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Area forecast discussion 
National Weather Service Jackson Kentucky
445 PM EST Monday Mar 2 2015

Short term...(this evening through Tuesday night)
issued at 332 PM EST Monday Mar 2 2015

While under a ridge of high pressure today...we will be
transitioning to the Lee side of an upper level troughing pattern
through the day tomorrow. This will be the introduction to a
major transitional period in the weather forecast as we head into
middle week.

To start out...high pressure at the surface will continue to shift east
across Kentucky this afternoon and evening...pulling out of eastern Kentucky by
late this evening. While it is in control...expect light variable
winds and partly cloudy skies through this evening. Then...once the
surface high shifts eastward...a strong low pressure system
currently over the 4 corner states plains will make a quick shift
eastward towards the Central Plains by 12z Tuesday. Ahead of this
system...a warm front will push from west to east across the County Warning Area
from 12z Tuesday through 18z...pulling in moist but generally light
southerly winds across the region. Expect cloud cover to begin
spreading across Kentucky this evening...with clouds lowering throughout
the night. Between 9 and 10z /generally/ precipitation will move in
starting in the south and spreading northward. While there will be a
push of warmer air...modeled surface temperatures continue to lag behind in
the latest data...creating a good scenario for freezing rain at
onset. While most locations will likely see some sort of freezing
rain...mainly in the northern half of the County Warning Area...it will thankfully
be short lived as surface temperatures quickly react and rise above
freezing just after 12z...changing all precipitation over to just rain.

Between 18z Tuesday and 0z Wednesday...the County Warning Area will be in between
the exiting warm front and the approaching cold front...with
continued strong southerly flow pulling in warm moist air.
Temperatures will rise into the 50s with stratiform light to
moderate rain expected throughout the duration of the day. There
could be enough elevated instability to produce a few rumbles of
thunder...so went ahead and added slight chance of thunder to the
forecast through the evening Tuesday. After about 3z Tuesday...we
lose some of the best Li/S and surface temperatures begin to drop so expect
thunder potential to die off at this point.

Long term...(tuesday night through monday)
issued at 445 PM EST Monday Mar 2 2015

The models continue to be in good agreement with a prolonged heavy
rainfall event pegged across eastern Kentucky from Tuesday night
through Thursday. A tight baroclinic zone will lay out east-northeast to west-southwest
across the Ohio Valley and gradually shift southeast into
Tennessee Valley through Thursday. In general...2 to 3 inches of
rainfall is forecast across eastern Kentucky between Tuesday night
and early Thursday morning. The snowpack has been dwindling
across most of the area...however some of the headwater areas in
the Cumberland and Kentucky will likely still have some remaining
as the heavy rains hit. Since there is continued agreement with
this scenario...have hoisted a Flood Watch from Tuesday night
through Thursday. Smaller stream and creek flooding will likely
peak on Wednesday...with larger creeks and rivers peaking Thursday
and likely running high into the first part of the weekend for
some of the more downstream points.

Additionally...there has been an emerging winter weather threat
with this system over the past few days...as the models continue
to indicate colder air making it in while deeper moisture and
forcing linger late Wednesday afternoon through early Thursday
morning. This would result in heavy snow/sleet accumulations...with
the highest amounts likely near the I-64 corridor and then lesser
amounts to the southeast. Given the continued trend of this
potential outcome...went ahead and issued a Winter Storm Watch for
the entire area from Wednesday afternoon through early Thursday
afternoon. On the brighter side...if this frozen precipitation
were to come to pass...it would certainly mitigate some of the
runoff potential. We will be eagerly awaiting future model runs
to see how all of this plays out.

High pressure will build in behind the front beginning late Thursday
night and remain over the area through late Sunday. Temperatures Friday
morning will likely dip into the single digits...even possibly below
0 degrees in our northern counties... which is well below normal for
March. However this appears to be fairly short lived as temperatures
start moderating back towards seasonable levels on Saturday and
should persist through the end of the period. The next chance for
precipitation will be Sunday into Monday. For now...have nudged probability of precipitation
towards a 12z European model (ecmwf)/superblend blend. Behind this system...high
pressure builds back into the region yet again.

&&

Aviation...(for the 18z tafs through 18z Tuesday afternoon)
issued at 1233 PM EST Monday Mar 2 2015

A brief area of high pressure will keep VFR conditions over
eastern Kentucky today...with generally light and variable winds. As we
head into tonight...the area of high pressure will begin exiting
to our east...and a warm front will push in from the west...with
winds becoming generally southerly though still light. As this
occurs...expect high clouds to thicken and quickly lower to MVFR
between 8z and 12z from west to east. Rain will also quickly move
in with the clouds...with most taf sites generally seeing precipitation
between 9 and 10z. A strong warm nose just above the surface
continues the indicate the possibility of freezing rain at
onset...quickly changing over to all rain as temperatures rise
above freezing after 12z. Unfortunately...models are pointing at
ceilings and visible continuing to lower to LIFR conditions during the day
tomorrow as rain persists through the region.



&&

Jkl watches/warnings/advisories...
none.
&&

$$

Short term...jmw
long term...geogerian/jvm
aviation...jmw

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