Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 192334

Area Forecast Discussion
National Weather Service Lincoln IL
634 PM CDT Thu Oct 19 2017

.SHORT TERM...(This evening through Friday)
ISSUED AT 300 PM CDT Thu Oct 19 2017

Nearly ideal fall harvest weather expected to continue across
central and southeast IL through Saturday as dry conditions and
above normal temperatures continue. Sunny skies prevailed this
afternoon with lighter winds near 10 mph or less and mild
temperatures in the mid to upper 70s. 1025 mb high pressure was
over the southeast US and ridging into IL/IN. Meanwhile an upper
level ridge was building into IL from 590 dm 500 mb high over the
north central Gulf of Mexico. Surface high pressure will stay se
of IL through Friday while upper level ridge shifts slowly east
over the ohio river valley. Fair weather will continue with some
passing thin cirrus clouds. Lows tonight mostly in the lower 50s
with winds staying light and some upper 40s from I-57 east. A bit
stronger southerly winds of 8-14 mph with gusts 15-20 mph by
Friday afternoon combined with ample sunshine to warm temps into
the upper 70s most locals with a few cities reaching 80F.

.LONG TERM...(Friday night through Thursday)
ISSUED AT 300 PM CDT Thu Oct 19 2017

Strong upper level ridge will be over the eastern states Saturday
while deep upper level trof over the Rockies. Another dry and warm
day on Saturday as skies become partly sunny with highs in the
mid to upper 70s and a few cities near 80F again. 12Z models bring
a cold front east toward the IA/IL border by sunrise Sunday and
have chances of showers and thunderstorms over the IL river valley
Sat evening and likely to categorical pops spreading east over CWA
during overnight Saturday night. Cold front to sweep east across
IL during Sunday and continues showers, with isolated thunderstorms
south of I-74 Sunday morning. Cooler highs Sunday range from low
to mid 60s over the IL river valley, to the upper 60s and lower
70s across eastern IL east of I-55.

A cutoff upper level low forms over the southern MS river valley
Sunday night and then tracks ne into TN/OH river valley Monday
keeping chances of showers around the area Sunday night and
Monday especially east of the IL river. Highs Monday mostly in the
upper 60s. A deepening upper level trof then digs SSE into IL
later Monday night and Tue bringing more cooler air along with
continued chances of showers. Highs Tue only in the mid to upper
50s central IL and lower 60s in southeast IL. Even cooler on Wed
with highs in the low to mid 50s. Tue and Wed nights will be
coolest with lows in the upper 30s to around 40F. Strong upper
level trof starts shifting east of IL during Wed but lingers
isolated light rain showers, with dry conditions returning Wed
night and Thu of next week. Highs next Thu moderate into the upper
50s and lower 60s with return of partly to mostly sunny skies.


.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 632 PM CDT Thu Oct 19 2017

VFR conditions will continue through this forecast period. Light
southeast winds expected tonight will veer more into a south
direction on Friday with speeds gradually increasing to around
10 kts by late morning. We may see a few gusts by late afternoon
over in PIA and SPI as the pressure gradient tightens up over
west central Illinois.




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