Scientific Forecaster Discussion
fxus61 Kiln 262005
Area forecast discussion
National Weather Service Wilmington Ohio
405 PM EDT Wed Jul 26 2017
low pressure and a cold front will approach the region on
Thursday and push through Thursday night into Friday morning,
bringing showers with embedded thunderstorms. High pressure
will gradually build in for the weekend.
Near term /until 6 am Thursday morning/...
increasing clouds and moisture overnight with the approach of
vigorous shortwave over the upper MS valley and into the western
Ohio Valley overnight. Southerly flow will allow for increasing
precipitable water values into the western forecast area
overnight, with leading edge scattered showers reaching the
western forecast area by daybreak.
Overnight lows tonight will be more seasonable in especially the
western area where reach to near 70 to low 70s with mid 60s
still in the east on the back side of the departing high.
Short term /6 am Thursday morning through Thursday night/...
for Thursday, decent ll shear but not a lot of support from an
instability standpoint, along with plenty of cloud cover and
relatively unimpressive lapse rates. So while the lingering
lower level support and some of the cams indicating surface low
tracking right along Ohio River, can't rule out the potential
for isolated severe storms with damaging winds, not as much of
a concern or confidence as previous forecast.
However, ample moisture and several hours of high precipitation
potential with precipitable water values approaching Max for this time of year
still yield a heavy rain potential. Concern is especially in
the south with areas more vulnerable due to recent flash
Ample cloud cover and precipitation will limit highs on
Thursday so continued to lean on the cooler side of guidance.
Long term /Friday through Wednesday/...
shortwave trof to drop southeast through the Great Lakes into the
upper Ohio Valley Friday. This will keep the threat of showers and
thunderstorms Friday into Friday night. Clouds and precipitation
will keep temperatures around 5 degrees below normal with highs on
Friday in the upper 70s to near 80.
Highly amplified mid/upper level flow pattern with ridge over the
west and trof over the east. This will place the Ohio Valley in a
northwest flow pattern this weekend. Surface high pressure of
Canadian origin will build southeast across the great. This high
will offer dry conditions and seasonably cool temperatures.
Temperatures Saturday and Sunday look to be 5 to 10 degrees below
normal, with highs generally in the mid and upper 70s.
As the surface high slide off to the east dry conditions will
persist into next week and temperatures will moderate. Expect
readings closer to seasonal normals through mid week.
Aviation /19z Wednesday through Monday/...
through 09-10z VFR conditions before showers move into the area.
Timing and exact locations/restrictions not confident at this
time to introduce visibility or ceiling restrictions, but some
possibility of MVFR visibility mainly after 12z with some
potential for heavy rain mainly after the 15z timeframe. For the
cvg extended taf, some potential for MVFR ceilings after 00z
Outlook...thunderstorms will be possible into Thursday night.
MVFR ceilings will be possible Thursday night into Friday.