831
FXUS63 KPAH 300521
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
1221 AM CDT Sun Aug 30 2026

.KEY MESSAGES...

- Another Heat Wave begins this week with daily heat index
  values of 100+ degrees. There is a 70-90% chance of meeting
  Heat Advisory criteria Tuesday-Friday. Major heat impacts are
  expected due to the long duration.

- Dry conditions will persist until Friday into Saturday when
  there is a 20-30% chance of isolated showers and
  thunderstorms. Rain chances will bring limited relief over
  next weekend.

&&

.DISCUSSION...
Issued at 1220 AM CDT Sun Aug 30 2026

The heat and humidity will begin to ramp up with the start of
another heat wave through all of this week as a 594 dm ridge of high
pressure builds over the FA today. Despite an increase in southerly
return flow, moisture advection will lag for another day as
dewpoints will once again mix down into the lower 60s this
afternoon. Given 850 mb WAA and deep layer mixing, nudged NBM maxTs
up today into the mid 90s. By Monday, the stout ridge will be parked
over the FA, with dewpoints ranging from the upper 60s to lower
70s. Due to the modest increase in moisture, temps are less
likely to overachieve heading into the middle of the week. The
NBM distribution is pretty tight through Thursday, falling in
line with the 2m temps on the AI GFS/EC for daily highs in the
mid to upper 90s. This translates to daily heat index values of
100+ degrees.

After collaborating with our WFO neighbors, have decided to hold off
on issuing any heat headlines as Monday looks to be pretty
borderline compared to Tuesday-Friday when the LREF supports a 70-
90% chance of needing a Heat Advisory. Unlike the previous heat
wave, dewpoints really struggle to rise above 70 degrees making it
difficult for heat index values to reach extreme levels. In fact,
the LREF only supports a 15-30% chance of values exceeding 105
degrees as it would take maxTs trending higher into the triple
digits to achieve these levels. The Heat Risk product may also be
running a bit "hot" compared to the impacts that are likely as it
does not factor in the previous long duration heat waves that
occurred well into this summer with much higher dewpoints and
similar temperatures. Overall, major heat impacts from the long
duration can be expected as a Heat Advisory will be needed by early
next week for what will be a much drier heat.

Limited relief begins to arrive by next weekend, but the
GFS and ECMWF differ on how quickly the ridge breaks down. NBM PoPs
have now increased to a 20-30% chance for isolated showers and
thunderstorms on Friday and Saturday as a frontal boundary stalls
south of the Great Lakes region. Some of the model ensembles suggest
there is still room for rain chances to trend a bit higher,
especially over northeast portions of the region. Timing is
uncertain as it is contingent on how quickly the ridge breaks
down.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1135 PM CDT Sat Aug 29 2026

Light and variable winds overnight will increase from the SW
around 5-10 kts this morning as southerly flow increases. Some
shallow ground fog is possible again at CGI and PAH during the
predawn hours, but confidence remains low. FEW- SCT high-based
diurnal CU development is expected after 12-15z.

&&

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

&&

$$

DISCUSSION...DW
AVIATION...DWS