Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 312312

Area Forecast Discussion
National Weather Service Lincoln IL
612 PM CDT Sat Oct 31 2020

Issued at 240 PM CDT Sat Oct 31 2020

A cold front will move across Illinois tonight bringing brisk
northwest winds and much cooler temperatures for Sunday. The
chill will be short-lived however, as temperatures are expected to
make it back into the 60s for highs by midweek. Weather is
expected to remain dry through the week.


.SHORT TERM...(This evening through Sunday)
ISSUED AT 240 PM CDT Sat Oct 31 2020

Breezy conditions should subside somewhat this evening ahead of an
approaching cold front currently over southeast Minnesota into
western Iowa. The front is associated with a strong northern
stream wave digging into the eastern U.S. Models are in good
agreement in bringing the front through between 04z and 09z. With
strong cold advection and height rises behind the front and
enhance subsidence on the backside of the wave, winds should come
up before sunrise west of I-55 and by mid-morning elsewhere.
Extended HRRR and SREF suggest wind speeds just below advisory
levels. By middle afternoon, the gradient is already exiting the
state and heights are rising so expect winds to gradually

Strong cold advection behind the front, should keep temps from
rising much on Sunday. 850 temperatures are progged to fall into
the -5C to -10C by range by Sunday evening. This should keep temps
in the 40s despite abundant sunshine.

.LONG TERM...(Sunday night through Saturday)
ISSUED AT 240 PM CDT Sat Oct 31 2020

Clear skies, cold Canadian air mass, and diminishing winds should
set up the region for low temperatures in the 20s Sunday Night.
However heights start to rise quickly in the wake of the
departing shortwave and 850 temps respond increasing some 20C by
Tuesday evening. Temperatures are expected to be around 10 degrees
above normal for an extended period.

Models are in unusually good agreement in building a broad ridge
across much of the U.S. next week. A weakness in the ridge does
move across the Midwest midweek, but the Gulf of Mexico remains
cutoff and the weak wave should have little impact on our weather.
Next significant system amplifies over the western U.S. toward
the end of the week, but is not expected to bring any chances of
precip until after the valid period of this forecast.


.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 612 PM CDT Sat Oct 31 2020

VFR conditions will prevail at all TAF sites next 24hrs. Mid and
high clouds are advecting into the area and will bring broken cigs
around 8kft to PIA and BMI this evening, but this should scatter
out around midnight. SPI/DEC/CMI will just see scattered cloud
later this evening and overnight. Skies will then become clear
early morning and continue through rest of TAF period. Winds will
be out of the south-southwest this evening, but as a front moves
into and through the area, wind direction will shift to westerly
around or just after midnight with gusts up to 22kts. After the
front moves through overnight, wind direction will become
northwest and wind gusts will increase to 25kts...then increase to
over 30kts during the early morning hours. This will continue into
the afternoon.




LONG TERM...Barker
AVIATION...Auten is the U.S. government's official web portal to all federal, state and local government web resources and services.