Downers Grove, Illinois 7 Day Weather Forecast
Wx Forecast - Wx Discussion - Wx Aviation
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NWS Forecast for Downers Grove IL
National Weather Service Forecast for:
Downers Grove IL
Issued by: National Weather Service Chicago, IL |
Updated: 6:56 pm CST Jan 1, 2025 |
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Tonight
Partly Cloudy
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Thursday
Partly Sunny then Chance Snow
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Thursday Night
Chance Snow then Mostly Clear
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Friday
Sunny
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Friday Night
Mostly Clear
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Saturday
Sunny
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Saturday Night
Mostly Cloudy
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Sunday
Mostly Cloudy then Chance Snow
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Sunday Night
Chance Snow
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Lo 22 °F |
Hi 31 °F |
Lo 17 °F |
Hi 23 °F |
Lo 11 °F |
Hi 21 °F |
Lo 14 °F |
Hi 24 °F |
Lo 19 °F |
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Tonight
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Partly cloudy, with a low around 22. West northwest wind 10 to 15 mph, with gusts as high as 20 mph. |
Thursday
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A 40 percent chance of snow, mainly after 3pm. Partly sunny, with a high near 31. West wind 5 to 10 mph, with gusts as high as 15 mph. |
Thursday Night
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A 30 percent chance of snow, mainly before 9pm. Partly cloudy, with a low around 17. Northwest wind 5 to 15 mph, with gusts as high as 20 mph. |
Friday
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Sunny, with a high near 23. West northwest wind around 15 mph, with gusts as high as 25 mph. |
Friday Night
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Mostly clear, with a low around 11. West northwest wind 10 to 15 mph, with gusts as high as 20 mph. |
Saturday
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Sunny, with a high near 21. |
Saturday Night
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Mostly cloudy, with a low around 14. |
Sunday
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A chance of snow after noon. Mostly cloudy, with a high near 24. |
Sunday Night
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A chance of snow. Mostly cloudy, with a low around 19. |
Monday
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A chance of snow. Mostly cloudy, with a high near 28. |
Monday Night
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Mostly cloudy, with a low around 16. |
Tuesday
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Partly sunny, with a high near 24. |
Tuesday Night
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Mostly cloudy, with a low around 10. |
Wednesday
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Partly sunny, with a high near 18. |
Forecast from NOAA-NWS
for Downers Grove IL.
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Weather Forecast Discussion
742
FXUS63 KLOT 020247
AFDLOT
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
847 PM CST Wed Jan 1 2025
.KEY MESSAGES...
- Accumulating snow Thursday afternoon and evening, primarily
south of I-80 with an inch or two likely.
- There is another chance for snow on Sunday/Monday, but
confidence in specific details remains low at this time.
&&
.UPDATE...
Issued at 847 PM CST Wed Jan 1 2025
Going forecast tonight through Thursday remains on track with
only minor adjustments needed.
A broad upper trough continues to spiral over the Midwest and
Great Lakes this evening with a couple of modest waves
traversing across WI and Lower MI. While there have been some
occasional flurries being observed across WI and northeast IA,
the drier air over northern IL and northwest IN has prevented
such activity from reaching the ground locally. That said, still
cannot rule out a stray flurry through midnight for areas near
the IL-WI line. Otherwise, expect mid-level stratus to remain
overhead through the night which should help hold temperatures a
few degrees warmer than originally thought. Overnight lows
could still dip into the lower 20s in far northern IL tonight,
but most other areas should see readings in the mid-20s to start
our Thursday.
The main forecast concern for Thursday continues to be the
expectation for accumulating snow to develop with an upper-level
shortwave trough and associated surface low. The latest
guidance remains in very good agreement on the surface low
tracking across central and north-central IL-IN Thursday
afternoon which should focus the band of snow along the elevated
frontal zone to the north of the lows center. While general
consensus continues to show this band occurring along and south
of Mendota, IL to Rensselaer, IN line; there has been a notable
wiggle northward in some of the hi-res guidance (namely the RAP
and HRRR) this evening. If this shift continues then the higher
snow totals could reach the I-80 corridor with lesser amounts
possibly extending as far north as I-88.
