797
FXUS63 KPAH 252319
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
619 PM CDT Mon Sep 25 2017

.UPDATE...
Issued at 619 PM CDT Mon Sep 25 2017

The AVIATION section has been updated for the 00Z TAF issuance.

&&

.SHORT TERM...(Tonight through Wednesday night)
Issued at 218 PM CDT Mon Sep 25 2017

The airmass overall is not as unstable as yesterday. The energy
that ignited yesterday`s convection is elongated and farther
north. Therefore, will keep PoPs 10 percent or below through
sunset, acknowledging that an isolated shower, and maybe lightning
is still possible. Tonight, calm and mostly clear again with
patchy fog expected.

NVA strengthens across the area Tuesday, so one more dry and
unseasonably warm day. Tuesday night should be mainly dry, with
a cold front pushing south across the area mainly after midnight.
This wind shift precedes the good push of cooler less humid air.

Wednesday, we will see a band of post frontal elevated moisture
move southeast across the area. There is evidence of an elevated
front moving toward the area with this moisture, though it rapidly
loses its identity. So just a slight chance of a shower through
the day. Wednesday night, decreasing clouds and turning cooler as
the true airmass change takes place.

Overall we favored a model blend, though the GFS may be overdone
with moisture both Tuesday and Wednesday (not uncommon). Temps
will be a blend of MOS and existing numbers.

.LONG TERM...(Thursday through Monday)
Issued at 218 PM CDT Mon Sep 25 2017

Expect a classic dry and pleasant early autumn weather pattern
through the long term period.

Thursday through Friday, a sharpening 500 mb trough will dig
southeast from south central Canada across the Great Lakes region
and upper Ohio Valley. The associated surface high pressure system
will track into the western Great Lakes on Friday, resulting in a
noticeably cooler and drier north wind flow. Highs both days will be
in the mid to upper 70s. At first glance, 850 mb temps would not
support highs that warm. However, model soundings suggest extremely
dry air and cloud-free skies will permit mixing to nearly 775 mb
Friday. Along with the warm days will come much cooler nights due to
the very dry air mass. Overnight lows will be around 50.

Saturday will be the coolest day of the period as the Great Lakes
surface high produces a northeast wind flow. After morning lows
around 50, daytime highs will be in the lower to mid 70s. A weak 500
mb ridge will build eastward across our region, keeping skies mainly
clear.

Sunday through Monday, surface winds will veer into the southeast
and then south on the back side of the retreating surface high.
Temps and humidity will be very slow to respond, with highs climbing
back only into the mid and upper 70s on Monday. By Monday, there may
be enough moisture for some increase in clouds and a slight chance
of showers. Any showers would be mostly the result of warm air
advection, since the models keep upstream 500 mb troughing way back
in the Rockies or Pacific states.

&&

.AVIATION...
Issued at 619 PM CDT Mon Sep 25 2017

High pressure at the surface and aloft will keep skies mostly
clear and winds light or calm through the period. The only threat
to VFR conditions is patchy fog potential near sunrise. KCGI as
usual will be the most likely site to experience fog.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&

$$

UPDATE...DRS
AVIATION...DRS