000
FXUS63 KPAH 221929
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
229 PM CDT Fri Sep 22 2017

.SHORT TERM...(Tonight through Sunday night)
Issued at 227 PM CDT Fri Sep 22 2017

Fairly high confidence continues into the weekend for the forecast.

Models continue in good agreement with the synoptic scale features
and timing. The main difference in model output arrives Sunday as
the high drifts off to the northeast. Some of the models namely the
GFS brings rain into the area Sunday. The ECMWF allows a little
precip into SEMO but keeps it west of the Mississippi. The NAM
continues to keep us dry. The subsidence inversion weakens as the
high drifts off which would be the main reason the models start to
allow convection. Right now severe weather does not appear likely
with CAPE`s at the surface and aloft around 1k j/kg2 and LI`s around
-5. PW`s do exceed an inch but stay under a one and half inches.
 Freezing level is above 13k feet. So would expect the main threat
 with any storms that do get going would be lightning or heavy
 rain. With such a weak signal will use low end chance for the
 Sunday time frame. In the overnight hours we will have a
 radiation inversion which should limit any nocturnal convection.
 As for temperatures we still keep much above normals through the
 weekend although dew points start a slow downward trend they will
 still be high for this time of year especially.

.LONG TERM...(Monday through Friday)
Issued at 227 PM CDT Fri Sep 22 2017

Heading into early next week, an upper level high will have migrated
to the mid Atlantic region with a highly amplified trough in the
western part of the country. Chances for rain will be minimal Monday
and Tuesday and likely tied to heat of the day diurnal air mass
showers and/or thunderstorms. The heat and humidity will remain in
place through Tuesday although dew points do not look as high as
they have been (around 65-67 degrees).

A much advertised cold front will be dissipating as it arrives on
Tuesday night. Could see some rain enter southeast MO before 12Z
Wednesday. The ECMWF really dries up the precipitation as it
approaches yielding mere hundredths of an inch for QPF. The GFS is a
bit more aggressive with the precipitation, especially during the
day on Wednesday. However, even it is pretty scant with the QPF. Not
looking like everyone will see rain with this frontal passage so
will keep POPs rather low for now. It looks like models have come
into better agreement with regards to timing, as the GFS, ECMWF and
Canadian show the best time frame for any precipitation will be
overnight Tuesday and through the day on Wednesday. The moisture
exits the area Wednesday night and we are dry for the rest of the
week.

The main item of conversation though is the much cooler air mass
that will be filtering into the area late in the week behind this
front. Wednesday will obviously be the transition day and be cooler
because of some clouds and possible rainfall. Highs will be in the
lower to mid 80s on Wednesday. However, 850 mb temperatures really
take a nosedive as we head into Thursday and Friday and especially
into the weekend. How quickly the cooler air makes it into the area
still has to be worked out by the models but relief is at least in
sight. We are at least looking at upper 70s for highs for Thursday
and Friday. Cooler readings are expected for the weekend. Much more
comfortable humidity levels will also result with this air mass.

&&

.AVIATION...
Issued at 1220 PM CDT Fri Sep 22 2017

It`s a VFR flight forecast with mainly fair weather cumulus
around. An isolated shower may develop but way too low coverage
for inclusion into the forecast. Patchy fog will yet again be
possible causing early am/sunrise restrictions to vsbys on
Saturday, where it develops. Quick burnoff is anticipated with
return to full VFR from mid morning on.


&&

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

$$

SHORT TERM...KH
LONG TERM...CW