Orel, Illinois Weather Forecast Discussion

686
FXUS63 KPAH 221852
AFDPAH
Area Forecast Discussion
National Weather Service Paducah KY
152 PM CDT Mon Sep 22 2025
.KEY MESSAGES...
- Additional rounds of showers and thunderstorms will provide
  more rainfall through the middle of the week. Additional
  rainfall between 0.5 to 1.5 inches is possible, with locally
  higher amounts.
- The risk of a stronger storm remains low, but is non-zero this
  afternoon and Tuesday afternoon. The main concern would be
  gusty winds, small hail, lightning, and heavy downpours.
- Slightly below normal temperatures in the latter half of the
  week rebound back to normal by the weekend with dry weather
  conditions.
&&
.DISCUSSION...
Issued at 152 PM CDT Mon Sep 22 2025
A highly amplified 500 mb synoptic pattern will cause multiple waves
of PVA associated with a broad trough over the central CONUS,
bringing intervals of pcpn. Peak diurnal heating with breaks of sun
is already causing scattered showers and isolated storms to
redevelop over the FA, and will become better organized into
this evening. A strong storm or two will be possible mainly
over the Kentucky Pennyrile and southwest Indiana where SPC has
a D1 marginal. The main concern will be gusty winds along with
lighting and heavy downpours given MLCAPE of 1000 to 1500 J/kg,
20-25 kts of effective bulk shear, and low level lapse rates
around 6.0-6.5.
Any storms should quickly diminish after sunset as the 12z CAMs
have trended drier for the overnight hours. However, areas of
fog are now progged for Tuesday morning as the time heights
show the condensation pressure deficit reaching 10 to 30 mb
near the sfc due to partial clearing. Given that the crossover
temperature will also likely be reached at many locations
combined with the recent rainfall, would not be surprised to see
some locally dense fog develop with winds turning calm.
While a bit of a lull occurs on Tuesday, the risk of heavy rainfall
still remains as a 500 mb vort max digs towards the FA and provides
more robust synoptic scale forcing for ascent Tuesday afternoon into
Tuesday night. Slowed down NBM PoPs a bit as the consensus on
the CAMs including the HRRR show the bulk of pcpn occurring
Tuesday evening into Tuesday night across the FA. It is worth
noting the HREF PMM only supports 0.5 to 1.5 inches of
additional QPF through 12z Wednesday as convection associated
with better instability remains focused in Arkansas and helps to
inhibit the moisture transport to some extent.
While WPC maintains a slight ERO, would lean towards any flooding
issues being more localized in the typical vulnerable locations, and
not enough to warrant a flood watch at this time. However, PWAT`s
are still progged to reach 1.7 to 1.9 inches, supporting heavy
rainfall rates with storms that will cause short duration runoff on
roadways. 1500 to 2000 J/kg of MLCAPE combined with 25 to 30 kts of
effective bulk shear and steeper low level lapse rates around 7.0
to 8.0 C/km support SPC`s D2 marginal severe risk for gusty winds
and hail mainly over southeast Missouri and western Kentucky.
Model guidance remains in better agreement with a 500 mb longwave
trough digging across the Ohio Valley on Thursday. The more
progressive scenario with an open wave versus closed cut off low
means the heavy rain risk will be over; however, residual 700 mb
moisture and lift will still support a few light rain showers during
the day, with only a stray shower or two lingering into Friday to
end the week.
Seasonable temperatures with highs in the low 80s trend about 3 to 5
degrees below normal into the mid to upper 70s through the latter
half of the week. Lows in the 60s trend into the 50s by the end of
the week, followed by highs rebounding back into the low 80s for the
weekend. Overall a pleasant weekend with dry conditions is
progressed as a ridge of high pressure will be in control,
suppressing unsettled weather associated with a cut off low down
south.
&&
.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1201 PM CDT Mon Sep 22 2025
The first round of showers and storms over the eastern terminals
will exit the region this afternoon. IFR/MVFR cigs will remain
probable mainly across the northern terminals. Additional
scattered showers and storms will be possible later this
afternoon and evening across all terminals. Brief vsby and cig
reductions can be expected with storms along with isolated
gusty winds.
Pcpn now tapers off quicker for the overnight; however, there
is a strong signal on the latest model guidance for areas of fog
to develop early Tuesday morning. Have included LIFR TEMPOs for
all terminals, but it is possible some of the western terminals
in particular could reach VLIFR with patchy dense fog.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
DISCUSSION...DW
AVIATION...DW

NWS PAH Office Area Forecast Discussion