National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KILN 130155
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
955 PM EDT Sat Aug 12 2017

.SYNOPSIS...
High pressure will extend across the area through the first half
of the week. An approaching front will bring the next chance of
showers and thunderstorms later Wednesday into Thursday.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
-- Changed Discussion --
Surface high pressure will build into the region tonight.
Outside of some cirrus at times, mainly clear skies are
expected overnight. This could lead to some patchy fog,
especially in the southern river valleys. Lows tonight will
mainly be in the mid to upper 50s.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
High pressure will extend across the region through the period.
Expect another day of diurnal cumulus. Little variation from day
to day in highs or night to night in lows.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
The long term will open up on Monday with two upper level lows. One
upper level low over the Hudson Bay and another over Canadian west
coast. This far south only weak amplification in the flow will be
present with mostly dry conditions for Monday into Tuesday. Both the
GFS and ECMWF have a weak shortwave rounding the base of the upper
level low and pushing through Michigan Tuesday morning, but with
enough dry air in place (PWATs ~1.15" via GFS) the area will remain
mostly dry. The main question for Monday into Tuesday will be how
much we warm up. Monday 850 mb temperatures remain around 15 degrees
C and then start to warm towards 18 degrees C by Tuesday. The exact
timing of when the upper level disturbance will eject east is still
unclear though so have only nudged temperatures up into the mid 80s
for Tuesday.

Wednesday into Thursday models begin to diverge on how to move the
upper level low east out of the western Canadian provinces. The GFS
has slightly more amplified flow which would allow for more of
warming trend to take place into Friday. The ECMWF has a much more
zonal flow advertised. Either way shower and thunderstorm chances
look to return to the forecast area Wednesday as moisture rich air
washes northeast with a warm front (PWATs rising to around 1.80" via
GFS).

Thursday into Friday a weak surface cold front will move through the
area with drier air working in from the northwest. Uncertainty
remains high this far out though as both the GFS and ECMWF don`t
know exactly what to do with a mid-level ridge over the Florida
Panhandle and how much to amplify the ridge off the west coast. By
Saturday morning the ECMWF only has the front stalled across
northern Ohio. If this occurs rain chances will continue into the
weekend. For now have kept the area dry given the uncertainty.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
Still a few lingering cu across the area but these should
dissipate over the next hour or so as we continue to lose the
daytime heating. With clear skies and light winds overnight,
some br development will be possible, especially in the river
valleys across the south, mainly affecting KLUK. Otherwise,
surface high pressure will build east across the southern Great
Lakes through the day on Sunday with just some fair weather
cumulus clouds expected through the afternoon.

OUTLOOK...No significant weather is expected.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...JGL
SHORT TERM...
LONG TERM...Haines
AVIATION...JGL