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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KILN 220533
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
133 AM EDT Fri Sep 22 2017

.SYNOPSIS...
A mid level ridge of high pressure will set up over the Great
Lakes and remain stagnant into early next week. Weather
conditions are expected to be generally dry, with temperatures
above normal through the weekend.

&&

.NEAR TERM /UNTIL 7 AM THIS MORNING/...
Dying convection currently located west of metro Dayton will
continue to lose its cohesiveness this evening. Other storms
that extended along a line from Dayton/Troy ssw towards
Cincy/Burlington have died out already and will not see any more
showers this evening. Cloud cover from this little batch of late
day convection will gradually dissipate by about midnight in
favor of clear skies. Light winds and the clear skies will make
another night of good radiative processes possible, and fog is
expected to be patchy overnight, but locally dense in river
valleys and fog-prone areas.

Have not adjusted temperatures yet but tried to show the
convective trend this evening with earlier updates.

&&

.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM SATURDAY/...
The stagnant pattern will continue into Friday, as the mid-level
ridge strengthens slightly, and the surface high establishes
itself a little more firmly into the northern Ohio Valley.
Another day of near-full sun should allow for a slight warming
in temperatures from today (Thursday), raising the possibility
of seeing some 90 degree readings, mainly in the southwestern
ILN CWA.

It is another day where it is tough to get a clean read on
precipitation chances, as forecast soundings again show that a
weak cap will be present near 800mb. Despite this, model output
again suggests that conditions may not remain completely dry.
With a pattern almost identical to today, some low-end chance of
showers may eventually need to be introduced, but this may not
be possible until real-time trends are monitored -- and it would
not be good to include this CWA-wide since almost all locations
will remain dry.

With a slight drop in dewpoints going into Friday night,
temperatures will be capable of falling a little more than on
Thursday night -- and min temps should be in the lower to mid
60s.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Large H5 ridge over the eastern U.S. will be the dominant feature
through the weekend and into early next week. It will work with a
surface high centered over the eastern Great Lakes to bring dry and
much above normal temperatures to the region. High temperatures will
be about 10-15 degrees above normal as they push into the mid and
upper 80s. Morning lows be in the lower 60s.

Extended models continue to differ in their strength and timing of
front for the middle of next week. The ECMWF is the quickest with
the front, brining pcpn Wednesday Evening into Wednesday night. The
GFS is doesn`t bring the front and pcpn in until Thursday. The
Canadian brings Maria into NC/VA and therefore doesn`t really have
the frontal feature. Ran with a blend of the ECMWF/GFS for the last
48 hours of the forecast.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --
A ridge of mid-level high pressure is currently centered just
west of the area this morning allowing for a very weak pressure
gradient across the area. Winds have decoupled at almost all TAF
sites with dewpoint depressions nearing or at zero degrees at
KLUK and KLCK. This means another morning of river valley fog
looks likely and therefore have kept mention in the TAF sites.

During the day today some more fair weather cu will be possible
with surface high pressure located to the northeast of the area.
The pressure gradient will remain weak keeping winds mostly
light.

OUTLOOK...No significant weather is expected at this time.
-- End Changed Discussion --

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.

&&

$$
SYNOPSIS...Haines/Hatzos
NEAR TERM...Franks
SHORT TERM...Hatzos
LONG TERM...Sites
AVIATION...Haines