Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 211032

Area Forecast Discussion
National Weather Service Lincoln IL
432 AM CST Wed Feb 21 2018

.SHORT TERM...(Today and tonight)
ISSUED AT 430 AM CST Wed Feb 21 2018

Cancelled winter weather advisory and flood watch for counties
along and west of Sangamon, Logan, Dewitt and McLean. Continued
the flood watch til 6 am for areas east of here. Also continue the
winter weather advisory through 6 am for east central IL.

Early morning radar mosaic shows the precipitation has shifted
east of I-55 with freezing rain and sleet west of a Rantoul to
Mattoon to Salem line, with freezing line pretty close to I-57.
Moderate rains occurring along and east of this area. Areas west
of I-57 have seen a light glaze of ice with up to a tenth inch
especially on elevated surfaces. The precipitation has been moving
eastward a bit quicker than earlier forecasted and have been able
to clear some counties from the flood watch and winter weather
advisory. Untreated roads though will may still be icy and slick
over areas west of I-57 for the early morning commute. Additional
rainfall amounts today should be less than 1 inch over southeast
IL. A strong cold front extended from nw Ohio through southeast IN
into western KY and nw TN and back into south Texas. Meanwhile
1038 mb Canadian high pressure was over central Nebraska. Clouds
were breaking up nw of IL over IA.

Latest forecast models continue rain over southeast IL through the
day, while diminishing it over east central IL next few hours.
Some sunshine possible over nw CWA later this morning/midday as
Canadian high pressure strengthens a t it tracks into WI by
sunset. But thicker cirrus to spread back north across central IL
during the afternoon. Much colder highs today in the mid to upper
30s, expect lower 40s near the Wabash river by Lawrenceville.

Strong high pressure moves east across the Great Lakes tonight
while weak surface low lifts ne along frontal boundary over TN and
southeast KY. Also a disturbance moves ne from southern plains
into MO/mid MS river valley tonight and likely continue rain over
southeast IL tonight, while spreading mixed precipitation
including light freezing rain into central part of CWA, with light
glaze north of I-70 to along I-72 corridor overnight into early
Thu morning. May need another winter weather advisory for this
area by overnight with ice accumulations up to a tenth inch. Have
20-30% chance of light snow overnight as far north as Peoria with
just flurries or dry north of Peoria overnight. Lows tonight range
from mid to upper 20s northern CWA to mid 30s in southeast IL,
with freezing line as far south as Charleston/Mattoon.


.LONG TERM...(Thursday through Tuesday)
ISSUED AT 430 AM CST Wed Feb 21 2018

On Thu morning have chance of mixed pcpn north of I-72 while rain
south of I-72 with a brief lull in pcpn chances Thu afternoon.
Highs Thu range from upper 30s to around 40F northern CWA to upper
40s in southeast IL. Have more rain likely spreading ne across CWA
during Thu night with a stronger disturbance lifting ne from the
southern plains and into IL by overnight Thu night, with chance
of mixed pcpn over Knox and Stark counties where lows near
freezing. Rest of CWA should be warm enough to support rain with
lows in the mid to upper 30s in central IL and lower 40s in
southeast IL. Have rain chances lingering se of IL river Fri
morning and highest in southeast IL, then just small pops in
southeast IL Fri afternoon as system departs with frontal boundary
ne or just se of Ohio river. Highs Fri in mid to upper 40s
northern CWA and mid 50s southeast IL.

Yet another stronger disturbance lifting ne from southern plains
toward mid MS river valley during Fri night and spreading rain
chances back ne across the area. Models show surface low and cold
front approaching western IL by sunset Saturday with widespread
showers over area along with isolated thunderstorms from I-55
southeast. Between 1-3 inches of rain possible se of I-55 with
highest amounts in southeast IL and this would aggravate flooding
problems again. Warmer highs Sat in lower 50s northern CWA and
lower 60s in southeast IL, and could be warmer if low pressure
tracks further north. Rain chances to diminish from west to east
during overnight Sat night as cold front passes east of IL.

A welcomed stretch of dry weather still expected Sunday through
Tue across central and southeast IL as high pressure settles near
IL Sunday and Monday. Temps are cooler, but still above normal
for late Feb early next week with highs ranging from 45-55F.


.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1147 PM CST Tue Feb 20 2018

The cold front continues to advance E-SE of the TAF sites, with
NW wind gusts diminishing to 20KT or less. Moderate to heavy rain
is mainly east of I-57 as of 0530Z/1130 pm, with some IFR
ceilings at BMI and CMI. Otherwise, flight categories have
improved to MVFR at SPI, and DEC and VFR at PIA. Potential for
periods of IFR due to low clouds and vis will continue for all but
PIA TAF sites until precipitations nears an end, when MVFR and
possibly VFR clouds develop. Freezing rain and icing will be the
other main concern the rest of the night. Temps will drop below
freezing at all terminal sites after midnight, with some light
freezing rain and sleet/snow possible for several hours before
precipitation ends from NW to SE between 07z (PIA) and 12Z (CMI).
Despite how much freezing rain/icing occurs during the
precipitation, travel surfaces could still re-freeze due to
residual water on the ground. Slippery travel is expected as the
night progresses.

NW winds should diminish below 10kt tomorrow morning, with clouds
improving to VFR. Winds will shift to the NE by later afternoon,
with speeds of 10-14kt.


Flood Watch until 6 AM CST early this morning for ILZ044>046-

Winter Weather Advisory until 6 AM CST early this morning for



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