Scientific Forecaster Discussion
fxus61 Kiln 270554
Area forecast discussion
National Weather Service Wilmington Ohio
154 am EDT Tue Jun 27 2017
a weak cold front will push through the region overnight.
High pressure will then provide dry weather through mid week.
Precipitation chances will increase toward the end of the week
as temperatures warm to near normal.
Near term /until 6 am this morning/...
a weak cold front will move southeast through the region
overnight. A few showers will accompany the front, with skies
clearing after passage. Lows will be chilly, ranging from near
50 north to the lower/mid 50s south.
Short term /6 am this morning through 6 PM Wednesday/...
precipitation could be lingering in the southeast very early
Tuesday, but will move off to the southeast. In northwest flow
pattern, surface high pressure to build into the region Tuesday.
With cold 800 mb pool over the region expect some shallow high based
cumulus clouds to develop. Tuesday will be dry with rather cool
highs from the lower 70s northeast to the mid 70s southwest.
Surface high pressure to slide east of the region Tuesday night.
Diurnally driven cumulus clouds will give way to clear skies
early Tuesday evening. Expect cool lows from near 50 northeast
to the mid 50s southwest.
Long term /Wednesday night through Monday/...
on Wednesday morning, surface high pressure will be centered over
West Virginia, with a relatively dry air mass remaining in place
across the Ohio Valley region. With heights rising, and southerly
flow firmly in place in the low levels, warm advection should be
notable -- with a temperature rise to near 80 degrees.
As a more progressive pattern begins to set up for Thursday and
beyond, mesoscale details will play a significant role in exact
timing and placement of precipitation. A frontal zone is expected to
set up east-to-west across the southern Great Lakes beginning early
Thursday, but despite this, Theta-E and wind plots suggest the iln
County Warning Area will remain in the warm sector (a regime of solid deep-layer
southwesterly flow) through Saturday afternoon. This will tend to
favor convective initiation upstream (north and northwest) of the
iln County Warning Area on Thursday and Friday, with eventual some propagation
downstream which should impact the iln County Warning Area. Pops have been focused
on the northern sections of the cwa, with greater expectations
during diurnal or Post-diurnal time frames (afternoon through
evening / early overnight). A shortwave moving east across Lake
Michigan will provide extra support for convection Friday evening,
but this too seems likely to not land a direct hit on the iln County Warning Area.
It may take until cold frontal progression on Saturday / Saturday
night before chances increase County Warning Area-wide, and pops were increased on
Saturday to reflect this. Through this period, how much of the County Warning Area
remains capped is a question, and mesoscale foci / localized forcing
will help decide if storms can develop within the warm sector. With
ample instability and at least somewhat favorable deep-layer shear,
some heavy rainfall / strong to severe storms could be possible from
Thursday through Saturday. Confidence in any specifics will keep
this out of the severe weather potential statement for now.
With a clearing push behind the cold front late Saturday, models
have trended drier for Sunday, before warm advection begins to bring
a chance of precipitation into the area again on Monday.
Aviation /06z Tuesday through Saturday/...
500 mb S/W will continue to swing across the srn Great Lakes early
this morning. Convection will continue to be shunted south and E
of the tafs as a weak front works through. Broken mid level
cigs will affect cmh/lck for the first few hours of the taf
period. Scattered clouds are then expected.
With weak cold air advection at 800 mb today, scattered cu around 3500-4000ft will
develop by 15z. The diurnal cu will dissipate with sunset as
high pressure builds into the region for tonight.
Outlook...thunderstorms possible Thursday through Saturday.