300
FXUS63 KILX 141022
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
522 AM CDT Sat Jun 14 2025

.KEY MESSAGES...

- Scattered showers will linger today across portions of east-
  central and southeast Illinois. Severe weather is not a concern,
  but there could be a few funnel clouds this afternoon.

- A more active weather pattern will bring additional periods of
  showers and thunderstorms to the region each day between Tuesday
  and Thursday, with an attendant severe weather and flood risk.


&&

.DISCUSSION...
Issued at 337 AM CDT Sat Jun 14 2025

A compact upper-level trough will continue to meander along the
lower Ohio River Valley today, with enough moisture and lift to
support widely scattered showers. Hi-res ensemble guidance points
the greatest coverage near and south of I-72, with activity
increasing later this morning with the heat of the day, then
diminishing by evening. Much like yesterday, thunder chances for
today are slim. This is primarily due to poor mid-level lapse
rates (< 6 C/km) and weak deep-layer shear (< 20 kts), suggesting
updrafts will struggle. Additionally, the risk for urban flooding
is lower today compared to yesterday. While cloud-layer winds and
Corfidi upshear/downshear vectors remain slow, the more anomalous
PWATs have begun to peel eastward out of the area. Rather than
pockets of 1-2 like we had yesterday, localized amounts between
0.5-1 seem more reasonable for today, and this is supported by
the latest HREF QPF guidance.

Funnel clouds will be a thing to monitor for today. Guidance from
both the HRRR and RAP13 depict quite a bit of vorticity along a
sfc boundary positioned somewhere in between I-72 and I-70 by this
afternoon. If we can get enough breaks in the clouds to boost
low-level lapse rates and low-level vorticity beneath the upper
low, there should be enough stretching to support funnel clouds
through the afternoon hours. For what its worth, the NST
parameter exceeds a value of 3 at times this afternoon across SE
Illinois.

Dry and seasonably hot conditions return Sunday and Monday as we
find ourselves in a bit of blocking pattern (split flow).
Deterministic NBM guidance is offering daily highs in the mid 80s,
and we see no reason to stray from that forecast.

The synoptic pattern becomes more conducive for showers and
thunderstorms from Tuesday onward, particularly across the
Northern Plains and Upper Mississippi Valley where a moderately
buoyant airmass will build beneath a strengthening mid-level jet
core. This influx of CAPE & shear will increase the specter of
severe weather as early as Tuesday night across our north, perhaps
becoming more widespread Wednesday or Wednesday evening.

Mid-range guidance remains in reasonable agreement for the back
half of next week, with an expansive 594-mb summer high building
across the central US. This would provide a spell of dry and hot
weather. Current deterministic NBM guidance offers daily highs in
the upper 80s by Saturday of next week, but with an upper tail of
its guidance in the lower 90s.

MJA

&&

.AVIATION...  (For the 12z TAFs through 12z Sunday Morning)
Issued at 506 AM CDT Sat Jun 14 2025

IFR/LIFR conditions will gradually improve to MVFR this afternoon
as a slow-moving weather system begins to depart eastward. Most
guidance supports the stratus lifting and breaking to MVFR prior
to 18z, and then improving to VFR by 00z as a shortwave ridge
builds into the region from the west. Otherwise, light NE winds
will persist through this TAF period.

MJA

&&

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

$$