatures of -1c or
30F, particularly in far eastern IA and northern IL bringing
the low risk for some sub-freezing temperatures. Latest NBM
probabilities of lows <32F by Saturday morning are around
15-25% in an area bounded by Independence to Cedar Rapids to
Macomb to Freeport. The growing season is still not quite in
full swing and thus no headlines will be issued, but if you
have any outdoor sensitive vegetation it may be a good idea
to be a little cautious and either bring it indoors if possible
or cover it, although the time period for below freezing
doesn`t look to be climatologically significant where it may occur.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 200 AM CDT Fri Apr 11 2025

An upper level ridge will shift eastward into the region over
the weekend. Attendant height rises will foster a broad
warm advection regime. Accompanying southerly surface winds
will become gusty both Saturday (west of the Mississippi) and
Sunday (area-wide mainly in the morning). This coupled with
ample sunshine will boost highs well into the 60s and 70s.
Winds don`t look to be too much of a hindrance, and in fact
seeing more consensus toward a surface low approaching
by Sunday afternoon to slacken the gradient and ease any fire
weather concerns. The surface low is attendant to an advancing
a progressive shortwave trough that will shift from the
Pacific Northwest early in the weekend to the Great Lakes region
by late in the day on Monday. Elevated moisture advection
late Saturday night and Sunday in advance will lead to shower
chances (20-40%) mainly north of Hwy 30. Prior to the
shortwave moving into the Great Lakes on Monday it will usher
in a cold front late Sunday night. Forcing and moisture look
quite limited to support any organized rain chances. Arriving
post-frontal on Monday will be some additional shower chances
with a bout of mid level frontogenetical forcing in the right
entrance region of a 120+ kt Upper Midwest 250-300 mb jet streak.
Right now NBM PoPs are low at 15-20% and mainly south, as there
will be some dry air to overcome. In the wake of this system,
a period of cooler weather is on tap heading into the middle of
next week, as high pressure builds in. The threat for near
freezing lows and frost will exist, particularly along and north
of Hwy 30 late Tuesday night/early Wednesday morning where the
latest NBM probabilities are 30-50% for temperatures less than
32F by 12z Wednesday.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1222 PM CDT Fri Apr 11 2025

VFR is expected the next 24 hours with high pressure in control.
Winds will remain light and variable through tonight then
increase out of the south Saturday morning.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...None.
IL...None.
MO...None.

&&

$$

SHORT TERM...McClure
LONG TERM...McClure
AVIATION...Uttech