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Area forecast discussion 
National Weather Service Jackson Kentucky
1233 am EST Wednesday Feb 10 2016

Update...
issued at 822 PM EST Tuesday Feb 9 2016

Hourly grids have been freshened up based on recent observations
and radar trends. Yet another in a series of disturbances in northwest
flow is moving through the Ohio Valley region. Continued cold air
advection should serve to steepen lapse rates a bit more over the
next few hours despite loss of daytime heating. This should lead
to an increase in coverage and intensity of snow showers in
several areas and evidence of this appears to be on radar with
higher returns now showing up along and west of the Escarpment in
portions of the northwest counties. Winds through the lower levels should
average a bit more west to northwest over the next 5 to 8
hours...and should also support continue snow showers and flurries
and the slight increase in intensity and coverage noted above as
well. Probability of precipitation were adjusted a bit to indicate this for the overnight
and the previously forecast min temperatures look on target.

&&

Short term...(this evening through Wednesday night)
issued at 330 PM EST Tuesday Feb 9 2016

Water vapor and mesoanalysis still depicting a deep and broad
area of cyclonic flow across much of the eastern Continental U.S.. this is
leading to snow showers and maybe even snow squalls at times.
Given this general flow and the open Great Lake waters some of our
moisture is coming off the lakes. Most of the snow showers will
remain light...but of few of these showers could be moderate to
even heavy at times. This will still lead to additional light
accumulations and reductions in visibility. Overall given this
will opt to leave our current advisory as is.

The other story will be the continual cold air advection
overtime...we will see temperatures dropping into the middle teens
overnight. Based on the soundings we could see occasional gusts
at times with decent mixing...so did keep some gusty winds at
times tonight. Now for Wednesday this broad low will begin to exit
east and this will aid in waining the snow showers through the day
from SW to NE. The clouds should also begin exiting the region in
the same fashion...temperatures will remain well below normal with highs
topping out in the low 20s and even teens in some of the higher
terrain. The potential for clearing skies could lead to a very
cold night Thursday night...however there is some uncertainty on
clearing in the SW due to another wave. There remains a fair
amount of uncertainty on the track and if we get any chance of
precipitation in that area...right now keeping it dry. Either way right
now temperatures look to drop into the single digits.

Long term...(thursday through tuesday)
issued at 455 PM EST Tuesday Feb 9 2016

The models are in good agreement aloft at least through the start
of the upcoming weekend as they all depict one deep northeastern
trough replaced by another. The agreement does break down into
Saturday evening with the GFS slightly deeper with the departing
eastern trough while the European model (ecmwf) is slower...but also weaker. For
Kentucky...benign northwest flow follows for Sunday with even
some ridging at middle levels late in the day. The latest European model (ecmwf) has
backed off its earlier idea of a moderately strong trough plowing
into the Ohio Valley Sunday night in favor of a slower version
building through the day Monday...more in line with...but slower
and stronger...the GFS. The 12z European model (ecmwf) continues to be more
aggressive with this pattern into Tuesday as it digs its wave down
into the Tennessee Valley in tandem with a strong one along the
Gulf Coast. The last two runs of the European model (ecmwf) is suggesting a more
dynamic situation than the GFS and its flatter trough. In
general...will favor a model blend through the first part of the
weekend with a lean toward the more amplified European model (ecmwf) for the start
of the new week.

Sensible weather will feature a moderating area of high pressure
passing over eastern Kentucky on Thursday with a weak surface wave
moving through Friday making another shot of snow showers
possible for our area from Friday into Saturday morning. Another
colder area of high pressure follows this setting the stage for a
very chilly night into Sunday morning. The next weather maker will
move into the middle Mississippi Valley later that day with snow
showers a possibility for Kentucky that night and into Monday.
Going more along with the European model (ecmwf) solution...a more robust surface wave
will pass through the Tennessee Valley...perhaps strengthening
along the Gulf Coast...on Monday. In this scenario...accumulating
snow...possibly rather wet...will be a concern. The GFS...by
contrast...moves the surface reflection of its weak middle level trough
through Kentucky Sunday night into Monday with a lesser chance of
accumulating snow. Given the large model differences at these
latter time steps confidence is much lower than average...but one
thing is certain -- the ground hog was wrong.

Adjusted the grids from the CR init to account for small ridge to
valley temperature differences each night. Also tweaked the pop
grids later in the period to reflect a forecast closer to the
latest and more extreme European model (ecmwf).

&&

Aviation...(for the 06z tafs through 06z Wednesday night)
issued at 1233 am EST Wednesday Feb 10 2016

Scattered to numerous snow showers will persist through the
remainder of the overnight period across eastern Kentucky. In
general...the taf sites will experience MVFR conditions due to
low clouds...snow showers...or both. The more intense snow showers
may produce IFR conditions at a give Airport along with 15 to 20
knots wind gusts. Winds will generally be out of the west at 5 to
12kts with gusts of around 15 kts outside of the snow showers. The
snow will begin to taper off around 12z this morning with only
isolated snow showers around by 18z today. The last remaining snow
should be exiting the area around the end of the taf period.

&&

Jkl watches/warnings/advisories...
Winter Weather Advisory until 10 am EST this morning for kyz044-
050>052-058>060-068-069-079-080-083>088-104-106>120.

&&

$$

Update...jp
short term...dj
long term...greif
aviation...Arkansas

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