Area Forecast Discussion
Issued by NWS Jackson, KY

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FXUS63 KJKL 291145 AAA

Area Forecast Discussion...UPDATED
National Weather Service Jackson KY
745 AM EDT SUN MAY 29 2016

Issued at 720 AM EDT SUN MAY 29 2016

Did a quick update to add in a potential for isolated
thunderstorms in the morning portion of the forecast. Also removed
fog from the grids and adjusted T/Td/Sky/PoPs per the latest
observations and trends. These have been sent to the NDFD and web
servers, along with a freshened set of zones.


.SHORT TERM...(Today through Monday)
Issued at 400 AM EDT SUN MAY 29 2016

07z SFC analysis shows relative high pressure over East Kentucky
early this morning as low pressure is found off to the northwest
as well as to the southeast associated with landfalling Tropical
Storm Bonnie. Mainly just some mid and high level clouds are
around the CWA - some loosely connected to the tropical system.
This is likely helping to keep the fog at bay for most places this
morning, though not enough to limit the development of a ridge to
valley temperature split. As such, readings vary from the low 60s
in the more sheltered valleys of the east to the upper 60s on the
ridges. Dewpoints, meanwhile, are in the muggy category for
another night, running from the low to mid 60s. Winds are light
and variable with a clean radar scope at this hour.

The models are in good agreement aloft through the short term
portion of the forecast. They all depict general ridge conditions
through the southeast, but one that has been hollowed out by the
arrival of the tropical storm into the Carolinas. At the same
time as the mid level energy arrives from the tropics, a trough
will brush by Kentucky to the northwest resulting in a gradual
decrease in heights for the area into Monday. Again the mesoscale
will be the more dominant driver of the weather details with the
higher resolution HRRR and NAM12 favored for forecast specifics.

Sensible weather will feature a bit of valley fog around this
morning followed by another warm day. The models suggest that the
best chances for convection will be over the eastern portion of
the CWA and that makes sense with the higher terrain helping to
initiate convection in an environment with little lower level
shear, but ample instability. The downstream influence of T.S.
Bonnie, resulting from from its broad region of uplift around its
core and areas of subsidence/enhancement spreading out from the
center, though weakening with distance, may be enough to give
the east an extra shot at convection later today. Accordingly,
have given the highest PoPs to those parts and lesser amounts to
the west. The NAM12 depicts this well and the gridded forecast -
pretty much followed suit. Another concern, affecting the area
later in the day and into the night, is a weak front sliding
southeast into the Ohio Valley possibly initiating more storms
thanks mainly to the inherent instability. This boundary could
bring isolated to scattered storms to the area well into the
night as it settles into far southeast Kentucky late tonight.
Have kept a small chance for this in the forecast along with a
potential renewal of convection in the far southeast on Monday,
while the rest of the area enjoys a pleasant, warm, and dry
Memorial Day.

Again used the ShortBlend and CONSShort as a starting point for
most of the weather elements with small to moderate adjustments
to temperatures at night for ridge to valley splits. Also, upped
temps a notch today and Monday. As for PoPs, ended up lower to
the MAV guidance thinking that the best chances will be further
east today compared to the MET offering.

.LONG TERM...(Monday night through Saturday)
Issued at 330 AM EDT SUN MAY 29 2016

The first part of the long term period will be mostly dry as surface
high pressure builds into East Kentucky Monday evening. The only
exception will be along the southeast Kentucky border where a few
afternoon showers may pop up as a cold front exits the region. The
dry, but warm weather will persist through Wednesday. Moisture and
humidity will then begin increasing again as a low pressure system
approaches the region. This system will bring a cold front into East
Kentucky by Thursday afternoon. Shower and thunderstorm chances will
increase throughout the day, as the front approaches, with the best
chance for thunderstorms mainly in the afternoon and evening. If
this ideal timing holds true, there will be a chance for at least
some strong storms. The frontal boundary may stall somewhere in the
region Thursday night through at least Friday, keeping the weather
unsettled. There is a chance that an upper level shortwave trough
will move through Kentucky on Saturday, kicking the frontal boundary
south of the area. However, confidence is low this far out in the
forecast on where the boundary will set up and for how long.

Temperatures will remain on the warm side, in the lower 80s, through
Thursday. A cold front will move through most of the region by
Thursday evening, allowing temperatures to cool down to below normal
values. This cool airmass will allow afternoon high temperatures to
stay in the low to mid 70s. Low temperatures each night will be in
the lower 60s.


.AVIATION...(For the 12Z TAFS through 12Z Monday morning)

A few showers or a thunderstorm may be seen across the forecast
area this morning, with better convective potential anticipated
for the afternoon. Based on current activity and near term trends
have expanded the VCTS to include the SYM and JKL sites in
addition to continuing it at SJS, albeit a tad earlier than the
06z TAF. Should any TAF site see rain today some MVFR fog can be
expected later tonight at that location. For now have just
included it in SJS. Look for winds to remain light, at around 5
kts or less, throughout the period.


.JKL Watches/Warnings/Advisories...


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