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 212000

Area Forecast Discussion
National Weather Service Jackson KY
400 PM EDT SAT MAY 21 2016

.SHORT TERM...(This evening through Sunday night)
Issued at 400 PM EDT SAT MAY 21 2016

19z SFC shows low pressure east of Kentucky but still swinging
showers and stray thunderstorms through the CWA. The latest
visible satellite loop shows mostly cloudy skies with only a few
breaks across the area. The clouds and isolated to scattered
showers also affected temperatures today with readings generally
kept in the mid to upper 60s this afternoon. Meanwhile, dewpoints
are holding in the mid to upper 50s most places. Winds through
East Kentucky are generally from the west at 5 to 10 mph with some
gusts to 15 mph or so in western areas.

The models are in good agreement aloft through the short term
portion of the forecast. They all depict the eastern trough
deepening and settling southeast of the area by Monday morning. A
key part of this development will be a mid level wave dropping
just west of the CWA tonight sending energy south through East
Kentucky. This will help to sharpen up the low and drag it
a tad southwest on Sunday. This upper low will further deepen and
close off Sunday night into early Monday as it shifts east. This
represents a return to an idea from a couple of days ago but with
more credence now given the good model clustering and zero hour
being only 36 to 48 hours out. Accordingly, have followed a
general model blend with a strong lean toward the HRRR and NAM12
for weather details through Monday morning.

Sensible weather will feature an unsettled evening with showers
and a couple of thunderstorms around. This will be followed by low
clouds and some patchy fog through the night. While Sunday will be
drier for most, as the upper low shifts southwest, there is a
decent shot at more convection in the east and even a few
thunderstorms. Sunday night will see the clouds start to break up
in the east and again some fog, especially for the valleys and
places that clear earlier in the night. Do expect temperatures to
be fairly uniform tonight and Sunday night owing to the clouds and
some slight CAA to neutral advection during the nights.

Started with the ShortBlend for most elements of the forecast
with only limited terrain adjustments to temperatures through the
period. During the latter part of the forecast the SuperBlend was
used to initialize the forecast with some tweaks made mainly to
increase the PoPs in the east Sunday afternoon.

.LONG TERM...(Monday through Saturday)
Issued at 350 PM EDT SAT MAY 21 2016

Patchy valley fog will kick off the week with surface ridging
extending from the Great Lakes into the Ohio Valley. Shortwave, but
amplified, upper riding will build across the Great Lakes through
the Mississippi Valley in wake of this weekend`s disturbance digging
across the Mid-Atlantic coast. Rising heights and deep layer
subsidence will bring clearing skies from west to east throughout
the day as temperatures warm back to near normal, topping out
generally in the mid 70s. Surface ridging will then be in control
once again Monday night into Tuesday, leading to another
ridge/valley temperature split ranging from the mid-upper 40s in
valleys and low 50s on ridgetops. Continued increasing heights and
plenty of solar insolation will propel highs into the upper 70s to
lower 80s Tuesday afternoon.

An unsettled pattern will then return for midweek through the end of
the week and likely into the upcoming weekend. Flow aloft will back
southwesterly in response to cyclonic flow developing from central
Canada through the Intermountain West. Subsequent increasing warmth
and moisture will lead to a more favorable thermodynamic environment
supportive of convective development. While the thermodynamics
should be conducive for showers and thunderstorms, dynamical
prospects may be lacking as the core of any upper forcing may lift
north well west of the Commonwealth. This will in turn keep a nearly
stationary frontal boundary west of the region through much if not
all of the upcoming week, furthermore decreasing the chances for
seeing any appreciable forcing locally. Nonetheless, scattered
thunderstorms certainly look possible in the warm sector whenever
forcing becomes realized, rather from passing upper perturbations or
at least along the higher terrain. High temperatures in the lower
80s and lows in the lower 60s look likely by midweek into the


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

A center of low pressure is sitting just NE of the state and as
this shifts slowly eastward this afternoon, wrap around moisture
will pull showers and even some isolated thunder back into eastern
KY into the evening. Cigs will vary between MVFR and times of VFR
this afternoon but scattered showers will be around the FA during
with lower vis and cigs possible should they go over any TAF
site. Tonight, the low will continue to depart eastward, and drier
air will begin filtering into the region. However, forecast
soundings time heights suggest llvl moisture lingering across
many of the northeast TAF sites during the overnight, likely
resulting in lingering low clouds and fog development with
lower VIS a potential overnight. The TAFs reflect this idea,
though confidence is on the low side for any individual site`s
forecast into Sunday morning. Skies should clear out more
completely on Sunday, from southwest to northeast, with VFR
conditions expected, except perhaps SJS where low clouds and the
threat of a shower may linger. Winds will be from the west through
the rest of the afternoon at 5 to 10 kts with occasional gusts to
15 kts, then light and variable this evening into Sunday morning.


.JKL Watches/Warnings/Advisories...


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