098
FXUS63 KJKL 120456
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1256 AM EDT Mon May 12 2025

.KEY MESSAGES...

- Showers/storms chances linger for much of this week, especially
  each afternoon and evening.

- Temperatures are forecast to be near normal for Mon to Wed, then
  moderate to about 10 degrees above normal on Thu and Fri.

&&

.UPDATE...
Issued at 1256 AM EDT MON MAY 12 2025

Forecasts have been freshened for the remainder of the night.
While conditions are currently rain-free across eastern Kentucky,
radar imagery shows extensive returns approaching from over East
Tennessee and beyond into Georgia and the Carolinas. This
activity, associated with stronger forcing from the approaching
upper low, will gradually spread north northwest across the
Eastern Kentucky Coalfields and adjacent areas through the early
to mid-morning hours. Modeled instability is weak overnight and
largely confined to Cumberland River basin. This should limit the
risk of any thunder mainly to our southern counties.

UPDATE Issued at 748 PM EDT SUN MAY 11 2025

Isolated to widely scattered showers, a few with embedded thunder,
are drifting northwest this evening and impacting locations
primarily south of the Mountain Parkway. This activity should
dissipate with the loss of daytime heating. However, more
sustained precipitation is forecast to develop from the south
overnight as deep moisture surges back into the Commonwealth.

&&

.SHORT TERM...(This evening through Monday night)
Issued at 435 PM EDT SUN MAY 11 2025

20Z sfc analysis shows a broad area of low pressure seeping into
the area from the southwest. This is making for partially cloudy
skies with a few showers starting to develop just across the
border in Tennessee and Virginia and drifting this way into the
JKL CWA. Additionally, a few thunderstorms are located further
south and deeper in Tennessee. Expect some of these to make it
across the Kentucky side late this afternoon and into the evening.
Currently, temperatures are topping out in the upper 70s and lower
80s. Meanwhile, amid east to northeast winds of around 5 kts,
dewpoints are ranging from the mid 40s north to the mid and upper
50s in the south.

The models, and their individual ensemble suites, continue to be
in pretty good agreement aloft through the short term period.
They all depict a slow and blocky pattern in place over this part
of the nation. Locally, this will be anchored by a large upper low
over the Louisiana Delta and Deep South that slowly drifts
northeast to start the upcoming work week. This will keep a flow
of relatively weak mid-level energy packets rotating through
eastern Kentucky from the southeast along with slowly falling 5h
heights from now through 12Z Tuesday. The continued small model
spread supported using the NBM as the starting point with minimal
adjustments needed through the period - mainly to include more
details from the CAMs for the PoPs and thunder chances - generally
high for each 12 hour period but lower at the hourly time step
than the NBM for Monday and Monday night.

Sensible weather features a milder and damp start to the new work
week as the influence of the nearby stacked low takes hold, from
south to north across eastern Kentucky with time this evening.
This will mean fairly uniform temperatures at night and a small
diurnal curve due to the cloudiness and times of pcpn around.
Accordingly, highs will not be far from normal on Monday - cooler
than those of today. Rainfall is not expected to be too heavy
overall, but training of storms could cause some local high water
issues through the period - even as most places end up with
around an inch or less through Tuesday. Additionally, with the
clouds around, do not anticipate much in the way fog each night.

The changes to the NBM starting point consisted primarily of
adjusting PoPs by adding some details from the CAMs consensus for
much of the area through the period. As for temperatures and
dewpoints - did not deviate far from the NBM.

.LONG TERM...(Tuesday through Sunday)
Issued at 330 PM EDT SUN MAY 11 2025

The period is expected to begin with an upper level low centered
southwest of eastern KY in the mid MS to TN Valley region, narrow
upper level ridging from Mexico into the portions of the Plains, A
trough from western Canada into the western Conus. Initially at the
surface, an occluded low is expected to be centered near the
confluence of the OH and MS Rivers with the occluded front extending
across the Commonwealth to a triple point in NC, with the systems
cold front extending off the coast of the Carolinas to south FL.
Further upstream a frontal zone preceding and associated with the
troughing from parts of Canada into the western Conus should extend
from low pressure near the Saskatchewan and Manitoba border into the
Dakotas to Southwest Conus. The sfc and upper level system is
expected to have a decent amount of moisture across the region
initially with PW values per the 00Z LREF mean on the order of 1.1
inches near the VA border to near 1.4 inches nearer to the I-64
corridor.

