Area Forecast Discussion
Issued by NWS Jackson, KY

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FXUS63 KJKL 150059

National Weather Service Jackson KY
859 PM EDT Wed Mar 14 2018

Issued at 858 PM EDT WED MAR 14 2018

Skies have cleared out this evening allowing temperatures to fall
sharply into the upper 20s to lower 30s. A steady southwest wind
is keeping them from dropping any faster. Still watching some
potential for cloud cover to come back in overnight as a weak mid
level impulse crosses the area. However, moisture is limited, so
not expecting any precipitation. The cloud cover could put the
halt on temperatures and with the low level jet developing
overnight, should see temperatures hold steady or rise through the
second half of the night. Updated temperatures, sky cover to
reflect these changes.


.SHORT TERM...(This evening through Thursday night)
Issued at 316 PM EDT WED MAR 14 2018

Northwest flow has kept clouds and flurries over the eastern part
of the forecast area through the afternoon, but flurries will
finally end by early this evening. The overnight forecast
challenge is the low temperature forecast. Based on current
observed temperatures, at least a temporary break in cloud cover
for part of the night, and snow on the ground in some areas,
overnight lows will likely be lower than the blended guidance and
also the MOS guidance for the main ASOS sites. Some COOP MOS
guidance indicates lows in the teens, but that seems too cold.
Warm advection does set in overnight, and how long a break in
cloudiness occurs is uncertain. Have gone with lows mainly in the
25 to 30 degree range, but this will need to be monitored this
evening and likely adjusted.

Northwest flow across the area continues to bring widespread
clouds to all but the far southwest part of the forecast area.
Ceilings were gradually lifting, but MVFR ceilings will persist
in the eastern part of the forecast area through the afternoon.
Scattered flurries and isolated snow showers have persisted,
resulting in very local visibility restrictions as well. Flurries
will end and clouds will continue to lift and decrease in
coverage, with VFR conditions expected overnight and into
Thursday. Late tonight and into early Thursday low level wind
shear is expected to for Thursday temperatures will
climb into the 50s in most areas, with highs ranging from lower
50s north and east to upper 50s southwest. A dry cold front will
pass through the area Thursday before stalling in the TN Valley
Thursday night. Some overrunning precipitation may develop north
of this front over southern parts of the forecast area by daybreak
Thursday. Thursday night lows should range from the mid 20s in
the northern part of the forecast area to the mid 30s in the
south. If precipitation does develop, thermal profiles support the
idea of the possibility of a narrow ribbon of very light snow or
sleet on the northern edge of the precipitation at the onset.

.LONG TERM...(Friday through Wednesday)
Issued at 403 PM EDT WED MAR 14 2018

The extended period will begin with a system coming in from the
west. The models are coming into better agreement with this first
disturbance, with both the ECMWF and GFS showing a cutoff low
transforming into more of a shallow trough as it moves over the
Ohio Valley the first part of the weekend. With the passage of
this first system, temperatures will be in the mid 40s to low 50s
during the day Friday. The precipitation will be mainly rain, but
a mix of sleet and freezing rain will be possible late Friday into
Saturday morning due to lower nighttime temperatures in the far
north/northeastern portion of the CWA. A brief period of ridging
will bring drier weather Sunday afternoon into the evening until a
more amplified trough moves in from the west later that night
into Monday morning.

This second disturbance looks to be a bit more amplified and has a
higher potential to bring in more precipitation than the early
weekend system. This is due to a warm front that will set up to
the south of the Commonwealth, and with south/southwesterly flow
will bring in ample Gulf moisture. The precipitation type will be
mainly rain for this second system, but a rain/snow mix is
possible late Tuesday into Wednesday morning as a passing cold
front ushers in colder air from the north into eastern Kentucky.
Therefore, after the weekend temperature warm up, temps will cool
down again into midweek next week.

The models agree overall in terms of timing for both systems.
However, there is still a bit of uncertainty with the
precipitation amounts due to the ECMWF running a bit cooler and
showing less QPF than the GFS. Confidence in timing has
increased, but future model runs will be monitored to see if the
models come into better agreement with the intensity of the second


.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)

VFR conditions will continue through the TAF forecast period. As
southwesterly flow increases overnight, some low level wind shear
will develop late tonight into early Thursday morning.




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