941
FXUS61 KILN 170802
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
402 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/...
Warm air mass continues to build across the region, leaving
overnight lows in the upper 60s to middle 70s. Other than the
mild overnight lows, conditions remain fairly quiet across the
area. Some CAMs try to bring the complex of storms in the Great
Lakes south into our area, generating shower activity across
our northern counties this morning. Not overly confident in this
occurring - thus have kept out PoPs mention through the morning
hours in our CWA.

Regarding the heat headline: We have decided to upgrade the
Excessive Heat Watch to a Heat Advisory for the entire week.

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. Even though storm potential still exists
today, it is expected that storm coverage has the best chance
of increasing by the late afternoon timeframe. Thus, heat
indicies near 100 degrees will likely still be observed by most
before any storms develop.

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.


&&

.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 SUNDAY/...
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 /08Z MONDAY THROUGH FRIDAY/...
Expecting mainly high level clouds to traverse the terminals
through the remainder of the overnight period. Mid and lower
levels will continue to saturate and provide a mix of mid and
low level clouds throughout the day Monday. 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.

OUTLOOK...No significant weather expected.

&&

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

&&

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