059 
FXUS63 KILX 221737
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
1237 PM CDT Fri Jun 22 2018

.UPDATE...
Issued at 1100 AM CDT Fri Jun 22 2018

1530z/1030am water vapor imagery shows a deep upper low centered
over southeast Illinois. Bands of convection are already beginning
to develop along the N/NW periphery of the low...with the most
significant band currently setting up along a Monticello to
Taylorville line. SPC mesoanalysis suggests SBCAPEs have risen to
around 1500J/kg across this area, while bulk shear remains
minimal. As was the case yesterday, the increased vorticity within
the environment near the low will likely help a few funnel clouds
to form as convection continues to percolate through the
afternoon. Have already issued an SPS highlighting the potential
for a few funnel clouds along/southeast of the I-55 corridor. Most
CAM guidance indicates this will be where showers/storms will 
become most numerous this afternoon, so have featured likely PoPs 
across this area as well. Further west, have maintained just
chance PoPs in the Illinois River Valley. An impressive summertime
temperature gradient will develop across the KILX CWA today...with
highs only reaching the upper 60s northwest of the Illinois River,
while approaching 80 degrees along/south of I-70.

&&

.SHORT TERM...(Today and tonight)
ISSUED AT 329 AM CDT Fri Jun 22 2018

Deep surface low is now over the mid Mississippi River Valley in
western IL this morning, with bands of sct precip still rotating
around the parent storm. The low is slow moving and will continue
to wobble a bit over the region. With that in mind, scattered
showers and thunder will be the forecast for the day. Slightly
cooler air in the north will result in high temperatures not
getting too far out of the mid 60s NW of the Illinois River.
Elsewhere will remain in the 70s. Should start to see some drying
out tonight as the low moves out to the east and some dry air
works its way southward into the region. Winds become more
northerly into the evening hours and cloudy, with lows only
dropping into the 60s. 

Overall, the models have struggled with the pattern shift behind
this low, and that trend continues. The wave that has acted as a
kicker for the current system is still progged to move across the
Plains tonight and into tomorrow...but thats where the
similarities end. Instead of bringing the next good chances for 
showers and thunderstorms, the wave is absorbed into the next
deep wave moving into the Pac NW tomorrow morning. The pattern
shift after this weekend has been through several iterations in
the last 72 hours and has not yet settled down.  

.LONG TERM...(Saturday through Thursday)
ISSUED AT 329 AM CDT Fri Jun 22 2018
Saturday is expected to continue to dry out for the region, with
relatively light winds and another warming trend as the eastern
ridge builds through the weekend. High temps in the upper 
70s/lower 80s for Saturday, mostly 80s for Sunday. According to 
the GFS, the dry weather will be unfortunately short lived, as it 
brings a wave across the southern half of the state. However, the
wave is considerably weaker than prev runs, and may well be slowly
transitioning with the new system absorbing the wave. The deeper
low over the Rockies will move out across the Plains late Sunday,
bringing showers through overnight Monday and into Wednesday. 
Other than that, the pattern shift behind the Wednesday low has 
diverged yet again, with the ECMWF setting up for a hot end of the
week.  

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1236 PM CDT Fri Jun 22 2018

Radar continues to show a band of convection east of the I-55 
corridor early this afternoon...with models generally shifting 
it slowly eastward through the afternoon. Based on radar trends,
have included VCTS at KDEC/KCMI...with no thunder mention at the
remaining terminals. Ceilings have improved to VFR at KDEC/KCMI,
but remain MVFR/IFR further west and north. Forecast soundings
suggest the low clouds will remain in place along/west of
I-55...with ceilings gradually lowering across the board tonight.
It appears a period of IFR ceilings will occur at all TAF sites late
tonight into early Saturday morning before ceilings improve to
MVFR toward midday Saturday. 

&&

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

$$

UPDATE...Barnes
SHORT TERM...HJS
LONG TERM...HJS
AVIATION...Barnes