Peotone Weather

National Weather Service Forecast for: 2 Miles SE Peotone, IL Issued by: National Weather Service Chicago/Romeoville, IL

Updated: Sat, 20-Jun-2026 1:11pm CDT

- Select Forecast - Peotone, IL Manteno, IL Beecher, IL Monee, IL Kankakee, IL Willmington, IL Braidwood, IL Manhattan, IL OakForest, IL Stelle, IL Ottawa, IL Amboy, IL Byron, IL Rockford, IL Quad Cities, IL Champaign/Urbana, IL Peoria, IL Bloomington, IL Springfield, IL Carbondale, IL Vienna, IL Culver, IN

Peotone, IL

This Afternoon Sunny Sunday Rain Showers Monday Chance Rain Showers then Partly Sunny Tuesday Mostly Sunny Wednesday Chance Rain Showers then Chance Showers And T-Storms Thursday Chance Showers And T-Storms Friday Mostly Sunny   Hi 77 °F Hi 73 °F Hi 73 °F Hi 76 °F Hi 77 °F Hi 76 °F Hi 77 °F     Tonight Partly Cloudy Sunday Night Showers And T-Storms Monday Night Mostly Clear Tuesday Night Mostly Clear then Slight Chance Rain Showers Wednesday Night Chance Showers And T-Storms Thursday Night Chance Showers And T-Storms then Slight Chance Showers And T-Storms Friday Night Slight Chance Showers And T-Storms   Lo 57 °F Lo 57 °F Lo 53 °F Lo 55 °F Lo 56 °F Lo 55 °F Lo 57 °F

Hydrologic Outlook issued June 20 at 3:30AM CDT
 

Forecast from NOAA-NWS for 2 Miles SE Peotone, IL.

986
FXUS63 KLOT 201726
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
1226 PM CDT Sat Jun 20 2026

.KEY MESSAGES...

- A soaking rainfall is likely for most or all of the area on
  Sunday. Some potential for thunderstorms and flooding also
  exists, though whether these threats will materialize here
  remains uncertain.

&&

.DISCUSSION...
Issued at 320 AM CDT Sat Jun 20 2026

Through Tonight:

Modest isentropic ascent within a low- to mid-level frontal
zone activated a pocket of modest elevated instability over our
forecast area a little while ago, allowing for a few storms to
develop near and just north of the I-80 corridor. This activity
has since dwindled as it has progressed to the east-southeast,
but with the isentropic upglide expected to persist across our
southern CWA for a while longer, scattered showers and perhaps
a few additional rumbles of thunder may continue to be observed
there through a little after sunrise this morning.

Otherwise though, expect another dry day today with plenty
of sunshine, comfortable humidity levels, and high temperatures
similar to or just a touch warmer than yesterday`s highs. A
lake breeze will also develop once again and keep some of our
northwest Indiana locales slightly cooler relative to elsewhere.
This lake breeze is likely to eventually make a push inland
into northeast Illinois as well, but likely not until the breezy
west-northwesterly synoptic gradient flow there today starts to
relax with the approach of sunset.


Sunday:

An upper-level shortwave trough will eject eastward out of the
central Rockies today, spurring the development of a surface low
beneath it while also inducing widespread convection across the
central Plains this afternoon and evening. The exact track and
strength of this disturbance and associated surface low is of
relevance for our area as this will largely dictate whether a
threat for thunderstorms (including ones that may be severe) and
flooding could materialize in our forecast area on Sunday
amidst 1.25-2" precipitable water values. Generally speaking, a
more northerly track for these features and a deeper surface low
would result in a greater threat for thunderstorms and flooding
in our area, while a more southerly and weaker solution would
tend to keep these threats suppressed to our south.

Compared to 24 hours ago, there does appear to more support in
general across the latest CAM and ensemble suites for a more
southerly solution that keeps the surface low, an attendant
warm front, richer boundary layer moisture, and appreciable
instability south to potentially well south of our forecast
area. With the expectation that at least one southeastward-
propagating MCS will come out of the central Plains convection
tonight, it appears more likely than not that convection will
just continue to regenerate along the associated outflow into
tomorrow morning and afternoon, which would prohibit the
aforementioned warm front from advancing northward much, if at
all, tomorrow. Thus, do believe that these more southerly model
solutions have some credence to them and that the threat for
thunderstorms and the greatest threat for flooding on Sunday
could very well remain to our south. That said, support for
this solution is not unanimous across the broader spectrum of
model guidance, and if the aforementioned morning MCS doesn`t
materialize, decays much quicker than presently expected, or is
delayed by at least a few hours, then that would open the door
for the warm front to surge northward towards our southern CWA
tomorrow.

Regardless of which scenario pans out, it is expected that most
or all of our forecast area will receive a soaking rainfall on
Sunday given the abundance of both forcing support aloft and
moisture through the tropospheric column (our northernmost
counties could still potentially miss out on this soaking
rainfall if one of the more extreme southerly solutions were to
play out, which is not out of the question at this point). There
has also been a consistent model signal for a pronounced
deformation band to develop along the northern flank of the
surface low. How efficiently this band is able to crank out
rainfall will depend on the strength of the surface low and the
associated frontogenesis, but most model guidance suggests that
a corridor of 2-4" rainfall totals will be observed somewhere in
or just south of our forecast area when all is said and done.
With many area creeks, streams, and rivers still a bit more
elevated than usual from our recent rainfall, amounts like
these do raise concern for additional river rises and flooding
and possibly areal flooding in some locations as well, so will
issue a Hydrologic Outlook to give greater awareness to this
possibility.


Monday through Friday:

After Sunday`s system clears the region, quieter and drier
conditions should settle into the area for the beginning of the
upcoming work week. However, there remains a fairly consistent
signal in ensemble and deterministic guidance for another upper-
level disturbance to arrive in the region mid-week and bring a
renewed likelihood for precipitation to our area. Late Tuesday
into Wednesday still appears to be the favored time frame for
precipitation associated with this system to occur in our
forecast area. Thereafter, guidance indicates that there could
be a couple of follow-up shortwaves embedded within the
northwesterly flow aloft that track through the Midwest during
the latter half of the week in this lead disturbance`s wake.
This may result in additional showery periods beyond Wednesday
into the following weekend amidst continued near to below normal
temperatures.

Ogorek

&&

.AVIATION /18Z TAFS THROUGH 00Z MONDAY/...
Issued at 1226 PM CDT Sat Jun 20 2026

Key Aviation Messages for the current TAF period:

- Breezy winds this afternoon before a weak lake breeze develops
  after 00Z

- Soaking rains reducing vis are expected Sunday late
  morning/afternoon

VFR conditions with west-northwest winds with gusts around 20
knots are expected through the afternoon. A weak lake breeze is
expected to push westward after 00Z. There is some uncertainty
in the exact time of arrival at Chicago terminals, but should be
less than 8 knots and eventually become light and variable
through the late evening.

Winds are expected to start out on Sunday out of the east-
southeast around 10 knots. The next disturbance will move in
from the southwest late morning. Rain rates are expected to
increase through the afternoon as the core of the system moves
in. Periods of soaking rains are expected in the afternoon
reducing conditions down to MVFR levels, with a chance for
IFR level cigs. Gustier winds to 20 knots are expected at times
during the heavier rain, eventually becoming northeasterly by
mid afternoon.

DK

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.

&&

$$

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