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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KILN 181926
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
326 PM EDT Mon Sep 18 2017

.SYNOPSIS...
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A weak cold front over Indiana and Ohio will further weaken and
wash out over the area, with a few showers and storms this
afternoon and evening. A disturbance shifting through later
tonight and Tuesday will continue the chance of showers and
storms, before a drying trend takes over for the middle and end
of the upcoming work week. Temperatures will remain above to
well above normal for the foreseeable future.
-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
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Weak cold front is decaying across eastern Indiana and western
Ohio this afternoon. Under weakly diffluent mid to upper
tropospheric flow, the peak of the diurnal destabilization cycle
will combine with a ribbon of anomalous precipitable water near
the decayed front to continue scattered showers and storms
through mid evening. 18.19z mesoscale analysis indicates SBCAPE
has risen to near 1000 J/kg, so there is plenty of instability
for showers and a few storms. Very weak flows evident on the
18.18z Jose special sounding from ILN...with bulk shears < 15kts
which keep updrafts unorganized and brief, so only locally heavy
rain from the strongest cores. Latest radar loops show that
strongest updrafts will propagate on developing cold pools,
which should keep any localized flooding threat brief. Will have
20-40% rain chances focused mainly west of I-75 through the
evening hours, trending back toward midnight.

Later in the night, shortwave trough clearly seen in GOES-16
water vapor loops over Iowa/Missouri will approach with the
trough axis cutting across the area after 12Z. Have rain chances
increasing again toward sunrise in eastern Indiana and then
western Ohio as this feature approaches.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
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The shortwave trough will move across the area Tuesday morning,
with a rather well defined 700-500mb trough axis/convergence
zone. As this feature interacts with the residual PWAT ribbon
from decaying frontal zone from this afternoon, should see
showers and a few storms increase in the morning into the early
afternoon especially across eastern indiana/western Ohio with
best focus across the northern half of the ILN forecast area.
Should see a diminishing trend in the activity through the
afternoon as the shortwave weakens as the large scale ridge
works against the smaller wavelength feature. Once a little sun
breaks out later in the afternoon, expect another mild afternoon
with highs a few degrees either side of 80F.

Skies will continue to clear slowly on Tuesday night with lows
in the lower 60s.
-- End Changed Discussion --

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
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Amplified flow pattern will dominate the pattern through the
extended with with strong ridging over the Great Lakes and Ohio
Valley with a deepening trough digging into the west and Jose and
Maria activity off the east coast.

For Wednesday, a weak short wave will work slowly into the area
undercutting the mean ridge. The greatest instability and weak
forcing will be along the fringe of the ridge mainly along the
western and southwestern forecast area.

As the ridge continues to strengthen during the latter part of the
week, with H8 temperatures in the 16-17C range for late week mid 80
high temperatures will work into the area.
-- End Changed Discussion --

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
Mainly VFR conditions are expected across the TAF sites through
the period, though there is some uncertainty on potential MVFR
ceilings and/or visibility later tonight with some light fog,
and then with showers on Tuesday morning.

Radar has quieted down over the past few hours with most showers
dissipating. A sct-bkn mid deck exists early this afternoon and
a few-sct cumulus deck will develop through peak heating. A weak
front in the area and differential heating boundaries will
likely spark mid-late afternoon showers and a few thunderstorms,
most likely near DAY/CVG between 20Z and 02Z. Some of these may
linger through the night especially near/north of KDAY.

Uncertainty rises later in the night with any fog formation
potential. Expect a fair amount of clouds to persist through the
night as shortwave trough approaches. If clouds end up less than
forecast, visibilities may be lower with more valley fog. Right
now playing less restrictions to visibility and more clouds,
but this will need to be watched. Expect showers to develop/move
across the area Tuesday morning, but rates are expected to be
light with minimal impacts to aviation.

OUTLOOK...No significant weather is expected at this time.

&&

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

&&

$$
SYNOPSIS...Binau
NEAR TERM...Binau
SHORT TERM...Binau
LONG TERM...JDR
AVIATION...Binau