Area Forecast Discussion
Issued by NWS Jackson, KY

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FXUS63 KJKL 251936

Area Forecast Discussion
National Weather Service Jackson KY
336 PM EDT WED MAY 25 2016

.SHORT TERM...(This evening through Thursday night)
Issued at 329 PM EDT WED MAY 25 2016

A cluster of showers, originating off the Cumberland Plateau and
currently approaching the I-75 corridor, will continue to track
northeast this afternoon. Surface-based CAPE of 500-1000 J/KG has
developed and led to an afternoon cumulus field amid a steady stream
of increasing mid to high clouds moving in from the west ahead of a
disturbance stretching from southeast Saskatchewan through the
Mississippi Valley. May see an increase in shower and thunderstorm
activity, mainly across the Bluegrass region, as this energy
propagates toward eastern Kentucky. Further development will be
possible across the higher terrain as additional low level
forcing for ascent will be nonexistent. Will see this pulse-type
activity quickly dissipate as poor deep layer shear will lead to
cold pools quickly overwhelming updrafts.

Lingering shower activity will be possible through the night as
southwest flow aloft will be characterized by microscale shortwave
impulses. Instability looks to be low enough to negate thunder
mention with a diurnally cooling boundary layer. Dewpoints in the
upper 50s to lower 60s will only allow overnight lows to fall into a
similar range as moisture from the Gulf of Mexico remains in place.
Despite mid to high cloud cover persisting, patchy valley fog will
be possible given near-surface saturation.

A similar story continues for Thursday with isolated showers and
thunderstorms developing in a weakly forced environment. Highs
rising into the mid 80s will again provide ample enough instability
for pulse storms in a weakly-sheared environment. Following any
lingering showers Thursday evening, lows in the low to mid 60s along
with patchy valley fog will once again be in the offing overnight in
a moist environment.

.LONG TERM...(Friday through Wednesday)
Issued at 332 PM EDT WED MAY 25 2016

More summer like weather will remain the story for a good portion
of the long term period. This is brought to us by a upper level
ridge that will reside along the east coast, meanwhile a upper
level closed low will be in place near the front range. This upper
level ridge will keep the trough well west of the region. The
issue here is we will reside on the periphery of this upper level
ridge. This will result in the potential for a few weak waves, but
right now models are remaining in little agreement overall. Given
no definitive lifting features will stick with isolated showers
and storms for now through much of the long term.

There is another caveat as we move into early next week focus
shifts to the tropics. There is a surface low that develops off
the Carolina Coast this weekend and then remains quasi stationary
with little if any steering flow. The NHC does paint the region in
a 50% chance for tropical development in latest outlook. The GFS
continues to and now the latest ECMWF bring a bit more moisture
into the region, as a result of the tropical system by Wednesday.
Therefore opt to introduce high chance pops along the VA border.

Also given increased moisture and summer like pattern will see the
potential for patchy valley fog in the mornings. Also areas that
see any storms would expect a better chances of fog formation
given increased moisture. Overall temps through the period will
remain above normal, with highs topping out in the lower 80s and
lows in the upper 50s to lower 60s.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)

VFR conditions to largely prevail through early Thursday
afternoon as middle to high clouds stream in complete with an
afternoon cumulus field. Not expecting any widespread ceilings to
threaten VFR criteria, but isolated to scattered showers and
thunderstorms will develop this afternoon and evening. Have
elected to keep mention out of all TAFs given expected low
coverage, but could very well see brief MVFR criteria where a
storm passes overhead. South to southwest winds should remain
below 10 knots this afternoon before further diminishing this
evening and tonight.


.JKL Watches/Warnings/Advisories...


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