663
FXUS63 KILX 081742
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
1242 PM CDT Wed May 8 2024

.KEY MESSAGES...

- Areas of dense fog along and south of I-70 early this morning.

- Severe weather is possible along and south of a Quincy to
  Danville line this afternoon and evening: however, the highest
  probabilities for damaging winds, very large hail, and
  tornadoes will be focused further south from the Ozarks into the
  lower Ohio River Valley.

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

&&

.UPDATE...
Issued at 1050 AM CDT Wed May 8 2024

Current forecast is on track, but needed to make some adjustments
with the pops/wx grids to account for current thinking. Update
will be forthcoming.

Auten

&&

.SHORT TERM...(Today through Thursday)
Issued at 329 AM CDT Wed May 8 2024

Drier air advected into central Illinois from the W/SW last
evening...resulting in 08z/3am surface dewpoints dropping into the
lower to middle 50s everywhere north of I-70. Further south where
dewpoints remain in the lower 60s, fog has formed thanks to
clearing skies and calm winds. Given lowering visby trends and IR
satellite signals suggesting expanding fog, have issued a Dense
Fog Advisory for all counties along/south of I-70 through 8am.

After the early morning fog dissipates, quiet weather will prevail
through midday as attention focuses on an area of low pressure
tracking slowly eastward through Missouri. CAMs have consistently
shown convection developing near the low across west-central
Missouri by mid-morning...with the storms then tracking E/SE
along the prevailing baroclinic zone into southern Illinois/western
Kentucky. Think this will be the primary severe weather threat
this afternoon/evening...and several CAMs suggest it will remain
south of the KILX CWA. Given enhanced low-level shear near and
north of the stationary frontal boundary, NAM 0-3km VGP values
increase to 0.3-0.4 as far north as I-70. As a result, think
scattered cells with a risk of damaging wind gusts, large hail,
and tornadoes will be possible mainly across the SE CWA between
3pm and 9pm. Further north toward I-72, decreasing instability in
the drier airmass will lead to a much lower risk for an isolated
strong/severe cell.

Widely scattered showers and thunderstorms will remain in the
forecast tonight as the low pivots through the region...while the
primary severe threat drops further southeastward into the
Tennessee River Valley. The low will exit into Indiana on
Thursday: however, an upper trough over the Upper Midwest will
drop southward toward Illinois by late in the day. Given
increasing synoptic lift and ample lingering moisture, showers and
a few thunderstorms will be possible as high temperatures drop
into the 60s everywhere north of I-70.

Barnes

.LONG TERM...(Friday through Tuesday)
Issued at 329 AM CDT Wed May 8 2024

A series of short-wave troughs dropping southward out of Canada
will ensure below normal temperatures and periodic shower chances
across central Illinois through Saturday. Highs both Friday and
Saturday will remain in the 60s while overnight lows dip into the
40s.

As the prevailing upper trough lifts northeastward and heights
begin to rise, temperatures will warm back to normal for this time
of year in the middle 70s by Sunday...then above normal to around
80 degrees by next Tuesday. Rain chances will increase as
well...particularly by the middle of next week as a southwesterly
flow pattern tries to establish itself.

Barnes

&&

.AVIATION...  (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1242 PM CDT Wed May 8 2024

All sites will start as VFR with only mid level cigs seen on
satellite for early this afternoon. Cigs will come down to around
5kft as more stratiform rain moves over the sites this afternoon.
Only site expected to see thunder will be SPI but will only have
as VCTS since storms will be well south of the area. Any lightning
in the SPI area will be from high anvil clouds. Other sites should
be well north of any lightning. Predominate showers will be seen
at PIA and BMI later this afternoon into this evening as a
inverted sfc trough rotates through the area. Other sites will
have VCSH into the late evening hours, then ending around
midnight. Cigs will also drop into MVFR category for later this
evening and continue into the overnight hours. In the morning,
cigs will drop further...into IFR category with 700-800ft
expected. Widely scattered showers may continue during the
overnight hours and into the morning, but believe scattered enough
to not warrant VCSH or predominate showers on station. Winds will
be south to southeast through the afternoon, however, westerly
winds are expected tomorrow morning at all sites. Wind speeds will
be around 10-12kts at all sites and through the TAF period.

Auten

&&

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

$$