Area Forecast Discussion
Issued by NWS Wilmington, OH-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KILN 190603
Area Forecast Discussion
National Weather Service Wilmington OH
203 AM EDT Wed Apr 19 2017
A weak upper level disturbance to the north across the Great
Lakes and to the south in the Tennessee Valley will push east
tonight into early Wednesday morning, providing increased cloud
cover in the area. A more potent system will move through the
region Thursday afternoon into early Friday morning.
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
Weak, low-level warm/moist advection will continue overnight
across the forecast area. This should result in an increase in
cloud cover. A few showers may occur, especially across the
southeast CWFA. Enough surface wind flow and the increase in
clouds should keep temperatures warm, only falling into the
upper 50s to lower 60s.
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
Wednesday morning will start off a bit overcast in the FA.
A few showers may linger longest across the southeast Wednesday
morning before dissipating towards late morning and early
afternoon. The focus will then shift to the potential for an
area of showers and thunderstorms to develop along/on the
southern fringe of a nearly-stationary boundary across northern
IL/IN/OH during the late afternoon and early evening hours.
Convection-allowing models continue to indicate the potential
for this activity /if it develops at all/ to clip the far
northern/northeastern FA late in the afternoon as it races
southeast. Have added chance PoPs to account for this potential.
Although cloud cover will be a bit more expansive during the day
Wednesday, still think that highs may approach 80 degrees
toward the Tri-State area during the afternoon.
By Wednesday night, the aforementioned frontal boundary will
begin to pivot back northward as a surface low pressure system
organizes across the mid/northern Mississippi Valley. With the
FA expected to be positioned squarely in the warm sector
Wednesday night, an unseasonably warm night is expected, with
lows dropping only into the low to mid 60s area-wide.
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Southwesterly flow ahead of an approaching cold front will help
push temperatures well into the 70s through the day on thursday
with some lower 80s possible across our south. This will allow
us to destabilize through the day on Thursday with an increasing
chance of thunderstorms through the afternoon hours along a pre
frontal boundary. The chance of showers and thunderstorms will
then continue into the evening hours until the cold front moves
through later Thursday night. Both deep and low level shear
values will be on the increase as some upper level energy and
the front approaches later thursday afternoon into Thursday
evening. This will support at least a lower end severe threat,
especially across our northwest fa where the better instability
and shear values should reside.
The front will push south of our area on Friday and then hang up
across the Tennessee Valley through the weekend. There are some
model differences as to just how far south of our area the front
will make it and then how far north precipitation will spread back up
into our area with various waves moving along the boundary Saturday
into Sunday. Will generally keep pops in the chance category both
days with the highest pops across our southern areas. Highs on
Friday will be seasonable, ranging from the upper 50s in the north
to the mid 60s in the south. Highs will then cool a bit for Saturday
into the mid 50s to lower 60s, before returning to the low to mid
60s for Sunday.
High pressure will build into the area for Monday before pushing off
to the east through the day on Tuesday. This will lead to dry
conditions and a bit of a warmup through the first part of the work
Very thin cirrus remain draped across parts of the region this
afternoon. Midlevel clouds associated with a very weak mid-
level disturbance over the Tennessee Valley region will
gradually overspread the area from the south late this afternoon
into this evening. Some of the hi-res suite of models continue
to indicate isolated SHRA development this evening across
southwestern parts of the area as a result of increased lift
with the midlevel disturbance. As of right now, because of
expected lack of coverage and ample dry air in the low levels,
have withdrawn even a VCSH for all terminals for the period,
even as isolated activity works ENE through the overnight
As light sfc winds go more southerly this evening and
eventually southwesterly tonight, low-level moisture will
increase in the area. This will allow for MVFR, and potentially
IFR, CIGs to develop and overspread the terminals after 06-09z.
Do think that pockets of IFR CIGs will develop in the area, but
do not yet have confidence on exact timing or location for
inclusion as a prevailing condition at any of the terminals.
CIGs may be slow to lift/scatter Wednesday, but do expect some
clearing and lifting to VFR around/after 18z.
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --Weak waa over the region has been producing mid clouds and a few
isolated showers. The waa will continue early this morning.
Models continue to indicate that mvfr cigs will develop later
this morning. Based on the latest satellite image, pushed back
the development by an hour to two. With the temp/dewpoint
closing this morning, there could be some mvfr fog at DAY or ILN
MVFR cigs will gradually lift back to VFR by mid morning with
the heating of the day. Meanwhile a cdfnt will drop southeast
into the srn Great Lakes. Scattered showers and thunderstorms
are forecast to develop along the front in nrn OH and sag into
Central OH late this afternoon. Added a VCSH at CMH/LCK to
cover the possibility.
OUTLOOK...Thunderstorms likely Thursday into Thursday night.
MVFR ceilings and visibilities possible Saturday into Sunday.
-- End Changed Discussion --