Area Forecast Discussion
Issued by NWS Jackson, KY

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FXUS63 KJKL 261732

Area Forecast Discussion
National Weather Service Jackson KY
132 PM EDT FRI AUG 26 2016

Issued at 132 PM EDT FRI AUG 26 2016

Diabatic heating has spawned a shallow cumulus field across
eastern Kentucky. Diurnal heating will be more than sufficient
enough to send temperatures generally into the lower 90s within
the next few hours.


.SHORT TERM...(Today through Saturday)
Issued at 330 AM EDT FRI AUG 26 2016

Mid/upper level ridging across the eastern CONUS will keep a hot
and humid air mass in place across eastern Kentucky through the
weekend. Can not rule out an isolated shower or thunderstorm
Saturday afternoon across our southern and southwestern zones as
a very weak upper level disturbance manages to track around the
south side of the mid/upper level ridge centered over the
Atlantic seaboard.

Sensible weather will see summer like weather with hot and humid
conditions continuing across the forecast area. Weather will also
be dry except for isolated showers and thunderstorms generally off
the Cumberland Plateau and higher terrain along the Virginia
border Saturday afternoon. Seasonably hot afternoon temperatures
will climb into the lower 90s today and Saturday. Very humid air
in place will keep overnight lows up around 70 tonight.

.LONG TERM...(Saturday night through Thursday)
Issued at 415 AM EDT FRI AUG 26 2016

A strong upper level high will be centered just to our east at the
start of the period, with a hot and fairly humid air mass in place
at the surface. Diurnal heating may be enough to get some
thunderstorms going in this regime, especially over higher/more
rugged terrain. With very weak flow aloft and nothing in the way
of meaningful features aloft to clearly focus convection,
convection will be disorganized and relatively low in coverage.

The upper high is expected to weaken during the long term period,
and an upper trough will deepen over the northeast CONUS. Both the
ECMWF and GFS show this scenario, but do not agree on how deep the
trough will be. Often in this scenario we will have a back door cold
front pass through. However, neither of the models shows a cold
front, but only a potential for a gradual filtering of slightly
drier air into our area by late in the week. One more factor in some
recent model runs involves a tropical system possibly moving through
the southeast CONUS, but the most recent GFS and ECMWF suggest this
may be less of an issue. With such a murky picture, slight chance
POPs are in order through much of the period.


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

VFR conditions with light easterly winds will persist today as the
afternoon cumulus field dissipates this evening. This will once
again set the stage for fog development, potentially becoming
dense in some river valleys. Current thinking would be that
terminals will see less of a threat for dense development given
strong heating and lack of precipitation today, but persistence
and nearby presence of weak surface ridging centered near the
Great Lakes warrants maintaining at least IFR visibilities for now
at LOZ/SME/SYM from approximately 8-13Z. Very light downslope
flow may provide just enough subsidence to keep fog from reaching
SJS/JKL. Have also seen dewpoints mix lower early this afternoon,
so perhaps crossover temperatures will have a little tougher time
being reached, thus inhibiting widespread fog development.


.JKL Watches/Warnings/Advisories...


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