697
FXUS63 KJKL 111855
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
255 PM EDT Mon Aug 11 2025

.KEY MESSAGES...

-Hot and humid conditions are expected today, with afternoon heat
 indices reaching the mid-90s. Scattered pop-up thunderstorms are
 possible, with the best chance (40-50%) for counties adjacent to
 the Virginia-Kentucky border.

-An unsettled weather pattern is forecast from Tuesday through
 Thursday, bringing multiple rounds of showers and thunderstorms.
 Some storms will be capable of producing torrential downpours,
 leading to a threat of localized flash flooding.

-For the upcoming weekend, the rain threat decreases and a more
 typical summer pattern of isolated popup showers and thunderstorms,
 along with hotter temperatures climbing back to near 90F, will
 return.

&&

.SHORT TERM...(This evening through Tuesday night)
Issued at 255 PM EDT MON AUG 11 2025

A strong high-pressure system remains over the eastern CONUS, while
surface features are tracking across southern Canada and the Central
Plains. A surface trough is also situated along the Atlantic
Seaboard and extends southwest toward the Gulf. Locally, the high-
pressure system is dominating the weather, leading to dry conditions
and warm temperatures.

This afternoon, increasing moisture will be advected into the region
due to enhanced southerly flow and anticyclonic flow around the
high. The enhanced lift associated with the surface trough will
favor the development of afternoon showers and storms. The highest
chances for precipitation will be located along and south of the
Mountain Parkway, though some CAM runs show the possibility of
convection developing farther north into the Bluegrass region. Apart
from the potential for showers and storms, temperatures will climb
into the upper 80s to low 90s. Showers and storms will dissipate
overnight, giving way to clearing skies and the development of
locally dense river valley fog.

On Tuesday, the strong upper-level ridge will begin a subtle
breakdown, allowing an upper-level shortwave to approach. The
strength of the ridge previously held this trough at bay, but as the
ridge weakens, the trough will move closer before pivoting northeast
toward eastern Canada. However, ridging to the southeast will
prevent the trough from shifting southeastward, keeping it northwest
of the Commonwealth. Nevertheless, better chances for precipitation
will exist Tuesday afternoon. Temperatures will once again climb
into the upper 80s to low 90s. As with Monday night, any showers and
storms will dissipate, leading to clearing skies and the development
of overnight river valley fog.

The period will be characterized by increasing chances for showers
and storms. High temperatures will remain slightly above average, in
the upper 80s to low 90s, and overnight lows will fall into the mid
to upper 60s.

.LONG TERM...(Wednesday through Monday)
Issued at 255 PM EDT MON AUG 11 2025

At the beginning of the period, a 500-mb trough - centered over
Ontario - will begin pivoting on its axis and lifting to the
northeast. As such, the associated surface cold front that has been
moving southeastward from the Upper Midwest will stall just
northwest of our forecast area and become stationary. Through
Friday, light, quasi-zonal flow aloft will cause this stationary
front to remain draped east-west just north of our area. As
shortwave features meander through this flow, an active weather
pattern will exist for the first half of the period. By Saturday and
Sunday, a weak ridge moves into the area, bringing with it quiet,
warm conditions that will prevail through the remainder of the
period.

The main show will be Wednesday afternoon through Thursday morning
with forcing associated with the east-west oriented stationary
front, near unidirectional flow, and deep moisture profiles. The
stationary front will serve as a moisture convergence zone. A weak
surface high over Florida will bring anomalous moisture northward
from the Gulf. The 850-300 mb mean wind is also forecasted to be
slow and westerly, further causing concern for training storms
parallel to the boundary. Additionally, all of the precip efficiency
parameters are in place for heavy rainfallhigh PWs (~1.8 inches), a
long, skinny CAPE profile, a deep warm cloud layer, and decent RH
values at low- and mid levels (>75-80%). With all of these factors
in place, WPC maintains a Marginal (level 1/4) risk for flash
flooding Wednesday through Thursday morning. Dry ground conditions
will keep higher-impact flooding concerns at a minimum, but multiple
rounds of heavy rain (or simply slow-moving, high-efficiency storms)
could lead to localized hydrologic concerns. Due to the broader
precip potential and cloud cover, high temperatures should also be
lower (mid to upper 80s) during this time.

By Friday, a weak ridge approaches from the west, leading to mid-
level northwesterly flow that cuts off the main moisture driving the
prior flooding concern. Thus, convection will become more isolated
and diurnally driven. By Saturday, the ridge will be over the area,
bringing with it quiet, warm conditions. Sunny days will lead to
highs of 90-95F that will prevail through the rest of the period.
Clear conditions will also lead to the potential for nighttime fog
in the river valleys, especially with increased ground moisture
after the Wed/Thurs event.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 133 PM EDT MON AUG 11 2025

Terminals are VFR with this TAF issuance. Showers and storms are
developing right now but not near any terminals; however, over the
next couple of hours, terminals KJKL, KLOZ and KSJS could see a
shower or storm. Any shower or storm could create brief
reductions in category. Once showers/storms dissipate, overnight
valley fog will develop and could sneak into a few sites and
cause a brief reduction in category. Outside of convection, winds
will be light and variable.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SHORT TERM...VORST
LONG TERM...HARDY
AVIATION...VORST