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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KILN 222303
AFDILN

Area Forecast Discussion
National Weather Service Wilmington OH
703 PM EDT Sat Jul 22 2017

.SYNOPSIS...
A humid airmass will combine with daytime heating and mid level
disturbances to produce a threat for thunderstorms through
Monday. High pressure and dry conditions are expected for
Tuesday into Wednesday. Another system will bring additional
showers and thunderstorms to the region for Thursday.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Storms firing on the instability of daytime heating and a
sufficiently moist lower level will continue to spark this
afternoon and early evening. Highest potential threat is heavy
rain with tremendous rainfall rates over 2"/hr and the chance
for those storms to train over a particular area. Flash flood
watch was considered but held off given the uncertainty of the
placement and evolution of the event today and tonight. Heavy
rain was introduced to the forecast as a compromise.

Heat indicies in the south are in the established
advisory/warning area and will likely be modified this afternoon
with blowoff cloud cover limiting runaway temperatures, but mid
70s and higher dewpoints increasing the oppressive nature of the
airmass. Will let the advisory/warning expire at 8pm.

All indications are for a pseudo w-e line of storms to drop
south tonight. This may occur a few hours earlier than models
are forecasting and could be initiating at the issuance of this
AFD.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
Temperatures will not be able to return to the lower 90s and the
threat for heat indicies is significantly lowered. However,
humid and sticky conditions will most definitely persist.

Storms that are around early in the day will probably push east
as a surface boundary sets up sw-ne and conditions improve from
nw-se as the day progresses.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Pattern change will offer break from the heat and humidity.
Weak front pushing through may bring widely scattered
showers/storms Monday afternoon. Have included small pop for
this mainly in the south/southeast portions of forecast area.
High pressure builds in for Tuesday and Wednesday with seasonal
temps with lower dewpoints. Another cold front will approach
late Wednesday night and push through Thursday and Thursday
night with scattered showers and storms. Front should continue
to the south and east Friday with cooler and less humid air back
in for Friday and Saturday.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
00Z TAF cycle will focus on the southern terminals for
thunderstorm impacts tonight (CVG/ILN/LUK and possibly DAY). It
seems per the latest data that new thunderstorm development
tonight will remain south of central Ohio (CMH/LCK), but this
a low confidence forecast with weak forcing signals. Back end of
mesoscale convective complex is currently south of the CMH/LCK
terminals and drifting southeast. New development across
southeast Indiana is an area that will likely continue to see
further upscale growth through the evening/overnight with the
potential for a training area of storms to develop along old
outflows and move through the CVG/LUK/ILN terminals
(particularly CVG and LUK). DAY lies on the northern end of this
potential thus have kept thunder coverage/duration less than at
sites further south. Carrying no precipitation on Sunday due to
lowered confidence. Plenty of moisture and instability remains
but will depend on overnight storms/outflows before timing/area
can be discerned. A little concerned for fog and/or low clouds
in central Ohio (CMH and LCK) later tonight but thinking cirrus
from thunderstorms to the south/west will temper that somewhat.

OUTLOOK...Thunderstorms will be possible Sunday and Thursday.
-- End Changed Discussion --

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
OH...None.
KY...None.
IN...None.
-- End Changed Discussion --

&&

$$
SYNOPSIS...Franks
NEAR TERM...Franks
SHORT TERM...Franks
LONG TERM...Padgett
AVIATION...Binau