085
FXUS63 KPAH 182324
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
624 PM CDT Sat May 18 2024

.KEY MESSAGES...

- An brief, isolated thunderstorm cannot be ruled out near the
  Tennessee border in west Kentucky this afternoon.

- Dry and very warm conditions are expected Sunday through
  Tuesday.

- Chances of thunderstorms return to the forecast Tuesday night
  and continue through next Saturday. Tuesday night through
  Wednesday night will have the best chances of thunderstorms
  and some potential for severe weather. A heavy rainfall and
  flooding threat could eventually develop.

&&

.UPDATE...
Issued at 623 PM CDT Sat May 18 2024

Updated aviation discussion for 00Z TAFs.

&&

.DISCUSSION...
Issued at 224 PM CDT Sat May 18 2024

The pesky upper low is slowly drifting southeast of the Quad
State this afternoon, but it is still forcing scattered showers
near the Tennessee border in west Kentucky. A stray thunderstorm
is possible. If one were to develop it would provide a brief
heavy downpour and period of lightning.

As the upper low progresses slowly to the southeast, a ridge of
high pressure aloft will develop over the Quad State tonight and
continue through Tuesday. The ECENS and GEFS both ping 700mb
temperatures with a 5-10 year return interval on Tuesday, so the
ridge is likely to prevent any convection from developing over
or moving into the Quad State through the day Tuesday. The 12Z
guidance and even the NBM now keep the entire area dry until
Tuesday evening.

South winds will increase on Tuesday and may require a Lake Wind
Advisory. The south winds will help temperatures soar into the
lower 90s over the western half of the region Tuesday afternoon.
Highs Sunday and Monday will generally be in the upper 80s. It
will definitely be hot, but the humidity is not ridiculous, yet.

The ridge finally gives way Tuesday night into Wednesday,
allowing one or more disturbances to bring showers and
thunderstorms to the Quad State. The 12Z guidance generally
holds it off through the evening, and then brings the first
round eastward overnight into Wednesday morning. A weak cold
front will attempt to move through the region Wednesday into
Wednesday evening, and that could provide our best chance of
severe storms, depending on how much the late night/early
morning convection muddles up the environment. For that initial
round of convection it looks like the best forcing and flow will
lag behind it, and the late night timing certainly is not good
for the instability.

It is not certain if the front will actually make it through the
entire area Wednesday/Wednesday night, and if it does, it
certainly won`t make it very far south of the area. Therefore,
there will be some chance of training thunderstorms over
southern portions of the region Wednesday into Wednesday night,
and that could lead to some flooding concern.

The flow aloft will become zonal by Thursday and with the
boundary not likely to be far south of the Quad State,
disturbances in the flow could easily bring the boundary back
across the region, resulting in more rounds of convection. The
NBM has a lot of likely PoPs late in the week, which are
probably overdone given the uncertainty displayed in the
models, but we cannot argue with some PoPs each day through next
Saturday. The repeated rounds of convection could eventually
lead to a heavy rainfall and flooding threat.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 623 PM CDT Sat May 18 2024

VFR conditions are forecast through much of the forecast period.
The main exception is the potential for patchy fog overnight,
which may reduce visibilities to MVFR or IFR at times. Calm
winds tonight will become light and variable on Sunday.

&&

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

&&

$$

UPDATE...RJP
DISCUSSION...DRS
AVIATION...RJP