722
FXUS63 KJKL 152009
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
409 PM EDT Sat Jun 15 2024

.KEY MESSAGES...

- Hot and somewhat humid weather arrives on Sunday and persists
  into the upcoming week. Afternoon heat indices may peak around
  100 at some locations Sunday through Friday.

- There is a potential for thunderstorms over the Cumberland Basin
  and near the VA border on Sunday, and area wide on Monday and
  Saturday. The greatest probability is in the afternoon and
  evening hours each day.


&&

.SHORT TERM...(This evening through Sunday night)
Issued at 408 PM EDT SAT JUN 15 2024

An updated short term forecast suggestion will be sent shortly.

.LONG TERM...(Monday through Saturday)
Issued at 408 PM EDT SAT JUN 15 2024

Models continue in agreement for the pattern that will affect our
area during the long term period. Strong upper level high pressure
will start out centered over NC. It is expected to shift north to
near NYC at mid week, with a ridge axis extending southwest over the
central Appalachians. It then shifts back south to the vicinity of
the Carolinas and weakens late in the week.

In the lower levels, moisture will have advected back north over our
area by Monday, with humidity being noticeable. Forecast soundings
show significant instability (3-4.5K J/Kg MU CAPE in the NAM)
developing during the day. The upper level ridge/high (and its
greatest influence to produce a cap and inhibit convection) should
be centered to our southeast, and our forecast soundings don`t show
a cap. This should allow thunderstorms to freely develop. However,
flow will be weak and shear negligible. This would suggest
unorganized, strong, pulse, diurnally driven convection. Without
storm organization, chance POPs given by guidance seem reasonable.
Activity will diminish Monday evening with loss of heating.

The upper level ridge axis will be building into our area by
Tuesday and should bring enough subsidence with a mid level cap
developing to help inhibit thunderstorm development. As we move
further into the week, our low level flow will emanate out of
high pressure to our east. Without sufficient time for the air
mass to modify, and along with deep mixing, this should bring dew
points down slightly, further reducing our potential for
thunderstorms. It looks like this scenario lasts through Friday.

The potential for thunderstorms could make a comeback by Saturday.
The GFS QPF shows spotty light amounts on that day, indicative of
sparse convective precip. The ECMWF remains dry. With the upper
level ridge shown to be weakening, from a synoptic viewpoint it
would make sense for at least a small possibility of thunderstorms
to return, and a 20% POP will be used.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 156 PM EDT SAT JUN 15 2024

VFR conditions are expected through the TAF period under mostly
clear skies. A few shallow cumulus are bubbling up this afternoon
over the higher elevations near the Virginia and Tennessee
borders but are not expected to impact the TAF sites. Some thin
high clouds are also expected tonight. A more substantial high-
base cumulus field may develop on Sunday afternoon around and
beyond the end of the TAF period. Winds will be around 5 kt today
but generally favor a northeast direction today and then east to
southeast overnight tonight.

&&

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

$$

SHORT TERM...GEERTSON
LONG TERM...HAL
AVIATION...GEERTSON/CMC