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000
FXUS61 KILN 151433
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
933 AM EST Sat Dec 15 2018

.SYNOPSIS...
A large, slow moving low pressure system will move from the
Tennessee Valley into the Southern Appalachians this weekend.
Widespread rain and mild conditions are expected into tonight.
The rain will taper off early Sunday as the low moves off to the
east coast.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Frontogenetic band will continue to slowly lift across the
forecast area. Looks like forcing may decrease a bit later so
band may have some breaks in it by the time it reaches the
northern part of the forecast area. Cannot rule out some ponding
of water or even minor flooding generally across the Tri-State
where greater amounts have already occurred with additional 1/2
to 1 inch possible. Not expecting much movement in temperatures
through the day.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
Large mid level low to track northeast through the TN Vly
tonight and east into the Delmarva region Sunday. As the mid
level low approaches - elongated surface low to pivot thru the
Ohio Valley tonight. Favorable moisture and forcing will
continue into this evening with the potential for localized
flooding continuing. As the system pushes off to the east, rain
will begin to taper off from west to east late tonight into
early Sunday. Expect considerable cloudiness through the night
with lows from the mid/upper 30s northwest to the mid 40s
southeast.

Northwest flow develops on Sunday with a good deal of clouds
early. Forecast soundings show moisture becoming more shallow
as the day wears on. Therefore, expect a decrease in clouds
Sunday afternoon. Sundays highs to range from the mid 40s
northwest to the upper 40s southeast.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
An upper ridge will travel from the Great Plains Monday to the Great
Lakes Tuesday and then to the East Coast on Wednesday. Surface high
pressure forming under the confluent northwest flow ahead the upper
ridge will push across the Ohio Valley, resulting in dry weather
conditions in the subsident anticyclonic circulation around the
high.

An upper trough will be approaching on Thursday. As the upper trough
deepens and a closed upper low and surface low develop, moisture and
lift will increase rather dramatically, producing the likelihood for
showers by Thursday night, with snow possibly mixing in Friday as
colder air filters in toward the end of the event.

Temperatures will start near normal Monday and Tuesday, with highs
averaging 40. Warm advection on a southerly flow will nudge readings
up to the 40s and low 50s by Thursday, before a retreat back to the
low 40s on Friday.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
Moisture to continue to increase ahead of surface and mid level
low slowly approaching from the TN Vly. Ceilings to drop down
thru MVFR into the IFR category from south to north with
widespread rain. MVFR visibility restrictions will also develop
with the rain. In favorable region of lift and moisture,
widespread rain and low clouds are expected to remain across the
TAFs through the day.

As the low moves into the Ohio Valley tonight - low ceilings to
continue and lower with low IFR conditions expected. Rain will
begin to diminish in coverage from the west late tonight.

Northeast winds at 10 to 15 knots will gust up to 25 kts this
morning and then back to the north around 10 kts by evening and
then northwest by Sunday morning.

OUTLOOK...MVFR/IFR conditions will be possible at times through
Sunday.

&&

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

&&

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