914
FXUS63 KJKL 170017
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
817 PM EDT Fri May 16 2025

.KEY MESSAGES...

- There is an enhanced to moderate risk of organized severe
  thunderstorms with significant severe weather possible this
  evening into tonight.

- After a break in rain chances on Saturday and Saturday night,
  shower/storm chances return at times through the middle of next
  week, especially during the afternoon and evening hours.

- Temperatures will be nearer to normal from Saturday through
  Tuesday, then are forecast to be below normal for Wednesday to
  Friday.

&&

.SHORT TERM...(This evening through Saturday night)
Issued at 550 PM EDT FRI MAY 16 2025

Following the initial morning to early afternoon convection, a
couple of storms/attempts at redevelopment that have moved across
parts of southcentral KY have produced lightning and have not been
as robust. Recently MLCAPE is analyzed at 1000 to 1500 J/kg in the
northeastern and eastern counties where clouds and heating
following earlier activity began the latest. Meanwhile, MLCAPE is
analyzed in the 2000 to 2500 J/kg range while MUCAPE ranges from
1000 J/kg east to 2500 to 3000 J/kg in Wayne County where heating
has been the most substantial and dewpoints are the highest. Shear
remains substantial generally in the 55 to 65KT range for
effective shear. Additional activity has developed upstream and
should evolve into the anticipated linear convection/QLCS later
this evening into the overnight.

Currently there is a lull in the activity other than the storm in
the western portion of the area. As the line approaches, an
increase in activity ahead of it seems probable over the next
couple or hours. RAP/SPC Mesoanalysis has the MLCAPE climbing to
roughly 2000 to 2500 J/kg with MUCAPE possibly increasing toward
3000 J/kg ahead of the linear convection over the next couple of
hours with effective shear in the 50 to 70KT range. Mid level
lapse rates are progged to increase as the evening progresses to
7 C/km or more over the next with low level lapse rates not as
steep. However, the main line should be well organized with a
strengthen cold pool while the steepening mid level lapse rates
indicate an increase in large hail potential in addition to a wind
threat. Any discrete cells that form ahead of linear convection
will pose a risk of all hazards, especially if they move along any
boundaries or differential heating boundaries in which case the
tornado potential would increase. Otherwise, with the anticipated
QLCS convection, a threat of wind gusts possibly to significant
levels (74+ mph) along with large hail and spin up tornadoes are
possible. The line should arrive over the next 3 to 5 hours from
the west with the convective complex crossing eastern KY into the
first half of the overnight hours.

The SPC Moderate risk in place for more western locations and
enhanced risk for the remainder of eastern KY remains valid given
the expected increasing parameter space and CAM and upstream
trends. Additional Watches are probable as the evening progresses.

In addition to the severe thunderstorm threat, if additional lead
cells move over locations that were hit with heavy rain earlier in
the day (between I-64 and the Cumberland Pkwy to Hal Rogers Pkwy
and KY 80 corridors into Pike County). Also if additional lead
cells produce heavy rain and are immediately followed by the
QLCS/MCS/linear convective rain high water or flash flooding would
also be possible.

The axis of upper level ridging and height rises follow from
Saturday and into Saturday night as the actual cold front moves
through, with drier air filtering into the area. This will result
in much quieter weather for Saturday and Saturday night. A
decreasing gradient following rain from earlier today and tonight
should set the stage for valley fog on Saturday night, especially
for valley locations near and south of the Mountain Parkway.

.LONG TERM...(Sunday through Friday)
Issued at 500 PM EDT FRI MAY 16 2025

The period is expected to begin with the axis of upper level troughing
from eastern Canada into the Northeast to near the eastern
seaboard and the axis of upper level ridging from the Gulf into
portions of the Central Conus/Plains to MT and into Saskatchewan.
A shortwave trough or two is expected to be moving from the mid MS
and Lower OH to TN Valley areas toward the Southeast/Southern
Appalachians. Meanwhile at the same time, the axis of an upper
level trough is expected to extend from BC into the Great
Basin to Southwestern Conus. At the surface, the boundary that
will have crossed the area during the short term period will have
stalled from the Carolinas to the TN Valley to Ozark vicinity to
southeastern CO/OK panhandle vicinity to low pressure ahead of the
trough moving through parts of the western Conus. Along the
western part of that boundary a sfc low should be developing in
the lee of the Rockies as the period beings. Locally, the southern
end of a ridge of high pressure over Canada and into eastern KY.

Sunday, the initial shortwave trough should pass through the TN
Valley and parts of the OH Valley to the Southern Appalachians and
dampen and likely interact with the stalled boundary to the south
of eastern KY. Some showers or storms could affect more southern
locations in closer proximity of this boundary as the shortwave
passes. Otherwise, some height rises occur behind this shortwave
with the axis of upper ridging working towards the OH Valley and
then shifting east of eastern KY by Monday night. However, a
couple of shortwaves could cross the OH Valley and eastern KY from
later Sunday into Monday night and by the time ridge axis shifts
east, organizing low pressure tracking through the Central Conus
should send the boundary initially stalled south of eastern KY
into the region. Despite ridging possibly leading to times of
capping or some suppression of the coverage of convection, the
passing shortwaves and then the warm front approaching will lead
to chances for showers and thunderstorms at times as early as
later Sunday night and into Monday night. These chances could peak
diurnally on Monday and as the warm front potentially nears late
Monday night.

With the ridge axis having moved east  troughing initially over
the western Conus that will have moved into the Plains and then
the Central Conus should approach the MS Valley and eastern Conus
by midweek. Some height falls should occur by late Monday night or
Tuesday and continue into midweek. This will be preceded by sfc
low pressure tracking from the Central Conus to the OH Valley
through Tuesday night and Wednesday and then to the eastern
seaboard through Thursday night and then off the east coast
Friday. Uncertainty remains with the timing of the upper level
troughing into and across the eastern Conus from midweek into
the second half of next week and details and evolution of that
trough. Following the warm front lifting across the area by
midweek, a cold front should cross the area at midweek as well.
Some strong storms cannot be ruled out as the low pressure system
tracks across the OH Valley and eastern KY by later Tuesday into
Wednesday, especially if any destabilization can occur ahead of
the mid week cold front. Following recent rainfall, if additional
heavy rain were to occur during the first half to middle of next
week, that could become the bigger concern as highlighted by most
recent WPC Day 4 and Day 5 EROs.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
ISSUED AT 816 PM EDT FRI MAY 16 2025

Conditions were primarily VFR at the start of the period, with the
exception of some occasional very isolated showers possibly
bringing sub-VFR conditions. Severe thunderstorms were occurring
to the west in central KY, and will move/develop eastward this
evening. The area of thunderstorms is forecast to shift
southeast through the JKL forecast area between about 01Z and 07Z
(while the individual severe storms move generally eastward). The
storms will bring localized IFR or worse conditions. They will
also have the potential to produce high winds, large hail, and
isolated tornadoes. Rapid clearing is forecast behind the area of
thunderstorms around dawn. Winds will increase out of the west
southwest during the day Saturday, with gusts around 30 kts.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 4 AM EDT Saturday for KYZ058>060-068-069-079-
080-083>088-104-106>120.


&&

$$

SHORT TERM...JP
LONG TERM...JP
AVIATION...HAL