Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wilmington Ohio
1258 PM EST Thursday Nov 26 2015
high pressure will continue to provide dry weather and above
normal temperatures today. A slow moving cold front will bring the
threat of rain Friday through Monday. Temperatures will stay above
normal on Friday before cooler air filters in Saturday.
Near term /until 6 PM this evening/...
latest radar loop is showing some light echos in southern Indiana. The
latest GFS and hrrr are showing that these might sneak into our
Indiana counties. Dont think they will be all that
significant...so just added a mention of sprinkles in the extreme
For the rest of the forecast...the previous forecast highs still
look good...so no changes there.
Short term /6 PM this evening through Saturday/...
clouds will continue to thicken tonight. Dry period is forecast
to end Friday when a slow moving cold front will push in from the
northwest. Deep moisture from the Gulf of Mexico will be
transported along the front...with showers developing in the
presence of frontal convergence and positive vorticity advection. Showers will reach most
locations including Cincinnati...Dayton and Columbus by Friday
evening. Showers may not reach far southeast counties until Friday
night. For Saturday...with the front located near the Ohio
River...showers will be likely in southern counties with chance
probability of precipitation farther north. Thunderstorms are not expected in an
environment that lacks sufficient instability. The prolonged
period of showers will cause streams to rise but flooding is not
anticipated through Saturday due to dry antecedent conditions.
Look for temperatures to stay near 60 Friday when warm air will
linger ahead of the front. Saturday will see cold advection behind
the front that is expected to drop readings back to near normal
low 40s north to middle 50s south.
Long term /Saturday night through Wednesday/...
as the southeastern ridge flattens...the moisture plume will
eventually shift to the south...with some disagreement on how much
of the forecast area ends up dry on Sunday. The 12z European model (ecmwf) kept a
more northerly solution...which seems to be in opposition to its
00z run and the 12z Gem/GFS forecast scenarios. A consensus
supports some degree of whittling away the probability of precipitation from the northern
sections of the forecast area on Sunday night and into Monday. A
slightly slower solution is also preferred with the eventual
progression of the upper low in the west...though rain chances
will again increase by Monday night into Tuesday as this system
moves through the Great Lakes and Ohio Valley. Based on gfse
spreads and the overall suite of model guidance...confidence in
the timing/placement/magnitude of the weather features beyond the
weekend is not particularly high.
Temperatures will drop significantly from Friday to
Saturday...thanks to the cold front moving south through the area.
However...with the warm starting point at the end of this
week...conditions will still end up very close to normal (perhaps
slightly below). A more significant drop in temperatures is likely
near the end of the extended forecast period (middle of next
week)...once the upper low ejects eastward and another cold front
Aviation /18z Thursday through Tuesday/...
tafs will remain warm sectored as models continue to trend slower
with front out over the MS valley. Therefore VFR conditions will continue
through the taf period. Area of 6kft clouds around Kiln will
gradually break up this afternoon...leaving just cirrus over the tafs
through the night.
Winds should lose their gusts around sunset...remaining southerly
around 10kts overnight. Gusts around 20kts will pick up again on
Friday after 14z.
Held precipitation out of the tafs for the next 24 hours...just adding a
vcsh at kcvg near the end of the 30 hour taf period.
Outlook...MVFR/IFR ceilings and visibilities possible Friday night into
Saturday night...then again Monday into Tuesday.