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000 
FXUS63 KJKL 291100
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
700 AM EDT Thu Jun 29 2017

.UPDATE...
Issued at 700 AM EDT THU JUN 29 2017

The forecast remains on track early this morning. Any remaining 
fog should be gone by 13Z. A few showers and storms may areas 
along and west of Interstate 75 from late this morning through 
early this afternoon. The latest obs were ingested into the 
forecast grids to establish new trends. No major changes to the 
forecast were needed at this time.

&&

.SHORT TERM...(Today through Friday)
Issued at 308 AM EDT THU JUN 29 2017

The ridge of high pressure that has brought dry and pleasant
weather to eastern Kentucky the past few days will finally break
down enough to allow a few showers and storms to move across the
Tennessee border and into eastern Kentucky later today. An area of
low pressure passing by to the south of the area will be the
trigger for any showers and storms that we see today. The first
precipitation should begin moving across the TN state line and
into our southern counties by late this morning. This activity
will increase in coverage this afternoon, and we may see scattered
showers and storms for a few hours along and south of the Hal
Rogers Parkway. The rain should be gone by 0Z, as we lost daytime
heating and low pressure moves off to our southeast. Another
better shot of rain is expected on Friday, as a second better
organized weather system moves out of the Tennessee valley and
across portions of eastern Kentucky. The best chance of rain with
this second system should be Friday afternoon.

Temperatures are expected to be around normal today and tomorrow,
with max values in the mid to upper 80s expected today, and the
lower 80s on Friday. Tonights lows will be a bit warmer as well,
with minimum readings in the mid to upper 60s expected along
ridges while the surrounding valleys fall into the lower 60s.
Winds should be out of the south at 5 to 10mph for most locations.
A few locations along and north of I-64 could see sustained winds
later today of around 10mph. 

.LONG TERM...(Friday night through Wednesday)
Issued at 358 AM EDT THU JUN 29 2017

Increasing southwest flow will take shape Friday evening/night 
across eastern Kentucky. Troughiness will extend south into the 
Missouri Valley from a closed low in Manitoba, as a cool front 
stretches from the Great Lakes into the southern Plains. The 
approach of this front along with subtle height falls Saturday into 
Saturday night will bring numerous showers and thunderstorms to 
eastern Kentucky. Given surface-based CAPE values of near 2 kJ/kg 
and deep layer shear of approximately 30 knots, could very well see 
a quick uptick in updraft intensity out of any storm. This would 
promote a few downburst wind gusts, but any semblance of a dry sub-
cloud layer appears pretty lackluster in terms of seeing much in the 
way of any damaging gusts.

The threat of showers and storms will continue into the second half 
of the weekend ahead of the greater moisture plume downstream of an 
approaching surface ridge. Rising height fields, as the flow 
aloft veers more zonal and large-scale difluence is lost, will 
likely keep any precipitation confined to the higher terrain near 
the Virginia state line. Airmass recovery remains questionable as 
to thunder chances, especially given a relatively drier pocket of 
air advecting in. Temperatures are still expected to warm into the
low-mid 80s as the northern extent of the core of the system's 
energy, coupled with high pressure from the western Atlantic into 
the Gulf of Mexico, precludes a solid cool frontal push through 
eastern Kentucky.

Northwest flow looks to keep conditions dry for Monday, before a 
shortwave trough passes through the western CONUS ridge and moves 
toward the Midwest. This will increase shower/storm chances for at 
least Tuesday and likely Wednesday, with the evolution/digging of 
the system determining how long into the week chances linger. Yet 
another amplifying upper high will develop across the intermountain 
West, potentially building east and sparking quite a warmup by the 
latter half of the week. 

&&

.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
ISSUED AT 700 AM EDT THU JUN 29 2017

VFR conditions will prevail through the end of the TAF period at
all five airports. Some fog will linger in valleys early this 
morning but should be gone by 13Z. Cloud cover will gradually
increase during the day, as a an area of low pressure moves by to
our south. A few showers and storms may affect areas along and
west of I-75, but these should not become widespread enough to
warrant mention in the TAFs. Winds will be out of the south or
southwest at 5 to 10 KTs, especially this afternoon and early this
evening. 

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

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