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000
FXUS61 KILN 151501
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
1101 AM EDT Tue Aug 15 2017

.SYNOPSIS...
A weak upper level disturbance will pass south of the region
offering a few isolated showers early this morning. A weak cold
front will approach the area from the northwest this afternoon
and stall across the region tonight into Wednesday. Isolated
thunderstorms will be possible with this front this afternoon. An
enhanced chance of storms will occur Wednesday night into Thursday,
as low pressure tracks through the Great Lakes and a cold front
approaches from the west.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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Very few changes to the forecast this afternoon. GOES16 visible
satellite/water vapor loops clearly show shortwave trough
progressing through the Great Lakes, and attendant surface
boundary drifting south through northern IND/OH. This boundary
has recently shown some agitation with shower development in
northern Indiana. Recent HRRR runs support other CAMS/ensembles
showing modest uptick in shower coverage into areas along/north
of I-70 during the afternoon hours, and have continued
isolated/scattered coverage in this forecast update. Forecast
soundings suggest meager boundary layer instability so getting
thunder will be tough as depth/magnitude of CAPE in the charge
separation region of the sounding is rather paltry.

Second area of concern is over northern Kentucky where an
isolated shower could develop later this afternoon, though
boundary layer forcing is lacking vs. further north. Thus, have
kept forecast dry here and will monitor visible satellite for
towering cumulus, and may amend forecast to a small rain chance
should expected cumulus field become agitated with diurnal
instability. Otherwise, modest tweaks to sky/wind/temps for the
day and overnight.
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&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
Weak frontal boundary that drops into central Ohio this
afternoon will wash out tonight. Any isold storms that develop
will quickly dissipate with loss of heating due to lack of
forcing. Light wind flow combined with abundant low level
moisture will lead to patchy fog development overnight. Expect
lows in the mid and upper 60s.

Shortwave ridge to pass east across the region Wednesday. Warm
front convective development to occur to our west Wednesday.
Instability is marginal and with best lift/moisture to our
west, have limited pops to slight chance of a thunderstorm in
the afternoon. Warm temperatures to continue with Wednesdays
highs in the mid and upper 80s.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Models are trending a bit slower with respect to a cold front
approaching from the west Wednesday night, so backed off on timing
of arrival compared to Superblend. Still kept a chance of showers and
thunderstorms Wednesday night, spreading from west to east. Showers
and storms will be likely Thursday with frontal passage. Low threat
for severe thunderstorms will exist Thursday in an environment
featuring ample wind shear and adequate instability. Precip chances
diminish Thursday night and Friday as the front travels east of the
area. For Saturday, latest ECMWF and GFS show a short wave trough
pushing in from the west with limited moisture and ill-defined
surface features. Went with slight chance pops for thunderstorms.

On Sunday through Monday, models indicate surface high pressure
followed by a ridge building aloft. This weather regime will exhibit
very little forcing or deep moisture, while surface temperatures and
humidity increase in the return flow around the high. Went with a
dry forecast for this period.

Temperatures start warm Thursday just ahead of the cold front, with
high reaching the mid and upper 80s. Highs are forecast to slip into
the low to mid 80s Friday and Saturday under clouds, precip, and
modest cold advection. A rebound back to the upper 80s is indicated
for Sunday and Monday due to insolation and warm advection.

&&

.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
Mid and high level cloudiness across the southeast area
associated with departing weak upper level disturbance.
A moist low level and light winds has lead to fog development
this morning, especially across the I-71 corridor. Moisture is
shallow so visibilities will improve quickly this morning.

A weak front will drop down from the northwest through this
afternoon which could lead to an isolated shower/thunderstorm
across the north. Expect main threat to remain north of the TAF
sites, so have omitted any mention of thunderstorms.

In moist airmass expect widespread fog development again
tonight. Have visibilities in IFR category at fog prone KILN
and KLUK locations.

OUTLOOK...Thunderstorms possible Thursday and Thursday night.

&&

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

&&

$$
SYNOPSIS...AR
NEAR TERM...Binau
SHORT TERM...AR
LONG TERM...Coniglio
AVIATION...AR