562
FXUS63 KILX 222014
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
314 PM CDT Wed May 22 2024

.KEY MESSAGES...

- There is a 70% chance for thunderstorms Friday, with a level 1
  of 5 (marginal) risk some of these storms become severe. The
  strongest storms could produce damaging wind gusts and large
  hail.

- Scattered thunderstorms are likely (70-80% chance) on Sunday
  with severe storms possible.

&&

.DISCUSSION...
Issued at 314 PM CDT Wed May 22 2024

The cold front that passed through the area last night has pushed
deep into southern IL and currently lies in the OH River Valley.
Some showers and isolated thunderstorms have pushed into the
Taylorville area and may bring some light accumulations of rain
to parts of the south and eastern zones through the rest of the
afternoon hours. The upper wave associated with these showers is
expected to clear central IL by the evening hours. A strong or
marginally severe storm is possible in the far southern zones
(Crawford, Clay, Richland, Lawrence), but trends have signaled the
likelihood is decreasing. We may see a return of showers/storms
late tonight in the far south in the vicinity of the stationary
front. Otherwise, expect Thursday to be rather quiet weather-wise
with highs in the low 80s with sunny skies north and partly sunny
skies south near the stationary front.

On Friday, an upper wave will move from the Northern Rockies and
into the Northern Plains, becoming negatively tilted. The surface
low will stay in the Northern Plains, but cold front will push
east into IL. We`ll see a surge of high theta-E air north into IL
on Friday ahead of the front, but the upper support will remain to
the north. As a result, we`ll just see a Marginal Risk for severe
storms on Friday. MLCAPE will be around 3000 J/kg and deep shear
around 25-35 kts, although some models have more shear.

We`ll see a break on Saturday as high pressure moves in over the
area behind Friday`s cold front. Sunday looks to have the best
chance for severe weather in the next seven days. We`ll see better
upper support as an upper wave moves through the area. We`ll
likely have a lead shortwave Sunday morning followed by the main
wave Sunday afternoon/evening. Central IL is currently in a 15%
(Slight) risk for severe weather for Sunday given +3000 J/kg of
CAPE and 40-55 kts of deep shear. The area could see 1 to 2" of
rain with this system as well.

Northwest flow is expected for Monday and Tuesday, with some light
showers possible in the northwest flow to start the week.
Generally, expect a break from precipitation by midweek next week.

Knutsvig

&&

.AVIATION...  (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1226 PM CDT Wed May 22 2024

Isolated showers may move through central IL this afternoon,
without much fanfare. Expect SPI to have VCSH early in the period,
but after that, will amend TAFs if any showers approach a
terminal. Thunder is unlikely as mean MUCAPE in the HREF model is
<100 J/kg, but it as high as 300-500 J/kg in the latest NAMNest
run (so it`s not out of the question). The upper wave responsible
for these isolated & elevated showers will move through central IL
this afternoon. So expect shower activity to be to the south and
east of the TAF sites after 00Z. Gusts this afternoon drop of
sharply around 23Z...with light and variable winds by 01Z or
shortly thereafter.

Knutsvig

&&

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

$$