Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington Ohio
150 PM EDT sun Jul 13 2014
a cold front will slowly sag southeast into the region through
tonight. Showers and thunderstorms will be possible ahead of this
front. On Monday...this front weakens and moves southeast while
another cold front approaches from the northwest. The secondary
cold front is expected to pass east through the area Monday night.
An unseasonably cool airmass will then follow in the wake of this
front into middle week.
Near term /until 6 PM this evening/...
precipitation ahead of the front has weakened as expected. Still
anticipate redevelopment of convection this afternoon as
temperatures rise well into the 80s while dew points remain around
70 giving cape over 2000 j/kg. In the presence of moderately
strong winds aloft...some thunderstorms could become severe...with
damaging straight line winds the main threat in an environment of
unidirectional flow. Heavy rainfall will also be a concern in a
regime containing a slow moving front nearly parallel to the upper
flow...and precipitable water 150 percent of normal.
Short term /6 PM this evening through Tuesday night/...
for tonight...the front will become more ill defined as it sags
southeast into The Heart of the County warning forecast area. Do not like the NAM/GFS grid
scale feedback which blow up high quantitative precipitation forecast values across the southern zones
toward morning. As such...have gone with the convection allowing
models which suggest that convection should diminish in coverage
toward Monday morning across the southern zones. The northern
zones are expected to remain dry overnight. Highs today will be
tricky due to clouds/pcpn. This calls for a bias corrected blend
which yields highs from the lower 80s northwest to near 90 southeast. Overnight
lows will range from the middle 60s northwest to the lower 70s along and
south of the Ohio River.
A large scale anomalous middle level closed low is still forecast to
dig southeast into the western Great Lakes on Monday. This process
should shift first area of convection/convergent axis southeast
of the region while a secondary cold front approaches the region
from the northwest. There still remains uncertainty on the amount of low
level convergence that is expected with the secondary front as it
enters our western County warning forecast area late in the day or early evening. As such...have
kept probability of precipitation in the chance category on Monday with 50 percent
employed across the west for showers/storms. Highs on Monday will
be a little cooler in most spots...ranging from the lower to middle
For Monday night into Tuesday...aforementioned upper level closed
low will traverse slowly across the Great Lakes. The cold front
will push east through the region Monday night and should be out
of the area by Tuesday morning. Will continue the chance for
showers/storms until frontal passage. After that...we should be in
the dry slot behind the front with partly cloudy skies expected on
Tuesday. The cool down will begin on Tuesday with highs ranging
from the lower 70s northwest to the middle 70s southeast.
For Tuesday night...partly cloudy skies are expected as weak surface
ridging moves into the area. Lows will be cool and will approach
record lows for July 16. Lows will bottom out into the lower and
Long term /Wednesday through Saturday/...
high pressure and an unseasonably cool airmass will settle into
the region through midweek. The cool airmass could allow for a
few diurnal showers during the afternoon/early evening
Wednesday and possibly even Thursday. However...chance and
coverage appears low enough at this point to leave out of
forecast. The airmass will remain on the cool side Wednesday into
Thursday as it gradually modifies with highs into the middle to
possibly upper 70s by Thursday. High pressure will then slide off
to the east through the end of the week. As we transition into
return flow...highs by Saturday will slowly moderate back into the
Aviation /18z Sunday through Friday/...
convection developing along a slow moving cold front will impact
taf sites. Conditions may include MVFR ceilings and IFR
visibilities...along with isolated wind gusts over 30 knots.
Activity will show a weakening trend this evening with loss of
After a lull in convection late tonight with winds becoming
west...more showers and thunderstorms may ignite on Monday as
winds back to southwest and instability returns.
Outlook...thunderstorms are possible early Monday night.