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Area forecast discussion...updated 
National Weather Service Jackson Kentucky
725 am EDT Monday may 25 2015

issued at 700 am EDT Monday may 25 2015

The forecast appears to be on track so have just updated the
sky/T/TD grids per the latest observation and trends.


Short term...(today through tuesday)
issued at 325 am EDT Monday may 25 2015

06z surface analysis shows a tightening pressure gradient over
Kentucky between broad low pressure in the plains and high
pressure along the East Coast. The inversion in place over
eastern Kentucky and nature of the terrain is keeping the winds
light to calm in most places. This...combined with a smattering of
high and middle level clouds...has led to another night of good
radiational cooling and ridge to valley temperature splits across
eastern parts of the County Warning Area. Readings currently vary from the middle 50s
in the most sheltered valleys to the middle to upper 60s on the
ridges and in more open locations. As is often the case in these
situations...ekq shows the results of a well mixed boundary layer
with south winds gusting to 17 kts and temperatures in the lower 70s at
last observation. While dewpoints have come up during the past 24
hours they are still on the relatively dry side ranging from the
lower 50s in the far east and on ridgetops to the middle 50s in our
western counties and valley locations.

The models are in fairly good agreement with the upper level
pattern through the short term portion of the forecast. They all
depict a Sharp Ridge pushed further east from the area in the
face of a broad and opening trough crossing the middle Mississippi
Valley today. A couple significant shortwaves will pass through
the region just to the northwest of east Kentucky. The first of
these GOES by from late this morning through the afternoon
resulting in further height falls. After a quiet night...a more
substantial wave passes on Tuesday afternoon in conjunction with
the bodily lifting to the northeast of the central trough/S
remnant core. This will bring a decent middle level wind field
through the area as it moves by and likely fuel stronger and
possibly severe storms for much of the state when combined with
moderate instability expected to be in place. Have followed the
higher resolution guidance from the hrrr and nam12 most closely
given the overall model agreement and smaller scale nature of the
determinant features.

Sensible weather will start off quiet enough for this Holiday...
and following several days of near perfect weather...but will likely
turn convectively active by midday starting in the western parts
of the County Warning Area and pushing east through the afternoon. The earlier
hrrr runs and hints within the nam12 suggested a possibility of a
stray shower around east Kentucky before 15z in advance of the
main area both models develop later in the day. This appears to be
overdone...and now discounted by the latest hrrr...given the
relatively dry air still in place over the eastern part of the
state. Nevertheless...they do agree on a fairly active afternoon
for most of the area as the lead middle level shortwave initiates
convection early on to the west as diurnal instability along with
progressive outflow boundaries are expected to do the rest. The
activity will wane early in the evening with a small chance for
showers/storms during the time of typical convective minimum.
Renewal of activity is anticipated for Tuesday as the next wave
brushes by aloft with a better wind field and as much...or
potentially more...instability in place. The main question for
organized development of storms and the overall severe potential
will rest on partial clearing and the ability of the air mass
over eky to overcome any earlier stabilizing effects of
convection/debris from that morning/S limited convection. With
the potential for stronger storms...and in conjunction with the
Storm Prediction Center outlook for Tuesday...will highlight concerns in the severe weather potential statement...a
web headline...and a heads up email to our partners. This should
ensure that decision makers are not caught unaware of the storm
potential coming off a long Holiday weekend.

Used the shortblend as a starting point for the T/dew point and wind
grids today before wrapping up with the superblend through 00z
Wednesday. Given the increase in moisture and cloud cover for
tonight made only minor terrain based changes to the low
temperatures. As for probability of precipitation...ended up a little higher than even the
wetter mav MOS for this afternoon. Following that...the probability of precipitation were
most similar to the lower met numbers tonight and in line with a
blend of the fairly high guidance Tuesday.

Long term...(tuesday night through sunday)
issued at 300 am EDT Monday may 25 2015

The extended period continues to look quite active...with repeated
periods of showers and thunderstorms forecast. The afternoon and
evening periods look to be the most active aided by peak heating and
maximum instability realization. The models continue to depict a
large scale pattern that would feature a series of large scale upper
level troughs migrating across the northern Continental U.S. And southern
Canada. A series of frontal boundaries that will be trailing from
the surface reflections of the upper troughs are also forecast to
traverse the eastern third of the Continental U.S.. these fronts would act as
the primary triggers for shower and storm activity. Tuesday night
and Wednesday look to be the most active a sluggish
cold front meanders about the area. A few of the storms Tuesday
evening could produce damaging wind gusts...large hail...and locally
heavy rainfall. The active pattern looks to continue through to the
upcoming weekend with another good shot of rain possible Saturday
and Sunday. Temperatures during the period are still on track to be
above normal for the time of year...with daily highs in the low to
middle 80s and overnight lows in the low to middle 60s across the board.


Aviation...(for the 12z tafs through 12z Tuesday morning)
issued at 725 am EDT Monday may 25 2015

VFR conditions will be in place through the morning hours.
However...ceilings will firm up and begin to lower during the day
as showers and thunderstorms take shape over central Kentucky and
move in from the west. This will bring the potential for some MVFR
and brief IFR ceilings/visible into the area in the afternoon with any
storm. These conditions will continue into the evening with a
diminishing trend to coverage and likely improvements in the
ceilings. Winds will increase from the south to southwest through the
day reaching 10 to 20 kts for a time this afternoon amid the
showers and storms. Look for the winds to settle during the
evening following sunset.


Jkl watches/warnings/advisories...


short term...greif
long term...Arkansas

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