Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 160441
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
1141 PM CDT Sun Oct 15 2017

.UPDATE...
Issued at 858 PM CDT Sun Oct 15 2017

High pressure continues to build into central IL following last
night`s cold frontal passage. Pressure gradients are weakening
rapidly as a result, causing winds to decrease rapidly. Clearing
skies will also take place overnight causing good radiational
cooling. The coldest night of the season so far looks on track for
the area, as lows dip into the upper 30s for many areas north of
I-72, and low 40s to the south. Dewpoints in the low 40s to 39 in
Galesburg will limit the temperature drop overnight, preventing
many areas from receiving frost, but the colder areas, mainly well
northwest of the Illinois River cold see some. No significant
updates needed this evening as the forecast is on track with these
features.

&&

.SHORT TERM...(This evening through Monday)
ISSUED AT 305 PM CDT Sun Oct 15 2017

Deepening 993 mb low pressure over southwest Quebec had a cold
front extending through central OH/KY/TN at mid afternoon. Breezy
nw winds behind the front over central/southeast IL had ushered in
much cooler air today. Temps at 3 pm were in the mid to upper 50s,
while dewpoints were in the low to mid 40s. A broad upper level
trof over the Midwest was giving an extensive area of
stratocumulus clouds over central and northern IL while clearing
skies in sw IL into MO and central and western IA. Expect the low
clouds to diminish during this evening especially after sunset as
some of these clouds are diurnally enhanced. High pressure over
the central Rockies/plains will move into OK by dawn Monday and
ridge into IL. Breezy nw winds will also diminish setting stage
up for one of the cooler nights of the season with lows in the
upper 30s and lower 40s. Patchy frost possible mainly nw of the IL
river late tonight and early Monday morning.

Surface high pressure ridge of 1027 mb extends from Ohio sw thru
the mid MS river valley by sunset Monday and brings more sunshine,
lighter west winds and seasonably cool highs in the lower 60s.

.LONG TERM...(Monday night through Sunday)
ISSUED AT 305 PM CDT Sun Oct 15 2017

A pleasant stretch of fall weather expected over IL during the
upcoming week. Expansive area of high pressure ridging across the
southeast 1/3rd of the country will return ssw flow of milder
air. Upper level ridge still expected to build across the MS
valley by Thu and eastern states late in the week aiding in the
warmup. Another cool night Monday night with lows in the lower
40s, with some upper 30s possible se of I-70 where patchy frost
possible late Monday night. Highs Tue in the upper 60s, climbing
to around 70F to lower 70s on Wed after Tue night lows in the mid
40s. Highs in the low to mid 70s Thu/Fri and in the 70s on
Saturday and back to low to mid 70s Sunday. Consensus of models is
keeping our area dry through Saturday, then low chances of showers
over mainly northern and western parts of CWA Sat night and
Sunday of next weekend as a cold front pushes toward the area by
next Sunday. Some timing difference between the GFS, ECMWF and
GEM models with this front so stuck close to model blend of pops
which remain low later half of next weekend.

&&

.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1141 PM CDT Sun Oct 15 2017

VFR conditions expected the next 24 hours as high pressure brings
clear skies and light winds. Winds WNW up to 8 kts overnight,
turning to WSW during the daytime, then turning to SSW after
sunset Monday.

&&

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

$$

UPDATE...37
SHORT TERM...07
LONG TERM...07
AVIATION...37



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