827 
FXUS63 KPAH 170448
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
1148 PM CDT TUE AUG 16 2016

.UPDATE...
Issued at 1148 PM CDT Tue Aug 16 2016

Aviation update.

&&

.SHORT TERM...(Tonight through Thursday night)
Issued at 125 PM CDT Tue Aug 16 2016

Water Vapor shows tropical connection still intact. Off and on
rainfall, mostly on, has persisted much of day, and as boundary only
slowly shifts eastward, it will continue to focus said connection
for lingering chance pcpn through the mid week period. And while
rainfall rates are not as extreme, even just a little bit in our
saturated areas continues to cause short-fused flooding issues.
Fortunately, the eastward drift should put it out of the most
extreme of the saturated zones soon.

Surface based instability is highest just to our east, and that's
where the best chance of thunder will be. But as long as the
boundary is in our vicinity, cannot rule out its mention. Will
continue to carry slgt chance mention, as a result.

Fog may plague areas mainly to our north and west tonight, where
pcpn departs, esp if there is any clearing. Anticipate low
clouds/fog developing then, and that could linger into early
morning. Best to monitor extent of eastward shift of pcpn, where
fog develops, and density, before headlining.

Models still say Wed night-Thur looks to be least chance Pop time
period, though not altogether, as chances are retained south and
east, and return from south, with time.

Seasonal temps continue with associated cloud affected daytime/
nighttime diurnal swing mutations.

.LONG TERM...(Friday through Monday)
Issued at 318 PM CDT Tue Aug 16 2016

A weakness in the weak ridging over the PAH forecast area (a subtle
shortwave at 700 mb) will represent a positive factor to the
enhancement of lift on Friday. This, combined with persistent
southwesterly low level moist flow, will result in increasing
likelihood of shower and tstm development from south to north,
mainly during the day.

By early Saturday, the influence of a significant northern stream
700 mb trof axis and surface cold front will begin to be seen for
our area. PoPs will ramp up to likely for the daytime hours
Saturday under large scale lift. 

However, the medium range models have had some trouble locking on to
the smaller features such as impulses in the mean trof, and the trof
axis itself. There have been some variances among model runs, and
the latest solutions are up to 24 hours different in timing of the
trof axis (GEM earliest, ECMWF latest). Model consensus suggests
that surface fropa, and therefore introduction of a new air mass,
will occur Sunday night, with at least chance PoPs through that
time. It is uncertain at this time, but if there is phasing of winds
aloft and some decent instability, perhaps a strong storm or two
could develop ahead of the front Sunday.

By early next week, it will be dry and still warm, but with a
noticeable decrease in dewpoints, and an increase in the diurnal
swing of temps. 

&&

.AVIATION...
Issued at 1148 PM CDT Tue Aug 16 2016

Light ra/shra observed south of a KCGI-KEVV line. This activity
should continue overnight, and is reflected in the forecasts. Cigs
will be difficult to pin down. We continue to expect variable
conditions, ranging from VFR to possibly IFR with an occasional
lower deck as low level moisture continues to stream northeast.
Conditions should improve Wednesday as slightly drier air begins to
work in. Winds will be light through the period. 

&&

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

$$