613
FXUS63 KPAH 040535
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
1235 AM CDT Thu Jul 4 2024

.KEY MESSAGES...

- Multiple rounds of strong to severe thunderstorms are
  possible tonight and again late Thursday night (Independence
  Day). Damaging winds will be the main threat.

- The thunderstorms will produce heavy rain, and areas of flash
  flooding are possible across parts of southeast MO into
  southwest IL. A Flood Watch has been issues for these areas
  from tonight through late Thursday night.

- Sultry heat and humidity will continue through early tonight
  for much of the area, and a Heat Advisory remains in effect
  until 8 PM CDT. Another Heat Advisory may be needed for parts
  of the area on Thursday as well.

- Drying out with less hot and humid conditions this weekend.
  The next chance the thunderstorms arrives early next week.

&&

.UPDATE...
Issued at 1232 AM CDT Thu Jul 4 2024

Updated Aviation discussion for the 06z TAF issuance.

&&

.DISCUSSION...
Issued at 254 PM CDT Wed Jul 3 2024

Complex mesoscale setup for the forecast for the rest of the
day. Satellite imagery shows an outflow boundary extending from
just south of CGI to PAH to EHR with robust CU development and
a couple of thunderstorms firing south of the this feature.
Further north is still recovering from morning debris clouds and
showers, with CU development still suppressed. Expect that as a
cold front approaches from the northwest, storms will fire and
grow upscale into clusters and bowing segments in the very
unstable (SBCAPE is round 3000-5000 J/kg) but modestly sheared
(effective bulk shear values are 25-40 kts). The primary severe
hazards will be from damaging winds as updrafts collapse and
gust out.

The other concern will be for possible flooding. PWATs remain
very elevated around 2.0-2.1", and there is a good chance that
storms that develop will train from west to east along the cold
front or outflow boundaries. This could lead to several inches
of rain falling in a short amount of time. Right now, the great
risk of flash flooding looks to be across east-central MO into
southeast MO and southwest IL. Collaborated with WFOs
Springfield and St. Louis on a Flood Watch that will begin at
00z Thursday and run through 06z Friday due to the potential for
additional rounds of rain Thursday morning and again late
Thursday night. Depending on how the storms evolve, an expansion
of the Flood Watch may be needed.

The final notable story today is the heat. The advertised
sticky dew point temperatures have arrived, and most areas are
seeing values in the middle to upper 70s (a few spots are even
over 80 degrees!). Combined with temperatures in the upper 80s
to lower 90s, nearly every station in the ongoing Heat Advisory
has reached criteria. Planning to let the Heat Advisory expire
as scheduled at 01z Thursday. Looking ahead to Independence Day
on Thursday, depending cloud and lingering rain shower coverage,
some areas near the AR/TN borders may need another Heat
Advisory for the afternoon hours. Either way, it will be a warm
and extremely muggy Fourth of July, with dew point temperatures
in the upper 70s to lower 80s forecast during the afternoon
hours, along with high temperatures in the middle to upper 80s
in most locations.

After tonight`s storms, expecting additional non-severe showers
and thunderstorm to persist through the morning and early
afternoon hours on Thursday as the frontal boundary becomes
stalled across the region. However, a period of dry conditions
is looking more likely as we go into the mid to late afternoon
and evening hours, especially across southwest IN and west KY.
Further west, the precipitation will be isolated to widely
scattered. This may allow most firework displays to proceed
without too much trouble (except for high humidity and muddy
viewing areas). However, another round of thunderstorms looks to
develop across the Ozarks late Thursday night, which will grow
into an MCS as it moves through our region late Thursday night
into Friday morning. This activity should be in a weakening
mode as it arrives, but a few damaging wind gusts are possible,
especially near and west of the Mississippi River. SPC has a Day
2 Slight Risk here, and that looks good right now.

Friday will see the lingering precipitation slowly shift south
and east of the region as cold front slowly clears the forecast
area. In its wake, cooler and less humid conditions will
arrive, setting the stage for a pretty nice weekend. High
temperatures on Saturday and Sunday will reach the middle to
upper 80s with overnight lows in the 60s. Our next chance of
showers and thunderstorms will arrive late Sunday night into
Monday as shortwave trough moves into the Central Plains. This
feature may try to draw some tropical moisture northward into
our region as we get into the middle of next week, but
confidence remains low at this time. Temperature and humidity
levels will begin to draw upward again Monday and Tuesday, with
forecast highs in the upper 80s to lower 90s and dew point
temperatures near the 70 degree mark.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1235 AM CDT Thu Jul 4 2024

Shower and storm activity has trended lighter across the area
though remains, mainly in the Kentucky Pennyrile. Fog
development is possible in the north, particularly at
climatologically favored sites. The next round of showers and
storms moves through in the morning, mainly as a line sweeping
through while training showers are looking likely to be north of
the I-64 corridor. A period of less shower coverage for the
afternoon and early evening gives way to another round of storms
entering late evening and continuing into the overnight hours.
MVFR cigs are more likely during the day in the north but are
possible at times in the south. Fairly calm winds through the
overnight hours increase to 6-10 kts out of the southwest during
the day.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...Flood Watch through late tonight for ILZ080-084.
MO...Flood Watch through late tonight for MOZ076-086-087-100.
IN...None.
KY...None.

&&

$$

UPDATE...ATL
DISCUSSION...DWS
AVIATION...ATL