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Area forecast discussion 
National Weather Service Wilmington Ohio
144 am EDT sun Jul 24 2016

upper level ridge will allow for continued hot and humid
conditions through the weekend. A cold front will move through the
area on Monday allowing for thunderstorms across the region.


Near term /through today/...
no significant changes to the overnight forecast other than to
tweak sky cover...trying to anticipate degree of cirrus blowoff
from western Great Lakes mcss. Did raise overnight low temps just
a bit but overall an insignificant edit. Think skies largely
remain clear to partly cloudy overnight as mesoscale convective system crosses Lake
Michigan/northern Indiana overnight and dramatically weakens per
multiple hrrr runs and 23.12z hrw-arw. Fog was maintained in some
areas as previously forecast given very moist boundary
layer...light winds...and a good period of clear skies into at
least the first half of the overnight.

On Sunday...decided to expand the heat advisory northward to
encompass entire County Warning Area...this based largely on trends seen in new
23.18z GFS/NAM and 23.15z sref (members and mean) which all
indicated higher dewpoints into the forecast area than forecast
based on previous runs. Thus...this allowed for a ~2f+ bump in
dewpoints in the forecast tomorrow which pushes central/west
central Ohio into the 100-102f range. There is still concern of
impacts from mcss crossing the Great Lakes later tonight and into
Sunday morning pushing outflow/convective debris clouds into this
area, but recent 23.18z runs are also drier in tropospheric relative humidity
hinting that cloud may not have much impact on temps overall
tomorrow. Tough call...but given accumulative impacts of
heat...decided this trend in 18z runs was enough to expand and get
this message out this evening.


Short term /tonight through Monday night/...
approaching shortwave trough later Sunday night will bring
increasing chance of storms as the night wears on...but coverage
is still not expected to be overly high during this time period.

On Monday there will be a better chance for thunderstorm activity
as a cold front moves through the region. In addition, some of
these storms may be severe with damaging winds. The best chance
for severe weather will be across the southern half of the
forecast area with better timing with peak heating. Before these
storms move through heat index values across far southern portions
of the forecast area are expected to be near 100 degrees.

Precipitation will gradually taper off Monday night with only some
thunderstorms across far southern portions of the forecast area
remaining by the end of the short term. With the passage of the
frontal boundary all but the far southern portions of the forecast
area are expected to drop down into the 60s Monday night.


Long term /Tuesday through Saturday/...
cold front will stall out near/just south of the Ohio River during
the mid-week. Lower precipitable waters are forecast to press
southward through much of northern and central Indiana/Ohio behind
the front, but near/south of the front drying will be minimal. As
such, will continue with a chance of primarily diurnal convection
Tuesday through Wednesday in the vicinity of the front, roughly
areas along and south of the Ohio River. Further north, enough dry
air should be present to preclude thunderstorm development.

By Thursday, whatever is left of the stalled boundary will lift back
north as a warm front, allowing a moist air mass to return to the
entire County Warning Area. Guidance suggests multiple shortwaves moving across the
Ohio Valley through the end of the week and perhaps even into
Saturday. This supports chance pops for thunderstorms during this

Temperatures are forecast to favor near average to slightly above
average values through the long term.


Aviation /06z Sunday through Thursday/...
VFR conditions are likely to be interrupted this morning by br
forming in calm and humid conditions. Once br Burns off by 12z,
expect mainly clear to partly cloudy skies to persist through
today. Sky cover will consist of mid and high clouds originating
from convection to the northwest, and cumulus that form in situ.
Will monitor convection for possible amendments in case taf sites
come under risk from thunderstorms this afternoon as suggested by
the NAM. Winds are forecast to transition from west to southwest
with speeds remaining under 10 knots.

Outlook...thunderstorms possible Monday and again Thursday.


Iln watches/warnings/advisories...
Ohio...heat advisory until 8 PM EDT this evening for ohz026-034-035-
Excessive heat warning until 8 PM EDT this evening for ohz061-
Kentucky...heat advisory until 8 PM EDT this evening for kyz089>100.
In...heat advisory until 8 PM EDT this evening for inz050-058-059-


near term...binau
short term...Novak
long term...bpp

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