Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 151727

Area Forecast Discussion
National Weather Service Lincoln IL
1227 PM CDT Thu Mar 15 2018

Issued at 1109 AM CDT Thu Mar 15 2018

Sunny skies dominating Central Illinois this morning. Todays
weather is expected to be rather benign for the region, and highs
are on the way to the 50s. A high pressure ridge will remain in
place with some variability to the light winds. In general, the
forecast is on track and no updates are anticipated at this time.


.SHORT TERM...(Today through Friday)
ISSUED AT 335 AM CDT Thu Mar 15 2018

A weak cold front pushing southeast toward I-70 in southeast IL
early this morning, will sweep through the Wabash river valley
during this morning. This front will pass through dry with very
limited moisture and lift and mainly scattered cirrus clouds
today along with north winds near or less than 10 mph. Highs today
range from lower 50s along and north of I-74, to the upper 50s to
near 60F over sw CWA and in southeast IL.

Low pressure deepening over eastern CO during today, will emerge
over nw KS by dawn Fri with a warm front extending eastward over
sw MO and near the western KY/TN border. Clouds to increase later
this evening and overnight especially sw of I-74, with chance of
light rain and sleet and possible light freezing rain toward dawn
over sw third of CWA overnight, especially late from Springfield
to Lawrenceville sw. Light mixed pcpn including light freezing
rain and sleet sw of I-74 thru mid morning Fri, then changes to
all rain by late Fri morning and Fri afternoon as precipitation
spreads into areas along and ne of I-74 during Fri afternoon. A
very light glaze possible over sw CWA Fri morning. Lows tonight
range from mid 20s from I-74 ne, to 30-32F over sw CWA. Cooler
highs Friday in the lower 40s, with Lawrenceville near 45F with
cloudy skies and east breezes.

.LONG TERM...(Friday night through Wednesday)
ISSUED AT 335 AM CDT Thu Mar 15 2018

Low pressure weakens as it tracks east to along the eastern NE/KS
border by sunset Friday, and into sw IL by dawn Sat. Surface low
will also have a 550 dm 500 mb low to its nw and moving thru
central IL Sat morning. East winds become more NE to ENE and cool
the boundary layer during Friday night, changing the rain showers
during friday evening, back to mixed precipitation, including
light freezing rain and sleet along and ne of I-74 overnight Fri
night into early Sat morning. Ice accumulations still appear less
than a tenth of an inch ne of I-74 with little or no snow/sleet
accumulations. Models have trended further north with the ice
accumulation overnight Fri night the past few runs. Lows Fri night
range from lower 30s along and north of I-74, mid 30s rest of
central IL and upper 30s in southeast IL.

Light showers will gradually diminish by midday Saturday as low
pressure system continues to weaken and move east to eastern KY by
early Sat afternoon. Low clouds likely linger Sat afternoon with
some drier air moving southward toward I-74 late in the day. Highs
Sat range from mid 40s northern CWA, upper 40s central part of CWA
and lower 50s in southeast IL. Weak 1019 mb high pressure settles
into the western Great Lakes Sat night and into the southeastern
great lakes on Sunday, with upper level ridging into IL bringing
dry wx and return of more sunshine Sunday and light winds. Highs
in the low to mid 50s Sunday, with some upper 50s southern reaches
of CWA.

Another low pressure emerges over the central plains by dawn
Monday and tracks east into the lower Ohio river valley by sunset
Monday. This will spread rain showers east across central/se IL
overnight Sunday night thru Monday. GFS and ECMWF models have
trended further south with this system, so isolated thunderstorm
chances Monday afternoon now appear south of CWA. GFS and ECMWF
models also have trended lighter qpf or even dry over northern
CWA on Monday and Monday night. Rain chances turn to mixed pcpn or
snow chances overnight Monday night into Tue morning before
changing back to light rain Tue afternoon with a deepening upper
level trof over the MS river valley by Tue. Highs Monday in the
upper 40s nw CWA and mid 50s in southeast IL. Cooler highs Tue in
the lower 40s central IL and mid 40s in southeast IL. Dry
conditions return overnight Tue night thru next Thu and temps
stay on the cool side with highs in the low to mid 40s Wed, and
45-50 next Thu.

Climate Prediction Center (CPC`s) 8-14 day outlook for Mar 22-28th
has 45% chance of below normal temperatures and above normal
precipitation over central and southeast IL. So a cool and
unsettled weather pattern looks to continue.


.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1205 PM CDT Thu Mar 15 2018

VFR conditions are expected through this forecast period. Quiet
weather will hold over the area through the first half of the
night with mainly cirrus clouds drifting in from the west. As
a weather system develops to our west, clouds will gradually
lower and thicken after 06z with precipitation developing
over northeast Missouri. Forecast soundings continue to indicate
plenty of dry air in the low levels so it may have a difficult
time reaching the ground until after 12z. At this time, will
carry a VCSH at SPI at or just after 12z while keeping the
remainder of the TAF sites precip-free at this time. Surface
winds will be light northerly this afternoon and then veer into
a northeast direction tonight at 10 to 15 kts. Easterly winds
are expected on Friday at 10 to 15 kts with gusts up to 20 kts
at times.




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