681
FXUS63 KILX 080800
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
300 AM CDT Sat Jun 8 2024

.KEY MESSAGES...

- A couple rounds of showers and storms are possible through this
  evening, with the highest chances being this morning.

- Near to slightly below normal temperatures will persist through
  early in the week, then things turn hot and humid late in the
  week.

&&

.DISCUSSION...
Issued at 300 AM CDT Sat Jun 8 2024

Broad northwest flow is positioned over a good portion of the
country to start the weekend, which will keep things somewhat cooler
than normal the next several days. Further west, a MCS is working
through central Missouri along the nose of a 40-45 kt LLJ. The LLJ
will lift toward southwest Illinois closer daybreak, working to help
eat away at low to mid-level dry air which was noted on the 08.00Z
KILX sounding. Showers and some storm activity should become likely
within a few hours of sunrise in our southwest, scraping mainly the
southern half of the forecast area through late this morning.
Rainfall amounts could approach 0.50" where the heavier pockets of
precipitation track near/south of I-72, but otherwise generally 0.10-
0.25" or less will be seen.

Later today, a shortwave trough working through the Great Lakes
Region will send a cold front into the area. Although cloud cover
may stick around through the afternoon, a few breaks in the clouds
paired with dewpoints in the middle to upper 60s should allow
instability to build. Most guidance shows 500-1000 J/kg over the
area, with the 08.00Z run of the HREF highlighting closer to 1500
J/kg. The HRRR continues to be the most bullish for shower and storm
chances this afternoon/evening ahead of the front, showing a line
more organized activity firing near I-72 right before sunset as the
CAP erodes. Despite this, the main thunderstorm activity is expected
to be focused south of here over southern Missouri/southern
Illinois/Kentucky where a remnant outflow boundary will be. This
activity could realistically consume all the available moisture and
skew our model projected instability, leading to much lower values
this far north. For now, have kept precipitation chances at 30% or
less, but confidence in afternoon/evening storm development is not
high at this point.

Upper ridging amplifies over the western CONUS at the start of the
new week, with central Illinois remaining under northwest flow. Near
to slightly below normal temperatures will prevail with things
looking to stay mostly dry through then. The ridge will spill
eastward and flatten out some due to a few upper shortwaves, turning
flow more zonal here. Upper ridging over the southwest US will allow
mid-level heights to increase through late in the week, turning
temperatures more summer-like late in the week. Rainfall looks
pretty minimal in the extended with perhaps a few passing upper
waves bringing occasional chances.

NMA

&&

.AVIATION...  (For the 06z TAFs through 06z Saturday Night)
Issued at 1159 PM CDT Fri Jun 7 2024

VFR conditions should continue through early this morning, with
MVFR ceilings materializing mid to late morning. These ceilings
should clear behind a cold front crossing the area between 22z
Saturday and 03z Sunday. Behind that front, gusty southwest winds
will veer to northerly and then gradually ease. A couple
thunderstorms could form along and just ahead of that front, but
uncertainty is too high to warrant a mention of lightning in the
TAFs at this juncture.

Bumgardner

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$