Area Forecast Discussion
Issued by NWS Wilmington, OH-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KILN 201327
Area Forecast Discussion
National Weather Service Wilmington OH
927 AM EDT Thu Apr 20 2017
A warm front will lift north from the Ohio Valley into the Great
Lakes region early this morning. A surface low pressure center
will cross east through Michigan and a trailing cold front will
spark thunderstorm activity later today and tonight. The front
will pass southeast of Ohio early Friday morning.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --A warm front is situated across northern Ohio this morning with
our area well into the warm sector. Given a fair amount of
sunshine and continued southerly flow, will nudge up temperatures
a few degrees for today with highs into the low to mid 80s.
This will allow us to destabilize through the afternoon. Expect
the best instabilities to be across our northwest late this
afternoon into early evening where some cooler air will start to
work in aloft. Most of the higher res models have trended a
little slower with the approach of the front and onset of
precipitation later this afternoon although the latest hrrr has
trended a little faster again. Nonetheless, expect some
thunderstorm development across western portions of our fa along
a weak prefrontal trough axis through mid to late afternoon.
This activity will work eastward through early evening with
some additional development possible along the actual front as
it moves in this evening. Expect the best severe threat to be
across our northwest where the better instabilities will
coincide with some better low and deep layer shear working in
from the northwest late in the day. The primary severe threat
will be damaging winds.
-- End Changed Discussion --
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
Storms will quickly race southeast in the evening ahead of the
front, which will cross the I-71 corridor after midnight,
marking the end to any lingering activity. Severe storms will
quickly wane and are not expected to be tapping a favorable
atmosphere after late evening.
Temperatures will fall into the 50s behind the front, with some
upper 40s found in northwestern CWA. Thunderstorms will lose any
instability before daybreak, so primarily showers are forecast
for the southeastern portions of the CWA by daybreak.
Cloud cover never quite clears up behind the front as storms
continue to fire over southern Kentucky during the day and upper
level flow remains west-southwest with a trailing longwave
trough still extending from the Great Lakes into the central
Plains. Surface high pressure will help usher in the colder air
and overnight lows Friday will drop into the 40s after daytime
highs only in the 60s. The better shot of cold air will occur
Saturday with highs topping out in the mid 50s as the upper
trough crosses south into the region and hangs up along the Ohio
Valley overnight Saturday.
The showers that were over southern Kentucky on Saturday are
expected to be pulled into southern and southeastern CWA on the
east side of the longwave trough. Showers that develop in this
area have a higher potential for prolonged moderate rainfall.
Have included a chance of thunder and moderate rainfall where
pops were likely and higher for Saturday. Overnight lows will
be in the 40s once again, and highs on Sunday will moderate
somewhat into the lower 60s.
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
High pressure and dry conditions are expected Sunday night into
Monday. A weak system moves through the region on Tuesday,
however moisture is limited and therefore kept precipitation
chances out of the forecast at this time. Dry conditions
continue through the daytime hours on Wednesday.
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
Some waa clouds have begun to form attm as moisture begins to
pool over the tafs early this morning. Expect them to remain VFR
however. River valley fog has formed at LUK. It is currently at
MVFR and is expected to dissipate quickly in the first hour of
The tafs will remain dry for a majority of today. Expect lower
clouds to be limited for the first part of the day, with mid and
high clouds coming and going. However sfc winds will increase
quickly this morning as mixing gets under the way in advance of
a cold front. Gusts around 25 to 30 knots will be possible
during the afternoon.
Focus then shifts to line of convection that is forecast to
develop across the lower Ohio Valley today and move into the
tafs. Models have remain consistent in the timing of bringing
storms into the tafs a little after 00Z. Storms should bring a
period of MVFR conditions between 00Z-06Z.
CDFNT passage will bring an end to the convection around 06Z and
will usher in MVFR cigs behind the front.
OUTLOOK...MVFR cigs possibly early Friday morning. MVFR
ceilings and visibilities possible Saturday.