Area Forecast Discussion
Issued by NWS Jackson, KY

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FXUS63 KJKL 222040

National Weather Service Jackson KY
440 PM EDT Sat Oct 22 2016

.SHORT TERM...(This evening through Sunday night)
Issued at 345 PM EDT SAT OCT 22 2016

19Z sfc analysis shows high pressure building into the area as low
pressure pulls away to the east. This is working to clear the sky
from west to east as the drier air advects in on northwest winds.
In general, the winds are running at 5 to 10 mph with a few gusts
to 15 mph, or so, thanks to good mixing. The return of sunshine
helped temperatures this afternoon climb into the mid 50s for
most locations while dewpoints mixed down to the low and mid 30s.
These lower dewpoints should make it tougher to get fog late
tonight but may hint at a potential for valley frost.

The models are in good agreement aloft through the short term
portion of the forecast as they all depict a large trough
gradually pivoting out of the Ohio Valley. The core of the initial
trough will depart tonight with heights rising locally, but
additional energy does dive into the Great Lakes, though on a
more shallow trajectory, Sunday night. Given the good model
agreement will favor a blended solution with a lean toward the
higher resolution HRRR and NAM12.

Sensible weather will feature a chilly night with mostly clear
skies and good radiational cooling. This should be enough for
some upper 30s in the valleys and a spot or two of mid 30s where
patchy frost is possible. Do not anticipate the frost being
extensive enough for an advisory tonight as it will be confined
to just the deepest, most sheltered valleys. Accordingly, will
highlight it in the HWO with a the potential for an SPS left to
the following shift. Saturday will be a very nice mid autumn day
with plenty of sunshine, breezy conditions, and temps in the mid
60s. A few wind gusts will approach 30 mph Sunday afternoon over
western parts of our area. Another cool night follows with mostly
clear skies and another ridge to valley temperature split, but
likely not quite cold enough for any frost.

Used the CONSShort and ShortBlend as a starting point for the
grids with some adjustments each night for lows - enhancing the
ridge to valley differences. PoPs are essentially zero - in line
with all guidance.

.LONG TERM...(Monday through Saturday)
Issued at 440 PM EDT SAT OCT 22 2016

The models are in fairly good agreement aloft through the bulk of
the extended. A flat ridge will spread through the South during
the first part of the week before another wave starts developing
over the Northern Plains moving east. It is this wave that leads
to a greater spread in the models as it moves into the Upper
Midwest with the GFS outpacing the ECMWF and both stronger than
the Canadian. The wave deepens into a strong trough Wednesday
into Thursday - deepening substantially as it moves into and
through the Great Lakes to end the work week. Its energy brushes
by the Ohio Valley with its trough axis passing through Kentucky
early Friday. Heights will then rise for next weekend, more so
from the GFS, and quicker, than the ECMWF. Given the broad
agreement through the majority of the period a blend looks to be a
reasonable starting point for the grids.

Sensible weather will feature a fairly nice stretch of weather
through mid to late week with dry conditions and moderating
temperatures. A dry front will shift east of the area Monday with
little change in air mass. The next cold front will move toward
and through the area on Thursday with a decent shot at showers
into Friday morning. Cannot rule out a stray thunderstorm with
this, but given the time of year will wait until it gets closer
to further evaluate the thunder threat. Dry weather follows into
the weekend, but there may be another front worthy of some PoPs by
Saturday afternoon per the GFS and that night in the ECMWF. For
now, will keep it dry Saturday while the models work this
difference out.

The main adjustments to the CR init was to hit the terrain effects
more each night and tighten up the PoPs late in the upcoming work


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

VFR conditions will be the rule throughout the period. Scattered
to broken stratocu in the 4-6k feet agl range will break up and
thin from west to east during the rest of the afternoon - SKC
conditions then follow through the night. Any fog will be
confined to the deepest river valleys towards dawn and not impact
the TAF sites. Northwest winds will continue at 5 to 10 kts, with
an occasional gust to 15 kts, through early this evening, before
diminishing thereafter. Winds will pick up again after mid morning
on Sunday with some gusts approaching 20 kts by afternoon under
clear/sunny skies.




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