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000
FXUS63 KPAH 271949
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
249 PM CDT Thu Jul 27 2017

.SHORT TERM...(Tonight through Saturday night)
Issued at 249 PM CDT Thu Jul 27 2017

A cold front over central Missouri and central Illinois this
afternoon is heading southeast. This front will bring much quieter
and drier weather by the weekend. In the meantime, there will be
some potentially strong convection to deal with.

As of mid-afternoon, scattered storms were developing across the
Lower Ohio Valley. These storms were developing on the northern
edge of a pool of very moist and unstable air that was unaffected
by the early morning mcs that tracked across Illinois. These
storms were supported by a mesoscale vorticity center over south
central Missouri, which was evident in radar loops. This vort
center was generated by an early morning mcs over western
Missouri.

In the near term, convection will likely expand in coverage across
the very unstable air over western Kentucky and extreme se
Missouri late this afternoon. Once the atmosphere is raked over
and the vort center passes to our southeast this evening, there
should be relatively little activity on radar. A second smaller
round of storms is likely late tonight along the actual cold front
as it moves southeast across the Ohio River and southeast
Missouri.

Heavy rain appears to be the primary hazard given high precip
water values over two inches. There is also some potential for
training cells if an organized mcs develops. Corfidi vectors
indicate a slow southward motion to any organized mcs that forms.
Individual cell motion is mostly to the east.

Once the front exits the Pennyrile region of western Kentucky
Friday morning, there will be a slow drying trend during the
afternoon. Some isolated weak convection could lag behind the
front as a strong 500 mb shortwave drops south-southeast across
the Great Lakes region. The drier air will be slow to filter south
initially, which means dew points will still be mostly in the 70s.
However, clouds should keep high temps mostly in the mid 80s.

Saturday and Saturday night will be noticeably cooler and drier.
Little if any cloudiness is expected. Model soundings indicate any
diurnal cumulus clouds would be scattered at most. Even with full
sun on Saturday, highs will range from 80 to 84 with a north
breeze. Overnight lows will be in the upper 50s and lower 60s
Saturday night, which will be the coolest night since June 28.

.LONG TERM...(Sunday through Thursday)
Issued at 249 PM CDT Thu Jul 27 2017

The overall forecast confidence is high.

The dominant feature on the weather map throughout the extended
forecast will be a strong upper-level ridge over the western half of
the country. This will result in troughing of some amplitude over
the eastern half, including our region. At the surface, cool, dry
high pressure will remain in place through much of the period. The
airmass will slowly moderate, but south winds never really get
established, so the moderating process will be slow.

The medium range models bring an upper-level storm system southeast
through the Great Lakes or Northeast on Thursday, which could push a
cold front into our region. Depending on the strength/path of this
system, some convection may reach our eastern counties Thursday
afternoon.

&&

&&

.AVIATION...
Issued at 1245 PM CDT Thu Jul 27 2017

Showers and thunderstorms are forecast to develop this afternoon
ahead of a cold front. The most unstable air is south of a line from
kmdh to kevv, where storms should be quite numerous and possibly
strong by late this afternoon. There is a good chance that the
relatively stable air in the kevv area will inhibit tsra, so there
is no mention of tsra there in the 18z tafs. Outside of storms,
widespread mvfr cigs have developed due to cumulus cloud formation.
These cigs should be persistent through the afternoon.

Tonight, mainly vfr conditions are expected early in the wake of
showers and storms. However, conditions are favorable for low
stratus and fog late tonight into early Friday. The low levels will
be very moist, and winds will be light. The low clouds and fog will
burn off later in the morning.

&&

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

$$

SHORT TERM...MY
LONG TERM...DRS
AVIATION...MY