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Area forecast discussion...updated 
National Weather Service Jackson Kentucky
1030 am EDT Monday Jul 28 2014

issued at 1030 am EDT Monday Jul 28 2014

14z surface analysis shows a deep area of low pressure spinning over
upstate New York. Attached to this this...a cold front extends
southwest...running just east of the southern Appalachians. The
approach of this front set up the conditions that were so favorable
for severe storms and very large hail yesterday. Now drier and
cooler air is building into this part of the state on northwest
winds. This will make for a pleasant afternoon...though expect rather
cloudy conditions for most of the area due to the cold air aloft
and the upper low swinging through the eastern Great Lakes. A few
light showers will be possible from the clouds in the afternoon...but
most places will stay dry. Have updated the forecast mainly to fine
tune the low probability of precipitation and high sky cover. Also tweaked the T and dew point
grids per the latest observation...trends...and consshort guidance. These
have been sent to the ndfd and web servers.

Update issued at 737 am EDT Monday Jul 28 2014

Moisture wrapping around a surface low currently moving into the New
England states has developed a mass of low clouds which are now
racing southward into the Ohio River valley region and eastern Kentucky.
This movement is faster than what was previously forecasted. Updated
the grids to better reflect the faster movement of theses clouds into
the region. However...given the lack of rainfall reports thus far in
the morning...precipitation timing still seems to be in rather good shape
for now. Also...after some heavy showers moved through the region
last night...some of the valleys in the higher elevations have since
developed some patchy dense fog. Did not include fog in this update
however due to the fact that latest trends show it burning off
quickly as drier air mixes in and temperatures continue to rise over
the next couple of hours. Finally...loaded in the latest
observational data for temperatures...winds...and dew points to make sure
that ongoing conditions were well reflected in the near term forecast
as well.


Short term...(today through tuesday)
issued at 420 am EDT Monday Jul 28 2014

The cold front which produced widespread convection yesterday will
continue to push off southeast of the region through the morning hours. As
it does...drier northerly air will filter into the region. Given the
unseasonable upper level troughing pattern continuing to push
southward from Canada across the eastern Continental U.S....this northerly air
will be much colder than normal. High temperatures today are only expected
to reach the low and middle 70s. The main forecast concern today will be
wrap around moisture from the surface low pressure system and upper
level shortwave...both of which are now moving into the New England
states. All models are in very good agreement that some moisture will
push into NE and Erly sections of the County Warning Area...but the extent of these
showers and whether they will be mainly isolated or scattered is still a
little uncertain. Given the lack of instability as high pressure
moves overhead...expect this to be more of a rain shower event. And
given the light amounts of quantitative precipitation forecast...expect the impacts to be very
minimal across the region.

By tonight...the low will continue to track northward along the
Canadian coastline. The upper level trough will keep unseasonably
cool temperatures across the area. This...coupled with clear skies and an
excellent radiational cooling set up...should be enough to drop lows
into the middle 50s overnight. Expect showers to briefly come to an end
during the evening hours. However...with lingering low level
moisture...upslope flow...and upper level support from the longwave
trough...models are pointing at yet another batch of isl to scattered
showers developing across far eastern Kentucky on Tuesday as well. Once
again...quantitative precipitation forecast values are very light and instability is weak at there is very little concern for impacts with these
showers. Highs will recover little Thursday...remaining in the middle
70s with low humidity values.

Long term...(tuesday night through sunday)
issued at 410 am EDT Monday Jul 28 2014

The models remain in good agreement with an amplified long wave
pattern to control across the Continental U.S. Through the end of the week.
Ridging will remain anchored across the western Continental U.S....while a
persistent trough reigns in the eastern Continental U.S..

Drier and cooler weather can be expected across eastern Kentucky
through Thursday some temporary dampening of the eastern
Continental U.S. Trough takes place...allowing for broad surface high pressure
to set up across the Ohio Valley. The trough will then reassert
itself from Friday Onward...with the threat of diurnally influenced
convection returning across the area.

Highs will gradually modify from the 70s the lower 80s
by the end of the week.


Aviation...(for the 12z tafs through 12z Tuesday morning)
issued at 750 am EDT Monday Jul 28 2014

Wrap around moisture from a strong low pressure system...currently
moving across the lower Great Lakes and towards New England...has
caused a mass of MVFR clouds to develop along the backside of the
low...north of the Ohio River valley. Due to its position in a
northerly wind flow regime...these clouds have quickly ejected
southward and are currently advecting into eastern Kentucky. Went ahead
and bumped up the time of arrival for these clouds by a couple hours
in the tafs based on latest satellite timing. There is the possibility
for some light rain showers today as well mainly at ksjs and kjkl.
However...due to the uncertainty of where these showers will set well as the lack of impacts these showers will have...chose
not to mention in the tafs at this time. Overnight tonight...expect
low level moisture to become trapped near the surface.
However...given a more northerly wind direction at the
surface...expect this to become more of a stratified low ceiling event
rather than fog. This is still far out in the period...and confidence
is not only trended down to MVFR ceilings at this time.


Jkl watches/warnings/advisories...


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

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