Area Forecast Discussion
Issued by NWS Jackson, KY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

FXUS63 KJKL 300756

Area Forecast Discussion
National Weather Service Jackson KY
356 AM EDT TUE AUG 30 2016

.SHORT TERM...(Today through Wednesday)
Issued at 356 AM EDT TUE AUG 30 2016

An upper level ridge will be in place across the region today and
tonight, keeping subsidence and calm weather across the region
during this time. Meanwhile, a closed upper level low will push
southeast along the shores of the Hudson Bay today. This will result
in upper level troughing as the low continues on into James Bay
overnight, and lowering heights across the eastern US during the day

As for sensible weather...
High pressure across the region has led to clear skies and light
winds early this morning. Locations that received rain yesterday
have been prone to patchy dense fog overnight, as have many of the
deeper river valleys. This fog will slowly dissipate through the
morning hours as temperatures begin to warm. Generally clear
conditions are expected through the day today under continued
light NE to N flow. That being said, afternoon heating could lead
to a few diurnal cumulus, and possibly an isolated shower or
thunderstorm. All hi-res CAM models are pointing at the best
potential for this occurring along the highest terrain in the far
southeast portion of the state, so did include some isolated pops
here. Under strong subsidence, temperatures will be similar to
that of yesterday, nearing 90 degrees by the afternoon. Thankfully
with the NE to N flow in place, this will keep some of the
humidity levels down, and apparent temps will remain close to the
actual temp values.

Any diurnal clouds will clear out once again tonight, with valley
fog formation being the only weather concern. Temperatures will fall
into the upper 60s to near 70, similar to that of this morning. The
big change will come during the day Wednesday. A surface low
pressure system associated with the above mentioned upper level
closed low will track southeast across Canada, pulling with it a
cold front. This cold front is expected to push eastward and towards
KY, reaching just north of the Ohio River by Wednesday afternoon. An
interesting thing to note, however, is that the winds never turn
southerly ahead of this front, instead they will shift from NE to NW
along and behind the frontal passage. That being said, a lot of the
convection along the frontal boundary will actually be diurnally
driven, with the aid of afternoon heat/instability. Clouds really
won`t start building in until just ahead of the frontal zone, along
with the best convection, given the lack of moisture. Did keep some
isl to sct pops in during the afternoon, though coverage may be
limited to the far northern portion of the CWA (closer to the actual
frontal zone), as well as in the high terrain as a result of upslope
NW flow across the CWA.

Overall, much of the CWA should see minimal impacts during the day
Wednesday, and much of the convection should cease by Wednesday
night with the loss of diurnally induced lift. Temperatures
Wednesday will still manage to boost back into the upper 80s, though
if cloud cover winds up being more extensive than originally
thought, this may keep temps a degree or two cooler.

.LONG TERM...(Wednesday through Monday)
Issued at 347 PM EDT MON AUG 29 2016

The long term period will offer a reprieve from the heat and
humidity that has plagued the area over the past few weeks. At
upper levels, a long wave trough in place over Kentucky (through
the work week) will shift east, being replaced with ridging for
Labor Day Weekend. At the surface, a weakening cold front will
drop through the region late Wednesday night into Thursday. This
late timing of the frontal passage along with limited instability
should keep precipitation to a minimum with only a slight chance
for showers or storms. A cooler and much drier air mass will then
push into the area as high pressure builds across the Great Lakes
Thursday afternoon. As a result, temperatures will fall from the
upper 80s on Wednesday into the upper 70s and low 80s behind the
front beginning Thursday and lasting through the first half of the
weekend. Humidity levels will also be lower and more comfortable.
Temperatures and humidity start moderating back towards summer-
time levels Sunday as the surface high shifts to our east and
southerly flow returns. Labor Day looks to be warm and muggy with
dew points in the mid 60s and temperatures in the upper 80s. No
precipitation is expected beyond Thursday.


.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)

Skies have cleared across eastern KY, and should remain clear
through the morning before some few/sct afternoon CU develops
around 4k ft. Given the rains of yesterday, and the ongoing
clear/calm conditions, patchy dense fog has formed across many of
the valley locations in eastern KY. While most of the TAF sites
should remain fog free, KJKL did receive a good dowsing of rain
yesterday and therefore may continue to see off and on fog
throughout the night. As such, LIFR VIS will be possible at times
into the morning, with off and on CIGs below airport mins. Can`t
also rule out some brief lowering of VIS and CIGS at other
airports near daybreak as fog lifts before dissipating. Winds will
remain light and variable throughout the period...generally 5
knots or less.


.JKL Watches/Warnings/Advisories...


AVIATION...JMW is the U.S. government's official web portal to all federal, state and local government web resources and services.