Area Forecast Discussion
Issued by NWS Paducah, KY

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FXUS63 KPAH 170821
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
321 AM CDT Sun Sep 17 2017

.SHORT TERM...(Today through Tuesday night)
Issued at 320 AM CDT Sun Sep 17 2017

The main forecast concern in the near term is the chance for
showers and thunderstorms across mainly southeast Missouri and
southern Illinois today and much of the forecast area Monday into
Tuesday.

The upper level pattern through mid week will be characterized by
a trough in the western U.S. with a ridge extending from the Gulf
of Mexico northeast into the Tennessee Valley. The ridge should
flatten somewhat today and especially Monday as weak impulses of
energy impinge on its west side. In the lower levels, a weak cold
front is forecast to drop southward into northern portions of the
forecast area later today into tonight. The front is forecast to
return north as a warm front on Monday. Meanwhile, surface high
pressure will remain anchored over the Appalachians through the
short term.

While models are in relatively good agreement synoptically, the
mesoscale situation is a bit messy as is typically the case with
such weak flow regimes. As a result, the forecast will take more
of a broad brush approach, with plenty of opportunity to tune the
finer mesoscale details as they become more apparent.

So for today, a small chance of showers and thunderstorms enters
southeast Missouri and southern Illinois with the approach of the
cold front. The chance for showers and thunderstorms encompasses
the entire area on Monday with the combination of weak upper level
energy, better integrated moisture, and greater instability.
Chances may continue into Tuesday as well, but perhaps to a lower
degree with less mid level energy at play. Thunderstorm coverage,
widely scattered to scattered at best, should be concentrated more
during the heat of the day.

With the upper level ridge just east of the region and southerly
flow in the low levels, warmer than normal temperatures will
persist through the period. Highs should range from the mid to
upper 80s with lows in the mid to upper 60s.

.LONG TERM...(Wednesday through Saturday)
Issued at 320 AM CDT Sun Sep 17 2017

Forecast confidence is quite high that we will experience well above
normal temperatures with the potential for mainly isolated diurnal
convection through the period.

A weak upper-level disturbance will be exiting to the east of our
region Wednesday. This will provide the best focus for convection in
the extended portion of this forecast. PoPs will max out around 40
percent in eastern portions of the region, so we are still only
looking at scattered coverage at this time.

After Wednesday, we will be in a summer-like pattern. Aloft, high
pressure will build over the region, and modest south to southeast
winds will prevail at the surface. This will keep rather high
humidity across the area with high temperatures around 5 degrees
above normal and lows 5 to 10 degrees above normal. With the
unseasonably hot and humid conditions expected, a few isolated
afternoon thunderstorms will be possible each day from Thursday
through Sunday.

&&

.AVIATION...
Issued at 320 AM CDT Sun Sep 17 2017

Even though more cloud cover is expected through tonight, VFR
conditions should persist. Widely scattered thunderstorms are
possible over portions of southern Illinois and southeast
Missouri, especially this afternoon. With chances less than 30
percent, will not include a mention in the TAFs at this time.
Winds will remain light from the south.

&&

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

$$

SHORT TERM...RJP
LONG TERM...DRS
AVIATION...RJP



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