Area Forecast Discussion
Issued by NWS Jackson, KY

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FXUS63 KJKL 290650
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
150 AM EST Tue Nov 29 2016

.UPDATE...
Issued at 1038 PM EST MON NOV 28 2016

One last forecast update has been made before the night shift
comes in. Freshened up the hourly forecast grids with the latest
obs data to establish new trends. Made sure to leave in a couple
of more hours of advisory criteria wind gusts to line up with our
wind advisory, which is set to expire at midnight. Also removed
thunder from the forecast grids and the hazardous weather outlook
products, as it as simply not materialized across our area this
evening.

UPDATE Issued at 652 PM EST MON NOV 28 2016

The forecast grids were updated to reflect a slower eastward
progression of the rain showers and thunderstorms that are
currently ongoing across central Kentucky. The air across eastern
Kentucky is still dry enough that incoming precipitation has been
having a difficult time progressing eastward. That being said, the
forecast grids were updated to reflect a 2 to 3 hour slower onset
of precipitation across eastern Kentucky this evening. The zone
forecast text product was updated to remove mention of the
cancelled red flag warning and to remove the late afternoon
period. The hazardous weather outlook was also updated to remove
the red flag warning.

&&

.SHORT TERM...(This evening through Tuesday night)
Issued at 424 PM EST MON NOV 28 2016

A large swath of rain ahead of an approaching cold front is
currently making its way toward the western fringes of our CWA.
Expect this rain to traverse eastern KY throughout the evening and
overnight, bringing a much needed soaking rain to the region. With
the latest forecast, generally 0.4 to 0.7 inches of rain is expected
before it begins tapering off behind the cold front late tonight and
into Tuesday morning. This will hopefully help with some of the
ongoing wildfires and drought conditions throughout the CWA. In
addition to the rains, we are continuing to monitor high winds that
will be impacting the region just ahead of the cold front. While
winds have thus far remained somewhat lighter than expected, they
should continue picking up throughout the afternoon, peaking just
before 0z in most locations. Sustained winds between 10 and 15 mph
will increase to 15 to 20 mph by this evening. Highest gusts will
be seen on the ridges, tapping into some of the strongest winds
aloft. Gusts of 30 to 40 mph in many locations between now and
late this evening will be possible, though some of the highest
terrain near the VA border may see some gusts in excess of 40 mph.

Given the impressive wind shear just ahead of the front, the heavy
rains, and some elevated instability present, went ahead and
included some isolated thunder in the forecast during widespread
rainfall. The cold front is poised to quickly pass through the CWA
starting around 3z. After the frontal passage, there will be little
overall change in the atmosphere other than rains tapering off, and
a slight wind shift/decrease in magnitude at the surface.
Otherwise...strong S to SE flow will continue aloft, so expect
continued moisture flow into the region. This will keep temperatures
up and clouds in the region through the overnight. Overnight
temperatures will only fall to the low 50s.

Drier air will infiltrate the CWA tomorrow briefly, allowing clouds
to erode from west to east. This, combined with continued SW flow,
will boost temps well above normal, in the upper 60s across much of
the region. This dry slot will be short lived, however, as a
secondary cold front begins approaching the region once more from
the West. Expect the secondary cold front to near the Mississippi
River Valley by 0Z Wednesday, quickly shifting eastward reaching our
CWA near 12Z. Moisture will be on the increase once more ahead of
this system, with another round of soaking rains expected.
Categorical pops will be possible through Wednesday night for a good
portion of our SW CWA, with likely pops elsewhere. While winds are
not expected to be as high, QPF will actually increase. By the time
this system moves out during the mid term, over an inch of rain
could be seen from this secondary system for many locations.

.LONG TERM...(Wednesday through Monday)
Issued at 408 PM EST MON NOV 28 2016

Widespread showers and embedded thunder will be ongoing Wednesday
morning downstream of the stacked low pressure system across the
upper Midwest. A 30-40 knot low level jet and nearby approach of the
right entrance region of a 150 knot upper jet will continue to
result in abundant lift across eastern Kentucky. This energy aloft
will combine with a plethora of gulf moisture to produce rainfall
amounts likely in excess of one inch across southeastern Kentucky as
winds gradually veer south/southwest in wake of a departing surface
low/trough Wednesday morning. Rainfall will end from west to east
through the day as the trough axis shifts east and drier air oozes
in along with cooler air behind a cold front.

Cyclonic flow in place from Hudson Bay through the Great Lakes, in
association with the eastward shifting upper low, will keep a cold
dome and lingering stratus locked in place through the end of the
week and possibly into the first half of the weekend as high
pressure slowly builds in from the west. After temperatures making
it into the low 60s Wednesday, high temperatures Thursday through
Saturday will likely only top out in the 40s with lows in the mid
20s to mid 30s.

Rain chances then look to increase by the latter portions of the
upcoming weekend as energy currently near the Gulf of Alaska digs
south across the Rockies and into the Great Plains. Still a great
deal of uncertainty in how the synoptic pattern will materialize
beyond this, with solutions ranging from one strengthening system
spreading abundant precipitation across the eastern CONUS late this
weekend, to a weak shortwave moving across the Ohio Valley with a
cutoff low slowly migrating northeastward out of Chihuahua early
next week. Evolution and track of this system will also determine
the potential for any wintry precipitation for the first week of
December.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 150 AM EST TUE NOV 29 2016

Conditions ranged from IFR to VFR at the start of the period, with
the worst conditions generally in an area of rain which stretched
from southwest to northeast across the middle of the JKL forecast
area. The area of rain was moving southeast and will engulf the
eastern portion of the area shortly. The back edge should then
exit into VA around 09z. Behind the precip, MVFR conditions due to
ceilings are expected for most places overnight. Ceilings are then
forecast to break up during the morning hours on Tuesday...leaving
mainly VFR until the end of the period.

&&



&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...AR
SHORT TERM...JMW
LONG TERM...GUSEMAN
AVIATION...HAL



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