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Area forecast discussion 
National Weather Service Jackson Kentucky
342 PM EDT Tuesday Oct 6 2015

Short term...(this evening through Wednesday night)
issued at 335 PM EDT Tuesday Oct 6 2015

As of middle afternoon...upper level shortwave ridge was centered
over the Appalachians with a stronger ridge centered over the
Southern Plains. A shortwave trough is moving through the southern
Great Lakes with a stronger trough extending from the Hudson Bay
region south into the western Great Lakes and upper MS valley. At
the area of low pressure was centered over Hudson Bay
with a cold front trailing south into the northern Great Lakes and
then southwest into the plains. High and some middle level clouds
were passing through the region on west to west northwest flow

The lead shortwave trough will pass north of the area through
tonight...and heights are projected to fall. The stronger
shortwave currently further north and west will rotate in the
Great Lakes tonight and into the St Lawrence Valley and northeast
on Wednesday. Rather zonal flow is expected in the its wake locally
with some height falls late in the period in advance of the next
more potent shortwave that will affect the area in the long term.
This will send the cold front further south through the Great
Lakes tonight and south of the Great Lakes by Wednesday evening
where it will begin to slow...if not retreat north late...ahead
of the next low pressure system. This will leave weak high
pressure at the surface dominating.

Dry and mild weather is expected through the period...with valley
fog a feature each night. River valleys should again experience
some dense fog and based on how low dewpoints dropped in the north
so far this afternoon...a few readings in the northern cold spots
around 50s if not 48 or 49 should occur. Clouds should be more
prevalent on Wednesday night and fog should be less extensive.

Long term...(thursday through tuesday)
issued at 313 PM EDT Tuesday Oct 6 2015

European model (ecmwf)...GFS...and NAM all lining up well with the timing of the
front on Friday. To start the period...dry weather will continue
through Thursday with unseasonably warm conditions as highs again
climb well into the 70s. Cold front will then drop south into the
Ohio River valley late Thursday night and Friday...bringing a period
of showers and a few thunderstorms to eastern Kentucky. The middle
level trough is fairly sharp with good have continued
to increase probability of precipitation areawide. We may need to watch some widely isolated
severe threat as the shear is tremendous through the day. The only
lacking ingredient seems to be instability...but both the NAM and
GFS bufr soundings continue to indicate the presence of some weak
instability. Regardless...with this much shear present...the severe
threat will be a possibility. If the severe threat were to
materialize...main threats would be damaging winds. Rain chances
will linger into Friday evening...but we should dry out heading into
Saturday. Much cooler weather will settle in for the weekend behind
the departing front. As high pressure centers itself over the region
Saturday night...we may see our coolest morning of the fall so far
with highs in the colder valleys possibly reaching around 40. A few
30 degree readings would be possible. Any 30s would be in the
valleys away from bodies of water.

The weather will remain dry through the remainder of the extended. A
dry quasi-warm front will push across the area on Monday...with much
warmer weather returning for next week.


Aviation...(for the 18z tafs through 18z Wednesday afternoon)
issued at 235 PM EDT Tuesday Oct 6 2015

High pressure in place across the area will keep for light and
variable winds and mainly clear skies with the exception of mainly
cirrus clouds. A few diurnally driven cumulus near 5kft cannot be
ruled out late in the period. Fog will again develop in the deeper
valleys around or after 6z...before lifting and dissipating around
14z. At this time...the fog is expected lift into the airfield at
sjs after 8z...and some IFR and near Airport min visible is possible
there. MVFR may affect sme...but at this time...the fog is not
expected to affect jkl...loz or sym.


Jkl watches/warnings/advisories...


long term...kas

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