From Tuesday to Wednesday night, the upper level low should meander
northeast and cross eastern KY, and may gradually become an open
wave as it begins to interact with the upper troughing initially
over the western Conus as it it moves across the Rockies and enters
the Plains and Central Conus. A brief window of narrow upper level
ridging should follow behind this system across eastern KY starting
late Wednesday. Within the upper trough moving from the western into
the central Conus, an upper level low may begin to close off over
the Northern Plains/Dakotas vicinity. The surface system associated
with the upper level low passing across the area through midweek
should also cross the area with the triple point low southeast of
the Appalachians becoming the primary low as the system tracks into
the mid Atlantic states. Further west, a low pressure system should
begin to evolve over the Central Conus in advance of the approaching
upper level trough with the warm front lifting toward the OH Valley
late Wednesday night. The passage of the upper level and sfc systems
across the region will keep the weather unsettled with shower and
thunderstorm chances generally peaking during the daylight hours of
Tuesday and Wednesday, with chances for convection lowest as the
upper level ridging works into eastern KY.

The window of upper level ridging working across eastern KY should
be rather short-lived with the ridge axis likely moving east of
eastern KY by Thursday evening. Meanwhile, the warm front associated
with low in the Central Conus tracking toward the Great Lakes region
through Thursday night and Friday should lift into the area by later
Thursday or Thursday night. As the surface low tracks to Ontario and
Quebec, the trailing cold front should approach the OH Valley late
Thursday night and Friday, nearing eastern KY around late on Friday
night or early Saturday. This should occur in advance of the closed
low in the Northern Plains to Dakotas early Thursday tracking to the
Great Lakes with an associated upper trough nearing the Lower OH
Valley/eastern Conus per guidance consensus through the Friday and
Friday night timeframe. After at least somewhat of a min in shower
and thunderstorm chances continuing into Thursday, chances increase
again on Thursday night with the warm front lifting through the area
peaking Friday into Friday night. Chances for showers and
thunderstorms appear to continue into Saturday as a shortwave trough
crosses the area and the cold front precedes it. A secondary
impulse/shortwave rotating around the upper level low that continues
to migrate form the Great Lakes toward Ontario and Quebec may be
preceded by a secondary cold front near the end of the period.
Chances at least for a diurnal peak in showers and storms appear to
linger into Sunday as well.

00Z ECMWF and 00Z GEFS based AI and Machine learning guidance
suggests probabilities for severe weather increase as early as late
Thursday, all generally peak Friday, and then decrease over the
weekend. 00Z LREF mean MUCAPE and bulk shear generally maximized
during these time as well in the 1500 to 2500 J/kg range for MUCAPE
and bulk shear reaching into the 30KT to 50KT range. Depending on
timing of any convection that could arrive from upstream in the
midwest or in advance of the warm front lifting through the area
late Thursday into early Friday and actual degree of destabilization
ahead of the cold front approaching on Friday and Friday night, some
strong to severe thunderstorms appear possible during this period.
There remains uncertainty with timing the evolution of upstream
convection and any possible outflows that could move across the
region. However, this will continue to be monitored as the week
progresses.

Temperatures will average near normal for highs for Tuesday to
Wednesday with clouds and precipitation limiting diurnal ranges and
resulting in lows a bit above normal. Then, temperatures are still
forecast to warm into the 80s for all of the area on Thursday and
Friday, with the 13Z NBM upper percentile max T forecasts for both
days are in record high territory for JKL and LOZ. The 13Z NBM
deterministic forecast highs and the NBM 50th percentile highs
are a little below records, when compared to record highs of 89
and 87 and 88 and 89 at JKL and LOZ, respectively, for Thursday
the 15th and Friday the 16th. Thereafter, following the initial
frontal passage, temperatures are forecast to cool from those
levels a few degrees over the weekend.

&&

.AVIATION...(For the 06Z TAFS through 06Z Monday night)
ISSUED AT 1256 AM EDT MON MAY 12 2025

VFR conditions are noted at TAF issuance. An approaching low
pressure system situated to our southwest will bring a gradual
lowering of ceilings and the arrival of more widespread showers
through the remainder of the night. The lowest ceilings should
generally be closer to the TN/KY border through sunrise before
lifting north during the daylight hours. Low ceilings (primarily
MVFR) then overwhelm the aviation area for a time on Monday with
IFR levels or lower possible at times when heavier showers and
thunderstorms impact the terminals. Easterly surface winds will be
mainly light - generally under 10 kts through the period. However,
locally strong and erratic winds are possible near any thunderstorm
on Monday afternoon.

&&

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

&&

$$

UPDATE...GEERTSON
SHORT TERM...GREIF
LONG TERM...JP
AVIATION...GEERTSON