900
FXUS63 KPAH 162353
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
653 PM CDT Tue Jul 16 2024

.KEY MESSAGES...

- Scattered thunderstorms are expected this afternoon mainly to
  the south of a Poplar Bluff Missouri to Madisonville Kentucky
  line. A stray strong storm with gusty winds remains possible.

- Another round of showers and thunderstorms is expected to push
  eastward across the Quad State tonight. Heavy rainfall and
  flash flooding will be possible. The Flood Watch will continue
  as is through 7 AM Wednesday.

- A cooler and much less humid air mass will remain over the
  Quad State from Thursday through early next week.

- A small chance of thunderstorms returns Sunday and increases
  through next Tuesday. At this time, severe storms and
  widespread heavy rainfall are not anticipated.

&&

.UPDATE...
Issued at 652 PM CDT Tue Jul 16 2024

Updated aviation discussion for 00Z TAFs.

&&

.DISCUSSION...
Issued at 320 PM CDT Tue Jul 16 2024

The Quad State will be in weak cyclonic flow aloft in the base
of an upper trough over Ontario and the Great Lakes. Two MCVs
will impact the region through tonight. The first is responsible
for ongoing flash flooding in Jefferson and Perry counties in
southern Illinois. It will ride along I-64 through sunset and
force scattered showers and storms over southern portions of the
region, generally south of a Poplar Bluff Missouri to
Madisonville Kentucky line. The shear is weak and instability is
considerably lesser than expected due to the ample cloud cover.
A stray strong to severe storm with gusty winds cannot be ruled
out.

The second MCV is located over southeast Kansas and will ride
eastward across the Quad State later tonight. It will likely
generate an area of showers and thunderstorms with torrential
rainfall as it moves through the region. The exact zone of
heaviest rainfall is hard to call, but in general, still seems
to be across the north. To this point the flooding concern has
been contained within the existing Flood Watch and the 1-2"
additional QPF is mostly within it, so will leave it alone and
let it go to expiration at 7 AM.

The cold front will push southeast through the Quad State
Wednesday. Although clouds could once again hamper heating ahead
of it to some extent, a juicy air mass should remain and allow
for scattered to numerous showers and storms along and ahead of
the front. Shear will once again be limited, and instability may
be as well, so organized severe storms are not expected at this
time. Heavy rainfall will be more isolated and generally
southeast the heavy rainfall expected through tonight, so
flooding concerns will also be limited Wednesday.

For Thursday through the weekend, the Quad State will be under
the influence of a persistent trough aloft and dry high
pressure at the surface. This will keep the area dry and
downright pleasant through at least Saturday. Highs will be in
the lower half of the 80s with low humidity and lows will be
around 60.

Some PoPs return to the forecast Sunday as a short wave trough
settles over the central Plains and the air mass tries in vain
to modify. The PoPs then ramp up to likely levels by next
Tuesday afternoon, as southwest flow aloft increases over the
region. The prospects for rainfall before then are rather slim,
despite the NBM PoPs. Temperatures will remain below normal
through next Tuesday.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 652 PM CDT Tue Jul 16 2024

This forecast is certainly one of lower confidence given the
thunderstorm activity and sky cover that were both more
persistent than expected today. Many of the CAMs suggest the
potential for another round of thunderstorms later tonight into
early Wednesday morning. However, latest radar trends indicate
most of the new development is occurring along and south of the
Missouri-Arkansas border. My gut tells me that we may not see
all that much as most of the activity stays just south of the
area. However, with subtle energy forecast to shift east into
the area, will maintain a mention of showers and thunderstorms
in the forecast for now, and will amend as necessary later this
evening. Most model data also develops MVFR ceilings across the
area late tonight into Wednesday morning, with a transition to
VFR by Wednesday afternoon. Light winds tonight will gradually
become northwest at 5 to 10 knots by Wednesday afternoon.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...Flood Watch through Wednesday morning for ILZ075>078-080>089.
MO...Flood Watch through Wednesday morning for MOZ076-086-087-100-
     107-108.
IN...Flood Watch through Wednesday morning for INZ081-082-085>088.
KY...Flood Watch through Wednesday morning for KYZ014-018-019.

&&

$$

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