241
FXUS63 KJKL 121343 AAB
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
943 AM EDT Wed Jun 12 2024

.KEY MESSAGES...

- Hot and uncomfortable weather builds through this weekend, with
  highs in low to mid 90s and heat indices peaking out around 100
  degrees in many locations each afternoon Sunday through
  Tuesday.

&&

.UPDATE...
Issued at 943 AM EDT WED JUN 12 2024

Morning update entailed tweaking up the hourly T and Td grids for
current observations and removing morning fog which has burned
off. Otherwise the forecast is on track. Regional satellite
showing considerable high clouds streaming across eastern Kentucky
this morning. Clouds are thin enough to get away with partly
cloudy wording...vs partly sunny. Also freshened up the zones to
remove morning references.

UPDATE Issued at 730 AM EDT WED JUN 12 2024

No real changes to the forecast with just the inclusion of the
latest obs and trends for the T/Td/Sky grids for this update.
These minor adjustments have been sent to the NDFD and web
servers.

&&

.SHORT TERM...(Today through Thursday)
Issued at 445 AM EDT WED JUN 12 2024

08Z sfc analysis shows high pressure holding over eastern Kentucky
keeping lower clouds at bay, winds light, and sustaining a
relatively dry air mass. These are excellent conditions for
radiational cooling even though some high clouds through the night
did mitigate the effects to some extent. Currently, temperatures
vary from the upper 50s on a few of the ridges to the upper 40s in
some of the most sheltered valleys. Meanwhile, dewpoints remain
in the upper 40s to lower 50s. Also noted is the areas of fog in
the river valleys - locally dense - this morning.

The models, and their individual ensemble suites, are still in
excellent agreement aloft through the short term portion of the
forecast. They all depict weak northwest flow over the state at
mid levels between general low 5h heights to the north and a
building ridge to the southwest. A minor impulse will pass by
eastern Kentucky this morning to the northeast with all but some
diffuse energy staying away from Kentucky through during the next
36 to 48 hours. 5h heights will be on an upward trend through
Thursday on account of the southwest ridge slipping east into the
Southern Plains and nosing into Kentucky late in the period. The
model spread remains at a very small level so that the NBM was
again used as the starting point for the short term grids with
little deviation necessary aside from the incorporation of
standard terrain distinctions for temperatures early this morning
and again tonight.

Sensible weather features the start of the warm up that will take
hold for the next week and perhaps longer. However, afternoon
temperatures today will only be slightly higher than normal most
places along with still fairly dry humidities. High pressure in
place tonight will also allow for a ridge to valley split but at
some 5 to 10 degrees warmer than those of this morning - with
still some river valley fog around. Thursday will start to become
more uncomfortable as temperatures peak in the mid to upper 80s,
most places along with an slight increase in humidity over this
afternoon - while winds remain light.

The main changes to the NBM starting point again consisted of
adjusting the temperatures in order to better represent terrain
details in a radiational cooling regime for this morning and
tonight. PoPs were kept near zero through the period.

.LONG TERM...(Thursday night through Tuesday)
Issued at 312 AM EDT WED JUN 12 2024

Upper-level northwesterly flow will continue to exist across the
region. A shortwave perturbation will pivot eastward over the Niagara
Region and while that occurs, the associated surface low will shift
northeast through the Ohio Valley. The accompanying cold front will
begin to approach the region by Friday afternoon bringing isolated
chances of showers and thunderstorms to the region. Timing of the
front is ideal but due to rather dry column, widespread showers and
storms aren`t expected. Also, not looking at a significant risk of
severe weather.

Upper-level ridging is forecast to build in from the southwest and
surface high pressure will firmly establish itself over the region
for the remainder of the weekend into next week. As the high shifts
north and east, increasing temperatures are expected as highs will
climb into the low to mid-90s for Sunday and Monday; this coupled
with increasing moisture will allow for heat indices to approach 100
degrees. Models have come back into better agreement for Monday into
Tuesday with deterministic runs keeping surface high pressure across
the area. Increasing Gulf moisture will allow for disorganized
shower and thunderstorm chances through the remainder of the period
with temperatures remaining in the low to mid-90s and heat indices
in the upper-90s.

&&

.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
ISSUED AT 740 AM EDT WED JUN 12 2024

VFR flight conditions will hold throughout the period outside of
the river valleys where fog will clear out through early morning.
There will be just some time of high clouds around through
Thursday morning. Light winds will be the rule through the
period, as well, averaging less than 5 kts and having a
predominant northerly direction.

&&

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

$$

UPDATE...RAY
SHORT TERM...GREIF
LONG TERM...VORST
AVIATION...GREIF