120
FXUS63 KILX 091725
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
1225 PM CDT Thu May 9 2024

.KEY MESSAGES...

- Cooler weather is on tap for the end of the week with overnight
  lows dipping into the 40s tonight through Saturday night.

- The next significant chance for widespread showers and
  thunderstorms will hold off until early next week.

&&

.SHORT TERM...(Today through Friday)
Issued at 334 AM CDT Thu May 9 2024

Low pressure currently centered over central Illinois will track
slowly eastward today. Despite rising surface pressures, a trailing
upper trough extending from the Great Lakes into the Plains will
sink southward...providing synoptic lift for scattered showers.
May see a couple thunderstorms as well, as NAM MUCAPE values
exceed 1000J/kg from late morning through the afternoon. High
temperatures will mainly be in the middle to upper 60s, but will
reach the lower to middle 70s along/south of I-70 where partial
sunshine will be observed. Widely scattered showers will persist
tonight as the trough drops into central Illinois. Overnight lows
will dip into the 40s. As the wave gradually departs, synoptic
subsidence on its back side will provide partial clearing and dry
weather on Friday with highs remaining in the middle to upper 60s.

Barnes

.LONG TERM...(Saturday through Wednesday)
Issued at 334 AM CDT Thu May 9 2024

Another short-wave trough evident on latest water vapor imagery
over northern Alberta/Saskatchewan will drop southeastward into
the Great Lakes Friday night into Saturday. While the strongest
lift will remain N/NE of central Illinois, scattered showers will
be possible across the N/NE KILX CWA Friday night...with the
showers pushing further east into Indiana by Saturday. Generally
dry weather is expected over the weekend...with highs around 70
on Saturday climbing into the middle to upper 70s by Sunday.

A cut-off upper low spinning over the Great Basin will gradually
get shunted northeastward early next week, with models showing
typical timing differences at this range. Based on consensus,
think the low will slowly approach from the southwest and begin to
impact the weather across central Illinois by late Monday. As the
feature gets closer and deep-layer moisture increases, showers and
thunderstorms will become likely Monday night into Tuesday.

Barnes

&&

.AVIATION...  (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1225 PM CDT Thu May 9 2024

Look for predominantly MVFR ceilings north of a line from near
KI63-KSPI-KPRG this afternoon, with perhaps periods of IFR
ceilings developing north of that line. Greater coverage of MVFR
ceilings will drop southward with time late this afternoon and
this evening as a frontal boundary moves southward. Coverage of
showers should be fairly extensive north of that line as well,
with lesser coverage southward. Enough instability is present for
an isolated thunderstorm or two to develop as well. That mention
has been added to the KDEC TAF, where the probability is greatest.

Look for ceiling heights to perhaps come up to low VFR overnight,
remaining MVFR in some locations. A gradual increase in ceiling
heights is forecast during the day Friday.

AAT

&&

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

$$