Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington Ohio
418 PM EDT Tuesday Sep 30 2014
a cold front pushing through the area will continue to nose into
Kentucky and West Virginia this evening. A narrow ridge of high
pressure in the middle atmosphere Wednesday night will mark the
return to southerly flow in the Ohio Valley. Warm air will be
pulled into the region ahead of the next front that will cross
Near term /until 6 am Wednesday morning/...
showers have exited the area with the lone exception of Hocking
County which will see them dissipate within the next hour. Fairly
solid stratus over much of the northern half of County Warning Area will be tough
to scour out this evening and could last the better part of the
overnight in central Ohio. With the core of the cold air running
from Kiln and to the northwest...there should be enough moisture
and turnover in the lower atmosphere to warrant the possibility of
some sprinkles in central Ohio tonight. Temperatures will hold
steady and experience a very slow drop where the cloud cover
is...and drop much more quickly where it is currently warmer and
sunnier this afternoon. A large temperature gradient behind the
front has readings range from the middle 50s in the north to lower
80s in the south.
Temperatures tonight will be tricky but the conglomeration of models were
indicating the coldest intrusion to be over Richmond in with the
axis keeping north of metropolitan Cincinnati and running towards Kiln.
Short term /6 am Wednesday morning through Thursday night/...
cold pool axis will migrate from Richmond/Wilmington to
Toledo/Zanesville during the day Wednesday with generally clear
skies expected everywhere on the southwest side. This will leave a
cloudy period early in central Ohio that will break up in the late
morning...enough to push highs to at least 70 degrees...likely
lower 70s. South of and along Ohio River will see readings well
into the middle and even upper 70s.
Forecast is in fairly solid shape for this period until the next
cold front crosses the region Friday morning. Things should stay
dry and warm ahead of the front...with showers and some
thunderstorms expected to really be on the increase after midnight
Thursday. This north-S oriented front will move east and the warm air
ahead of it will be driven by a low level nocturnal jet of 40kt or
so right off of the deck. PM lows Thursday night will be
mild...about a 10 degree jump from the previous nights with mild
lows in the low to middle 60s.
Long term /Friday through Tuesday/...
the cold front will be just on the doorstep of the western County Warning Area at
the start of the extended forecast period. The 30.12z NAM and
Canadian push the front through a bit faster than the GFS and European model (ecmwf).
Additionally...the last few runs of the GFS/European model (ecmwf) have been slowing
the front down a bit while the Canadian has been speeding it up.
Have gone with a blend of these deterministic models with a little
more weight given to the European model (ecmwf) for its slightly better run to run
With strong low level southerly flow ahead of the front...lower 60
dewpoints will be advected into the region. Forcing from the front
and a deepening upper level trough will allow for showers and
embedded thunderstorms Friday morning...tapering off from west to
east during the afternoon and evening. Additional shortwaves
rotating around this trough will result in chance or slight chance
probability of precipitation at times through the weekend and into early next week. With the
upper trough becoming established over the region on Saturday...
temperatures will drop well below normal with highs in the middle to
upper 50s. Lows Saturday night are forecast to be within a couple
degrees of either side of 40. Temperatures will moderate a bit
Sunday through Tuesday with highs back in the 60s.
Aviation /20z Tuesday through Sunday/...
precipitation associated with the quick moving 500 mb short wave has pulled east of
kcmh/klck. Meanwhile Post frontal IFR stratus has slowed its
southward progress and is now looking like it wont reach the southern
tafs. That leaves the big question of what will happen to the
stratus this afternoon and into tonight. Models are showing their
typical spread of either clearing things out or lingering the
stratus into tomorrow.
Based on the cold air pool behind the fnt...have decided to linger
the stratus across the northern tafs through the night...while allowing
kcvg/kluk to scattered out overnight. Kiln will be the tricky
location. Does the stratus expand down into Kiln overnight as the
southern edge is just to the north. Decided to keep the stratus north
of the Kiln...but brought MVFR/IFR fog in after 06z. In the northern tafs
lowered visibilities down to IFR towards Sunrise. Valley fog should bring
kluk down to IFR conditions overnight...with possible MVFR fog
Expect improving conditions late Wednesday morning.
Outlook...thunderstorms possible Thursday night and Friday. MVFR
ceilings possible Friday night and Sunday.