Area Forecast Discussion
Issued by NWS Jackson, KY

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
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
000
FXUS63 KJKL 140305 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
1005 PM EST Fri Jan 13 2017

.UPDATE...
Issued at 1005 PM EST FRI JAN 13 2017

Dense fog is setting up on the ridges of eastern Kentucky along
with development just to the southwest of the CWA - and
indications in the HRRR and CONSShort for low vis in these areas
through the night. Accordingly, have updated the forecast to
include this along with issuing an SPS in conjunction with LMK and
OHX. with this updated also fine tuned the rain chances through
the rest of the night along with a tweaking to T and Td grids per
the latest obs and trends. These have been sent to the NDFD and
web servers. Along with the SPS an update to the ZFP and HWO have
been issued.

UPDATE Issued at 745 PM EST FRI JAN 13 2017

00z sfc analysis shows the cold front through the southern portion
of the CWA with patches of rain of a scattered to numerous nature
passing through the breadth of eastern Kentucky. The amount of
moisture in the air is keeping the clouds rather low through the
night and into Saturday along with patchy fog. Currently the front
shows up quite well in the obs with temperatures varying from the
lower 50s in the far southeast to the upper 30s/low 40s north.
Dewpoints are generally within a degree or two of the dry bulb
temperatures while winds are mostly from the northeast at 5 to 10
mph. Have updated the grids through the night to reflect the
timing and placement of the PoPs across the area based on current
radar trends and consensus model guidance. Also loaded in the
latest ShortBlend temp/dewpoint guidance through 12z Saturday and
tweaked them for the current obs and trends. The updated grids -
including beefed up amounts of fog - have been sent to the NDFD
and web servers.

&&

.SHORT TERM...(This evening through Saturday night)
Issued at 316 PM EST FRI JAN 13 2017

An east to west oriented line of precipitation continues to track
across the Ohio Valley into much of central and northern Kentucky.
This will remain in the liquid phase across all of eastern Kentucky
as temperatures will hold in the mid-upper 30s across the Bluegrass
region with warmer readings farther south. This is thanks to surface
high pressure sliding across the Great Lakes and lower Canada
keeping a more substantial cold dome from building south into the
Coal Fields. Upper level features further support above freezing
surface temperatures as an upper high nudges north across the Gulf
coast into the western Atlantic with a trough traversing the St.
Lawrence Valley, allowing for today`s earlier frontal/moisture
convergence boundary to surge back north toward the Ohio River,
thus ushering warmer air back in aloft. Have gone ahead and also
inserted patchy fog into the forecast given the plethora of low
level moisture and overall light winds in place.

After a lull in the more widespread rain for a brief period tonight,
a band of precipitation will develop across the Ohio Valley early
Saturday as another upper trough skirts the western shores of Hudson
Bay, subsequently sending the frontal boundary back toward eastern
Kentucky. This will bring numerous to widespread rain showers back
in through the day. At the same time, cooler air will once again
infiltrate the Commonwealth, although temperatures near and above 40
degrees will keep only rain in the offing. In fact, temperatures
near the Tennessee border may again reach the mid 50s without a
significant southward push of colder air behind the front. Rain
chances will decrease from north to south through the evening and
overnight into Sunday morning along the front, but rain showers will
remain likely with the front in proximity to the region in
combination with a saturated airmass.

.LONG TERM...(Sunday through Friday)
Issued at 200 PM EST FRI JAN 13 2017

Very mild and damp weather will continue through next week.
To begin the period, a deep layer of low level moisture will be
in place with the frontal zone still over the region. This
will provide lots of clouds and steady temperatures from Sunday
through Monday morning. Moisture profiles are also very
supportive of a prolonged period of drizzle into Monday morning.
With this said, models continue to run too low with the rain
chances and have opted to go into the likely range for rain
chances, staying above model guidance. This is a situation, where
models are never high enough on the rain chances. Heights will
finally start to build on Monday as a sharp shortwave trough
helps to develop a strong area of low pressure across the central
plains. This will send the nagging boundary off to the north with
eastern Kentucky breaking into the warm sector. This will send
temperatures much higher into the 60s, setting up another very
warm mid January day. We could have a few spotty showers pop up
in the warm sector on Monday, most likely from the Cumberland
Plateau up across central Kentucky.

With the deep system developing out to our west, models
still showing uncertainty heading into the Tuesday and Wednesday
time period with the strength of the system likely dictating how
our weather unfolds. Either way confidence is fairly high a
frontal boundary will get pushed into the region Tuesday or
Wednesday, providing another good chance of rain. With deep
southwesterly flow in place and a frontal boundary lined up with
the flow, we will have to watch the potential for locally heavy
rain somewhere in the Ohio River Valley. Right now, models tend
to be targeting areas more in central Kentucky for heavier rain
potential, but with lots of details yet to be sorted out, this
could easily shift east or west. Certainly something to monitor
heading into next week, given the saturated ground conditions. We
may dry out Wednesday night or Thursday, but another system may
follow quickly on the heels of the midweek system. Thus, rain
chances will continue into the end of the week. One thing is for
sure, the mild weather isn`t going anywhere through the end of
next week. In fact, several more days of highs in the 60s will be
possible from Tuesday through Thursday.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
ISSUED AT 700 PM EST FRI JAN 13 2017

LIFR/IFR conditions remain in place across the area, for the most
part. The band of rain across the area will continue - more off
than on - through the night and into Saturday - with more in the
way of convection expected from midday Saturday into the
afternoon. Visibilities will be variable through this time
depending on the movement and impact of the showers on each site.
Due to this, ceilings will stay IFR/LIFR through Saturday morning
and into the afternoon. Winds will be generally light from the
northeast through the period.

Note: icing concerns still look to remain north of all JKL
terminals through the weekend. Pilots flying west into the
Missouri Valley or north toward CVG/CMH need to be aware that
icing potential will greatly increase tonight into Saturday.

&&

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

$$

UPDATE...GREIF
SHORT TERM...GUSEMAN
LONG TERM...KAS
AVIATION...GUSEMAN/GREIF



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