541
FXUS63 KJKL 092218
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
618 PM EDT Wed Jul 9 2025

.KEY MESSAGES...

- There is an elevated concern for high water and isolated flash
  flooding across the area into tonight due to torrential
  downpours and possible training of showers and thunderstorms.

- High temperatures will be near normal through the week though
  they may trend above normal over the weekend and early next
  week.

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

&&

.SHORT TERM...(This evening through Thursday night)
Issued at 407 PM EDT WED JUL 9 2025

At 4 PM EDT, regional radar mosaic shows the more organized
convection from earlier in the day now in Virginia/West Virginia.
Looking aloft, this activity appears to have been forced, at least
in part, by a stronger pulse of energy ejecting northeast out of
a 500 hPa trough that currently extends from James Bay south
through Lower Michigan and Western Kentucky. Additional shower and
thunderstorm activity has developed and is moving over Eastern
Kentucky ahead of another modest pulse of mid-level energy. Over
much of the area, several hours of partial sunshine have allowed
temperatures to heat up into the 80s and generate about 1,000 to
2,000 J/kg of MLCAPE. PWATs still around 1.9 to 2.0 inches along
with a deep warm cloud layer favor torrential rainfall under the
stronger convection. Additionally, nearly unidirectional flow
through the cloud-layer as well as weak upwind propagation vectors
favor back building and training.

The upper level trough will fill as it slowly slides into the
Mid-Ohio Valley tonight and exits east on Thursday morning, taking
the higher PWATs with it. However, until that trough axis
departs, there will be a continued threat for torrential
downpours, leading to isolated flash flooding, even into the
overnight. Another subtle mid-upper level disturbance will
approach Thursday afternoon/evening with the renewed threat of
showers and a few thunderstorms, but PWATs will be much lower,
around 1.25 to 1.50 inches, north-to-south, which should minimize
any further excessive rainfall threat. At nighttime, abundant low-
level moisture will combine with any clearing of the clouds to
promote radiation fog formation, with the most favored locations
being in typical valley locales.

In sensible terms, the warm, muggy and unsettled July weather
pattern will continue through the short-term. Look for showers and
thunderstorms to gradually diminish this evening/overnight,
though they could linger deep into the night for a few locations.
Torrential downpours in the strongest activity could lead to
isolated instances of flash flooding. It will be mild and muggy
with areas of fog and lows in the mid 60s to around 70 degrees. On
Thursday, look for partial sunshine giving way to rising shower
and thunderstorm chances during the late morning/afternoon, most
likely near the Kentucky/Tennessee and Kentucky/Virginia borders.
Conditions will again be warm and humid with high temperatures in
the middle 80s for most locations. Rain chances taper off again
Thursday evening and night with partial clearing and areas of fog
developing overnight. It might be a bit cooler with low
temperatures ranging in the mid to upper 60s.

.LONG TERM...(Friday through Wednesday)
Issued at 500 PM EDT WED JUL 9 2025

The period is expected to begin with an upper level ridge
centered over parts of the western Atlantic near or northeast of
Bermuda and extending into the eastern Gulf with another upper
level ridge centered off the CA and Baja coast and extending into
parts of the southwest Conus. In between an upper level trough is
expected to extend into the Northeast Conus to mid Atlantic states
from Quebec with a trend of rising heights into the Southeast and
Southern Appalachians as the period begins. Further west, upper
troughing is progged initially from parts of the upper MS valley
to Central and Southern Plains between the two areas of upper
level ridging. In addition, an upper level trough per the
consensus of guidance should extend from the Hudson Bay vicinity
into MT and portions of the Great Basin with another trough
upstream from the Gulf of Alaska to west of the BC coast. At the
surface, a frontal zone should extend from Quebec to south of the
Great Lakes and north of the OH Valley into the Plains while
another sfc low is anticipated in Ontario as the period begins
with the trailing cold front into the Dakotas to portions of the
western Conus.

