Area Forecast Discussion
Issued by NWS Wilmington, OH-- Highlight Changed Discussion --
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FXUS61 KILN 202339
Area Forecast Discussion
National Weather Service Wilmington OH
739 PM EDT Thu Oct 20 2016
Occasional showers will continue into tonight before tapering off
through the day on Friday as a cold front pushes slowly through
the area. A much colder airmass will filter into the region behind
the front with below normal readings expected for Friday and
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
The frontal boundary is pushing slowly southeast across our area
this afternoon, currently situated along or just southeast of the
I-71 corridor. Cloud cover across the region has helped to limit
instability this afternoon and as a result, the severe threat
looks fairly slim through the rest of the day. That being said,
there is some weak instability present across southeast portions
of our forecast area so will hang on to a chance of thunder there
through the rest of the afternoon before tapering it off early
this evening. Meanwhile, the upper level trough will shift east
across the area tonight with an associated 850-500 mb deformation
axis pivoting slowly east into our area. Pcpn associated with
this feature is currently lifting up across eastern Indiana into
northwest Ohio and this should very gradually work its way east
across our area tonight.
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
The upper level trough and the deformation axis will continue to
shift off to the east through the day on Friday. This will allow
for light showers to gradually taper off from west to east across
the area through the day. In northerly low level flow on the back
side of the trough, decent CAA will persist through the day with
850 mb temperatures dropping down below zero degrees celsius by
late afternoon. The combination of this and some lingering clouds
should help limit temperatures through the day with highs only in
the low to mid 50s.
Northwesterly low level flow will continue Friday night and this
could allow for a few lingering clouds as we get a bit of a fetch
off of Lake Michigan. Lows Friday night will be dependent on the
amount of cloud cover and whether or not the winds stay up a
little. For now will go with lows in the upper 30s to lower 40s
but if we end up with more clearing and light winds, this may be
too warm and frost would become a concern. Surface high pressure
will begin to build up into the Tennessee Valley through the day
on Saturday. This will lead to dry conditions heading into the
weekend but with the cold air mass still in place, expect highs on
Saturday only in the mid 50s.
.LONG TERM /SUNDAY THROUGH THURSDAY/...
On Sunday the upper level low and trough axis will be over the
Northeast United States with surface high pressure located over the
Southeastern United States. 850 mb temperatures will slowly rise to
just below 10 degrees C which will support high temperatures in the
mid to upper 60s. Sunday night into Monday morning a shortwave will
push southeast down mid-level ridging and around the upper level
low. The GFS is slightly more progressive and weaker with the
shortwave compared to the ECMWF. Both 20.12z model runs bring the
shortwave slightly further west than yesterday and therefore try to
bring the heart of the colder air slightly further west as well. The
ECMWF and the GFS push the front through the area by Monday evening.
The frontal passage also appears to be a dry frontal passage as PWATs
remain around 0.60". Behind the front highs will cool down back to
normal as the heart of the cold air still misses the area (850 mb
temperatures around 4 degrees C).
Tuesday the upper level trough will finally head east of the area
taking the cooler air with it. Wednesday into Thursday a shortwave
will eject out of the midwest and approach the area. This means
clouds will begin to increase on Wednesday and into Thursday. Have
also introduced a chance of rain into the forecast Thursday as the
low approaches. PWATs on the GFS rise to above 1.00" with limited
instability. Upper level forcing looks good though as the ILN
forecast area is in the diffluent side of the trough axis and
widespread PV moves over the area. For now have just edged the
chance of precipitation up as model consistency remains low at this
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --Cold front and waves of low pressure are now east of TAF sites,
leaving a moist northerly surface flow. Showers in the vicinity
and in tempo groups will show a diminishing trend as the system
continues to shift farther east. Ceilings down into the LIFR range
will linger for the first several hours of the forecast period.
Drier air eventually working in behind the front will allow
ceilings to increase to the MVFR category starting around 10z.
Continued improvement to VFR will be possible by Friday afternoon
at CVG and LUK, while other sites may see MVFR linger through the
end of the forecast. North winds will become brisk, with gusts
above 20 knots.
OUTLOOK...No significant weather expected.
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