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Area Forecast Discussion (AFD)

Issued by Wilmington, OH (ILN)

FXUS61 KILN 220912

National Weather Service Wilmington OH
512 AM EDT Sat Jun 22 2019

An unsettled weather pattern will be in place through Monday
night with several systems moving through the region. High
pressure and dry conditions will briefly work into the region
for Tuesday before another system brings a return of
precipitation chances on Wednesday.


A complex of thunderstorms across Illinois will continue to move
towards the southeast. Expect most of the precipitation with
this system to stay southwest of the region, however the far
southwestern portions of the forecast area could see a few
showers and thunderstorms from this system. 

In addition, there are some bands and scattered shower activity
across the forecast area. There is an upper level disturbance 
that will continue to push southwards through the day and as it
does this will gradually push the shower activity further south.
There will be a little bit of instability near and south of the
Ohio River today and therefore cannot rule out a few
thunderstorms as well.

Went close to guidance for high temperatures today with high
temperatures in the upper 70s to around 80 degrees.


Most locations will remain dry tonight, however some shower and
isolated thunderstorm development will be possible across
western and southwestern portions of the region tonight due to
a weak disturbance moving through.  

The focus turns towards Sunday afternoon and into the evening
hours as a stronger disturbance approaches the region. Models do
differ on the details of this system including the strength of 
the system. Models are in general agreement however on that the 
best upper support with this system will be across northwestern 
and western portions of the region. 

The NAM is stronger with this system and one of more concern as
can be seen in the CIPS analog run. There is a clustering of 
solutions that highlight a damaging wind and at least isolated 
tornado threat across western portions of the region. This 
solution keeps surface winds backed to the southeast a little 
longer into the evening hours. Due to at least some potential, 
have a mention in of an isolated tornado possible across 
northwestern portions of the forecast area for Sunday. Have 
mention areawide in the HWO for damaging wind potential for 
Sunday afternoon into the evening hours. Will continue to 
monitor as models come more in line to fine tune the severe 
threat and severe threat area during this time. 

With soils already saturated and the potential for thunderstorms
on Sunday, there will be flash flood concerns with this system.

Also on Sunday, although the high temperatures are
generally only in the lower 80s, dewpoints will be in the upper
60s to lower 70s leading to some heat index values near 90. 


Convection will continue into Sunday evening with some remnants 
persisting into the overnight hours. A short wave will slowly 
deamplify as it lifts up the Ohio Valley into the eastern Great 
Lakes Monday into Monday night. This will bring another round of 
showers and thunderstorms. Very moist environment coupled with 
saturated ground will lead to additional flood potential. Also 
cannot rule out some strong to severe storms. While the bulk of the 
convection will move east by early Monday evening, there could be 
some additional showers overnight Monday night as the mid level 
support swings through.

Broad mid level ridging will develop through the rest of the week 
with a trend towards higher heights into the forecast area. A 
disturbance passing north of the area on Wednesday could be strong 
enough to push a front south into the forecast area which would 
bring a chance of storms. This boundary will wash out Wednesday 
night with surface high pressure taking over through Friday. 

Lows will be above normal through the period. Highs will be closer 
to normal Monday and Tuesday, although Monday will be humid. Highs 
will then warm as upper heights rise with parts of the area getting 
into the upper 80s later in the week.


At the start of the TAF period there will be light shower
activity around the KCMH and KLCK TAF sites. This precipitation
is falling out of a mid deck of a clouds and therefore expect
precipitation to be very light. Transitioning through the
overnight hours these light showers will shift leading to the 
potential for light shower activity around KDAY and KILN. By 
morning this light shower activity will continue to be further 
south around KCVG and KLUK in addition to those TAF sites being 
on the edge of thunderstorm activity currently in Illinois. 
While thunder cannot be ruled out at KCVG and KLUK, the 
probability is low and therefore left out of the TAF sites at 
this time.

Extensive cloud cover across the region is expected to keep any
fog from forming during the overnight hours and therefore do not
expect any vsby restrictions.

OUTLOOK...Thunderstorms are possible at times from Sunday
through Monday night.