000
FXUS63 KPAH 211656 AAA
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
1155 AM CDT WED SEP 21 2016

.UPDATE...
Issued at 1155 AM CDT Wed Sep 21 2016

Updated the AVIATION discussion for the 18Z TAF issuance.

&&

.SHORT TERM...(Today through Friday night)
Issued at 240 AM CDT Wed Sep 21 2016

High confidence in the short term.

The combination of clear skies, calm winds, and moisture trapped
below the nocturnal inversion has produced patchy dense fog over
portions of the quad state region. Hard to describe the areas
affected due to the random nature of where the fog has formed and
how rapidly it changes. Decided to issue a Special Weather Statement
to that effect until 14Z. Do not plan to issue a Dense Fog Advisory
at this time.

Same old song, different verse in the short term period. High
pressure at the surface and ridging aloft is forecast through the
period producing dry, warm, and humid conditions.

Temperatures will remain well above normal through the period.

.LONG TERM...(Saturday through Tuesday)
Issued at 240 AM CDT Wed Sep 21 2016

It always is a challenge to incorporate remote sensing sampling of
ocean area systems via satellite, aircraft, and ship reports and
ingest them into numerical model guidance. This evening`s model runs
suggest the first guess of the model guidance is with observations,
especially in and near California. Since the low and trough expected
to develop just west of the area next Monday will come from this
genesis region, there is some concern regarding model accuracy.

At this time, the 00z Wednesday ECMWF seems to have the best handle
on height, vorticity, and moisture advection, moving and closing off
in the Central Plains and the front range of Colorado. This still
holds off precipitation from reaching the WFO PAH forecast area
until late Sunday night. The vast majority of moisture appears to
run parallel with the trough axis, and will place rain chances
further west into parts of Southeast Missouri and Southwest Illinois
through next Wednesday, eventually moving small rain chances over
the rest of the forecast area next Thursday, as the baroclinic zone
sharpens with the cold air advection flow within the surface and
upper low across the Central Plains.

Little change made to the gridded sensible weather elements, except
to enhance the influence of the ECMWF in the regionally blended
model guidance suite.

&&

.AVIATION...
Issued at 1155 AM CDT Wed Sep 21 2016

Under high surface pressure, and ridging aloft, VFR conditions are
expected, with the exception of patchy late night fog, mainly in
southern IL/southeastern MO. It appears there will not be quite as
much low level moisture available tonight compared to previous
nights, but patchy dense fog is still possible at, for example, KCGI
and KPAH. Winds will be out of the east for most of the 24 hr TAF
period, and generally light, with a probable shift to the south
Thursday morning.

&&

.PAH Watches/Warnings/Advisories...
IL...None.
MO...None.
IN...None.
KY...None.
&&

$$

SHORT TERM...JP
LONG TERM...Smith
AVIATION...DB