Peotone Weather

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

Updated: Wed, 19-Jun-2019 3:16pm CDT

- Select Forecast - Peotone, IL Manteno, IL Beecher, IL Monee, IL Kankakee, IL Willmington, IL Braidwood, IL Manhattan, 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 Showers And T-Storms Likely Thursday Rain Showers Likely then Mostly Cloudy Friday Partly Sunny then Slight Chance Showers And T-Storms Saturday Showers And T-Storms Likely then Chance Showers And T-Storms Sunday Showers And T-Storms Likely Monday Chance Showers And T-Storms Tuesday Slight Chance Showers And T-Storms   Hi 77 °F ↓ Hi 69 °F Hi 78 °F Hi 82 °F Hi 86 °F Hi 82 °F Hi 82 °F     Tonight Showers And T-Storms Thursday Night Partly Cloudy Friday Night Chance Showers And T-Storms Saturday Night Showers And T-Storms Likely Sunday Night Showers And T-Storms Likely Monday Night Chance Showers And T-Storms Tuesday Night Slight Chance Showers And T-Storms   Lo 58 °F Lo 53 °F Lo 62 °F Lo 69 °F Lo 68 °F Lo 63 °F Lo 63 °F

Forecast from NOAA-NWS for Peotone, IL.

000
FXUS63 KLOT 192028
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
328 PM CDT Wed Jun 19 2019

.SHORT TERM...
247 PM CDT

Through Tonight...

Well-defined vort max on water vapor imagery early this afternoon
is cartwheeling across northern Missouri with an associated
expanding/developing warm conveyor to the east. Based on satellite
and radar loops, the center of this cyclonic circulation--arguably
convectively-reinforced--seems to be located over of just east of
Chillicothe, Missouri. To the east of this feature, a very moist
airmass has spread north and eastward, with PWATs now analyzed in
the 1.6 to 1.9" range--nearing the 99th percentile for this time
of year. At the surface, a lake-enhanced cold front can be seen
dropping southwestward towards Rensselaer and Ottawa. To the north
of this boundary, conditions are cooler and stabilizing with a
rapid decrease in instability noted the farther north and east you
go towards the lake.

As this aforementioned shortwave/developing surface low
intercepts this southward-moving boundary, expect a proliferation
of widespread light to moderate rainfall and embedded heavier,
convectively-enhanced precipitation rates into the evening hours.
Upstream observations have indicated rainfall rates inching
upwards into the 1-2 in/hour range, with 30 minute rainfall rates
nearing one inch in some instances. Radar imagery depicts classic
low-echo centroid features in the embedded heavier cores currently
spreading east of Peoria and a lack of appreciable lightning
activity confirms warm rain processes are dominating in this
tropical airmass. Guidance has clearly been struggling with the
evolution of the parent circulation, but has continued to latch on
to a farther north solution over the last several hours and this
is confirmed based on satellite and radar loops.

It appears as if a strung-out surface low will probably track
across our far southern tier of counties this evening and
overnight. As an associated 850 mb low deepens, guidance suggests
a pivoting deformation band may yield a longer residence time of
heavier precipitation into our CWA. Given all of this, we`ve opted
to hoist a Flash Flood Watch for our counties south of I-80 where
hi-res guidance is now keying in on a potential for widespread
rainfall amounts of 1-3 inches with pockets of potentially 3-5
inches of rainfall through Thursday morning. This threat could
potentially spread a bit farther north and west of the current
watch, but rapidly decreasing instability in the post-frontal
airmass should keep overall rainfall rates in check.

Continue to think the severe weather risk remains low, but can`t
rule out some gustier winds across our far southern counties this
afternoon from precip-loaded downdrafts.

Dense fog will continue into the early evening hours across the
nearshore waters. Conditions may improve for a period this evening
as rain begins, but a rapid deterioration in visibilities may re-
develop and attempt to push inland overnight and into Thursday
morning with a potential for pockets of dense fog across parts of
the region.

Carlaw

&&

.LONG TERM...
328 PM CDT

Friday through Wednesday...

Thursday: The surface low and shortwave trough axis responsible for
tonight`s rain is progged to be over north-central Indiana around
12Z Thursday. The back edge of showers should be shifting east of
the I-39 corridor at this time, then gradually edge eastward through
northwest Indiana by early afternoon. With the axis of heavier
showers likely still over NW Indiana for a few hours after daybreak,
will continue the Flash Flood Watch through 15Z. Clouds should
briefly scatter west of the showers in the morning hours before a
healthy cumulus field develops during the afternoon. Most high-res
guidance attempts to initiate an isolated shower or two during the
afternoon where enough heating behind the departing system builds
convective cloud depths. As has been the case this month, guidance
appears to be a bit too high on surface dewpoints, so may be a
little aggressive on producing sufficient cloud depths to generate
precip. Have therefore kept the forecast dry, but would not be
surprised to see an isolated shower or two in the afternoon across
primarily the west half of the CWA.

