291
FXUS63 KPAH 030832
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
332 AM CDT Wed Jul 3 2024

.KEY MESSAGES...

- A Heat Advisory will be in effect from 11 AM to 8 PM CDT today
  for most of the Quad State. Only Perry county Missouri and the
  northwest portions of southern Illinois are not in the
  Advisory. More triple digit heat indices are possible mainly
  over the southwest half of the region Thursday afternoon.

- Strong to severe thunderstorms are possible this Wednesday
  afternoon and evening and again Thursday afternoon and night.
  Damaging wind gusts and heavy rain/flash flooding will be the
  primary hazards.

- Turning drier and more comfortable for the weekend, with a
  small chance of thunderstorms returning to the forecast early
  next week.

&&

.DISCUSSION...
Issued at 332 AM CDT Wed Jul 3 2024

Heat indices today will likely reach 105 over the entire Quad
State, but there will be some potential for morning convection
and associated cloud debris to hold temperatures down in our
northwest counties, mainly in southern Illinois. For that reason
decided to only add Carter, Wayne MO, and Bollinger counties to
today`s Heat Advisory. Heat indices could even reach 110 degrees
in Carter and Ripley.

There will certainly be potential for another Heat Advisory on
Thursday, but the area will be dependent on the uncertain
convective details tonight into Thursday morning. That decision
may not be possible until tomorrow morning`s midnight shift.

Convection moving east across central Missouri will outrun the
better low-level moisture as it attempts to move into southern
Illinois later this morning. A few showers may make it, but the
outflow boundary may be the bigger impact for the Quad State
today. There is a signal in much of the guidance for scattered
convection to develop this morning into the afternoon over west
Kentucky. Middle 70s surface dewpoints are expected to
overspread much of west Kentucky today, and that coupled with
the outflow boundary or differential heating boundary may
support convective development for much of the day.

Later this afternoon, scattered to numerous thunderstorms are
likely to develop over northern portions of the area. Exactly when
and where will be hard to determine until this morning`s
convection plays itself out. With the building heat and humidity
expected today, instability will be moderate to strong across
the Quad State, while shear will be rather weak. Expect storms
to be outflow dominated with a damaging wind threat the primary
severe concern. Thunderstorms will advect eastward and build
southward into the best instability through this evening. It is
not certain if they will progress bodily southward through the
entire area or not. Given the anomalous moisture expected, any
storms are likely to produce torrential rainfall and could lead
to some minor flooding issues.

A weak disturbance in the zonal flow aloft will bring a second
round of convection eastward into southern Illinois late
tonight. It will continue eastward through the Tri State
Thursday morning. Heavy rainfall and flooding are the most
likely concerns with this round of convection.

Thunderstorm development Thursday afternoon is likely to the
southwest of the morning convection, where significant heating
occurs. Moderate to strong instability will be possible and
shear should be a bit stronger. A few severe storms will be
possible again with damaging winds the main concern. Flash
flooding will be a greater concern with this round of convection
since it could be falling over areas that received significant
rainfall from one or more of the earlier rounds.

A final round of convection is possible later Thursday night
into Friday in association with the cold frontal passage. Shear
will be better with this convection, but instability may be
limited due to previous convection. For now would expect
torrential rainfall and flash flooding to be the most likely
concern.

It appears that most of the region will be dry by Friday
evening and stay that way through the weekend. Temperatures will
drop to around normal levels Friday and stay that way through
the first half of next week. South winds will develop on Sunday,
and that should eventually lead to increasing moisture and more
chances of thunderstorms Sunday night, or more likely on
Monday. The chances of thunderstorms will continue through
at least Tuesday. At this time, severe storms and widespread
heavy rainfall do not seem likely for early next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 544 PM CDT Tue Jul 2 2024

A cold front approaches late tonight and tmrw. Associated
showers/storms will begin blowing off some mid and high level
bases late tonight, offering lowering Visual Flight Rules CIGS.
As the front nears the FA tmrw during peak diurnal heating,
showers/storms will become active with associated restrictions
to CIGS/VSBYS entering the planning phase hours of the forecast.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...Heat Advisory from 11 AM this morning to 8 PM CDT this evening
     for ILZ077-078-083-086>094.
MO...Heat Advisory from 11 AM this morning to 8 PM CDT this evening
     for MOZ086-087-100-107>112-114.
IN...Heat Advisory from 11 AM CDT /noon EDT/ this morning to 8 PM
     CDT /9 PM EDT/ this evening for INZ081-082-085>088.
KY...Heat Advisory from 11 AM this morning to 8 PM CDT this evening
     for KYZ001>022.

&&

$$

DISCUSSION...DRS
AVIATION...DH