Area Forecast Discussion
Issued by NWS Wilmington, OH-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KILN 131833
Area Forecast Discussion
National Weather Service Wilmington OH
133 PM EST Fri Jan 13 2017
Increasing southwest low level flow will allow for precipitation to
develop across the region later this afternoon and into tonight.
With temperatures near or below freezing, periods of freezing
rain will be possible tonight into Saturday morning.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --Showers moving across southern Indiana and Kentucky will affect
the far southern counties late this afternoon with light rain.
Otherwise clouds will continue to increase. Temperatures may rise
another degree or two.
-- End Changed Discussion --
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
Southwesterly low level flow will continue through tonight and
increase a bit through the overnight hours with a fairly
persistent 20-30 knot 850 mb low level jet nosing up toward the Ohio
River into Saturday morning. This will keep central and southern
portions of our fa in an extended period of isentropic lift
tonight into Saturday morning. As we continue to warm in the mid
levels, any mixed precipitation should continue to transition
over to all liquid across all but possibly our far northern areas
overnight. However, some model differences exist as to the
northward extent of the better pcpn overnight with the 00Z CMC and
00Z GFS taking the better pcpn up to just north of I-70 while the
00z NAM and moreso the 00Z ECMWF keep it farther south. Several of
the higher res models are suggesting the more northern solutions
may be correct, but then the 00Z NSSL WRF is farther south. Will
therefore take likely pops up to just north of I-70 and then trim
back to just chance across our far north. Surface temperatures
across our north will be cold enough that any liquid pcpn will
fall as freezing rain. This makes the northern extent of the
freezing rain advisory a bit tricky and for now will generally
limit it to areas where we have at least likely pops. This will
give some wiggle room to later shifts depending on how later
models trend. Meanwhile across the south, the limiting factor
will be the surface temperatures as readings may struggle to drop
below freezing. As a result, the southern extent of the advisory
is a little tricky too. Here, we have used the forecast southern
extent of the freezing surface temperatures as the cutoff for the
advisory. This will again allow later shifts to tweak farther
south if necessary. Of interest is that the METRo road model
actually keeps road surface temperatures above freezing tonight
from about Franklin County Indiana over to Ross County Ohio and
points south. If this ends up being true, it would likely help
limit the travel impacts across southern portions of the advisory
Light northeasterly surface flow will keep temperatures from
rising too much through the day on Saturday but they should
eventually push above freezing across the north through the
afternoon. This should allow for any lingering pcpn to transition
over to all rain before tapering off as drier air begins to work
in from the northwest. The drier air will continue to push south
Saturday night so will drop back to just slight chance pops across
the south overnight. The low level flow will back around to the
southwest through the afternoon with some weak isentropic lift
redeveloping from the southwest. This will allow for chance pops
to spread back up across the area Sunday afternoon. Any pcpn looks
to be fairly light, but temperatures may be cold enough to support
some additional light freezing rain later saturday night into
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Non-diurnal temperature trends will inhibit any chances of ZR
over the northern CWA early on Monday, and the subsequent warm air
push will keep rain as the wxtype from that point onwards.
By Monday night and especially Tuesday, the surface low tracks
northeast into the Great Lakes region and drops a cold front and
subsequent surface low development in the lower Mississippi Valley.
This continues to bring an ever-increasing threat for persistent
rainfall on Tuesday, possibly becoming moderate rain overnight.
Added moderate rain to the forecast between 3 and 14z Wed where pops
On Wednesday, a cold front will track east through the Ohio Valley
and any rain will end from northwest to southeast during the day.
Latest runs of the GFS hang the cold front back over southern CWA
Wednesday and the European keeps the surface circulation in eastern
Ohio and a threat for rain over southeastern CWA, decreasing through
Wednesday night. Thursday shows a weak surface low tracking sw-ne
through CWA and an increased chance of rain.
Ran with slightly warmer than guidance on temperatures in the warm
sector for the bulk of the extended forecast.
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
-- Changed Discussion --Linger low clouds will continue to scatter early in the period.
Rain tracking south of the terminals will spread into the
Cincinnati area before 00Z and then diminish in the evening. Light
precipitation will then be possible across the entire region
overnight. Not enough confidence to go with much more than VCSH.
But any precipitation north of the Cincinnati area may occur as
freezing rain, so light icing is possible at other terminals, even
with just passing patchy light precipitation. Ceilings will lower
from south to north after 00Z eventually falling to IFR at all
sites expect the Columbus area, which will stay MVFR.
OUTLOOK...MVFR/IFR ceilings and MVFR visibilities are possible at
times Saturday afternoon through Tuesday.
-- End Changed Discussion --
OH...Freezing Rain Advisory from 7 PM this evening to 1 PM EST
Saturday for OHZ042-051>056-060>065-070>074-077>080-082.
KY...Freezing Rain Advisory from 7 PM this evening to 1 PM EST
Saturday for KYZ091>093.
IN...Freezing Rain Advisory from 7 PM this evening to 1 PM EST
Saturday for INZ050-058-059-066-073>075.