553
FXUS63 KJKL 031932
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
332 PM EDT Fri May 3 2024

.KEY MESSAGES...

- Shower and thunderstorm potential returns to the forecast
  through the next 7 days.

- Cooler than in recent days, but temperatures are forecast to be
  above normal through the next 7 days.

&&

.SHORT TERM...(This evening through Saturday night)
Issued at 332 PM EDT FRI MAY 3 2024

An active pattern remains across the Bluegrass State through the
short term. Large upper low/trough configuration remains over the
far northern US and south-central Canada with an active jet stream
from the Central Plains to Upper Great Lakes region. Meanwhile,
upper ridging remains persistent along the East Coast, and will
begin to move offshore Saturday night as the aforementioned upper
low begins to move northeast toward eastern Canada at that time.
This leaves eastern Kentucky under the influence of a moist and
active regime with periodic shortwave disturbances moving across the
region through Saturday evening.

Currently a disturbance is beginning to exit to the east this
afternoon, but will be followed by another tonight into Saturday
morning that will bring another round of showers and possibly a few
thunderstorms. Models suggest low-level instability is somewhat
lacking but there is sufficient elevated instability to warrant a
few claps of thunder from time to time, especially west of I-75. Fog
formation overnight will be dependent on any lulls in precipitation
as well as any potential partial clearing. Lows tonight will range
from the mid-50s in the cooler sheltered valleys to lower 60s
elsewhere.

Another disturbance appears to be well-timed with any daytime
heating to help produce more widespread showers and thunderstorms
Saturday. Given high PoPs and cloud cover through the day
temperatures will struggle to reach the current forecast highs of
upper 70s.

PoPs gradually lower through Saturday evening through the overnight
as a trailing shortwave crosses the area with shortwave ridging
building in from the southwest after midnight. Sky cover will likely
trend downward but this would likely then promote fairly widespread
fog formation late Saturday night into Sunday morning, especially in
the river valleys. Expect forecast lows Saturday night similar to
tonight`s forecast, with mid 50s to lower 60s.



.LONG TERM...(Saturday night through Thursday)
Issued at 500 AM EDT FRI MAY 3 2024

A rather wet long term period should be in store. However, it
looks overall rather short on details/specifics. Prevailing large
scale flow aloft will be persistent from the west southwest, while
low level flow will be from the south southwest off the gulf.
This pattern of warm/moist advection will favor precip. A wavering
frontal boundary will approach from the northwest at times, but
being largely parallel to the upper level flow, it will not have
much momentum and is not likely to make a clean passage during the
period (possibly just beyond the current long term period). This
will leave us in a modestly humid air mass with surface dew points
in the upper 50s and lower 60s most of the time. The main drivers
for precip will be convection associated with diurnal heating
cycles and mid/upper level waves. While the diurnal cycle is
simple, weak upper level features are much more problematic. The
most obvious and predictable feature at this point is a shortwave
trough which all models have approaching on Monday. The highest
POP (70% area wide) of the long term period coincides with this.
The remainder of the 12 hour periods have POPs mainly in the
40-60% range.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 129 PM EDT FRI MAY 3 2024

Periodic rain showers will continue through much of the period,
though nailing down timing at any one TAF location is difficult.
Models seem to be slower in bringing sufficient instability for
VCTS mention into the region this afternoon, so pared back any
mention to primarily KLOZ and KSME. Once the sun goes down, the
storms should become more isolated with time with rain showers
being the dominant precipitation mode. Any storm could produce
locally heavy rainfall and gusty winds, along with brief periods
of MVFR or IFR VSBYs. MVFR CIGs will also be possible at times
today into this evening during peak shower/thunderstorm activity.
If shower activity tapers sufficiently overnight will likely see
at least some fog develop at some if not all terminals, even
moreso if there is any partial clearing.

&&

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

$$

SHORT TERM...CMC
LONG TERM...HAL
AVIATION...CMC