475 
FXUS63 KILX 090830
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
330 AM CDT Sun Jun 9 2019

.SHORT TERM...(Today and tonight)
ISSUED AT 329 AM CDT Sun Jun 9 2019

Upper low over the Ohio River Valley will continue to be the main
weather-maker today...providing plenty of cloud cover and a few 
showers. 08z/3am regional radar mosaic shows widespread showers 
across central/southern Indiana pivoting N/NW toward east-central
Illinois. With the low lifting slowly northward, the best rain 
chances will likely be confined to locations along/east of the 
I-57 corridor where high chance to likely PoPs are warranted. 
Further west, areal coverage will be considerably less across the 
remainder of the KILX CWA. While instability will initially be 
negligible, SBCAPEs will increase to 500-1000J/kg this afternoon, 
supporting at least isolated thunder. Thanks to ample cloud cover 
and scattered showers, highs will be several degrees cooler than 
yesterday...with afternoon readings topping out in the upper 70s 
and lower 80s. Scattered showers will linger through this evening 
before an approaching cold front pushes any remaining precip into 
Indiana overnight. Once the front passes, brisk northwesterly 
winds will develop late tonight as lows range from the middle 50s 
west of the Illinois River...to the middle 60s south of I-70. 

&&

.LONG TERM...(Monday through Saturday)
ISSUED AT 329 AM CDT Sun Jun 9 2019

The pressure gradient between the departing cold front and a
high building into the Plains will tighten sufficiently to 
produce W/NW wind gusts of 30-35mph on Monday. Despite full 
sunshine, strong CAA will keep temperatures in the middle 70s.
After a chilly night with lows in the lower 50s, the airmass will
moderate on Tuesday as highs rise into the upper 70s to around 80
degrees.

The upper air pattern for the remainder of the extended will
feature anomalously low heights as a short-wave diving out of 
Canada carves a significant trough over the Great Lakes/Ohio River
Valley. Scattered showers and thunderstorms will develop in 
advance of this feature late Tuesday night into Wednesday, 
followed by a return to cooler/drier conditions for Thursday and 
Friday. 00z June 9 models are in good agreement with the 
timing/strength of the wave, with both the GFS and GEM showing 
the 555dm 500mb height line dropping into central Illinois by 12z 
Thu. With corresponding 850mb temps of 4-6C, low temperatures may 
dip into the upper 40s in some locations Wednesday night.

Further out, some key model differences arise as the operational
GFS digs yet another short-wave southward into the region on
Friday...while the GEM/ECMWF are more progressive with the upper
trough shifting eastward. The operational GFS is the odd model out
at this point, as the GFS Ensemble supports the more progressive
GEM/ECMWF solution. As a result, think heights will rise and temps
will rebound by next weekend with highs back into the 80s by 
Saturday.


&&

.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1128 PM CDT Sat Jun 8 2019

Showers have diminished in coverage late this evening across
central Illinois and anticipate dry conditions to prevail
overnight into much of Sunday morning. The chance for scattered
showers will increase again with daytime heating and under the 
influence of an upper low over the region late morning through the
afternoon. Precip coverage should be greatest near the IL/IN 
state line, but isolated to widely scattered near the terminals. 
The other main concern will be ceilings, especially late tonight 
and through the day Sunday. MVFR ceilings are already occurring 
along portions of the Ohio Valley and in southern Indiana and are 
expected to spread and expand northwest across central Illinois 
late tonight into Sunday morning. Models are not consistent in 
handling the low moisture and have trended less pessimistic with 
ceilings heights and slower timing...thus confidence in the 
details remains low and will have to monitor observational trends 
overnight.


&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Deubelbeiss