Thursday night and Friday: Dry weather is expected through much of
this time as the transition to an active set-up for the weekend
begins. However, the initial stages of WAA may be ongoing across the
southern CWA Friday afternoon. This may be enough to generate a few
showers and possibly an elevated storm or two, though chances do not
look overly high.

Friday night through Monday: An active period of weather is expected
during this time as several disturbances, some convectively
enhanced/induced, round an amplifying mid-level ridge across the
lower half of the Mississippi River Valley. The overall message of
the potential for multiple rounds of thunderstorms, some severe,
Friday night into Monday remains the same as an increasingly
unstable air mass advects northward into the region. Additionally,
high pwats up to 1.8" will support very heavy rain with any
thunderstorms, increasing flash flood potential through the weekend.

Predictability in overall timing and intensity of convection remains
low as convection on each day across the region and the central
Great Plains will have significant impacts on convective evolution
on the following day. However, the overall pattern combined with
guidance suggests the first round of convection will lift NE toward
the CWA Friday night into Saturday morning in response to
substantial WAA and moisture transport on a 50kt low-level jet over
northern MO and southern IA. Impressive steepening of mid-level
lapse rates over this forcing will support robust nocturnal
convection arcing from western IA into west-central IL in the
evening. Modest 1-6 km effective shear around 30 kts along with
decent MUCAPE within the steep lapse rates will support a risk for
severe hail with any thunderstorm. It appears most of the
significant convection should remain south and west of the CWA, but
as the LLJ veers through the night, some severe convection may reach
roughly the southwest half of the CWA through daybreak Saturday.

Uncertainty increases beyond Saturday morning as Friday night`s
convection may hinder the northeastward expansion of the warm sector
through the CWA until late in the day and ultimately change where
and when additional convection develops on Saturday. The forecast
trend has been toward a slightly cooler Saturday with a decent
amount of convective debris clouds around, but actual precipitation
looks to be isolated to scattered at best given an overall lull in
forcing. LLJ activity may then focus convection west of the CWA
Saturday evening before veering and shifting storms into northern IL
Saturday night. Additional rounds of storms will be possible through
Sunday night until a trough axis clears the CWA during the day
Monday.

Kluber

&&

.AVIATION...
For the 18Z TAFs...

Several aviation weather concerns throughout the forecast period
including:

/1/ Increasing rain potential into this evening and overnight with
a low but non-zero threat for a few stray lightning strikes
/2/ Deteriorating cigs/vsbys this evening
/3/ Uncertain cig/vsby trends into Thursday

A lake-enhanced cold front is pushing through the region resulting
in the development of some breezier northeast winds. Thus far, the
lowest cigs/vsbys (into the VLIFR category) are remaining just
offshore, although recent observations from PWK indicate some
lowering clouds pushing inland. Will indicate a brief tempo for
low-MVFR cigs at ORD to account for this, with a lower potential
at MDW. Spotty showers may bubble this afternoon, but the main
window for widespread precipitation looks to hold off until this
evening and overnight as the shield of precipitation immediately
to our south and west pushes northeastward.

Cig trends pose a big challenge from later this afternoon and
through the overnight hours, especially at the Chicago-area
terminals. With the loss of heating and an expansive stratus deck
waiting in the wings, would expect some inland push of IFR cigs
this evening, although this may be somewhat short-lived. As rain
begins to fall this evening and overnight, another push of very
low cigs is looking increasingly likely, although timing this
potential out (and just how low cigs get) remains uncertain. For
the 18z TAFs, opted to trend things downwards with the most likely
period of LIFR to even VLIFR cigs after about 07z this evening.
Conditions should begin to improve late Thursday morning and
during the afternoon as drier air migrates into the region,
although GYY may remain socked in through the day with a
persistent north wind off the lake.

Winds will favor a northeasterly direction today but may attempt
to become more northerly tonight and into Thursday.

Carlaw

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Flash Flood Watch...ILZ023-ILZ032-ILZ033-ILZ039 until 7 AM
     Thursday.

IN...Flash Flood Watch...INZ001-INZ002-INZ011 until 10 AM Thursday.

     Flash Flood Watch...INZ010-INZ019 until 7 AM Thursday.

LM...Dense Fog Advisory...Winthrop Harbor to Burns Harbor until 9
     PM Wednesday.

&&

$$

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NWS LOT Office Area Forecast Discussion