Area Forecast Discussion
Issued by NWS Wilmington, OH-- Remove Highlighting --
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FXUS61 KILN 181717
Area Forecast Discussion
National Weather Service Wilmington OH
1217 PM EST Sat Feb 18 2017
A few rain showers will possible this afternoon and this evening across
southern Ohio and northern Kentucky, as an upper level disturbance
tracks through the Tennessee valley. Temperatures are expected to
be 20 to 25 degrees above normal, today through Tuesday, with the
next chance for rain showers Tuesday with the approach of a front.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Low pressure can be seen on water vapor this morning rotating
over Arkansas with only a weak surface reflection. Latest KILN
sounding revealed 850 mb temperatures at 10 degrees C with a
PWAT of 0.27". The upper level low will push east this afternoon
with the highest chance of precipitation across our far
southern zones. The best lift from the low will remain south
with only a deformation band/ weak WAA across the southern
zones. PWATs on the GFS/ NAM all appear to aggressive with
values for KILN above what the 12z sounding showed. Also, 850
mb temperatures of 10 degrees C will allow surface temperatures
to quickly rise into the 60s today. Clouds will move in from
the south though which should help us from completely realizing
that 850 mb temperature.
In warm sector mid level ridge to flatten some and slide off to
the east. Meanwhile, southern mid/upr level low over the
southern Plains to to open up some and track east into the
Tennessee Valley. Mid/high level clouds will increase through
the day ahead of this system. Model solution differences exist
regarding how far north the rain showers will make it. GFS/ECMWF
solns differ on timing some but both bring northern periphery of
pcpn associated with 700 mb deformation zone into northern Ky
and far southern Ohio. NAM soln is an outlier and is further
south. Will side with consensus of GFS/ECMWF solns which have
better continuity, bringing chance pops of rain showers into
the far south this aftn into this evening. Expect highs to be
around 20 degrees above normal, generally in the lower 60s.
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
Mid/upper level trough to track east through the TN Valley this
evening with rain showers across the southeast counties coming
to an end. Weak surface ridge across the region with weak front
dropping into northern Ohio. In weak flow pattern, low clouds
look to linger tonight especially across the southeast. Lows
will be mild, with readings above normal highs. Expect lows from
the lower 40s north to the upper 40s south.
Sharp full latitude mid level ridge to build into the MS Valley
and western Great Lakes Sunday as weak surface ridge slides
east. Lingering morning clouds, especially across the southeast
will give way to increasing sunshine in the afternoon. Warm high
temperatures to be 20 to 25 degrees above normal, ranging from
the lower 60s north to the mid/upper 60s south.
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
For Sunday night and Monday, surface high will be centered to the
northeast, with the axis of a high amplitude upper ridge crossing
the ILN area. This regime of scant moisture and forcing points to a
warm and dry period to start the long term. Next system to produce
precip will be a front extending from the polar regions into the
tropics. This front has been very consistently represented on models
for several days, raising confidence that showers will be moving in
Tuesday afternoon through Tuesday night. Weak temperature gradient
and lack of cold air aloft should keep thunderstorms from
High pressure and a dry airmass are forecast to return Wednesday.
For Thursday, some increase in moisture along a developing warm
front may produce a few showers. Showers will be likely and
thunderstorms possible Friday along a strong cold front swinging in
from the west.
Geopotential surfaces that will be well above normal for February,
coupled with a southerly surface flow carrying warmer air, will
produce temperatures that are far above normal. Highs in the 60s
each day will contrast with normal highs in the lower to middle 40s.
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
-- Changed Discussion --All TAF sites are currently VFR with mid and high clouds
increasing across northern Kentucky. Weak returns are appearing
on the radar this afternoon and will likely remain near and
southeast of interstate 71. This is thanks to weak isentropic
upglide and a weak 700 mb deformation band. High res models also
in general support this with better coverage south and east. By
6z Sunday morning any precipitation that does form will be
starting to exit the region. Sunday morning a weak frontal
boundary will sag and stall just north of KDAY. Not surprisingly
right ahead and along the front high res models are restricting
visibilities and ceilings. The SREF probabilities also support
this. Later Sunday morning lower PWAT air will filter into the
northern zones (GFS PWATs < 0.5") and help to clear some of the
low clouds out (esp. towards CMH/LCK). Further towards the south
and west the lower PWAT air will not ever make it. Due to this
some high res models never clear out KCVG/ KLUK and keep them
MVFR. Overall think this is overdone. Most likely KCVG/KLUK will
eventually breakout Sunday afternoon.
OUTLOOK...MVFR ceilings are possible Tuesday and Thursday.
-- End Changed Discussion --
Record High Temperatures
Date CVG CMH DAY
Sat 2/18 68(1948) 63(1948/1994/2011) 64(1948)
Sun 2/19 74(1939) 70(1939) 70(1939)
Mon 2/20 72(1891/2016) 68(1891/2016) 69(2016)
Tue 2/21 70(1930) 71(1997) 68(1930)