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Area forecast discussion 
National Weather Service Wilmington Ohio
644 am EDT Monday Jul 25 2016

Synopsis...
showers and thunderstorms will be observed in the hot and humid
air mass which is in place, ahead of cold front which will move
through the region this afternoon. This front will stall out
across Kentucky, bringing a continued threat for storms across
southern portions of the region Tuesday and Wednesday. The front
is expected to lift north as warm front, as a wave of low pressure
tracks through the Great Lakes late in the week. This will bring
the threat for widespread thunderstorms Thursday night and Friday.

&&

Near term /until 6 PM this evening/...
upper level ridge stretches east from the Central Plains into the
Ohio Valley with band of westerlies across the upper Mississippi
Valley and Great Lakes. Progressive shortwave trof to pivot east
through the Great Lakes flattening the northern portion of the
ridge. This will allow a surface cold front to drop southeast
though the Ohio Valley this afternoon.

Numerical models continue to have a difficult time pin pointing
storms in weakly forced, unstable airmass in the warm sector.

Ongoing mesoscale convective system tracking east across Indiana is weakening. However,
outflow boundary well ahead of this feature has lead to new
convection over se Indiana where blyr CAPES values of 2000-2500
j/kg exist. Expect a few storms to continue to fire along this
outflow boundary and then become more numerous in coverage later
today with blyr CAPES of 3000-3500 j/kg expected across southern
Ohio/northern KY ahead of the approaching cold front. Have high
chance pops Jump Up to likely across the south this afternoon in
this favorable environment. In this environment where strong
instby is expected a few storms may become severe with damaging
winds being the primary threat. Will continue to mention this
threat in the severe weather potential statement product.

Heat again will be a factor today across the south where highs
are expected to be in the lower 90s. These hot temperatures
combined with dewpoints in the lower and middle 70s will result in
heat indices of 100 to 104 degrees. Therefore, will continue
previous heat headlines.

&&

Short term /6 PM this evening through Wednesday/...
surface cold front to push south of the Ohio River and stall out
south of the Ohio River tonight. Storms will end from the north
across all but the far south overnight. Temperatures will be a
little cooler with lows from the mid 60s north to the lower 70s
south.

Surface cold front to stall out east-west just south of the Ohio
River at the south end of the mid level westerlies. This front
will be the focus for diurnal storm development Tuesday. Will
mention this potential along and south of the Ohio River. Further
north, drier air should inhibit thunderstorm development. Highs on
Tuesday will be slightly cooler and generally in the mid and upper
80s.

Weak surface high pressure to build acrs the Great Lakes with a
continued threat of showers and thunderstorms along and south of
the Ohio River Wednesday. Have limited mention to slight chance.
Generally expect highs in the upper 80s Wednesday.

&&

Long term /Wednesday night through Sunday/...
boundary will lift north as a warm front late Wednesday night
into Thursday. This will allow precipitable water values to
increase northward, placing the County Warning Area back in a very moist
environment for Thursday.

Models show a shortwave approaching late Thursday or Thursday night.
Timing is still somewhat in question, but there is decent consensus
on the track which will bring it across the Ohio Valley. Therefore,
begin to increase pops for Thursday afternoon and will continue
chance pops into Thursday night for possible influence from
shortwave.

Additional shortwaves may affect the Ohio Valley Friday through
Saturday. Details associated with the shortwaves (such as
track/timing/strength) are in question and will need to be resolved
with time. But the potential for shortwaves combined with a warm
moist air mass means that chance pops for convection will continue
through at least Saturday. Eventually, a cold front may move through
and this could occur late Saturday into Sunday but confidence is low
on the timing of the frontal passage.

Temperatures are forecast to favor near average to slightly above
average values through the long term.

&&

Aviation /12z Monday through Friday/...
cold front lies across Illinois, moving toward Ohio.
Thunderstorms that developed in the very humid airmass along and
ahead of the front have now dissipated west of taf sites. VFR
conditions are forecast to persist through the early part of the
taf period.

Thunderstorms are expected to develop in the vicinity of taf
sites this afternoon as forcing increases near the approaching
front, while instability rises toward daytime maxima. The chance
for thunderstorms will then linger into evening as the front
makes its way toward the Ohio River. Will issue amendments to
better indicate timing and effects of thunderstorms closer to
their time of occurrence. Look for improving conditions late in
the forecast as instability drops off with loss of daytime
heating. Winds will generally out of the west with speeds close to
10 knots during the afternoon. Br may reduce visibility at iln and
luk late in the forecast. Cvg should see VFR and light northwest
winds after 12z Tuesday.

Outlook...thunderstorms possible Thursday.

&&

Iln watches/warnings/advisories...
Ohio...heat advisory until 8 PM EDT this evening for ohz073-074-
078>082-088.
Excessive heat warning until 8 PM EDT this evening for ohz077.
Kentucky...heat advisory until 8 PM EDT this evening for kyz089>100.
In...heat advisory until 8 PM EDT this evening for inz075-080.

&&

$$
Synopsis...Arkansas
near term...Arkansas
short term...Arkansas
long term...bpp
aviation...coniglio

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