Area Forecast Discussion
Issued by NWS Wilmington, OH-- Remove Highlighting --
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FXUS61 KILN 192356
Area Forecast Discussion
National Weather Service Wilmington OH
756 PM EDT Sun Mar 19 2017
Surface high pressure extending from the western Great Lakes to the
Mississippi River Valley will extend across the region this
afternoon. The ridge will then move east of our area tonight. A
cold front will push southeast across the Great Lakes and Ohio
Valley Monday into Monday night, bringing showers and a few
embedded thunderstorms. Precipitation may linger into Tuesday as
a disturbance moves across the region.
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Surface high pressure overhead this afternoon will slowly push
east tonight with clouds also slowly eroding this evening. High
temperatures will also average in the mid 40s across the region
as clouds have helped to keep temperatures down a bit. Tonight
low temperatures will be in the mid 30s with weak southerly flow
returning Monday morning. Cirrus will also start to move into
the area Monday morning as the next upper level disturbance
approaches from the west.
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
Monday morning surface high pressure will be east of the region
with pressure falls occurring over the midwestern United
States. Also at this time weak pockets of PVA in the mid-levels
will be traversing the region. Adding to the lift will be weak
widespread WAA ahead of a low level trough axis. The GFS is
fairly weak with the PVA but still has enough of a disturbance
for weak lift (via Omega) to occur over the area. The NAM is
slightly stronger with the disturbance and has correspondingly
higher Omega values. Not surprisingly the ARW, NMM, NCEP WRF,
WRF Dart, and NSSL WRF all show a decaying system of weak storms
Monday morning in some form or fashion. Forecast soundings at
this time don`t look all that impressive on the GFS (not fully
saturated) but there is a stout inversion in place at 900 mb.
The NAM forecast soundings look similar to the GFS but show
better saturation. Both soundings show the inversion at 900 mb
which support the development of elevated thunderstorms. 850 to
500 mb lapse rates on the NAM also approach 7 degrees C/ km.
Monday afternoon into evening another weak upper level
disturbance will approach from the west with a disorganized
surface low. The NAM tries to pull the surface low further east
than the GFS which allows for slightly higher MU CAPE values. A
surface cold front will also be pushing through at this time.
Again high res models show a line of showers and embedded
thunderstorms forming along the front. Given the lapse rates
some small hail will be possible in any stronger storms that
form. Monday night the cold front will push south of the
forecast area with high pressure building in from the north.
.LONG TERM /TUESDAY THROUGH SUNDAY/...
Frontal boundary will be south of the Ohio River on Tuesday. With
models trending toward a drier solution showing the front farther
south, kept a chance of showers mainly in southern locations. As the
upper flow turns northwest, surface high pressure is forecast to
provide dry weather on Wednesday.
Unsettled conditions are expected to return Thursday and Friday when
a warm front develops near the Southern Great Lakes, resulting in a
chance of showers mainly in northern counties. A cold front swinging
through on Saturday will bring the likelihood for showers and a few
thunderstorms. A few showers may linger Sunday in residual moisture
and forcing behind the slow moving front.
Temperatures will exhibit variations typical of early spring. Highs
in the 50s Tuesday will be followed by readings around 40 Wednesday
under cold advection on a northerly flow. Highs will rise to the 60s
by Friday with the area in the warm sector. Highs are forecast to
settle back into the 50s Sunday due to weaker cold advection.
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --Surface high pressure over the region will slide off to the east
with mid lvl ridging building in overnight. Lingering MVFR clouds
over KCMH and KLCK will clear out this evening, yielding VFR
conditions through the overnight hours.
Mid level flow backs westerly with a fast moving wave inducing
a surface low that tracks from the Mid MS Vly Monday morning
across the Ohio Valley Monday night.
Favorable isentropic lift develops ahead of this wave and its
associated warm front. Expect elevated thunderstorms to develop
northwest of the TAFs early Monday, with the remnants of this
weakening convection providing some showers during the morning
with the best threat across KDAY. Expect CIGS to lower during
the morning but to remain VFR.
Monday afternoon into evening weakening surface low pressure
will push east across the area ahead of a surface cold front.
Have a mention of showers and MVFR conditions developing at
all TAF sites during the late afternoon. With elevated instability
likely, embedded thunderstorms will also be possible. For now
have continued the mention of showers.
OUTLOOK...MVFR ceilings and visibilities possible Tuesday and Friday.
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