Friday to Saturday night, guidance generally has a trend of
rising heights at 500 mb across eastern KY for Friday into Friday
evening/night. During this time, upper level ridging is expected
to continue to extend from near Bermuda to the Gulf and parts of
the southeast Conus with upper level ridging remains from the
Southwest Conus into the eastern Pacific. A weak shortwave may
pass north of eastern KY and across the Great Lakes later Friday
night to early on Saturday while guidance generally has near
neutral height tendencies at 500 mb for Saturday or perhaps some
slight height falls late on Saturday. This will be in advance of
the shortwave moving across portions of Canada and the Northern
Plains reaching western Ontario to the Great Lakes by late
Saturday night. At the same time another shortwave moving around
ridging that builds north across the western Conus as the weekend
begins should move into the Upper MS Valley and portions of the
Northern and Central Plains/Central Conus. Further south, upper
level ridging should become centered from off the Southeast US
Coast to Gulf to begin the weekend. Meanwhile, at the surface, a
ridge of high pressure should be in place from the eastern Gulf to
Southern Appalachians while the boundary initially north of
eastern KY lifts north into Canada as a sfc low tracks to near
James Bay and the trailing cold front moves across parts of the
western and central Great Lakes and sags toward the Lower OH
Valley. Diurnally driven convection is anticipated across eastern
KY with coverage similar to climatology for eastern KY with no
discernible triggers anticipated at this point. Some periods of
height rises and relatively warm temperatures aloft should tend to
limit coverage of convection. Nevertheless isolated to scattered
showers and storms should be a fixture each afternoon and evening.
Also, valley fog is anticipated each night as well. Near normal
temperatures are anticipated to end the work week and begin the
weekend.

Sunday to Monday night, the next upper level shortwave trough
should move east across Ontario and the western and Central Great
Lakes and enter the Lower OH Valley from Sunday to Sunday night
while upper level ridging remains across the Gulf and parts of
the southeast and another upper level ridge remains centered from
the Southwest Conus to the eastern Pacific. This shortwave trough
at 500 mb should work into Quebec and across the eastern Great
Lakes and reach the Maritimes to Northeast and mid Atlantic states
through Monday night. This would have the shortwave trough
crossing the Lower OH Valley and eastern KY later Sunday night to
Monday evening. In advance of this shortwave trough passing a cold
front should sag south of the OH River by later Sunday night and
Monday and perhaps across eastern KY Monday to Monday evening and
then south of the area on Monday night as sfc high pressure
builds to the eastern Great Lakes to portions of the OH Valley
and Appalachians ahead of shortwave upper ridging behind the late
weekend to early week shortwave passage. Somewhat greater
coverage of convection is anticipated as the shortwave trough and
cold front approach and cross the area to end the weekend and
begin next week. Pending the degree of heating in advance of the
front and resultant instability a few stronger storms cannot be
ruled out. Temperatures should remain near normal.

Tuesday to Wednesday, upper and sfc ridging extending from the
Southeast to OH Valley should gradually shift east from Tuesday
into Wednesday with the boundary south of the region becoming
diffuse. Another trough is expected to have moved across western
Canada and across the Northern Plains and into the upper MS Valley
and begin to the western Great Lakes around the middle of next
week. This should be preceded by a sfc frontal zone that works
into the Great Lakes to mid MS Valley late in the period and
may near the Lower OH Valley late. Under the ridging a slight
uptick in temperatures perhaps to a few degrees above normal may
occur across eastern KY. Some diurnally driven convection is also
possible though coverage on Tuesday could be more limited with
ridging dominating. In addition, as on other nights in the long
term period, valley fog development is favored.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
ISSUED AT 210 PM EDT WED JUL 9 2025

Scattered to locally numerous showers and thunderstorms are
anticipated through 00z across most of eastern Kentucky. While
MVFR to VFR conditions will generally prevail, brief but
significantly worse conditions are possible in torrential
downpours associated with stronger showers and storms. Areas of
fog are likely again tonight with MVFR/IFR or worse visibilities,
especially at locations which experience decent clearing of cloud
cover after afternoon/evening rainfall. 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