Area Forecast Discussion
Issued by NWS Jackson, KY

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FXUS63 KJKL 160535

National Weather Service Jackson KY
1235 AM EST Fri Feb 16 2018

Issued at 1100 PM EST THU FEB 15 2018

Latest scans of the nearby WSR-88D radars continue to show most
robust showers remain to out north and west this evening. However,
these showers will slowly move southward and make it into northern
Fleming County by around 06Z. Some of these showers could be gusty
given the 850mb jet is still around 60 knots across the region.
Did plan on expiring the Lake Wind Advisory given the weather
stations near the site have indicated winds have remained below
criteria. However, will continue to indicate some gusty winds in
the HWO given the low level jet mentioned above and continued
gusty winds being experienced from time to time. Otherwise made
some adjustments to POP trends with short term models struggling
on timing of main band.

UPDATE Issued at 855 PM EST THU FEB 15 2018

The latest scans of the area WSR-88D radars shows the bulk of the
showers and isolated storms are well north of the CWA this hour.
Given this will slow the progression of POPs, with a nudge toward
the short term model blend. Also took thunder out this evening
given the lack of showers across the area this hour. There will
be a period of dry weather before the showers across southern
IN/OH progress southeast through the night, along with a frontal
boundary. We do continue to see strong southwest flow and
therefore will continue to run the NPW through 11 PM. Will update
the text products and send out the latest grids to NDFD.

UPDATE Issued at 541 PM EST THU FEB 15 2018

WSR-88D radar shows isolated rain showers mainly north of the
Mountain Parkway late this afternoon. Some of the showers north of
I-64 have had a history of producing lightning and therefore added
some isolated thunder mainly north of I-64. Overall the trend for
lightning will be down through the evening based on the
mesoanalysis data. Otherwise more minor adjustments were made to
deal with the latest obs and trends and updated the text products
including the HWO to mention thunder.


.SHORT TERM...(This evening through Friday night)
Issued at 303 PM EST THU FEB 15 2018

A cold front over the northern Ohio river valley will slowly push
southward into tonight with a passage across eastern Kentucky late
Friday morning through the afternoon. The gradient has tightened
up to the south of this front with gusty southwest winds
continuing this afternoon. While winds have decreased ever so
slightly from earlier readings, still opting to continue with the
lake wind advisory through the evening as wind could pick back up
as the front approaches.

Rain is expected to spread in from the north along the front after
05z tonight, with a few isolated or scattered showers possibility
developing out ahead of this more widespread activity. The
widespread rain will push on through late tonight through Friday
morning before slowly exiting from the north to south Friday
afternoon. Rain chances a certainty, so will maintain the high
rain chances. In fact, upwards of an inch of rainfall could be
seen along and north of I-64 with that area located in an area of
better forcing with the shortwave energy aloft. Rainfall amounts
will then trail off as the front pushes south and shortwave energy
departs by Friday morning. Rainfall amounts in the south may
struggle to reach a half an inch. With this said, outside of some
ponding on roadways, only some minor bumps on area creeks and
streams are expected, so no plans for a flood watch at this time.
Temperatures will take a quick tumble Friday afternoon as cold
advection kicks in behind the cold front.

Friday night is shaping up to be dry as the front exits off to the
south and colder air briefly returns for the overnight period.
The cold advection could push our low temperatures down into the
low to mid 30s.

.LONG TERM...(Saturday through Thursday)
Issued at 359 PM EST THU FEB 15 2018

A mid level trough is expected to be moving east through the
Plains at the start of the period, with a shortwave trough
approaching from the west and southwest at the start of the
period. Deeper moisture is expected to return back north into the
area on Saturday with PW that will have decreased to about a
quarter to two thirds of an inch late in the short term period,
should return to the 0.75 to about one inch on Saturday afternoon.
An inverted trough should also develop north into the area on
Saturday as a surface low tracks across the southeast US. The
shortwave trough will move through the area on Saturday evening
with deeper moisture again departing. Models have a few hours of
rather deep lift on Saturday and this combined with PW points
toward the potential to receive up to an inch of rain that day.
the model consensus is for the highest rainfall in the southern
and southeastern counties where PW will be highest. Those
locations are expected to have received lighter rainfall in the
near term. However, this rainfall could lead to rises to near
bankfull on some of the larger creeks, streams, and rivers
especially if rainfall were to exceed an inch on Saturday.

Mid level height rises and sfc high pressure should build in to
end the weekend. However, the pattern should quickly return to
west to southwest flow aloft to start the new week and generally
persist through the end of the period. Over the weekend, a
shortwave trough should dig from the northwest into the Rockies
with and then progress east and into the Plains and then into
Ontario. Downstream of this, deep moisture should again return
north into the TN Valley by late Sunday as high pressure moves to
the eastern seaboard with PW likely returning to over 1 inch late
Sunday night and remaining close to an inch or more through the
middle of the week. The greater values during much of that
period, however, should be north and west of the region closer to
a slow moving baroclinic zone. That baroclinic zone/front should
approach the region at midweek as surface low pressure associated
with the above mentioned shortwave that moves form the Plains to
Ontario tracks across the Great Lakes and to Ontario and Quebec.
This boundary should remain over or possibly push southeast of the
area by the end of the period.

The focus for the heaviest rainfall next week appears to be closer
to the baroclinic zone closer the OH and MS Rivers and generally
north or west of the region. This scenario will continue to be
monitored as the ground is already saturated and multiple rounds
of heavy rain would lead to rises on streams, rivers, and creeks.

Except for behind the boundary with rain falling on Saturday,
above normal to well above normal temperatures are anticipated.


.AVIATION...(For the 06Z TAFS through 06Z Friday night)

Strong southwest flow continues to keep the potential for wind
gusts to around 20 KTs tonight and this will be the primary
aviation concern to start the TAF period. A cold front will push
southeast tonight and bring the potential for showers overnight
into early Friday. This will also lead to lowering CIGs into IFR
range or lower through the night and at least MVFR VIS. This front
will slowly push southeast Friday, and winds will begin to shift
from southwest to northwest and begin to wane through the day on




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