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Area forecast discussion 
National Weather Service Jackson Kentucky
1022 PM EDT Tuesday Sep 23 2014

Update...
issued at 1022 PM EDT Tuesday Sep 23 2014

The forecast remains on track this evening. The latest observations
from around the area are already showing the start of a Ridge Valley
temperature split that will eventually occur across most of eastern
Kentucky tonight. Fog formation is still anticipated along creeks
streams and near lakes. The fog should be quite shallow with good
subsidence and dry air aloft. The fog could also be locally dense at
times but only in patches. No update to the zone forecast text
product is planned at this time.

Update issued at 739 PM EDT Tuesday Sep 23 2014

Not much happening with the forecast this evening. A strong ridge of
high pressure will remain in place across the region for the next
several days...bringing dry and very pleasant weather to eastern
Kentucky. Tonights weather will feature clear skies...light
winds...and valley fog...which could be patchy dense at times. The
current observation data was ingested into the forecast grids to establish
new trends. The forecast text product was in good shape with no
changes needed there.

&&

Short term...(this evening through Wednesday night)
issued at 300 PM EDT Tuesday Sep 23 2014

The weather pattern through the short term will be dominated by a
surface ridge axis and a meandering cut off upper low. The upper low
currently located near Augusta in forecast to drift due north and
be located over West Virginia by Wednesday evening. This will result
an in inverter trough in the surface ridge axis across the area and
may result in some increased cloudiness...however will keep things
dry through the end of the period. The models are all consistently
indicating some warming over the next 36 hours with both the low and
highs gradually rising. The models are in very good agreement for the
first 36 hours of the forecast. Went with a model blend for the
temperatures and then had to make some adjustments for elevation.

Long term...(thursday through tuesday)
issued at 300 PM EDT Tuesday Sep 23 2014

A strong upper level ridge will remain the dominant weather feature
through the upcoming weekend. Surface high pressure will remain
strong over the region...providing a pleasant stretch of Fall
weather. A gradual air mass modification will continue with
temperatures slowly warming through much of the extended. The next
chance of rain may arrive sometime early to the middle part of next
week as some kind of tropical disturbance pushes north into the middle
Mississippi River valley. Latest 12z GFS and European model (ecmwf) continue to slow
down the progression of this system...and have accordingly pushed
back any probability of precipitation until Monday night and Tuesday. The GFS would support
even later than this...but opting for a compromise for now and only
push it back one period at a time. Regardless...any system that
tracks north into the middle Mississippi River valley will likely keep
US in southeasterly downsloping flow...so initially there is going
to be lots of dry air to overcome prior to any precipitation.
Thus...precipitation chances will remain in the slight chance
category...until flow can become more southerly with better moisture
transport.

&&

Aviation...(for the 00z tafs through 00z Wednesday evening)
issued at 739 PM EDT Tuesday Sep 23 2014

Dry and pleasant weather and VFR conditions are expected to prevail
through the end of the taf period all the taf sites except sj. Based
on current model data and observation from last night into early this
morning...jkl...loz...and sme should remain free fog overnight. The
reason for this is likely going to be due to the deep layer of dry
air that is in place just above the surface and strong downward
vertical motion associated with the area of high pressure that is in
place across the area. Most fog that forms tonight should be confined
to the deepest river valleys and near large bodies of water. The fog
should also be very shallow due the aforementioned sinking motion of
the area overhead. As for sj...with conditions similar to last
night...it seemed reasonable to put fog in that taf once again. The
first wisp of fog are forecast to form at 5z or so...with dense fog
possible between 10 and 13z...and MVFR fog and ceilings possible between
5 and 7z. The fog should burn off there between 13 and 14z on Wednesday.



&&

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

$$

Update...Arkansas
short term...jj
long term...kas
aviation...Arkansas

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