Area Forecast Discussion
Issued by NWS Wilmington, OH-- Remove Highlighting --
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FXUS61 KILN 210609
Area Forecast Discussion
National Weather Service Wilmington OH
209 AM EDT Fri Oct 21 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 THIS MORNING/...
The frontal boundary is now southeast of the area. Marginal severe
weather threat has diminished with decreasing forcing and
instability. Put slight chance of thunder back in after noticing a
few lighting strikes. 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 lifting up across western Ohio and
this should continue to very gradually work its way east across
our area tonight. Breezy conditions will be evident tonight in the
tight pressure gradient behind the front and gusts will reach
close to 30 mph out of the north. Lows will be in the upper 40s
to around 50.
.SHORT TERM /6 AM THIS 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 /06Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --A weak area of low pressure east of the terminals continues to
lift northeast away from the area. Waves of -SHRA will continue to
push northeast through the area during the overnight hours as the
deformation axis slowly pivots eastward. Have seen some
redevelopment of -SHRA west of main pcpn and hi-res models are
picking up well on this additional development. As such, have
added prevailing pcpn at all sites except KCVG and KLUK through
Latest model runs are suggesting that back edge of deformation
axis pcpn will be a bit slower to swing east through the area
during the morning and early afternoon. As such, expect pcpn to
come to an end around 14z for western sites of KDAY, KCVG, and
KLUK and around 18z for eastern sites of KCMH and KLCK. Heaviest
pockets of pcpn may result in brief MVFR VSBYs.
CIGs will hover around 1k ft across all terminals through 15z and
will likely bounce periodically between IFR and low MVFR during
that span. IFR CIGs will be more likely in pockets of higher pcpn.
CIGs will gradually go MVFR and potentially even VFR for western
sites during the afternoon. However, do think that CIGs will
remain MVFR across the east through at least 00z Saturday.
As the sfc low continues to pull away from the area, a tighter
pressure gradient will move in, allowing for
northerly/northwesterly winds of around 15 kts with gusts to 25
kts through the afternoon. Although the tight gradient will
persist longer for eastern sites into the evening, do expect a
gradual weakening trend past 00z Saturday.
OUTLOOK...No significant weather expected.
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