Area Forecast Discussion
Issued by NWS Jackson, KY

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FXUS63 KJKL 252306

Area Forecast Discussion
National Weather Service Jackson KY
706 PM EDT THU AUG 25 2016

Issued at 706 PM EDT THU AUG 25 2016

WSR-88D radar showing the afternoon convection has diminished and
this is in line with the forecast grids. Otherwise we are looking
at a warm and humid evening under the upper level ridging and
return flow at the surface. Grids are on track and only overnight
issue will be valley fog potential. Therefore only minor tweaks
needed for current conditions tonight in the grids and taking the
thunder out of the HWO.


.SHORT TERM...(This evening through Friday night)
Issued at 348 PM EDT THU AUG 25 2016

Upper ridging across the Tennessee Valley will edge northeast
into the Appalachians and Mid-Atlantic Friday into the weekend,
keeping a hot and humid airmass in place across eastern Kentucky.
This airmass has led to isolated shower and embedded thunderstorm
activity this afternoon along a weak moisture gradient. Will see
these diminish into late afternoon as this gradient and subsequent
low level forcing decrease. Decay of diurnal cumulus field and
increasing subsidence will allow for patchy fog development
tonight and Friday morning, especially in sheltered valleys. An
influx of relatively drier air coupled with another generally
precipitation free day should limit more widespread development.

Deep layer subsidence, stemming from the above mentioned upper
ridge moving overhead, and a lack of forcing for ascent should
lead to a dry Friday. An upper shortwave trough and weak cool
front look to remain confined to the Ohio Valley and north as
ridging holds strong locally. Best chance of any development would
be off the Cumberland Plateau and higher terrain along the
Virginia border, but a theta-e minimum in place along with
subsidence aloft should preclude mentionable chances. This will
allow for a hot afternoon as temperatures soar into the upper 80s
to lower 90s.

.LONG TERM...(Saturday through Thursday)
Issued at 348 PM EDT THU AUG 25 2016

Not the best agreement amongst the extended this time around. The
ECMWF was consistently drier through out the period than the GFS.
The blended model data settled around a solution that features
showers and storms moving into the area Saturday afternoon, and
persisting Monday afternoon, with the most active periods being the
afternoon and evening hours. It then appears that a ridge of high
pressure will settle over the area from Monday evening through
Tuesday morning, bringing a brief respite from shower and storm
activity. A sluggish cold front will attempt to push into the area
from early Tuesday afternoon onward. This boundary may spark a few
showers and storms in our far western counties on Tuesday. After
that, another ridge of high pressure is progged to spread over the
area Tuesday evening and early Tuesday night. More showers and
storms are then expected to plague the area from late Tuesday night
through the end of the week. With the amount of uncertainty in the
model data, decided to keep only very low rain chances in the
forecast, at least until the models have a better handle on things.

Hot and muggy conditions are expected to persist through out the
period, with highs around 90 expected from Saturday through
Wednesday. The expected clouds and precipitation should allow
temperatures on Thursday to not be quite as warm, with highs in the
mid to upper 80s on that day.


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

Isolated showers and thunderstorms will continue this afternoon,
but will likely remain outside of the vicinity of any terminal.
Generally, light west to southwest winds of near 5 knots this
afternoon will diminish this evening. Will see speeds a little
higher, in the 5-10 knot range, near SYM with a few gusts of up
to near 15 knots. Attention will then turn to fog potential
tonight. Subsidence moving in will promote clearing skies after
the diurnal cumulus field decays. Light winds and low level
moisture pooling will promote typical valley fog, but more
widespread development should be hindered by an influx of
relatively drier air overnight combined with a lack of
precipitation near any site. Quicker clearing and persistence
perhaps points to the best chance of sub-VFR conditions near


.JKL Watches/Warnings/Advisories...


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