917
FXUS63 KJKL 141935
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
335 PM EDT Wed Aug 14 2024

.KEY MESSAGES...

- Daytime temperatures will average around normal through the
  remainder of the week.

- Humidity, along with the possibility of showers and
  thunderstorms will increase late in the week, with the highest
  probability of storms during the Friday afternoon and evening
  time frame.

&&

.UPDATE...
Issued at 149 PM EDT WED AUG 14 2024

Early afternoon update amounted to minor adjustments to the temps
and sky cover. Observed hourly temps have been running slightly
higher than advertised in the grids. Consequently, made a small
nudge upward for afternoon highs. Based on regional satellite, our
afternoon Cu field had shown a bit more substantial development
than expected, especially over our higher terrain to our southeast
and across our northern zones. Thus increased cloud cover just a
bit to account these most recent trends. While at it freshened up
the zone wording as well.

UPDATE Issued at 1019 AM EDT WED AUG 14 2024

Forecast is pretty much on track this morning. Clouds have cleared
across our southeast and valley fog has lifted and dissipated. We
can expect some additional thin high clouds to stream across the
area through the day along with some fair weather Cu. But overall
we expect to see more sun than not. Adjusted temps towards hourly
surface observations and made some minor tweaks to the sky cover
for clearing across the southeast. Updated the zones to remove
morning fog. Otherwise, no other changes to the forecast package.

UPDATE Issued at 739 AM EDT WED AUG 14 2024

Update this morning increases Sky cover for the next few hours
over the southern part of the forecast area to match current cloud
trends. This activity should diminish and move south into
Tennessee over the next few hours. Grids were updated with
initialization using the latest hourly observations.

&&

.SHORT TERM...(Today through Thursday)
Issued at 310 AM EDT WED AUG 14 2024

Northwest flow aloft continues through the first half of Thursday,
when a disturbance moving into an upper ridge axis approaches the
Mid-Ohio River Valley. At the surface, high pressure continues to
usher a drier air mass in from the north and east, but warm moist
advection increases through the day Thursday ahead of the
approaching upper disturbance, with a warm front moving to the
northeastern third of the forecast area by the end of the period
early Thursday evening.

For today, drier air moves into the region from the northeast
through the daytime hours as a disturbance skirting us to the
northeast moves away from the area. With the drier air and nearly
full sun for most locations, highs should rise a degree or two
from yesterday, with highs on the upper end of the mid-80s.

Upper ridge axis approaches tonight from the west, while the lower
atmosphere begins to transition from departing surface high pressure
to approaching low pressure. This sets up an ideal situation for
decent ridge/valley splits, especially in the deeper sheltered
central and northeastern valleys that are removed from any bodies of
water. Lows tonight will range from the lower to mid-50s in the
coldest valleys to lower to mid-60s on the ridgetops.

Warm, moist advection gradually increases from the southwest
during the day Thursday. A couple of CAMS even develop isolated to
widely scattered showers in the afternoon, particularly the 4-km
NAMNest and to a lesser degree the NSSL-WRFARW-4km models.
However, most models remain dry with just increasing cumulus in
the afternoon as the lower atmosphere begins to moisten and
stability decreases, so will keep PoPs less than 10 through
Thursday afternoon. With warm advection increasing, highs will
begin to rise to as high as 5 degrees above normal for mid-August,
warmest in the northeast where clouds will be slowest to increase
and where there will be some south to southeasterly surface winds
causing some weak downslope compressional warming through much of
the daytime hours.

.LONG TERM...(Friday through Wednesday)
Issued at 335 PM EDT WED AUG 14 2024

The flow pattern aloft in the extended will start off with hurricane
Ernesto churning its way northward through the west central
Atlantic, with a trough of low pressure departing the coast of Maine
and southeastern Canada. Further west, we will see our weather maker
in the form of a slow moving and well developed trough of low
pressure moving through the Great Lakes and into New England. This
system will bring showers and storms to eastern Kentucky Friday
through Saturday, as its surface cold front moves into and then
stalls over the area. The rain associated with the front should
begin to exit the area to the east Saturday night into early Sunday.
After a brief reprieve from the rain behind the front, we are
expecting further rounds of rain Sunday through Monday, as a trough
aloft moves off to our northeast, and pumps residual moisture into
the region. With lift from the low also present, we expect to see
scattered showers and storms at times Sunday and Monday, especially
during the afternoon and early evening hours each day. Once these
two rounds of rain come to an end, a ridge of high pressure will
settle over the region, and will bring dry weather, mostly clear
skies, and light winds to eastern Kentucky from Monday night into
the middle of the week.

As the ridge moves overhead, conditions will be prime for nightly
ridge valley temperature splits the first half of the new work week.
With clear skies, light winds, and dry air all on tap, decided to
cool the valleys off a bit more than previously forecast, since
conditions seem ideal for the ridge/valley differences. A
combination of the latest runs of the GFS, ECMWF, WPC guidance, and
GFS Ensembles were all used to create the forecast, with the
evolution of the flow pattern aloft being emphasized.

Temperatures will be quite warm overall, with daily highs in the 80s
expected. The coolest days will see max values in the lower 80s,
while the warmest days could warm into the mid and upper 80s.
Nightly lows will be quite pleasant as well, with nightly values
ranging from the mid to upper 50s in valleys to the 60s on the
surrounding ridgetops.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
ISSUED AT 149 PM EDT WED AUG 14 2024

VFR flight conditions expected through the period. Based on
regional satellite, our diurnal Cu field had shown a more robust
development than expected, around 060 AGL, especially over our
higher terrain to our southeast and across our northern zones.
This impacts mainly KJKL, KSJS, and KSYM. Winds will be light
and variable through the afternoon, around 5 kts or less becoming
light after sunset. Similar to last night, fog will develop
within the river valleys overnight, but impacts will be negligible
at our terminals.

&&

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

$$

UPDATE...RAY
SHORT TERM...CMC
LONG TERM...AR
AVIATION...RAY