Area Forecast Discussion
Issued by NWS Wilmington, OH-- Remove Highlighting --
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FXUS61 KILN 301101
Area Forecast Discussion
National Weather Service Wilmington OH
701 AM EDT Fri Sep 30 2016
A large upper level low will remain in place over the Ohio Valley
today, and then begin lifting north through the Great Lakes this
weekend. Under the influence of this upper low expect cool and
occasionally rainy conditions. Chances for rain will begin to
diminish on Saturday, as the low gradually begins to move to the
northeast. Drier and warmer conditions are expected for Sunday and
Monday, with surface high pressure building in from the west.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Upper level low evident on water vapor imagery centered over central
Kentucky this morning. Model solns generally similar with this upper
low drifting a little north into se Indiana by evening. As this
movement occurs best lift/moisture will pivot north into ILN/s
northern counties by late afternoon. Marginal instability,
especially around the periphery of this low will allow for an
occasional rumble of thunder. Cloudy skies and occasional rain
showers will keep temperatures around 5 degrees below normal today.
Expect highs in the mid and upper 60s.
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
The large upper level low will drift north into central Indiana
overnight. Best lift to remain around the periphery of this low but
can not rule out some scattered rain showers. Will continue pops
in the chance category tonight. Lows will be close to normal,
generally in the lower 50s.
On Saturday the upper level low will drift north toward the
Indiana/ Michigan border. Weak forcing in the form of low level
convergence rotates around this low into ILN/s fa during the day.
Therefore, will continue likely pops over the western counties.
Temperatures will continue to be cool with highs ranging from
upper 60s nw under the low to the lower/middle 70s southeast.
Will diminish rain chances Saturday night as the low drifts into se
lower Michigan. Again, lows look close to normal in the lower 50s.
As the lower drifts ene into srn Ontario Sunday expect to see
more in the way of sunshine. Still can not rule out a rain shower
with the best chance across the northeast counties. Will limit
pops to slight chance. Expect highs on Sunday to range from near
70 north to the lower/middle 70s south.
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
The 12Z ECMWF and the 12Z CMC are now maintaining a closed upper
low through a good part of next week as it shifts off to the east,
with the 12Z CMC slower pushing it east and even retrograding it
some back across Pennsylvania through mid week. Meanwhile, the 12Z
GFS continues it trend to weaken the upper low as it moves
northeast while building some ridging across our area through the
rest of the long term period. Likely as a result, there is also
quite a bit of variability on the track of Matthew with it
possibly riding up off the east coast through mid week. This all
spells out some uncertainty in our sensible weather as we progress
through the upcoming week. At this point will discount the CMC and
lean toward more of a blend of the ECMWF and GFS, which would keep
us mainly dry through mid week along with a gradual warming trend
each day. The ECMWF is faster than the GFS with a possible front
moving in through late week. Will again go with a blend and allow
for some lower chance pops to work in from the west through the
day on Thursday.
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --Slow moving low pressure in the upper atmosphere coupled with waves
of surface low pressure and persistent moisture will continue to
produce less than ideal flight conditions. Showers and
thunderstorms have developed early this morning in a band of lift
and convergence circulating around the upper low. Ceilings as low
as LIFR are accompanying the some of the showers and
Convection will likely continue and perhaps expand in coverage
today as instability increases a bit in limited daytime heating
under a cold pool aloft. As the low pressure system begins to
travel slowly northward, improvement to MVFR and then VFR is
expected by the end of the forecast period as somewhat drier air
moves in from the south. However, BR may reduce visibilities
again at ILN and LUK late in the forecast period.
Winds will stay light in the weak surface pressure gradient, with
direction shifting from northeast to southeast.
OUTLOOK...MVFR ceilings and visibilities possible with showers
through Saturday. IFR ceilings possible Sunday morning.
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