Scientific Forecaster Discussion
fxus61 Kiln 182030
Area forecast discussion
National Weather Service Wilmington Ohio
330 PM EST sun Nov 18 2018
a low pressure system moving through the Ohio Valley will bring
a chance of precipitation to the region tonight into Tuesday.
High pressure will then build into the region through mid week,
leading to dry conditions and a gradual warmup through Friday.
Near term /through tonight/...
clouds are now pushing back across the southern sections of the
fa, as the weak frontal boundary is slipping a little to the
The front will continue to sag slowly overnight. As a 500 mb S/W
swings east in the zonal flow, a surface low will develop in the
Mississippi Valley. Isentropic lift ahead of the low in srn
Ohio will produce an area of overrunning, which will be working
in from the southwest around 06z and then it will expand to the
northeast during the early morning hours. Upped pops to likely
in the cinci tri-state for tonight with decreasing pops on
either side of main band. Left the northwest counties dry.
Critical thicknesses are showing that the majority of the
precipitation will fall as rain. Some wet snow flakes will be
possible on the northern edge however.
Low temperatures tonight will range from the lower 30s in west
central Ohio to the lower 40s in northeast Kentucky.
Short term /Monday through Monday night/...
as the S/W swings through the upper Ohio Valley on Monday, the
sfc low will cross through srn Ohio. This will keep pops likely
across the south. The northern edge of the pcpn will spread back
to the north a little during the day on Monday. Similar to
Sunday night, the majority of the pcpn will be rain, except on
the northern edge where cooler air will produce a rain/snow mix.
Not expecting an significant accumulation however. Highs will
range from the upper 30s in the north to the mid 40s in the far
By Monday night the initial S/W will be east of the region in the
Appalachians. However, a digging longwave trof will swinging
through the Great Lakes. This will keep upper support and
therefore will delay the exiting of the pcpn to the east. A
rain/snow mix will linger in the east for much of the night.
Long term /Tuesday through Saturday/...
an upper level disturbance will be moving through at the start of
the long term period. Colder air will be working into the region
and therefore expect primarily light snow showers across the region
Tuesday morning. As the day progresses this feature pushes to the
east and with a wind trajectory shift any lake enhancement will cut
off. Cloud cover will decrease into the evening and overnight hours
allowing for temperatures to fall down into the 20s Tuesday night.
On Wednesday a weak frontal boundary will work into the area,
however moisture is very limited with this feature and therefore do
not expect any precipitation. High pressure will allow for
continued dry conditions for Thursday and Thursday night.
Late in the day Friday and moreso into Friday night precipitation
will begin to work into the region as the next system approaches.
Models are coming in quicker with this system overall, however there
are more model timing difference today than yesterday. In general
expect precipitation to be tapering down Saturday night.
There are some model timing differences with the late weekend and
into early next week system. With these differences decided to go
closer to the European model (ecmwf) which would be a slower solution and allowed for
dry conditions on Sunday.
Aviation /20z Sunday through Friday/...
VFR conditions have been dominant so far today as weak frontal
boundary has been slow to move. Latest satellite loop is now
showing that MVFR clouds are starting to develop in southern
Indiana and are moving to the east.
The front will sag slowly overnight allowing the MVFR and then
IFR ceilings to overrun the tafs. Latest mesoscale models are
showing that a sfc wave will lift up the front overnight. As
this occurs precipitation will push into the cvg/luk between
06z-09z. Thicknesses are showing that the pcpn will be rain at
the srn tafs.
IFR ceilings will linger after 12z and the pcpn will spread
northeast reaching the nrn tafs around the end of the period.
Outlook...MVFR ceilings will likely continue into Tuesday.