Information is from the NWS Wilmington, OH Office

ILN Area Forecast Discussion/SKEW-T

FXUS61 KILN 181904

Area Forecast Discussion
National Weather Service Wilmington OH
304 PM EDT Fri Aug 18 2017

An upper level disturbance will move through the region on
Saturday bringing showers and thunderstorms to the region. High
pressure will then be in place for Sunday and Monday. A cold
front will approach the region on Tuesday bringing a return of
precipitation to the area.


The cold front and shower activity have moved east of the area
therefore expect dry conditions for the remainder of the
evening and through a large portion of the overnight hours. CAA
cu will dissipate this evening, however there will be an
increase in clouds during the overnight hours in advance of the
next system. An upper level disturbance will begin to bring
precipitation to northwest portions of the forecast area at the
end of the near term.


A decent upper level disturbance will move through the region on
Saturday. The limiting factor with this system will be that
there is not a lot of moisture with this system, however given
the support with this system and model agreement, increased
precipitation chances across northern portions of the region.
Precipitation chances will be less along and south of the Ohio
River. It looks like there will be an initial round of
precipitation that works through the area Saturday morning,
then there will also be the potential for additional
thunderstorm development across extreme eastern portions of the
forecast area with daytime heating during the afternoon. There
is some instability during the day therefore went with a chance
thunderstorm mention as well. Cannot rule out an isolated
damaging wind gust or large hail across extreme eastern portions
of the forecast area with the afternoon development, however
the more likely scenario would be small hail and some gusty

Went close to conshort for highs which is close to the cool
side of guidance values. With extensive cloud cover expected
with this system and the timing of this system, believe that
most locations will be limited to the upper 70s to low 80s.
Locations along and south of the Ohio River where there will be
less cloud cover and precipitation will see potentially higher
temperatures around the middle 80s.

Winds will pick up during the afternoon as the system begins to
pass through and some wind gusts around 20 mph outside of
thunderstorms will again be possible. Winds will quickly
diminish during the evening hours and cloud cover will begin to
decrease. This will allow for temperatures to drop down into the
upper 50s to low 60s across the area.


Models are in good agreement that a surface high pressure will be
centered over the region Sunday morning. This will bring mostly
sunny skies and seasonable temperatures in the mid to upper 80s.

The center of the high will pull east of the region Sunday night,
allowing a little of a return flow for Monday/Eclipse Day. There
should be some cumulus development in this flow, but the clouds
shouldn`t spoil the viewing. Kept the forecast dry, but there is a
model or two that pops a shower on Monday.

A more substantial chance of rain will develop Tuesday into Tuesday
night as cold front swings through the Great Lakes and Ohio Valley
ahead of a strong H5 s/w. 12Z models are a little slower with the
system on Tuesday, so adjusted the timing back. The best chance of
thunderstorms will looks like Tuesday afternoon into Tuesday night.
Upped PoPs to likely to cover this system.

Behind the front Wednesday, a cooler and drier airmass will begin to
settle in for the later half of the week.


Cold front and associated shower activity is east of the TAF
sites therefore expect dry conditions for the remainder of the
day. An upper level disturbance will approach the region
tonight and work into the TAF sites on Saturday. Although there
are dry low levels a decent upper level disturbance will allow
for some shower activity across the region. Cannot rule out
thunder, however expect thunder to be limited and therefore
decided not to include at this time. Isolated wind gusts around
20 knots will be possible this afternoon and also tomorrow

OUTLOOK...Thunderstorms are possible on Tuesday.






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