413
FXUS63 KPAH 231953
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
253 PM CDT Mon Sep 23 2024

.KEY MESSAGES...

- Chances for showers and thunderstorms will continue through
  tonight and the first part of Tuesday. An isolated strong to
  severe thunderstorm cannot be ruled out. Heavy rain will also
  be possible.

- A cold front will move through the region Tuesday, bringing a
  brief spell of dry weather Tuesday night through Wednesday
  afternoon.

- The remnants of tropical system look to bring rainy and breezy
  weather beginning Thursday through part or all of the
  weekend. Locally heavy rain is possible during this time.

&&

.DISCUSSION...
Issued at 253 PM CDT Mon Sep 23 2024

Tonight through Tuesday night...Tricky forecast for near term
part of the forecast, particularly with the potential for severe
thunderstorms. Aloft, there is a positively-tilted longwave
trough moving through the Central Great Plains towards the
region. An H5 shortwave is also embedded within this flow
pattern. At the surface, a weak surface low is located over
eastern MO, with an associated warm front extending through
southeast MO into far southern IL and far western KY. A trailing
cold front extends southward over central and southern MO.

Ongoing elevated convection across the EVV Tri-State will be
exiting the region by 20-21z, but isolated to scattered surface-
based convection will develop through the afternoon hours.
Tonight, as the H5 shortwave approaches, more organized
convection may develop across southeast MO and sweep eastward
through the region of the region. Confidence regarding how
severe tonight`s storms will be is low. Surface winds may be
locally-backed to the SE just south the warm front, which could
enhance low-level shear. However, cloud cover is pretty
plentiful, and mid-level lapse rates are very low. The bullish
scenario is that a few low-topped supercells with with a
marginal wind and tornado risk develop over southeast MO and
grow upscale into clusters and bows as they move east, with
primarily a damaging wind risk. The bearish case is that non-
severe clusters of storms develop tonight, with a marginal risk
of localized heavy rain.

By Tuesday morning, the surface cold front will begin to move
through the region, bringing a brief return of dry weather. A
few thunderstorms may develop ahead of the front in the mid to
late morning hours over the EVV Tri-State southward into the KY
Pennyrile. Cannot rule of these storms becoming strong to severe
before exiting the forecast area, but the better severe
thunderstorm environment looks to be across southern IN and
central into southern KY.

Wednesday through Sunday night...Forecast confidence remains low
for the extended part of the forecast. While Wednesday looks to
be the driest day of the next several, the region will still be
under the influence of broad synoptic troughing. This will bring
a modest chance of showers during a good part of the day. Cloud
cover will be fairly plentiful as well. The big question mark
remains how will the remnants of future Tropical System Helen
impact the region after making landfall along the Florida Gulf
Coast sometime late Thursday.

The remnant surface low and tropical moisture may interact with
and eventually be drawn westward into the Lower Ohio Valley by
the deep trough over the Midwest and Mid- South. If this occurs,
rain chances will be plentiful as the disturbance will be very
slow to exit the region. The NBM initialization brings the
heaviest rains to the region Thursday night through Friday
night, with rain chances slowly diminishing over the weekend.
Given the very moist environment, heavy rainfall is possible.
The latest QPF from WPC shows a broad brush of 1.5-3.0" over the
region during this time. The heaviest rainfall totals at this
time look to be over southeast MO, and the lightest amounts are
across the Wabash River Valley. There are a lot of moving parts
to this forecast, and any change in that may significantly
affect the forecast. Check back frequently for updates over the
next 24-48 hours.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1225 PM CDT Mon Sep 23 2024

Low confidence TAFs for the 18z package. The expectation is that
steady SHRA/TSRA activity will depart the MVN/EVV/OWB areas by
19-21z, with a relative lull in storm activity until this
evening when a cold front will begin to move into the region.
This will kick off more storms, mainly scattered in coverage
during the 00-09z window. Rainfall activity will diminish
thereafter. Cigs will jump around a lot this afternoon between
MVFR and VFR as CU decks build and dissipate.

Overnight, there is a better signal for widespread low MVFR or
IFR cigs, as well as some fog. Cigs/vsbys will improve a bit
late in the period as drier air arrives. Winds will be light and
variable this afternoon, becoming S to SW overnight AOA 5 kts.
Behind the cold front, winds will shift to the W or WSW at 5-10
kts.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.

&&

$$

DISCUSSION...DWS
AVIATION...DWS