104
FXUS61 KILN 161902
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
302 PM EDT Sun Jun 16 2024

.SYNOPSIS...
Building high pressure aloft will combine with surface pressure
increases and a southerly flow in the Ohio Valley to bring an
atypically extended period of high temperatures for the coming
week. Highs in the mid to upper 90s will be compounded by low
temperatures from 70-75, worsening any heat related issues a
little more each successive day. Some weak disturbances along
with daytime heating may trigger thunderstorm activity on
Monday and possibly Tuesday.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
H5 high pressure center over the Carolinas will slowly
strengthen tonight and Tuesday. Impulses over the CWA will cross
northeast around the high and potentially spark isolated
thunderstorm activity overnight, mainly over KY and south
central OH. Sounding forecast shows that elevated instability is
present, but would need a mixed lower level or surface trigger
to initiate, neither of which is showing any tell-tale sign of
being present overnight.

Overnight low temperatures with a light southerly wind will
drop to around 70 for most locations, some mid 70s possible
closer to west central Ohio and coolest east/southeast of
Columbus in the Hocking Hills region.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
More than a handful of convective allowing models are showing
scattered storms over the CWA in the afternoon and early
evening, then rapidly calming down with the setting sun. If
storms develop in this weakly sheared atmosphere, they should be
short-lived but have a higher than average for strong downburst
winds. Outflow boundaries would also have a decent potential for
initiating more activity.

High temperatures should reach into the low to mid 90s.
Convective temperatures in 88-90 range will also help to spur
development of afternoon storms. Any cooling from outflows
and/or thicker cloud cover associated with the storms is
probably the best limitations to where these storms remain
scattered.

Dew points rising into the upper 60s to lower 70s will create,
maximum heat indices will be around 100. This is the bare-
minimum heat advisory criteria. Continue to keep the excessive
heat watch in favor of new model guidance overnight or
potentially early Monday if forecast later tonight is
inconclusive. Expect watch to resolve in an advisory or no
headline for Monday, but heat messaging is solidly in place.

Overnight lows will range from the mid 70s in west central OH to
the lower 70s south of the I-70 corridor into northern KY.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
With an anomalously strong high pressure centered to the east
through the period, hot temperatures are the main story. Latest
model blend shows highs in the low and mid 90s Tuesday and
Wednesday, rising to the mid and upper 90s Thursday through
Saturday, then back to the low and mid 90s Sunday. Apparent
temps are a few degrees higher, peaking around 100 in isolated
spots. Nighttime readings in the 70s will offer little relief.
Though temps will be borderline for heat headline criteria, the
duration of the heat will be a problem. Excessive heat watch
remains in effect into Friday evening, while upgrading to heat
advisories or warnings may be necessary over the coming days.

Dry weather is expected for the most part. Thunderstorms will
be possible Tuesday afternoon as a shot of moisture and PVA
circulates around the high. The threat for showers and storms
returns next Sunday when the high is forecast to break down
ahead of a trough and cold front. That will leave a dry period
from Wednesday through Saturday when the heat may be unimpeded
by precipitation and widespread clouds.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
VFR conditions will be found over the region, with some 5-6kft
sc/cu possible from about midnight through daybreak. Some few
models are trying to indicate some low chances of precip, but if
something were to fire overnight, it would be very isolated in
nature and not likely to affect any terminal.

A similar setup is in the offing for tomorrow afternoon as
heating and mid level energy combine to spark scattered
thunderstorm activity beyond 18z. Given the detractors of
unknown placement and if the convection starts, did not include
this in the extended 30 hour CVG TAF.

Light southerly winds are expected to be 5-6kt this afternoon
and during daylight hours on Monday. Overnight they will be
generally light from the south if it does not go calm or
light/variable.

OUTLOOK...No significant weather expected.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...Excessive Heat Watch from Monday afternoon through Friday
     evening for OHZ026-034-035-042>046-051>056-060>065-
     070>074-077>082-088.
KY...None.
IN...Excessive Heat Watch from Monday afternoon through Friday
     evening for INZ050-058-059-066-073-074.

&&

$$
SYNOPSIS...Franks
NEAR TERM...Franks
SHORT TERM...Franks
LONG TERM...Coniglio
AVIATION...Franks