Area Forecast Discussion
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FXUS61 KILN 270600
Area Forecast Discussion
National Weather Service Wilmington OH
200 AM EDT Thu Apr 27 2017
A cold front will approach the region tonight and move across
the area on Thursday. High pressure will briefly build in behind
the front. Then conditions will become unsettled over the
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A few thunderstorms may briefly edge near extreme northwestern
portions of the forecast area early this evening, otherwise
expect dry conditions for most of the night. Showers and
isolated thunderstorms will begin to move into the region
towards the end of the near term as a cold front approaches.
Winds will pick up during this time as well. With southerly flow
winds are only expected to drop into the 60s overnight.
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
Initial short wave will track northeast through the area during
the morning. This will take scattered showers and perhaps some
thunderstorms along with it. 12Z guidance has become less
organized with this first round of precipitation and cannot
justify anything higher than chance PoPs. Although low clouds
will be left behind the precipitation, it does appear that some
instability will develop as cooler temperatures aloft associated
with a short wave trough spreads across the region. This may be
sufficient for new development of showers and thunderstorms as a
cold front crosses the area. At this point, expect activity to
be scattered at most. High pressure will build in Thursday night
allowing for skies to clear. Expect sufficient cloud cover to go
a bit below guidance for highs Thursday while MOS seemed
reasonable with lows Thursday night.
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Friday morning is the calm before the storm, as the day starts
off dry. Some weak shower activity is possible nw of I-71 Friday
afternoon. Highs on Friday will range from the lower 70s in the
nw to upper 70s along the Ohio River.
While all models are suggesting a widespread rain event in the
Ohio Valley beginning Friday night, there continues to be a
large spread in the timing and placement of the heaviest QPF. Models
bring a swath of convection ne into the region Friday night along
a developing frontal boundary. It appears that the best chance of
rain by 12Z Saturday while be across central Indiana into the
Whitewater and upper Miami Valleys.
The boundary tries to buckle northward on Saturday, pushing the
better chance of rain to the north and northwest of the fa.
Still held onto chance PoPs in case something pops in the warm
sector. The region will see a wide range of highs for Saturday,
with southern section making the mid 80s, while the nw counties
will be held around 70 or the upper 60s due to the clouds and
As a deep H5 low kicks out of the Rockies on Sunday, the warm
sector will expand northward. An isolated shower will be
possible and highs will be in the upper 70s to lower 80s.
Models have adjusted the timing of a strong cold front passage.
The 12Z run now have the front around the Ohio/Indiana border
around 12Z Monday. Expect a line of showers and thunderstorms
late Sunday night and Monday morning with fropa. It looks like
highs will be early in the day with falling temperature during
Temperatures will be much colder behind this front for the
middle of next week. Highs will be down into the 60s. Models are
now suggesting that precipitation might try and develop along
the Ohio River for the middle of the week.
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
As low pressure lifts north toward eastern Lake Superior today,
a cold front will advance east across the region. Before any
precipitation arrives toward the western terminals by sunrise,
we first must deal with winds increasing along with a strong low
level jet aloft. The strong low level jet requires at least a
period of non-convective LLWS at the terminals roughly between
06Z and 12Z.
For today, high resolution models/convection allowing models are
really backing off on precipitation coverage ahead of the front
across our western forecast area. Also, instability is expected
to be fairly low this morning. As a result, just have a chance
of showers for western terminals this morning. It is unclear if
ceilings will lower into the MVFR category west due to lack of
widespread rain. Have kept ceilings VFR. As the front moves east
this afternoon, there may be enough diurnal instability for a
chance of thunderstorms toward the KCMH/KLCK. Winds will be
gusty with a subtle shift in wind direction from south to
southwest behind frontal passage. Expect wind gusts in the 25 to
30 knot range.
For tonight, front will be east of the area. Weak surface high
pressure will build briefly into the middle Ohio Valley. Post
frontal stratocumulus clouds should scatter through the evening
with some mid and high level clouds arriving from the southwest
aloft. Gusty winds should diminish fairly quick after sunset.
OUTLOOK...MVFR ceilings and visibilities with a chance of
thunderstorms are possible Friday night into Monday. Wind gusts
to 30 kt possible Sunday through Monday.