713
FXUS61 KILN 030733
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
333 AM EDT Wed Jul 3 2024

.SYNOPSIS...
Hot and humid conditions are expected today along with
increasing chances for showers and thunderstorms as a cold front
approaches from the northwest. This boundary will then remain
in the area on the Fourth of July. Embedded mid level
disturbances will interact with this boundary, resulting in
multiple rounds of showers and thunderstorms. A stronger weather
system is expected to move into the Great Lakes and Ohio region
Friday into Friday night, continuing the threat for showers and
thunderstorms.

&&

.NEAR TERM /THROUGH TONIGHT/...
A cold front was located from the western Great Lakes,
southwest across the middle Mississippi River Valley, then into
the southern Plains. This front will make its way southeast
toward our region today. For this morning into early afternoon,
we should see a mix of high clouds (spilling in from the west
from upstream convection) and scattered cumuliform clouds. Winds
will increase from the south and southwest between 10 and 15
mph with gusts up to 25 mph. This low level flow will bring
higher dewpoints into the region. In fact, dewpoints are
forecast to peak this afternoon into the lower to mid 70s. This
will combine with forecast highs in the upper 80s to the lower
90s. As a result, heat indicies will range from the upper 90s to
the lower 100s. Where heat indicies are expected to approach
100 or above, a Heat Advisory has been issued, which is mainly
along and south of the I-70 corridor. Elsewhere, mid and upper
90s heat indices are expected, and this will be mentioned in the
HWO. With the heat and humidity, the airmass will become
unstable with moderate instability forecast. This will be
occurring in an environment with weak to low end moderate deep
layer shear. The big question of the day will be how showers and
thunderstorms will be triggered. Well, perusing the various
CAMs and models, it appears that either an outflow boundary/MCV
will rotate east into our area by late afternoon, or perhaps a
low level prefrontal trof in advance of the cold front. This
forcing should be enough to produce scattered to numerous
showers and thunderstorms in an uncapped sounding regime. There
is some uncertainty on how fast convective initiation will
start, ranging from 2 pm to 5 pm or later. As a result, have
taken a blended/broad brush approach for this afternoon. We will
likely see multicellular clusters or small bowing segments of
convection. With pwats 2+ inches, pcpn loading in the strongest
updrafts will likely lead to some strong to damaging winds as
the the cores descend back to the surface. In addition, there
should be some DCAPE values between 500 and 900 negative J/kg
for wet microburst potential. Poor mid level lapse rates and
overall thin CAPE soundings indicate that large hail is not a
big concern. Heavy rainfall will be possible which could lead to
localized flooding. Will mention the strong to damaging winds
and localized flooding in the HWO. As we head into tonight, the
cold front will eventually move into our northern CWFA where it
will become quasi-stationary. Ongoing convection will undergo a
weakening trend as instability wanes some and overall forcing
weakens. It will be warm and muggy with lows in the lower 70s.

&&

.SHORT TERM /THURSDAY/...
Quasi-frontal boundary will remain across our northern forecast
area on Thursday. In a very moist airmass (pwats still 2+
inches), a mid level disturbance (perhaps convectively induced)
is forecast to ripple west to east across our region during the
day. This feature will couple with a modest 850 mb low level jet
to result in the likelihood of showers and thunderstorms,
particularly across our southern two thirds CWFA. With marginal
low end moderate instability, can not rule out isolated strong
to severe convection. Strong to damaging winds will continue to
be the main concern. In addition, heavy rainfall will still be a
concern as well, which may result in localized flooding. Will
mention these threats in the HWO. Clouds and the threat for
additional pcpn will keep highs in the lower to mid 80s. So a
little cooler but still humid.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Weather will be unsettled to start the period as a cluster of
showers and thunderstorms forming under a disturbed westerly mid
level flow is likely to be affecting much of the area on
Thursday night. Threat for thunderstorms continues through
Friday when a cold front trailing Canadian low pressure pushes
through from the west. Strong to severe storms and heavy rain
cannot be ruled out from an environment containing ample
moisture, instability, and winds aloft.

For Saturday and Sunday, high pressure is expected to provide
tranquil weather. The threat for showers and storms returns
Monday and Tuesday as moisture and lift increase ahead of an
upper trough and weak surface boundary.

Temperatures should remain relatively consistent and close to
normal, with highs generally in the 80s each day, and lows
mainly in the 60s.

&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions are expected overnight as a mixture of a FEW-SCT
cumliform clouds mix with high level convective debris blow off
from storms upstream in the middle Mississippi River Valley.
Southerly winds will increase some overnight to 10 to 12 knots
with gusts up to 20 knots possible by 12Z. There will be a brief
period of LLWS at KDAY/KILN/KCVG/KLUK where south/southwest
winds of 40 knots at 2000 feet will be possible by a transient
low level jet.

For today, LLWS threat will end around 12Z. Otherwise, focus
will be on the potential for showers and thunderstorms. A cold
front will approach our region from the northwest late in the
day. It will become hot and humid ahead of this front, leading
to moderate instability. Convection allowing models show varying
convective initiation timing and coverage, so a blended
approach will have to be used at this time. It appears that
showers/storms will become induced by either a remnant outflow
boundary/mid level weak disturbance or subtle prefrontal trof
convergence. Have showers/storms developing in the 18Z to 00Z
time frame. Given very moist airmass, MVFR ceilings and IFR or
less visibilities will be possible in the stronger storms. For
now, will put some MVFR visibilities in the terminals with
predominant showers with a VCTS/CB until timing can be better
pinpointed. Gusty south/southwest winds between 20 and 25 knots
will continue into the afternoon, then diminish between 22Z and
00Z.

For tonight, showers/storms should gradually decrease in
coverage overnight as the cold front pushing into our northern
forecast area weakens and becomes more diffuse. The recent
rainfall, if it comes to pass, may help to develop some MVFR
ceilings and visibilities late tonight.

OUTLOOK...MVFR conditions possible Thursday morning.
Thunderstorms possible Thursday through Friday.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...Heat Advisory from noon today to 8 PM EDT this evening for
     OHZ053>056-060>065-070>074-077>082-088.
KY...Heat Advisory from noon today to 8 PM EDT this evening for
     KYZ089>100.
IN...Heat Advisory from noon today to 8 PM EDT this evening for
     INZ050-058-059-066-073>075-080.

&&

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