Area Forecast Discussion
Issued by NWS Central Illinois

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095
FXUS63 KILX 281952
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
252 PM CDT Sun May 28 2017

.SHORT TERM...(This evening through Monday)
ISSUED AT 252 PM CDT Sun May 28 2017

A slow-moving cold front is triggering widely scattered convection
across east-central Illinois this afternoon...primarily along/south
of a Danville to Decatur line.  Based on speed of frontal boundary
dropping southeastward through the area and the latest HRRR
analysis, think most of this activity will push into Indiana prior
to 00z.  Will linger just a slight chance PoP south of I-70 into the
early evening hours...followed by dry conditions across the board
for the remainder of the night.  Skies will clear in the wake of the
front, with overnight lows dropping into the middle to upper 50s.

Monday will start out sunny, but diurnal clouds will develop in
advance of a weak trough pivoting around low pressure centered over
the Great Lakes as the day progresses.  Moisture will be limited:
however, NAM indicates MUCAPE values of 1500-2000J/kg across mainly
the southern KILX CWA by late afternoon.  NAM/GFS/WRF-ARW/WRF-NMM
all agree that widely scattered convection will develop in advance
of the trough, so have included 20 PoPs across all but the far NW
late Monday afternoon.  Have lingered low chance PoPs south of I-70
into Monday evening as the trough slowly settles southward into the
Ohio River Valley.

&&

.LONG TERM...(Monday night through Sunday)
ISSUED AT 252 PM CDT Sun May 28 2017

Upper low centered over Ontario will be the primary influence over
the weather across central Illinois through the middle of the week.
Another weak impulse rotating around the low may bring a few showers
to northern Illinois on Tuesday: however, most model solutions
keep this activity just north of the KILX CWA.  Yet another wave
tracking through the northwesterly flow pattern around the low
will skirt across Missouri and south-central Illinois Tuesday
night.  Despite an overall lack of deep-layer moisture, enough
synoptic lift will be generated to create cloud cover and perhaps
a few showers.  Have therefore included low chance PoPs across
all but the far NW CWA Tuesday night.

Surface high pressure will build into the Midwest on Wednesday,
bringing sunny skies and mild temperatures in the 70s.  Once the
high shifts off to the east, a warm front will lift northward into
the area on Thursday.  Models have been suggesting an MCS will
develop across the Plains Wednesday night, then track E/SE toward
central Illinois by Thursday morning.  The exact track of this
system is still in question, but it appears chance PoPs are
warranted on Thursday with the frontal boundary in the vicinity.
After that, unsettled weather will be on tap for the end of the
week with daily rain chances through Sunday.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1243 PM CDT Sun May 28 2017

1730z/1230pm radar imagery shows widely scattered showers
developing in the vicinity of a slow-moving cold front from KCMI
southwestward to KSPI. HRRR suggests showers/thunder will continue
to develop in this corridor over the next couple of hours before
pulling into Indiana later this afternoon. Based on latest trends,
have included VCTS at KBMI/KDEC/KCMI through the 20-22z time
frame. Ceilings have risen to VFR and are expected to gradually
scatter as the day progresses. Mostly clear skies will prevail
tonight through Monday morning before an approaching trough
once again triggers scattered showers/thunder by Monday
afternoon. Winds will remain W/NW through the entire 18z TAF
period.


&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Barnes



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