650
FXUS63 KPAH 230802
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
302 AM CDT Mon Sep 23 2024

.KEY MESSAGES...

- Multiple rounds of showers and thunderstorms are expected
  through Tuesday. A few severe storms with damaging winds and
  possibly some hail cannot be ruled out this afternoon and
  evening and again Tuesday afternoon. Locally heavy rainfall
  will occur with thunderstorms.

- A cold front moves through Tuesday leaving behind cooler
  conditions for the remainder of the forecast.

- Daily chances of rain are forecast Wednesday through next
  weekend, as an upper-level low pressure center lingers over
  the Quad State.

- A tropical system developing over the western Caribbean Sea
  is expected to develop as it moves north through the eastern
  Gulf of Mexico this week. There is some potential that the
  remnants of this system could bring some heavy rain to the
  Quad State late in the week.

&&

.DISCUSSION...
Issued at 302 AM CDT Mon Sep 23 2024

A positively-tilted upper trough over the central Plains early
this morning will move eastward through the Mid-Mississippi
Valley through Tuesday. An associated diffuse cold front over
the region will be held up today and tonight, as an area of low
pressure rides northeast along it. The front will shift east of
the Quad State later Tuesday. This situation will allow multiple
rounds of showers and thunderstorms to develop and lift northeast
across the Quad State through Tuesday.

Much of the 00Z and later guidance indicates that there will be
a round of convection this morning, mainly over southeast
Missouri and southern Illinois, with a relative lull across the
region this afternoon. The most persistent signal in guidance
has been for widespread convection with heavy rainfall tonight
into Tuesday. Although there are some timing differences, the
general consensus is for the convection to come to an end from
the west through the day Tuesday.

With widespread cloud cover expected through the period, it will
be difficult to destabilize, leading to meager instability.
Shear will generally be increasing through Tuesday when the
upper trough passes. This very marginal environmental set up
could support a few severe storms with mainly a damaging wind
concern this afternoon and early evening. With better shear
expected Tuesday, a few severe storms will be possible again in
the east, if there is any instability to work with.

Additional rainfall through Tuesday will average 1" to 1.5"
over most of the Quad State. Lesser amounts are expected over
southern portions of west Kentucky. These amounts should not
result in significant flooding issues, but drainage systems may
be briefly overwhelmed in the heaviest downpours.

Once the cold front and associated convection exit the area late
Tuesday, surface high pressure should result in cooler
temperatures for the remainder of the week. Highs will be at or
a bit below normal, while lows will remain around 5 degrees
above normal.

In the wake of the early week storm system, more energy will
descend from Canada and settle as a closed low somewhere across
the mid-Mississippi Valley by Wednesday. The low will support
daily chances of showers through next Monday. The tropical
system attempting to develop over the western Caribbean Sea is
expected to lift north through the eastern Gulf of Mexico and
will interact with the upper low.

There is considerable uncertainty in the location of the upper
low and in how it will interact with the tropical system.
However, there is the possibility that some tropical moisture
could be drawn around the east side of the upper low and into
the Quad State. This would lead to increased humidity and more
widespread heavy rainfall potential. At this time, it looks like
this would be most likely late Thursday into Friday. WPC QPF
from Wednesday night through next Monday ranges from around 1"
in Pike county Indiana to over 4" in Ripley county Missouri. We
will have to keep a close eye on this situation for some
potential flooding concerns, especially given the rainfall that
has recently fallen and that is expected to fall early this
week.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1221 PM CDT Sun Sep 22 2024

High MVFR ceilings will slowly rise over parts of southeast
Missouri as convective clouds begin forming. Thunderstorm
development is expected over the region later this afternoon and
through early evening. A decrease in activity is then expected
after sunset. After midnight increased influence from an
approaching storm system is expected to lead to lower ceilings
with rain showers and embedded thunderstorms possible from about
08-15z. The new forecast calls for low MVFR ceilings although
IFR ceilings are possible. Below VFR ceilings are expected
through midday Monday with areas of rain and a few thunderstorms
remaining possible.

&&

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

&&

$$

DISCUSSION...DRS
AVIATION...DH