231
FXUS63 KILX 051745
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
1245 PM CDT Wed Jun 5 2024

.KEY MESSAGES...

- A cold front is passing through central Illinois this morning,
  bringing showers and thunderstorms ahead of it. The front should
  exit to the east of Illinois around early afternoon.

- A mainly dry pattern sets up starting this afternoon. A small
  (10- 20% chance) opportunity for rain arrives this weekend as
  some MCS type systems pass to our south.

-  High temperatures stay in the mid to upper 70s through next
   Wednesday, before warming back up into the 80s for late next
   week.

&&

.UPDATE...
Issued at 1014 AM CDT Wed Jun 5 2024

15z/10am surface analysis shows a cold front approaching the I-55
corridor...with widely scattered showers/thunder lingering across
the eastern half of the KILX CWA. Latest runs of the HRRR/RAP are
showing re-development along the cold front across east-central
Illinois this afternoon as the atmosphere becomes modestly
unstable with SBCAPEs peaking at 1500-2000J/kg. Have updated PoPs
to better reflect current trends and have added likely PoPs
along/southeast of a Danville to Effingham line after 17z/12pm.
Rain chances will end across the far E/SE by late afternoon.
Further west, skies have cleared northwest of the Illinois River
and this clearing will work its way eastward to the I-57 corridor
by mid-afternoon. High temperatures will top out in the upper 70s
to around 80 degrees.

Barnes

&&

.DISCUSSION...
Issued at 244 AM CDT Wed Jun 5 2024

As the cold front approaches from the west this morning, some
showers and thunderstorms push across central Illinois just ahead of
it. Severe threats appear to be low with these storms. These storms
will be scattered in a semi-line formation. As it works eastward,
locally heavy rainfall is possible. The activity should be out of
the area by 18/19z this early afternoon (based on the 06z HRRR),
exiting to the east into Indiana.

There is secondary weak cold front that will pass through overnight,
which could cause some showers to pop up in our far northern
counties of the CWA. However, confidence is low so only have 15-20%
POPs in the forecast for late this evening through tonight. Once
these fronts pass, a surface ridging pattern sets up to our
southwest and a upper trough sets up to our northwest, trapping
us in the middle. This will allow a mostly dry period for the
extended forecast. The next tiny chance for rain comes Saturday
and Sunday as MCS activity transverses to our south. There is a
10-20% chance that the systems move just north enough to affect
our southern portion of the CWA. As we move closer we can get a
better idea of the exact location of these southern MCS systems
and if they will directly affect us here in central and
southeastern Illinois.

Daytime temperatures following this cold front will hang around the
mid to upper 70s through next Wednesday. Then it will warm back up
into the 80s starting Wednesday afternoon. CPC shows below normal
temperatures for the 6-10 day period and near normal to above for
the 8-14 day period.

Copple

&&

.AVIATION...  (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1245 PM CDT Wed Jun 5 2024

Cold front is crossing the I-55 corridor early this afternoon...so
have maintained VCSH at all terminals except KPIA for the next
couple of hours. 1730z/1230pm satellite imagery shows MVFR cloud
cover along/ahead of the frontal zone...with skies clearing
along/west of the Illinois River. Based on satellite timing tools
and 12z NAM/RAP forecast soundings, have scattered the low clouds
at KSPI by 19z...then further east to KCMI by 22z. After that,
clear skies will prevail through the evening before a secondary
cold front brings a band of SCT-BKN mid-level clouds at around
9000ft late tonight into early Thursday morning. Winds will
initially be SW at around 10kt ahead of the front, then will veer
to W/NW after FROPA. Given tightening pressure gradient and
favorable mixing conditions behind the second front, strong/gusty
NW winds will develop on Thursday. Have added gusts of 20-25kt
after 15z Thu accordingly.

Barnes

&&

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

$$