Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 172006

Area Forecast Discussion
National Weather Service Lincoln IL
306 PM CDT Thu Aug 17 2017

.SHORT TERM...(This evening through Friday)
ISSUED AT 306 PM CDT Thu Aug 17 2017

19z/2pm surface analysis shows a cold front advancing slowly
eastward across central Illinois, with the boundary essentially
along the I-55 corridor. Am watching a line of enhanced CU on
satellite imagery from Paris to Effingham for potential isolated
convective development over the next 2-4 hours. Have maintained
slight chance PoPs across the far E/SE KILX CWA into early evening
accordingly. Once the front passes, skies will become clear and low
temperatures will drop into the lower to middle 60s.

The next weather system of interest is already evident on water
vapor imagery over Montana and will be approaching Illinois from
the northwest by Friday afternoon. Based on 12z model consensus,
think any convection associated with this feature will remain
along/west of the Mississippi River until Friday evening. As a
result, am expecting a mostly sunny and dry day on Friday with
highs in the middle 80s. Scattered showers and thunderstorms will
develop Friday night as the upper wave arrives across the area.


.LONG TERM...(Friday night through Thursday)
ISSUED AT 306 PM CDT Thu Aug 17 2017

A few showers may linger into Saturday morning across the far
E/SE, but these will quickly exit as the upper wave tracks into
the Ohio River Valley. The remainder of the weekend is expected to
be dry, with temperatures climbing into the upper 80s to around 90
degrees by Sunday. The next system will come into the picture
early next week, bringing rain chances back to central Illinois
by late Monday into Tuesday. As is typically the case, the GFS is
quicker and more bullish with precip than the ECMWF. Model
consensus suggests the strongest lift and deepest moisture will
coincide on Tuesday when the wave passes through the region. Have
therefore kept PoPs confined to the north and in the chance
category for Monday/Monday night...before spreading them further
south and increasing them to high chance to likely on Tuesday.
After that, upper troughing digging across the Great Lakes will
bring cooler/drier weather by next Wednesday and Thursday.


.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1233 PM CDT Thu Aug 17 2017

A couple bands of MVFR clouds persist across central Illinois ahead
of an approaching cold front early this afternoon, but these will
dissipate/lift northeastward over the next 1-2 hours. Have
lingered MVFR ceilings at KBMI/KCMI through 19z accordingly. The
cloud cover will rapidly dissipate by sunset, followed by mostly
clear skies across the board tonight into Friday morning. SW winds
gusting to 20-22kt this afternoon will diminish by early evening,
then will gradually veer to the W/NW late tonight.




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