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000
FXUS61 KILN 161019
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
619 AM EDT Mon Oct 16 2017

.SYNOPSIS...
A large area of high pressure will settle into the Ohio Valley for
the upcoming week, with dry conditions expected. After some frost on
Tuesday morning, temperatures will begin a gradual warming trend
through next weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
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The below-mentioned lake-enhanced band of clouds has been
producing a few light showers over NE Indiana, and a few of
these are drifting toward the far northwestern sections of the
ILN CWA. A 20-PoP was added for a few hours this morning.

Previous discussion >
With surface high pressure still centered well west of the Ohio
Valley, and a mid-level trough crossing through the southern
Great Lakes, a cold advection pattern remains in place across
the area this morning. Unsurprisingly, patches/bands of
stratocumulus clouds remain in place, with a more solid area of
clouds across eastern Ohio and into Pennsylvania. Another area
of clouds further to the west appears to be at least partially
lake-enhanced, undoubtedly aided by the relative min in
850mb/700mb temperatures currently near and downstream of Lake
Michigan. Nonetheless, a large portion of the ILN CWA is in a
clear spot, which has only expanded in size over the course of
the night.

Over the course of the day, the surface high will expand and
built into the area, only enhancing the deeply dry air mass
behind the mid-level trough. Though steep lapse rates will allow
for some diurnal cumulus (or a continuation of the morning
stratocumulus), clouds should dissipate quickly by mid/late
afternoon, leading to clear skies heading into the evening.

Max temperatures today will be the coolest of the month so far
by a comfortable margin -- reaching only the upper 50s.
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&&

.SHORT TERM /TUESDAY/...
The only real concern for the short term forecast period is in
frost potential for Tuesday morning. Radiational cooling
conditions will be near-ideal, with clear skies and very light
winds in most locations (possibly around 5 knots in the
northwestern sections of the CWA). It is interesting that when
looking at raw model output (WRF-ARW/WRF-NMM/NAM) there is not
uniform agreement on where the coolest temperatures are actually
going to occur on Tuesday morning. What there is agreement on is
that the potential is there for temperatures to drop into the
middle 30s, which would certainly support frost development.
This could occur anywhere in the ILN CWA, but is most likely in
the far eastern counties, where a frost advisory will almost
certainly be needed (collaboration with surrounding offices
necessitated delaying this until later today).

Otherwise, the rest of Tuesday needs little discussion, with the
surface high centered near the Ohio River in the
Cincinnati/Louisville vicinity. Conditions appear dry, clear,
and slightly warmer than Monday -- lower to middle 60s.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Surface high pressure will extend across the Ohio Valley Tuesday
night into Wednesday.  The airmass will modify will temperatures
warming into the upper 60s and lower 70s.

Mid level energy will be passing to our north Thursday into Thursday
night, which will allow a dry cold front to slip south into the
southern Great Lakes. The southern end of the front is expected to
wash out by Friday as surface high pressure reestablishes itself
while a mid level ridge builds across the Tennessee and Ohio
Valleys. Highs Thursday and Friday will be in the lower 70s.

For next weekend, the upper level ridge will slowly traverse east
while a mid level trough pushes toward the Mississippi River Valley.
We should remain dry with highs in the lower to mid 70s. Next chance
for precipitation will either arrive Sunday night or Monday as the
mid level trough and its associated cold front move east.

&&

.AVIATION /10Z MONDAY THROUGH FRIDAY/...
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The TAF sites have become mostly clear early this morning,
though a few patches of VFR stratocumulus may still pass through
the region at times this morning.

Through the rest of the period, the TAFs are fairly
straightforward. Today, the expectation is for NW winds at
around 10 knots, along with diurnal cumulus (or a lifting /
continuation of the morning stratocumulus) safely within the
VFR range. Light winds and clearing skies are expected
overnight.

OUTLOOK...No significant weather expected.
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&&

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

&&

$$
SYNOPSIS...Hatzos
NEAR TERM...Hatzos
SHORT TERM...Hatzos
LONG TERM...Hickman
AVIATION...Hatzos