Given that this trend is only being seen a few select models
have opted to maintain the going forecast for now, but did
broaden the northern extent of POPs in the forecast to hint at
this trend. Regardless, accumulations with the peak of the snow
band should top out in the 1-2 inch range though locally higher
pockets upwards of 3 inches could occur especially near and west
of I-39. That said, those in the aforementioned favored area
should be prepared for some slippery travel Thursday afternoon
and evening due to snow accumulating on roads and reduced
visibilities. The snow is expected to taper from west to east
between 9 PM and midnight Thursday with dry conditions expected
for the rest of Thursday night.
Yack
&&
.DISCUSSION...
Issued at 215 PM CST Wed Jan 1 2025
Through Thursday Night:
Conditions are rather quiet out there this afternoon following a
burst of some moderate snow this morning that managed to coat
roads around the north and northwest suburbs. Area webcams show
that the snow has melted off of the roads ridding concerns for
slick travel, but a dusting remains on grassy surfaces. The low
stratus and ongoing cold advection have kept temperatures from
moving much during the day. Early this afternoon, temperatures
are sitting in the upper 20s and lower 30s. The cold advection
has also enabled us to regularly mix down gusts in the 20 to 25
mph range. Winds will gradually step down some, but remain
breezy through tonight as mixing looks to continue.
Additionally, a few flurries may get going this afternoon into
this evening. Our radar is currently picking up on some light
returns around the area, although nothing appears to be making
it to the ground at the moment, at least as far as we can tell.
This drier near-surface air may continue to be too much for any
flurries aloft to survive their trip to the ground. Conditions
will be cold tonight into tomorrow with lows progged in the
lower and middle 20s and with wind chills in the teens and even
single digits forecast near the IL/WI state line.
Tonight, a low amplitude, low level shortwave will spin up off
the lee of the Colorado Rockies and track eastward over the
central Plains and then lower Midwest tomorrow into tomorrow
night. This will bring us our next potential for accumulating
snow beginning tomorrow afternoon. A region of efficient warm,
moist upglide will develop out ahead and help to fuel the
system. Guidance is also resolving appreciable forcing for
ascent focused in the 800-600mb layer which includes through a
nearly-saturated DGZ. Just beneath this better omega, an
impressive low level f-gen circulation is expected to extend
north and east from the low center, along the storm`s cold
conveyor. While the snowfall should largely be on the lighter
side, a rather narrow band of higher rates is anticipated near
where this f-gen tracks.
Guidance is in pleasantly good agreement on the behavior of this
storm tomorrow and general distribution of the snow. The actual
surface low will track across central IL during the latter part
of the day. Nearly all deterministic guidance paints a narrow
swath of higher totals somewhere between the I-80 corridor and
our southern CWA border, so confidence is rather high that the
southern half of the CWA is the area to watch for greatest
impacts. Confidence could be higher in actual accumulations, but
most guidance generally supports 1-2" in this corridor of
higher totals. There is some support for less than an inch, but
almost none for anything much greater than 2". Lesser
accumulations up to several tenths are expected to spread north
of I-80. However, a good chunk of our northern CWA will probably
get away with little to no accumulation, particularly north of
the I-90 corridor as well as in and around Chicago.
Snow will begin moving in from the west during the early
afternoon with the heaviest snow potential during the late
afternoon and evening, meaning travel impacts will be possible
for PM commuters. The snow will move away to the east by the end
of the evening. We will continue on our cooling trend following
this system, but discrepancies in snow cover is leading
uncertainty regarding temperatures tomorrow night. The going
forecast reads lows in the middle and upper teens accompanied by
wind chills in the single digits to near zero into Friday
morning.
