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392
FXUS61 KILN 171516
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
1116 AM EDT Mon Jun 17 2024

.SYNOPSIS...
Hot and humid air mass settles into the Ohio Valley. While heat
is the primary concern, a few storms are possible Monday
afternoon and evening. Limited chances for rain exist on
Tuesday, with drier conditions favored the remainder of the
week. A subtle drop in humidity expected the latter half of the
work week, but hot conditions will persist.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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There is reasonable confidence today that a majority of our
counties will reach or exceed 100 degree heat indicies, which is
standard criteria for a Heat Advisory. These values could be
met as early as 1-2PM.

While thunderstorm potential remains high, it is expected that
coverage would be scattered over the CWA. Initiation would be
triggered by temperatures in the 90-92 range and occur where h5
s/w and vorticity maxima occur. Placement dependent on h5
conditions is sketchy given the high variability from one model
to another. It appears models are bullish on the potential from
Dayton northward and westward within the CWA.
Previous discussion:

As for storm potential, there are plenty of CAMs that still
want to initiate convection later this afternoon, with coverage
increasing into the early evening. No large scale forcing or
frontal boundary will help with timing and tracking storm
activity... this is more of your typical single cell (popcorn)
thunderstorms that we observe during the summertime. Shear
profiles will be quite unfavorable for any long-lived or multi-
cell thunderstorm development. Thermodynamics on the other hand
are quite alarming, with SBCAPE values near or exceeding 2000
J/kg, DCAPE values near or exceeding 1000 J/kg, along with steep
0-3km lapse rates. Any storms that do initialize could produce
strong downbursts, with perhaps some hail if the storms can grow
tall enough before collapsing.
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&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
Storm coverage expected to wane through the late evening and
early overnight hours with the loss of diurnal heating. A slight
uptick in overnight lows will occur Monday night as everyone in
our fa is expected to observe low temps in the low to mid 70s.

Heat Advisory continues through the period on Tuesday as another
hot and muggy day will be in store. Heat indicies are once again
expected to peak near or just over 100 degrees. The area of
high pressure continues to expand westward. As this does, precip
chances will lower across our counties. However, still cannot
rule out a stray shower or storm developing on Tuesday - mainly
along/NW of I-71.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Upper ridge will become more expansive and reach its maximum
strength and extent in the middle of the week. It will then very
slowly start shifting south and become a little less intense later
in the week. The pattern will then change over the weekend as a
trough emerges out of the Canadian Rockies and strengthens as it
heads into the Great Lakes squelching the ridge entirely.

Heat will build with highs reaching the mid 90s by Thursday and
Friday. However, relatively drier low level air will get into the
region on southeasterly flow allowing dew points to not be as high
when temperatures are a few degrees warmer than previous days. This
results in little change in maximum heat indices from day to day,
generally peaking between 95 and 100 Wednesday through Saturday.
Although this falls short of the criteria of 100 for a heat
advisory, this is a longer duration event with cumulative effects
that could be hazardous to the public. Thus the time period
previously covered by the excessive heat watch is now a heat
advisory. There is the potential that at some point down the line
the advisory will have to be extended into Saturday.

A cold front will be approaching the area on Sunday and this will
bring the net appreciable chance of showers and thunderstorms.

&&

.AVIATION /15Z MONDAY THROUGH FRIDAY/...
Mid and lower levels will continue to saturate and provide a
mix of mid and low level clouds that will move in from the south.
Winds generally remain below 10 kts out of the south-southwest
through the taf period.

Main thing to keep an eye on is storm potential. While no large
scale forcing is in place, there is a chance for pop-up
showers/storms today, mainly in the afternoon/evening period.
The environment would be conducive to producing downbursts with
any of these storms today. Given uncertainty in coverage/timing
of isolated storms, just have a VCTS mention for now.

Precip chances will diminish early tonight. KLUK will have the
potential for some vsby reductions due to BR.

OUTLOOK...No significant weather expected.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
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OH...Heat Advisory until 8 PM EDT Friday for OHZ026-034-035-042>046-
     051>056-060>065-070>074-077>082-088.
KY...Heat Advisory until 8 PM EDT Friday for KYZ089>100.
IN...Heat Advisory until 8 PM EDT Friday for INZ050-058-059-066-
     073>075-080.
-- End Changed Discussion --

&&

$$
SYNOPSIS...Clark
NEAR TERM...Franks/Clark
SHORT TERM...Clark
LONG TERM...
AVIATION...Clark