Peotone Weather
National Weather Service Forecast for: Peotone, IL
Issued by: National Weather Service Chicago/Romeoville, IL
Updated: Fri, 07-May-2021 1:15am CDT

Peotone, IL

Friday: Partly Sunny
Partly Sunny

Saturday: Areas Of Frost then Mostly Sunny
Areas Of Frost then Mostly Sunny

Sunday: Rain Showers Likely
Rain Showers Likely

Monday: Mostly Sunny
Mostly Sunny

Tuesday: Mostly Sunny
Mostly Sunny

Wednesday: Partly Sunny then Slight Chance Rain Showers
Partly Sunny then Slight Chance Rain Showers

Thursday: Slight Chance Rain Showers
Slight Chance Rain Showers
  Hi 60 °F ↓ Hi 59 °F Hi 55 °F Hi 56 °F Hi 60 °F Hi 63 °F Hi 66 °F

Overnight: Mostly Clear
Mostly Clear
Friday Night: Mostly Clear then Areas Of Frost
Mostly Clear then Areas Of Frost
Saturday Night: Rain Showers Likely
Rain Showers Likely
Sunday Night: Chance Rain Showers
Chance Rain Showers
Monday Night: Partly Cloudy
Partly Cloudy
Tuesday Night: Partly Cloudy
Partly Cloudy
Wednesday Night: Slight Chance Rain Showers
Slight Chance Rain Showers
Lo 38 °F Lo 35 °F Lo 41 °F Lo 38 °F Lo 36 °F Lo 38 °F Lo 43 °F  


Mostly clear, with a low around 38. Southwest wind around 5 mph.
Partly sunny. High near 60, with temperatures falling to around 57 in the afternoon. Northwest wind 5 to 15 mph, with gusts as high as 30 mph.
Friday Night
Areas of frost after 2am. Mostly clear, with a low around 35. North northeast wind 0 to 15 mph, with gusts as high as 25 mph.
Areas of frost before 7am. Mostly sunny, with a high near 59. East northeast wind 0 to 5 mph, with gusts as high as 15 mph.
Saturday Night
Rain showers likely after 7pm. Mostly cloudy, with a low around 41. East wind 5 to 10 mph. Chance of precipitation is 70%.
Rain showers likely. Mostly cloudy, with a high near 55. Chance of precipitation is 70%.
Sunday Night
A chance of rain showers before 1am. Mostly cloudy, with a low around 38. Chance of precipitation is 50%.
Mostly sunny, with a high near 56.
Monday Night
Partly cloudy, with a low around 36.
Mostly sunny, with a high near 60.
Tuesday Night
Partly cloudy, with a low around 38.
A slight chance of rain showers after 1pm. Partly sunny, with a high near 63.
Wednesday Night
A slight chance of rain showers. Mostly cloudy, with a low around 43.
A slight chance of rain showers. Mostly sunny, with a high near 66.


Forecast from NOAA-NWS for Peotone, IL.

FXUS63 KLOT 070524

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
1224 AM CDT Fri May 7 2021

857 PM CDT

No significant changes to going forecast this evening.

Surface low pressure and weak attendant cold front has moved well
off to the southeast of the area at mid-evening. While dry air has
spread into the region in the lower levels, a pocket of cooler
mid-level air and associated steep mid-level lapse rates continues
to allow an area of high-based (7000-8000 ft) strato-cu and a few
isolated sprinkles to drift southeast across the area. Much of
this is likely not reaching the ground given dry sub-cloud layer,
though a few drops will be noticed here and there across mainly
northeast IL for the next couple of hours. A period of clearing is
likely in the wake of this strato-cu layer later tonight, though
our next upstream wave is already approaching from MN and
northwestern WI and will bring clouds and the potential for a few
light showers back into the region toward morning.

Going forecast has these trends well in hand, and outside of the
usual tweaks to hourly gridded details, no significant changes are



315 PM CDT

A cool season pattern prevails the next 36 hours with multiple
short waves in northwest flow and cold air aloft both more
indicative of March. This will bring multiple periods of
isolated/scattered showers for at least parts of the area.