Doom
Friday through Wednesday:
Friday will be windy and cold with highs in the low to mid 20s
and wind chills in the single digits. Guidance continues to
suggest we will see a good deal of sunshine Friday. I`m always
worried about stratus potential in cold air advection regimes
this time of year, but struggling to find evidence to support
beefing up sky cover for Friday with guidance unanimously
showing mostly sunny skies. Saturday looks to be a carbon copy
of Friday with just less wind and more moderate wind chills.
Very little change in thinking for the system progged to affect
the region late Sunday through early Monday. The 12z GFS/GEFS
and ECMWF/EPS haven`t shown any appreciable trends with this
system, other than more consolidation of individual ensemble
members closer to their respective ensemble means. The consensus
track of this system would continue to place the band of
heaviest snow just south of our CWA, though with measurable
snowfall still making it into at least our southern CWA.
While there is a shrinking ensemble spread and pretty good run
to run consistency, it is important to remember that we are
still in the time frame of the forecast where substantial
changes in the forecast track and intensity of this system could
occur. So even though the brunt of the heaviest snow is progged
to miss our CWA to the south, can`t rule out a northward or
southward shift in the track in coming days, so stay tuned.
One other wildcard to keep an eye in coming days is the
potential for lake effect snow, possibly even into northeast IL.
Who sees lake effect Sunday into Monday will depend on the
exact track and strength of the sfc low and the positioning and
strength of the sfc high, neither of which can be forecast with
the degree of specificity needed to narrow down exactly where a
lake effect potential could exist. Given the current
expectations, there could be a window for some lake effect
potential into northeast IL for a time before any lake effect
shifts east into northwest Indiana. But stay tuned, a lot can
change between now and then.
Finally, slightly colder air will filter into the region later
Monday into early Tuesday, but with this system not forecast to
phase with the polar front jet, the initial push of cold air
should be moderately cold. However, medium range guidance
suggests that lurking a day or so behind this system will be an
Arctic front and a more substantial push of Arctic air Tuesday
night into Wednesday. The operational 12z ECMWF and GFS both
have 850mb temps approaching -20C into the area with that cold
push, but their respective ensembles both suggest that -20C is
toward the 10th percentile, in other words toward the coldest
end of the spectrum of guidance. Bottom line, it looks like a
formidable push of Arctic air could arrive by the middle of
next week, but the magnitude of the cold is still uncertain.
How much, if any snow cover, that will be present over the area
by then could also impact how much modification could take place
to this air mass when it gets here.
- Izzi
&&
.AVIATION /00Z TAFS THROUGH 06Z THURSDAY/...
Issued at 537 PM CST Wed Jan 1 2025
Forecast concerns include...
Mvfr cigs tonight.
Gusty westerly winds tonight.
Chance of snow Thursday afternoon/evening.
Cig trends tonight are a bit uncertain. They`ve lifted to near
3kft and also scattered out across parts of the area but another
area of mvfr cigs across northeast IA and northwest IL may move
across the terminals. Have opted to maintain mvfr cigs through
the night with scattering possible Thursday morning but trends
will need to be monitored. There also could be a few flurries
tonight, if the mvfr cigs become prevailing.
Westerly winds gusting into the lower/mid 20kt range will slowly
diminish through the evening with gusts expected to end
overnight. Westerly winds will continue into Thursday afternoon
with speeds at 10kt or less. Directions may turn more to the
northwest Thursday afternoon into Thursday evening.
A clipper system will move across central IL Thursday afternoon
and into central IN Thursday evening bringing a narrow swath of
snow. There remains uncertainty as to how far north the northern
edge of this snow will move and it will likely be near MDW/GYY
and have added prob mention to both forecasts. Any slight jog
north with this system would result in the need for prevailing
snow mention with prob/tempo for lower conditions, including at
ORD and changes with later forecasts are possible. For locations
south of the terminals, ifr cigs/vis can be expected with this
snow. cms
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...Small Craft Advisory until 9 PM CST this evening for the IL
nearshore waters.
Small Craft Advisory until 3 AM CST Thursday for the IN
nearshore waters.
&&
$$
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