Area Forecast Discussion
Issued by NWS Jackson, KY

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FXUS63 KJKL 212331

National Weather Service Jackson KY
731 PM EDT Tue Mar 21 2017

Issued at 629 PM EDT TUE MAR 21 2017

Updated the forecast to just add the latest observations into the
forecast and trend them appropriately into the evening. The area
is still enveloped under a veil of cirrus this hour and will
hinder the drop off of temperatures this evening and into later
tonight. Due to this will keep the sky cover forecast as is. The
erst of the forecast is right on track and the grids have been
sent to the NDFD and web servers.


.SHORT TERM...(This evening through Wednesday night)
Issued at 405 PM EDT TUE MAR 21 2017

A complex of storms continues to move into far western Kentucky
and northwest Tennessee immediately ahead of the axis of a
shortwave trough pushing through the Upper Midwest and Great
Lakes. A frontal boundary currently sits across far northern
Tennessee, with temperatures to the north in Kentucky in the mid
60s to low 70s, and a few 80 degree readings down across the
Volunteer state. Surface convergence remains maximized across
Tennessee as early day mixing, albeit shallow only to 2500-3000
feet, and stratus have kept this boundary stalled right along the
state line. With higher pressure and subsequently drier air slowly
oozing south across the Ohio Valley, expect any showers/storms to
remain south of Kentucky where better forcing/instability will
reside. Will see an increase in clouds as this complex moves along
the Interstate 40 corridor, but conditions should remain dry.

Passing of the aforementioned shortwave trough axis will filter in
cooler and drier air from the north overnight, dropping temperatures
into the upper 20s to near 30 in the Bluegrass region late tonight.
Have therefore hoisted a Freeze Warning with at least a couple of
hours of temperatures at or below 30 degrees anticipated as skies
eventually clear underneath the southern periphery of high pressure
sliding across the Great Lakes. Elsewhere, temperatures look to
remain in the low 30s to near 40 degrees along the Tennessee border.

Surface ridging will traverse toward Lake Erie Wednesday, keeping
cool and dry conditions in place as temperatures remain below normal
in the mid 40s to mid 50s. While minimum relative humidity values
will drop into the mid 20 percent range, north/northeast winds of 5-
10 mph look to keep any burns from spreading too rapidly.

High pressure moving across the Appalachians will promote at least a
brief period of radiational cooling Wednesday evening/night, before
warm air advection and cloud cover increase later into the night
toward Thursday morning. This may keep the Lake Cumberland region
and Interstate 75 corridor above freezing, but points north and east
will likely see temperatures dip below freezing, especially in the
valleys of far eastern and northeastern Kentucky. Additionally,
frost formation will also be in the offing given light winds. Will
hold off for now on frost/freeze headlines until details on exact
placement become a little clearer, and to avoid confusion with
tonight`s Freeze Warning.

.LONG TERM...(Thursday through Tuesday)
Issued at 327 PM EDT TUE MAR 21 2017

A warm front will work east late Thursday and Thursday night with
warmer air spilling into the Ohio river valley. We could squeeze
out a few sprinkles as the boundary pushes across the area, but
the boundary layer will be so dry, shouldn`t be much reaching the
ground. The warm air really makes its presence felt by Friday with
highs well into the 60s. A cold front will work east towards the
area on Saturday. Very warm air will continue to be pumped up
ahead of this boundary with temperatures pushing into the mid 70s.
Models continue to slow down the approach of the cold front. It
looks like the better period of rainfall will come Saturday
evening into Saturday night as the front makes its way across the
area. Still some question as to how strong storms could get, but
something we will have to monitor as it has potential to be some
strong storms with modest shear in place. More uncertainty arrives
in the forecast by Sunday as another system will quickly be on
the heels of the first and there is some question on if we see a
lull between the two systems, or the weather stays active right on
through the early portion of next week. Regardless, will go with
the blended rain chances from Sunday through Tuesday. Mild weather
looks to continue well into next week.


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

Expect VFR conditions across eastern Kentucky through the TAF
period. Some mid level and upper level cloud cover will continue
to pass through the area as a cold front pushes south through the
area. With the passage of this dry front, winds will shift to
northerly with speeds being around 5 to 10 knots. These winds will
continue into the day on Wednesday.


Freeze Warning from 5 AM to 10 AM EDT Wednesday for KYZ044-



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