The earlier convection in the far southeast forecast area is
exiting to the southeast along the cold front. Low-level drier
air is filtering into the area on northerly winds, however an
upper level disturbance is providing ascent and saturation across
Wisconsin. There have been scattered light echoes on upstream
radar but a fair amount of this is not reaching the ground. As the
vorticity center swings southeastward over the forecast area late
this afternoon through mid-evening, should see this spread over
locations north of I-80. A gradual downtick in coverage after 6
pm or so is forecast with the loss of peak heating. While some
cloud tops have shown the presence of frozen/mixed phase
hydrometeors over Wisconsin, have not seen any lightning with
this activity thus far, and after 6-7 pm the risk should diminish
even further.

The next disturbance/vorticity maximum will be arriving from the
northwest in the pre-dawn hours. The pocket of ascent and
attendant saturation with this will slide just northeast of the
area, however close enough where it did warrant including a small
chance for some showers especially over northeast Illinois and
far northwest Indiana.

As for temperatures tonight, low confidence in specific lows as
there will be a break in clouds between the two aforementioned
disturbances. Readings could drop cooler than forecast, although
some west-northwesterly wind will continue. Cannot rule out an
isolated mid 30s reading if clearer longer than forecast. Highs
will once again be below normal with mid to upper 50s along/north
of I-88 and also near the lake, while lower 60s elsewhere.

For Friday, the cold pocket aloft (as seen by 500 mb and 700 mb
temperatures both near record cold for this time of year) will
remain anchored over the Great Lakes. Should see cumuliform clouds
develop fairly quickly late morning/early afternoon. In far
northeast Illinois, a low-level convergent axis is likely, and
given the colder temperatures aloft, some weak instability is
forecast to pool along this. Similar to today, a capping inversion
between 700-600 mb is forecast, so not a great sounding for
lightning. Have a chance for showers in mainly northeast Illinois
for this.



309 PM CDT

Friday night through Thursday...

The main items of interest for the extended period include a center
of low pressure tracking through the area this weekend, then another
weak disturbance possible late Wednesday into Thursday.

The track of the low this weekend will of course have a large
influence on precipitation amounts and daytime highs.  While the
latest deterministic GFS has the center tracking across the southern
portion of the CWA, the ECMWF/GEFS/ECMWF-Ensemble show this feature
as more of an open and weakening progressive wave farther south.
Thus the heaviest precip axis also should remain farther south, and
areas along the WI border may only see a tenth or two at most.  The
key period for this rainfall would be Saturday night into Sunday
afternoon.  For much of the area, except our far southwest, most of
the daytime period Saturday appears likely to remain dry.

For Monday through at least midweek, high pressure sits across the
area in the wake of the departing low.  Precip chances do not return
until late Wednesday into Thursday, and even these are in question
given model disagreements at this time range.

As for temperature trends, the coolest day of the period appears to
be Sunday with highs generally in the 50s, or about 10 degrees below
normal.  Overall the entire period appears favored to remain on the
cool side during daytime hours, especially near the lake, with
seasonably normal highs forecast only for Wednesday. Overnight lows
also could pose a concern for patchy frost in some northern
locations, especially Friday night and possibly again early next



For the 06Z TAFs...

There are several mainly minor aviation weather impacts over the
next 24-30 hours. The first is our next incoming disturbance,
which is currently producing spotty VFR -shra across portions of
west-central Wisconsin and southeast Minnesota. While the
disturbance behind these showers is fairly robust, the expectation
is for the shower coverage to gradually diminish as this feature
tracks into a pretty dry airmass. Can`t discount a few light
showers surviving the southeastward trek--mainly INVOF RFD--but
vsbys/cigs with any shower activity would remain VFR.

Breezy northwest winds will develop in the wake of this feature
later this morning, with deep mixing by mid-afternoon supporting
occasional gusts to around 20-25 kts or so. A secondary boundary
will drop down the lake (likely augmented by a lake breeze) and
will turn winds northeasterly, first at GYY, followed by MDW and
eventually ORD. Timing of this wind shift remains generally medium
confidence and the advertised times will likely continue to be
refined with future TAF issuances. VFR cloud cover is expected to
increase through the afternoon hours, and a sliver of instability
may help sprout a few showers across northeast Illinois and
northwest Indiana. Coverage is currently expected to remain under
25% or so, and is too low for even a PROB30 mention at this time.

Winds will ease Friday evening and may go light and variable away
from the lake as high pressure builds across Wisconsin.





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