271
FXUS63 KJKL 081855
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
255 PM EDT Tue Jul 8 2025

.KEY MESSAGES...

- High temperatures will return to near normal through the week as
  humidity increases.

- Chances for shower and storms persist through the upcoming
  weekend, mainly during each afternoon and evening.

&&

.SHORT TERM...(This evening through Wednesday night)
Issued at 255 PM EDT TUE JUL 8 2025

A seasonably hot and muggy early July afternoon is underway over
eastern Kentucky as a weak cold front sags into the area. This
cold front is roughly located from Vanceburg southwestward to
Lexington, then westward through Louisville. In the moderately
unstable (1,500-2,000 J/kg) environment ahead of the boundary,
scattered showers and thunderstorms have developed north of the
Mountain Parkway as of 2:45 PM EDT, and isolated activity has
begun developing further southeast. Through the remainder of the
afternoon and early evening, anticipate that the convection will
continue expanding in coverage and become more focused on the
eastern half of the JKL CWA. While the vast majority of the
convection should be of the garden variety, a few of the strongest
cells could produce gusty winds. Additionally, any location
affected by multiple heavy showers and thunderstorms could develop
isolated localized high water issues.

This unsettled weather pattern will persist through the short-
term period as a 500 hPa trough, extending from Northern Ontario
to over the Ozarks, drifts east to roughly James Bay to the Lower
Ohio Valley by sunrise Thursday. At the surface, the
aforementioned cold front is forecast to stall over Eastern
Kentucky this evening/tonight and dissipate. A subtle surface low-
pressure system ahead of the incoming 500 hPa trough will then
pass over the Great Lakes Wednesday into early Thursday and drop
another cold front toward eastern Kentucky by Thursday morning.
The combination of weak perturbations passing through the
troughing aloft and diurnal destabilization will favor scattered
to numerous shower and thunderstorm development again on
Wednesday. The lack of shear will limit the severe weather threat
to marginally strong wind gusts. The threat for isolated localized
high water issues will return on Wednesday afternoon as well,
particularly in locations affected by the most persistent
convection.

Sensible weather will feature continued scattered to numerous
showers and thunderstorms, reaching maximum coverage late this
afternoon and early evening. Some of these thunderstorms could
produce torrential downpours. Wednesdays temperatures will peak in
the mid-80s to near 90 degrees. Shower and thunderstorm activity
will wane quickly after sunset with only a low-end isolated shower
threat overnight. It will be mild and muggy with lows in the
mid-60s to around 70 degrees. Wednesday and Wednesday night will
feature similar temperatures and humidity levels. Fog is probable
each night, especially in favored valley locales and where
rainfall occurs late in the day, conditional upon partial
clearing.


.LONG TERM...(Wednesday through Monday)
Issued at 400 PM EDT MON JUL 7 2025

The period is expected to begin with an upper level low over
Ontario and an associated trough south through the Great Lakes to
OH Valley to the Arklatex to western Gulf between an upper level
ridge centered near Bermuda and another upper level ridge centered
over the Southwest Conus. Guidance continues to have a shortwave
trough moving through the upper trough and across portions of the
OH Valley as the period begins while upper level trough should
extend from an upper level low in western Canada into the
Northwest Conus to CA. At the surface, a ridge of high pressure
is expected to extend from the Gulf of Mexico into the Southern
Appalachians with a frontal zone extending from off the Northeast
Coast to the mid Atlantic sates to a surface low in the Great
Lakes and then southwest and west to the mid MS Valley to Central
Plains. Another sfc system should be in advance of troughing in
western Canada and centered in Saskatchewan with a warm front
extending into the northern Plains and a cold front across
southwest Canada. Early on Wednesday, PW per the 12Z HREF mean is
forecast generally the 1.5 to 1.8 inch range a bit above normal
for this time of year nearer to the 75th percentile.

From Wednesday to Thursday night, the upper level low is expected
to move into Quebec with the northern portion of the trough
shifting into the Northeast to Mid Atlantic states through the
axis of troughing at 500 mb nears but generally remains west of
eastern KY. A couple of shortwave troughs are progged to cross
eastern KY during this time, one Wednesday to Wednesday evening
with another crossing the area about Thursday. As this occurs,
upper level ridging should remain centered in the western Atlantic
in the vicinity of Bermuda while upper level ridging remains from
the Southwest Conus/northern portions of Mexico into the eastern
Pacific. Meanwhile, upper trough should advance east toward
Central portions of Canada/Hudson Bay southwest to the Northern
Rockies crossing the Great Basin. Meanwhile, at the surface, as
the trough moves into eastern Canada and toward the Northeast, the
boundary north of eastern KY is expected to sag south of the
Great Lakes and extend from the mid Atlantic coast to OH to north
of the Ohio River to the next sfc system in the Plains. With the
trough axis near or west of eastern KY during this period,
convection cannot be ruled out at any point, with coverage likely
to peak each afternoon and evening. Valley fog should continue to
be a fixture each night to early morning and would be more
widespread or dense if clearing at night were to follow a period
of heavier rainfall. With the trough in place/come cooling aloft
cloud cover and precipitation should keep highs nearer if not
slightly below normal for this time of year.

Friday to Saturday night, some height rises are anticipated
across the Southeast for Friday into Saturday as an upper level
low organizes near the US/Canadian border near the
Ontario/Manitoba border to Northern Plains/Upper MS Valley areas
with troughing developing/moving into the Central Conus. During
this time, upper level ridging should remain in place across much
of the western Conus. At the surface, low pressure is expected to
trek from Manitoba toward the Hudson/James Bay region with the
trialing front advancing across parts of Ontario and into the
Central Great Lakes to mid MS valley to portions of the Plains. At
the same time, a sfc ridge of high pressure is expected to
generally remain from the Gulf into the Southeast/Southern
Appalachians. The region will remain in the warm sector with
convection possible through the period, generally each afternoon
and evening.

Sunday to Monday, upper level ridging is expected to remain from
the Southeast/Gulf of Mexico and across the Southwest Conus as the
upper low in Canada is progged to weaken and move toward Hudson
and James Bay. The shortwave trough to the south is generally
forecast to advance east across the Great Lakes and toward the
Northeast with run to run variability with timing and strength.
Another shortwave should also have moved across western Canada and
US/Canadian border. With the shortwave trough generally passing
north of the region, the surface low in Canada should move into
Quebec/eastern Canada with the trailing sfc front may become
diffuse with southern/southwest extent. Meanwhile, a ridge of sfc
high pressure should persist from the Gulf to the Southeast. With
no clear features to time for more organized convection at this
point, diurnal peaks in convection are anticipated to begin next
week as well. Temperatures per guidance should be near normal.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 143 PM EDT TUE JUL 8 2025

Scattered to locally numerous showers and thunderstorms are
anticipated this afternoon into this evening as a weak cold front
settles into Eastern Kentucky. This activity is covered by PROB30
groups, as it could easily lead to brief reductions in ceilings
and visibilities. Fog formation is probable in the typical valley
locales tonight and at terminals where shower activity lingers
late in the afternoon and/or evening (most likely at JKL and SJS).
Winds will generally be under 10 kts through the period, except
locally stronger and erratic near thunderstorms.

&&

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

&&

$$

SHORT TERM...GEERTSON
LONG TERM...JP
AVIATION...GEERTSON