Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 171729

Area Forecast Discussion
National Weather Service Lincoln IL
1229 PM CDT Wed Oct 17 2018

Issued at 1047 AM CDT Wed Oct 17 2018

Weak cold front is currently dropping through north-central
Illinois. Despite brisk N/NW winds across the entire KILX CWA,
full sunshine is efficiently heating the very dry airmass. As a
result, 15z/10am temperatures are running about 3-5 degrees higher
than previously forecast. Weak CAA will develop as the front
passes, so additional warming will be limited...especially across
the far north. Have adjusted afternoon highs, with readings
ranging from around 50 degrees far north near around
60 far south at Lawrenceville.


.SHORT TERM...(Today and tonight)
ISSUED AT 256 AM CDT Wed Oct 17 2018

07z surface analysis showed a subtle trough pushing into the area
early this morning. This will re-enforce the cold pattern today
with highs struggling to get into the 50s north of I-74. A fairly
tight pressure gradient exists again today, as we lie between deep
low pressure well of to the northeast, and a surface ridge
building eastward from the Plains. Momentum transfer off Bufkit
indicates 20+ mph gusts likely from mid morning into early
afternoon. The gustiness should subside through the afternoon as
the ridge approaches the Mississippi River by 00z.

With the center of the Canadian high settling over the state
tonight, ideal radiational cooling will send lows into the lower
to middle 30s. Have issued a frost advisory for counties along and
south of I-70, where 33-35F lows are forecast. Farther north, we
have ended frost/freeze headlines for the season, as widespread
26-30F lows were reported Tuesday morning. This effectively ended
the growing season for sensitive outdoor vegetation.

.LONG TERM...(Thursday through Tuesday)
ISSUED AT 256 AM CDT Wed Oct 17 2018

Dry and seasonably cold weather will continue on Thursday, as the
ridge begins to shift to our east. Friday still shows the
potential for rain showers, as a temporary flattening of the mid
level pattern allows some moisture to to shift northeast into the
Midwest, out of a SW US trough. A cold front tracking through the
Midwest should provide enough lift for most of the area to see
scattered showers, though QPF is under 0.10" most areas.

Blustery northwest winds behind the front, will bring strong cold
advection, for Friday night and Saturday. A shortwave rotating
through the deep upper trough centered over the Great Lakes, could
bring a few showers to far northeast portions of the CWA Saturday
afternoon. Another strong Canadian high building into the Midwest
for the last half of the weekend, will keep temps around 10
degrees below normal. Some thermal moderation is expected for
early next week, as the Great Lakes trough pushes into the
northeast US and heights rise over the Midwest.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1229 PM CDT Wed Oct 17 2018

VFR conditions will prevail through the entire 18z TAF period.
Northwesterly winds will gust 18-24kt through the afternoon before
quickly diminishing to 5kt or less by early evening. Skies will
remain clear through Thursday afternoon.


Frost Advisory from 1 AM to 8 AM CDT Thursday for ILZ062-063-



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