876 
FXUS63 KILX 271613
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
1113 AM CDT Thu Jun 27 2019

.UPDATE...
Issued at 1110 AM CDT Thu Jun 27 2019

Forecast pretty much on track and just some minor adjustments to
sky cover today. A swirl of mid/high clouds was se of I-55 late
this morning with mostly cloudy skies in southeast IL. Sunny skies
along and west of I-55 late this morning. Radar mosaic shows a
narrow band of very light showers just se of Lawrence county with
more more showers over far southern IL into the mid MS river 
valley. Thunderstorms mainly over ne AR and western TN and far nw 
MS. Most of the CAMs keep CWA dry this afternoon and evening due
to a CAP/CIN over the area with strong upper level ridge over IL
with 500 mb heights of 589-591 dm over central IL, despite 
unstable airmass with CAPEs ranging from 1000-1500 j/kg in se IL 
to 3500-4500 j/kg over west central IL. Temps currently range from
75-83F, coolest in cloudier areas of southeast IL. Muggy with
dewpoints in the upper 60s and lower 70s. Highs this afternoon in
the upper 80s to near 90F with peak heat indices in the lower 90s
in central IL. SSW winds of 5 to 10 mph does not provide much
relief from the high heat and humidity.

&&

.SHORT TERM...(Today and tonight)
ISSUED AT 328 AM CDT Thu Jun 27 2019

High pressure settled over the southeastern CONUS, but a
persistent MCS moved into the Ohio River Valley last night. THis
morning, the remnant MCV will continue to drift over the southern
tip of IL and the Ohio River Valley. As a result, have put in some
slight chance pops at the very least south of I-70 for today. Some
weak returns on radar back that up this morning, through the more
significant convection is in southeastern MO. Today continues a
period of warm temperatures, as temps are expected to near 90 in
most locations along and west of the I-55 corridor. East central
and southeastern Illinois may be limited by a few degrees with
cloud cover from the weakening MCV over the south.

Overnight tonight, models develop an MCS over the Upper Midwest,
and storms along the outflow dive south after midnight. So far,
the convection stops as it gets to NWrn IL. However, the
HRRR/NAMNest/GFS/NAM are different in where the convection
weakens. Depending on the strength of the cold pool, the southern
extent of the pops may shift in the next few runs of the CAMS.
Given the warm and muggy airmass, if the lifting mechanism is
strong enough, that precip/storm threat may need to move into
Central IL. For now, that is not the way the operational models
are looking, so most of the forecast through tonight is dry. 

.LONG TERM...(Friday through Wednesday)
ISSUED AT 328 AM CDT Thu Jun 27 2019
Extended is keeping the same forecast more or less... hot and
muggy. 850 mb temps remain in the 18C-20C range through the
weekend and into next week. A deep ridge builds over the center 
of the country, and some short waves ripple through the flow to 
the north and northeast... but Central IL remains largely dry from
synoptic systems. Of course, with the temperatures around 90, and
heat indices in the upper 90s...the airmass has plenty of 
conditional instability should it get triggered by mesoscale 
boundaries/outflow. There are some slight chances in the extended,
particularly in the north and northeast, closer to the apex of 
the ridge. The low pops more or less reflecting the waves that 
sneak a little closer to Central IL. 

&&

.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 612 AM CDT Thu Jun 27 2019

Modest south winds and VFR conditions are expected through the
period. There may be a few afternoon showers or storms near and
east of the I-57 corridor, however, coverage and confidence is too
low to include any mention in the CMI TAF at this time. Otherwise
fair weather should prevail through the period.

&&

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

&&

$$

UPDATE...07
SHORT TERM...HJS
LONG TERM...HJS
AVIATION...Deubelbeiss