312
FXUS63 KJKL 312038
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
438 PM EDT Thu Jul 31 2025

.KEY MESSAGES...

- There is a possibility of showers and thunderstorms at times
  through the next week, mainly during the afternoon and evening
  hours on most days.

- Thunderstorms could bring isolated excessive rainfall into this
  evening.

- A cold front will bring significant relief from the heat and
  humidity starting late tonight into Friday.

&&

.SHORT TERM...(This evening through Friday night)
Issued at 400 PM EDT THU JUL 31 2025

Late this afternoon, an upper level low was centered over the
Maritimes with an upper level trough axis southwest to the Great
Lakes to mid MS Valley. Meanwhile, an upper level ridge was over
the Atlantic centered near Bermuda and extended into FL while
another upper level ridge was centered in the Southwest
Conus/northern Mexico area in the NM vicinity. At the surface, a
cold front preceding the axis of the upper trough extended from NJ
to northern WV to near Fleming County and then to south central KY
to the Southern Plains. A min in PW/moisture was analyzed over SW
VA near the KY and VA border near 1.3 inches while near the
boundary PW increases to 1.8 to near 2.0 inches. MLCAPE ahead of
the front is generally in the 1000 to 1500 J/kg range across
eastern KY with effective shear of 20 to 30KT in northern sections
of the area.

This evening and tonight, the cold front should continue to sag
south and southeast across the remainder of eastern KY through
the evening and then sag south and southeast overnight with only
slight mid level height falls as the axis of the 500 mb trough
approaches. PW is progged to increase near the boundary as it sags
south and isolated to scattered convection is anticipated near or
in advance of it especially through sunset, with chances
lingering into the overnight in the south and east. Colder and
drier air begins to arrive overnight in the north where lows are
expected to be in the mid 60s tonight with upper 60s to around 70
south. The boundary is expected to continue sagging south on
Friday, with colder and drier air arriving around a ridge of sfc
high pressure sagging into the Great Lakes. Northwestern portions
of the area should remain dry on Friday, with isolated to
scattered convection more probable in the south and southeast.
Highs for Friday should end up around 10 degrees or more colder
than recent days. Drier air continues to move into the region for
Friday night, with dewpoints and PW remaining the highest near to
the VA border. Despite an inverted trough developing at the sfc
and extending into southeastern KY on Friday night, convection
should wane by sunset. Clearing in the north and northwest and
enough breaks in clouds in the southeast should favor development
of valley fog especially in the southeast on Friday night. Lows
should be noticeably colder and refreshing than recent nights in
the upper 50s to low 60s.

.LONG TERM...(Saturday through Thursday)
Issued at 400 PM EDT THU JUL 31 2025

The period is expected to begin with with upper level ridging in
the western Atlantic centered to the east of Bermuda and
enlongated ridging extending east to west from the Southern Plains to
the Southwest Conus to portions of the eastern Pacific. The
western upper level ridge should initially extend north into
portions of the Rockies while a trough is expected to extend
south west of the west coast of Canada and the Northwest Conus
from an upper level in the Gulf of Alaska vicinity. Meanwhile
broad upper troughing is progged to extend from the Maritimes
into the Northeast Conus to eastern Great Lakes to OH Valley
region on to the Arklatex region. At the surface, a frontal zone
should extend from the Atlantic to southeast US Coast/GA/SC border
vicinity across the Gulf coast states to the Southern Plains and
then north across sections of the High Plains to eastern MT. A sfc
high pressure should be in place centered in the Great Lakes and
extending from sections of the Northeast to the mid MS Valley and
upper MS Valley regions. East of the axis of the upper troughing,
an inverted trough may extend from a sfc wave moving along the
boundary across the Gulf states into sections of the
Appalachians/eastern KY. Also as the period begins, the 00Z LREF
had mean PW of 1 inch or less to the north and northwest of the TN
and VA border counties.

Saturday to Sunday night, the Lower OH Valley and eastern KY
should remain near or to the east of the axis of upper level
troughing that persists between upper level ridging that remains
in place in the western Atlantic centered to the east and
northeast of Bermuda and upper level ridging centered in the
southwest Conus and extending into the Rockies. Although the axis
of troughing in Canada and into the Northeast COnus shifts east
during this timeframe, upper troughing should strengthen a bit
over the Central Conus/MS Valley as the weekend progresses.
Meanwhile, sfc high pressure should settle over the mid Atlantic
states/PA by late Sunday night. As this occurs, return flow of
moisture back to the west and northwest across eastern KY and into
the Lower OH Valley is anticipated with PW per the 00Z LREF mean
increasing a bit Saturday into Saturday night to about 1 inch or
more areawide by Sun morning and to the 1 to 1.4 inch range
through late Sunday into Sunday night. Areas nearer to the VA and
TN border where the moisture gradient is anticipated will have a
better chances for isolated to scattered convection Saturday
afternoon and Saturday evening compared to areas further to the
west along and west of the escarpment and north of the Mtn Pkwy.
Convective chances will spread across the entire area for Sunday
to Sunday evening with the chances likely best in the western half
of the area where more substantial moisture return is
anticipated. The colder airmass will persist with temperatures
remaining a few degrees below normal over the weekend.

For Monday to Wednesday, upper ridging is expected to build across
from the Southwest Conus/NM vicinity and into much of the Plains
while another upper ridge remains in place in the Atlantic. Upper
level troughing the axis of which should extend near the MS River
Valley early on Monday should gradually migrate east to the Great
Lakes to OH Valley to TN Valley to Lower MS Valley vicinity. 00Z
LREF mean PW increases to the 1.3 to 1.6 inch range across
eastern KY by Tuesday to Wednesday. Meanwhile, the sfc frontal
zone initially near the Gulf coast to portions of the Plains is
progged to only gradually lift north and east and remain west of
eastern KY while sfc high pressure remains centered to the
northeast of the area. This pattern will be favorable for times of
clouds as well as the possibility of convection at any point,
though a diurnal peak is expected each afternoon and evening. With
clouds and convection in the area temperatures should average a
little below normal.

For Wednesday night and Thursday, guidance has an upper level low
or trough extending across the OH Valley region into the TN Valley
region though the axis of the trough may reach eastern KY by late
Thursday. Diurnally driven convection should continue to be a
feature and clouds and convection in the area should keep
temperatures near to slightly below normal.

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 205 PM EDT THU JUL 31 2025

A cold front will move across the area including all 5 TAF sites
during the first 6 to 9 hours of the period. Scattered convection
is anticipated near and ahead of it, which could bring briefly
gusty winds as well as ceilings and or visibility down to MVFR or
IFR. Behind the boundary, low clouds and or some fog, perhaps the
stratus build down variety is anticipated to prevail with low
clouds arriving in the northwest around 03Z and by 08Z across the
remainder of the region. These low clouds or stratus build down
fog is expected to reduce ceilings and or vis into the MVFR or IFR
category if not briefly lower for several hours during the 06Z
and 15Z timeframe in particular. During the last 3 to 6 hours of
the period, conditions should gradually improve into or through
the MVFR category for most.

&&

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

&&

$$

SHORT TERM...JP
LONG TERM...JMW
AVIATION...JP