-- Discussion containing changed information from previous version are highlighted. --
879
FXUS61 KILN 220526
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
126 AM EDT Wed May 22 2024

.SYNOPSIS...
Seasonably warm temperatures continue through the entire week,
but a subtle cooldown occurs on Thursday with the passage of a
cold front. Periods of showers and storms will continue through
majority of the work week, with stronger storm potential later
on Wednesday into Wednesday night.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
Showers and thunderstorms in Illinois will continue to progress
east through the night. However, that activity will be weakening.
But some lingering showers and possibly thunder will move into
the western part of the forecast area before daybreak. Forecast
temperatures still look reasonable with lows only falling into
the upper 60s.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
CAMs continue to have a robust signal for a weakening MCS moving
into the Tristate area early Wednesday morning. Overall
maintenance of this complex remains uncertain, but the Tristate
area has the best potential to observe showers and perhaps a
few rumbles of thunder. Bufkit soundings suggest that if any
storms persist into our CWA, they will remain elevated and sub-
severe.

The remainder of Wednesday and Wednesday night has had growing
uncertainty recently, but there has been a trend towards a less
active severe weather day in our fa. As we progress into
Wednesday afternoon, the thermodynamic environment will be quite
impressive. SBCAPE will increase to around 2000 J/kg and steep
lapse rates (esp low-level) will develop. Shear profiles are not
favorable however, so if anything is able to develop,
downbursts and perhaps large hail would be the primary daytime
threats.

Shower/thunderstorm activity expected to increase Wednesday
night as the primary upper level forcing and associated surface
cold front begin to work through the area. Shear profiles begin
to improve but are more unidirectional, limiting the potential
tornado concern. Will continue with severe mention mainly
through the beginning of Wednesday night, but the evening and
early overnight period appear to be the best window based on how
CAMs are trending. Hydro threat should be limited but if any
training storms exist, PWATs of 1.3-1.5" will lead to some
efficient rainfall and could lead to localized flooding.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A fairly progressive zonal flow pattern will continue aloft into
early next week. This will allow for a series of mid level short
waves to move east across the Tennessee and Ohio Valleys, leading to
occasional chances for showers and thunderstorms.

The first couple of short waves will move across mainly the Tennessee
Valley Thursday and then again Friday, resulting in a better chance
for showers and thunderstorms across our southern areas. It looks
like we could be in between systems for Saturday so will go with
lower pops for the start of the weekend. A stronger short wave will
move east across the Ohio Valley Sunday into Monday. This will be
accompanied by some better wind fields/deep layer shear and the
potential for a few stronger to severe storms. Some secondary short
wave energy will lead to falling heights and a lingering chance for
showers and thunderstorms continuing into Tuesday.

Temperatures will remain a few degrees above normal through the
weekend with daytime highs generally in the upper 70s to lower 80s
before some more seasonable readings return Monday into Tuesday.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
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A few VFR Cu are lingering about the area amidst
increasing/thickening mid/high level clouds, which will
continue to overspread the area through daybreak. An
elongated/broken cluster of convection will move in from the W
around/after sunset, with latest guidance suggesting it will
hold together long enough to bring some SHRA, as well as ISO
TSRA potential, to KCVG/KDAY/KLUK and even KILN between about
10z-14z. Did not yet have confidence to add TS to the fcst, but
did add tempo SHRA at each of these sites to account for the
slightly better coverage of activity as it moves in through
the morning hours.

The broken/loosely-organized convection will continue to fall
apart beyond 15z, with some ISO SHRA/TSRA expected to develop in
its initial wake between 15z-18z or so. Activity through the
daytime, especially for the afternoon, will be very disorganized
and somewhat spotty, with some indications for better coverage
of development past 22z near KCVG/KLUK, but confidence is rather
low in whether the sites will have much SHRA/TSRA activity
beyond the decaying AM convection. A chance of SHRA/TSRA may
linger toward/beyond the end of the period, especially for srn
sites of KCVG/KLUK.

Some MVFR CIGs cannot be ruled out between about 14z-18z in the
immediate wake of the weakening AM activity, but conditions
(outside of SHRA/TSRA) should be mainly VFR. Southerly winds
around 5-10kts will increase to 10-15kts, and gust to around
20-25kts, out of the SW past 14z or so. The gustiness should
subside just a bit toward/beyond 21z, with sfc flow going more
westerly at around 5kts by the end of the period.

OUTLOOK...Thunderstorms possible Wednesday night and Thursday
and then again on Friday into Saturday as well as Sunday. MVFR
ceilings possible Wednesday night into Thursday.
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&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.

&&

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