Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 182348

Area Forecast Discussion
National Weather Service Lincoln IL
648 PM CDT TUE OCT 18 2016

.SHORT TERM...(This evening through Wednesday)
ISSUED AT 255 PM CDT Tue Oct 18 2016

A cold front will continue to drift south over the forecast area
this evening, with a band of lower clouds just ahead of it...and a
slight chance for rain and thunder in the southeast this evening.
Cooler air filtering in behind the boundary will result in overnight
lows in the 50s north of the I-70 corridor...low 60s south.  This
same boundary stalls in the region, near the Ohio River
valley/southern borders of the state later tonight.  Small waves
rippling through the region bring a chance for showers along and
behind the boundary through the southern half of the state for
Wednesday. Models differing somewhat with the northern extent of the
showers through tomorrow afternoon before the bulk of the
wave/precip develops for the evening hours.

.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 255 PM CDT Tue Oct 18 2016

The cold front moving through central Illinois early this afternoon
is expected to slow down as it becomes parallel to the upper level
flow near the Ohio River Valley later tonight. A shortwave, seen on
water vapor imagery approaching the Rockies, is expected to approach
just west of the MS River Valley Wednesday evening. This will be
provide upper level support for showers and t-storms in parts of
central and southern Illinois - mainly south of a Springfield to
Danville line. Many of the models continue to show mainly elevated
storms north of the surface boundary, however south of I-70 CAPEs
are higher and wind shear sufficient for a few storms to become
strong or even severe with hail and wind gusts during the evening.

The GFS and European are similar with the timing and intensity of
the deepening upper level trough as the western shortwave moves east
of the MS River Valley Thursday. The NAM and Canadian are a bit
slower and are holding on to the rain longer into Thursday afternoon-
early evening. Prefer the quicker GFS/European blend and will only
hold on to lingering showers near the Indiana border Thursday

High pressure and a northwest upper level flow will allow
temperatures to drop toward more seasonable levels for Friday and
through the weekend. Will hold off on mentioning patchy frost for
Friday morning north of I-74 with temperatures in the upper 30s and
northwest winds around 5-10 mph.

After several days of dry weather through the weekend and into early
next week, the next shot at showers may be next Tuesday. The GFS has
warm front draped across parts of central IL. However, there is
fairly low confidence with this solution since the GFS Ensembles are
all over the place, and the inconsistent European is showing dry
weather. Thus, will only introduce a chance of showers near the
potential frontal boundary location around the Peoria area and to
the northwest.


.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 647 PM CDT Tue Oct 18 2016

The cold front has pushed south of all the terminal sites, and NW
winds have developed in its wake. Gusts have not been showing up
in the OBS so far behind the front, and expect that trend to
continue the rest of the night. High pressure building into
Illinois over the next 24 hours will set the stage for wind
directions to gradually shift from NW to N and then NE by sunrise.
Winds should remain NE through the day tomorrow, with speeds
generally remaining less than 10kt.

The frontal boundary will stall out in the Ohio River Valley, but
a weak shortwave lifting NE along the front will bring chances of
showers into SE IL. DEC and CMI may see a stray shower nearby
later in the afternoon, and thunder could also develop, but we just
added a VCSH late in the TAF period for now. VFR conditions will
prevail for the majority of the next 24 hours, barring any storms
at a terminal site.


.ILX Watches/Warnings/Advisories...


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