Area Forecast Discussion
Issued by NWS Jackson, KY

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FXUS63 KJKL 281157
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
657 AM EST Mon Nov 28 2016

.UPDATE...
Issued at 657 AM EST MON NOV 28 2016

Temperatures are already creeping upwards from overnight lows and
in some spots are already 10 degrees warmer than the lows. This
warming trend will continue right into the daylight hours. Winds
have already been sustained at 15 to 20 mph up on the higher
terrain near the Virginia border. Winds will continue to ramp up
as we head through the day and the front approaches from the west.
Made some tweaks to temperatures this morning to account for
ongoing warming taking place. Also, based on latest HRRR, have
sped up the precipitation chances a bit.

&&

.SHORT TERM...(Today through Tuesday)
Issued at 321 AM EST MON NOV 28 2016

Presently, we have a mid/upper level ridge across the eastern
CONUS with a stacked low sitting over the northern plains. A cold
front is advancing east across the plains. Short term concerns
today involve fire weather (see fire weather section) and strong
winds as the front moves closer to the area. Skies are expected to
stay cloudy today with the mid/high clouds advancing across the
area. Outside of a sprinkle, most of the rain should hold off
until after 6 or 7 pm this evening. However, as the front advances
into the Ohio river valley this evening, winds will start
cranking. Looking at a BUFKIT sounding for this evening at LOZ,
allows for a Momentum transfer around 35 knots. This generally
falls close to the top wind gust potential. Thus, some 40 mph wind
gusts seem likely. Thus, have coordinated with surrounding offices
to issue a wind advisory for much of the area. The exception will
be in northeast Kentucky where winds will stay just under the
needed criteria. With south-southeast flow off the high terrain,
temperatures should still recover nicely despite the cloud cover
into the upper 50s to lower 60s. Even a few mid 60s will be
possible in the far east. Tonight, the cold front will work east
across the area with widespread rain accompanying the front.
Strong lift and good moisture is present, so rain chances will
remain categorical. It looks more likely that rain will exit by
daybreak Tuesday with much of Tuesday seeing a return of dry
weather. In fact, sunshine may return and help boost temperatures
well into the 60s with some 70 degree readings likely.

.LONG TERM...(Tuesday night through Sunday)
Issued at 427 AM EST MON NOV 28 2016

There are two main weather systems to contend with during the
period. The first one will come into play as the period starts,
and as the situation evolves it is looking more
active/interesting. The second potential system is next weekend.
However, there is poor model agreement for this one.

For system number one, a large stacked low pressure system will
still be centered over the north central CONUS Tuesday evening,
beginning to accelerate eastward. An impulse rotating around the
larger scale system will support another cold front to move
through Kentucky Tuesday night and Wednesday. Gulf of Mexico
moisture is expected to surge northward ahead of the front. This
will lead to showers developing Tuesday night and lasting into
Wednesday. There is even instability shown, especially in the NAM,
but it is mainly elevated. There is also more than ample shear
expected to support organized convection. If the instability could
become surface based, a severe wx threat is not out of the
question, but this is more likely to be to our south. At this
point, will just mention a slight chance of thunder for the JKL
forecast area. This system moves out on Wednesday, and drier
weather with persistent cold air advection sets up for late in
the week.

System number two is advertised by the ECMWF, but is lacking in
the GFS. It originates from an upper trough currently over the
Aleutians in the North Pacific. After moving eastward to the
Canadian coast, the system drops southward to the Mexican border,
setting up a highly amplified flow. The ECMWF remains progressive
with the system, which leads to surface low development over the
western Gulf of Mexico as the upper support advances. The low then
deepens rapidly as it moves north northeast to IL by late Sunday.
The GFS instead keeps the upper level system festering over
northern Mexico, without the major surface cyclogenesis.
Considering the better track record of the ECMWF and at least a
couple runs in a row showing the solution, have raised POPs above
those of the model Superblend for late next weekend.

&&

.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
ISSUED AT 657 AM EST MON NOV 28 2016

VFR conditions will continue through this evening. However, main
aviation concern will be on winds. In the immediate short term, a
low level jet will lead to some low level wind shear through mid
morning. This wind shear will dissipate by mid morning as the
inversion dissolves, but with daytime mixing, gusty south winds
will develop through the late morning and afternoon hours. An
approaching cold front will bring even stronger winds as we head
into the evening hours tonight. Wind gusts could approach 30 knots
at times. Rain will move into the area after 00z as well, but
winds should remain gusty through 06z. Some reduction in wind
speed can be expected for the second half of the night.

&&

.FIRE WEATHER...
Issued at 157 AM EST MON NOV 28 2016

Have opted to upgrade the fire weather watch to a red flag
warning. Models are continuing to be too aggressive on moisture
recovery today, especially in the east with wind trajectories off
the high terrain and not favorable for moisture advection. Thus,
there should be a period this afternoon or evening where the low
RH overlaps with the increasing wind speeds. While we won`t mix
that deep, Winds are so strong just off the surface that it won`t
take much to bring down some good wind speeds. Also, went a little
later into the evening with the red flag warning as low RH`s and
even stronger winds may linger well into the evening. Rain is
still expected to move in after 9 pm and should bring a quick
increase in moisture with the onset. One other thing to watch is
for winds to pick up as the shower activity moves into the area
late this evening, so a brief period of very gusty winds, coupled
with the already dry conditions could create a dangerous setup for
any ongoing wildfires. Fire weather concerns erode for the
remainder of the week, with lots of rain in the forecast.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 4 PM this afternoon to midnight EST tonight
for KYZ044-050-051-058>060-068-069-079-080-083>088-108-111>118.

Red Flag Warning from noon today to 9 PM EST this evening for
KYZ088-104-106-107-109-110-112-113-115-117>120.

&&

$$

UPDATE...KAS
SHORT TERM...KAS
LONG TERM...HAL
AVIATION...KAS
FIRE WEATHER...KAS



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