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Area forecast discussion 
National Weather Service Jackson Kentucky
958 PM EST Sat Feb 28 2015

issued at 958 PM EST Sat Feb 28 2015

Made some more tweaks to temperatures. Some valley locations are
already down to 31 degrees with several more right on their heels.
Do not expect temperatures to get too much colder as clouds are
spread into the region and should halt their fall. However...the
question continues...will these temperatures come back up prior to
precipitation onset late tonight. As it appears now...this may be
a struggle and thus...the freezing rain threat continues. Hrrr has
begun to fluctuate on precipitation developing around dawn...but
the latest run has it back in there. Will hold off on any Winter
Weather Advisory for now as still not certain how much freezing
rain will actually occur and whether it has any impact as ground
temperatures recovered fairly well with the sunshine earlier
today. Outside of some tweaks to temperatures...will maintain the
forecast as is.

Update issued at 715 PM EST Sat Feb 28 2015

Opted for a Special Weather Statement for the freezing
rain/sleet/snow potential late tonight. Last several runs of the
hrrr have shown pretty good precipitation development after 09z
tonight. With the uncertainty on whether temperatures can stay
above certainly looks like a setup for some freezing
rain. With the dry air in place...some sleet may be possible early
on as well. Any snow potential will likely stay to the north as
the warm nose pokes across the area. Tweaked temperatures and
dewpoints through the night and re ran the weather to match the
expected transition zones through daybreak. We should see a
transition to rain shortly after daybreak as any remaining cold
air gets scoured out in the valleys.


Short term...(this evening through monday)
issued at 350 PM EST Sat Feb 28 2015

Winds will shift to a more srly direction on the backside of exiting
high pressure this evening...creating a pseudo warm frontal
boundary along a developing low level jet. Overrunning precipitation will
then develop by this evening in northern portions of central
Kentucky...into Indiana as well as Ohio. This will bring precipitation
into eastern Kentucky by or shortly after 06z tonight. There
continues to be a few concerns with this system...namely a light
ice and snow potential.

Latest forecast soundings are continuing to support a steady or
gradual warming of temperatures throughout the night as southerly winds...
cloud cover...and precipitation take control. However...given the
antecedent cold is likely that even as surface temperatures
slowly rise...the pavement and ground temperatures will take an hour to 3
hours longer. Temperatures in the llvls will rise above freezing
between 0 and 6z...however...surface temperatures will likely lag behind by
a few hours. This will create the set up for some snow/ice pellets potential
just at onset /and continuing in the north for a bit longer/...then
a freezing rain potential given the latest nam12 and gfs40 forecast
soundings through around 12z...before surface temperatures finally warm
enough across the region that all precipitation falls as rain after 12z to
15z. Given the warmer srly flow tomorrow...temperatures will finally
increase to closer to seasonable normal values during the
afternoon...generally in the 40s.

From here...forecast soundings show a deep layer of moisture
continuing throughout the day and into the overnight hours Sunday
night with some continuous/widespread rainfall possible. Rain will
then change back over to snow as temperatures drop below freezing after
dark...before finally losing intensity and tapering off Monday
morning as high pressure moves in overhead.

Long term...(monday night through saturday)
issued at 451 PM EST Sat Feb 28 2015

The models are in good agreement with an amplified long wave
pattern to rule across the Continental U.S. Through next weekend. A
positively tilted trough out west will result in deep southwest
flow to setting up across the Mississippi Valley. This will allow
for a Stout baroclinic zone to meander through the Ohio and
Tennessee valleys through the middle of the week...with much
warmer and wetter air being advected into the region. This will be
followed by another sharp cool down...with any lingering
precipitation going over to snow before ending the work week cold
and dry.

Details on how all of this evolves continues to be lower
confidence until we get a little closer to the have
stuck close to a blend of the solutions. In general...the models
seem to be coupling the moisture and best forcing initially
further to the northwest...resulting in not quite as significant
rainfall totals across eastern Kentucky from Tuesday through
Thursday...with generally 2 to 3 inches forecast. Still...this
will be more than enough to cause flooding concerns and will
continue to highlight this threat in an ongoing hydrologic

Precipitation may start out as a wintry mix late Monday into early
Tuesday morning...depending on how quickly it can cool down as
winds veer around to the southeast and thicker clouds overspread
the area once again. A surface warm front will lift through on
Tuesday...with rainy conditions moving in. The cold front will
follow and very gradually slide southeast through the area
Tuesday night through Wednesday night...providing the bulk of the
heavier rainfall.

Much colder air will move in Wednesday night into Thursday behind
the front...with any lingering precipitation going over to
snow...with some light accumulations possible. After enjoying
highs in the 50s Tuesday and Wednesday...readings will fall back
into the 20s and 30s for Thursday...with lows bottoming out near
the 10 degree mark Friday morning. Highs will return to the 40s
for Saturday.


Aviation...(for the 00z tafs through 00z Sunday evening)
issued at 715 PM EST Sat Feb 28 2015

VFR conditions will last into the night. the low
level jet strengthens overnight...better moisture will be
transported into eastern Kentucky with ceiling heights lowering late
tonight. Some MVFR ceilings are possible by daybreak. In
addition...some sleet/freezing rain will also be possible around
daybreak...before transitioning to all rain by middle morning.
Confidence on forecast tomorrow is not high and thus...ceiling
forecast remains very uncertain. Its possible some MVFR ceilings may
hold on through the day...but southerly flow could erode these
away through the day with a slight downsloping component. the very least...we should see a mix of VFR/MVFR
conditions. Some rain showers could also persist through the day.


Jkl watches/warnings/advisories...


short term...jmw
long term...geogerian

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