517
FXUS63 KJKL 050015 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
815 PM EDT Fri Oct 4 2024

.KEY MESSAGES...

- A passing cold front brings a chance of showers to mainly
  eastern parts of the area on Sunday evening and Sunday night.

- Temperatures will average 5 to 10 degrees above normal through
  Sunday before typical autumn-like readings arrive on Monday.

&&

.UPDATE...
Issued at 815 PM EDT FRI OCT 4 2024

23Z shows weak high pressure over eastern Kentucky, but this has
been enough to clear out most of the clouds as the showers and a
couple storms have dropped south out of the state. Look for the
conditions and light winds to lead to another night of decent
radiational cooling and patchy valley fog with some locally dense
areas by the early morning hours. Currently, temperatures are
running in the lower 70s on the ridges and in the mid 60s valleys.
Meanwhile, dewpoints remain rather elevated in the low to mid 60s
across the area - driest north. Have updated the forecast mainly
to add in the latest obs and trends for the T/Td/Sky grids. These
minor adjustments have been sent to the NDFD and web servers along
with a freshening of the zones, HWO, and SAFs - to drop thunder
and PoPs.

&&

.SHORT TERM...(This evening through Saturday night)
Issued at 415 PM EDT FRI OCT 4 2024

Late this afternoon, an upper level ridge was centered north of
the Bahamas and extended north off the coast of VA and the
Carolinas with another upper level ridge was centered over the
Southwest/Southern Rockies vicinity with the axis of this ridge
extending to Saskatchewan. In between, a trough axis extended from
the James Bay area south across Ontario and the Central Great
Lakes to eastern KY and then into the southeast to the lower MS
Valley. Further west, an upper level trough was moving across
western portions of Canada into the Northwestern Conus. At the
surface, a wavy frontal zone extended from the Maritimes to the
eastern Great Lakes/upstate NY to north of the OH River to a weak
wave in MO and then southwest and south to the Southern Plains
where it was becoming increasingly diffuse. Sfc high pressure
meanwhile, was centered in the vicinity of the Southern
Appalachians with a more substantial high building from the Upper
MS Valley into the western and central Great Lakes. Well ahead of
the boundary, shower activity has generally been confined to
areas from the TN border east to the Cumberland Mountains along
the VA and KY border. A few showers or sprinkles occurred earlier
this afternoon further north and northwest. Temperatures ahead of
the boundary have climbed into the upper 70s to low 80s for most
locations.

Through tonight, the upper level trough axis will continue east
moving east of the area around or shortly after sunset. At the
same time, the sfc cold front that was generally lagging the upper
level trough/support will sag south across the Commonwealth
tonight as the sfc high builds east toward the eastern Great Lakes
to mid OH Valley to Southern Appalachian region in advance of the
upper level ridging that builds into the Southern Plains to
western Great Lakes by late tonight and early on Saturday. The
upper level ridge axis will move east and near eastern KY by late
Saturday, before shifting east and southeast on Saturday night.
Meanwhile, the upper level trough that is currently entering the
northwestern/western Conus will move rather quickly east in
rather strong westerlies with the guidance consensus an upper
level low develops over Saskatchewan later tonight and early on
Saturday then moves across Manitoba and then to northern Ontario
to end the period. At the same time, the associated trough axis
will work across the eastern Conus and cross the Northern and
Central Plains and reach a Upper MS Valley/western Great Lakes to
mid MS Valley late late Saturday night preceded by a cold front
that will affect eastern KY early in the long term period. For
Saturday to Saturday night, the sfc high is expected to gradually
shift to the Sat Lawrence Valley to mid Atlantic states to
portions of the Southeast with a center of high pressure
developing over the Southern Appalachians Saturday night.

Moisture with PW on the order of 1 to 1.3 inches lingers across
the region at present and the passing shortwave trough and daytime
heating will lead to a lingering chances for showers and perhaps
a storm mainly from near Williamsburg are to the Cumberland
Mountains and vicinity over the next couple of hours. Some of the
cumulus further north and northwest may become deep enough to
produce a few sprinkles. Otherwise, this activity will diminish
and end toward sunset from northwest to southeast as the shortwave
trough passes. Otherwise, lows tonight should be coldest in the
north behind the front where cooler and drier air arrives first.
Despite the passage of the cold front by Saturday, the airmass
will be drier and should head to above normal levels again by
about 5 to 8 degrees or so. The pattern ahead of the front with
sfc high pressure remaining/reasserting itself over the Southern
Appalachian should result in colder overnight lows for the more
southern valleys on Saturday night as compared to tonight with a
larger ridge/valley split as the nocturnal inversion develops. The
differences will also be influenced by increasing southerly flow
ahead of the approaching front that will affect some ridgetops and
more open terrain locations toward dawn on Sunday.

.LONG TERM...(Sunday through Friday)
Issued at 330 PM EDT FRI OCT 4 2024

Model guidance shows a strong 530-540dm low over the northern plains
Sunday morning. Downstream a ridge of high pressure will occupy the
skies aloft over the northeastern CONUS. Some diffluent flow aloft
is indicated over Kentucky Sunday, with light SW to W winds expected
at the surface. Generally quiet weather is expected through the day
with highs in the low to mid 80s for most. Sunday night a cold
front, associated with the the upper low well north, will move
through the state with limited moisture producing some light
showers, with only a few hundredths expected. Lows Sunday night
will be in the upper 40s for valleys with low 50s along ridgetops.

Monday, cooler conditions are expected following the cold frontal
passage. Highs temperatures are currently expected to be in the
upper 60s north, with mainly low 70s in the south. Winds will
generally be light and out of the north. This will help cooler
temperatures stick around. Lows Monday night should be around 40
for valleys, and low to mid 40s along ridgetops. Some cooler
locations will dip into the upper 30s.

Tuesday though Friday, dry and seasonable conditions are expected
with light winds. High temperatures will generally range in the
upper 60s to lower 70s for most, with nighttime lows in the upper
30s to low 40s in the valleys, and low to mid 40s along ridgetops.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
ISSUED AT 755 PM EDT FRI OCT 4 2024

VFR conditions prevailed at issuance time as all convection has
dropped south of the area. These benign conditions should hold
through about 04Z. After that, fog is expected to develop again
tonight mainly in the river valleys with impacts possibly reaching
some of the TAF sites. Kept a more optimistic forecast for
visibility during the 08Z to 13Z timeframe at KLOZ and KSME and
left fog out of the TAFs for KJKL, KSJS, and KSYM. Where valley
fog does occur IFR or lower visibility is possible starting around
04Z and dissipating by no later than 14Z. Winds will be light
and variable through the period.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...GREIF
SHORT TERM...JP
LONG TERM...GINNICK
AVIATION...JP/GREIF