-- Discussion containing changed information from previous version are highlighted. --
316
FXUS61 KILN 261041
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
641 AM EDT Sun May 26 2024

.SYNOPSIS...
At least two rounds of showers and thunderstorms are expected
across the region today into tonight as embedded mid level
disturbances interact with an increasingly moist and unstable
airmass ahead of low pressure and a cold front. That low
pressure system and cold front will move across the Great Lakes
and Ohio Valley on Monday, continuing a chance of showers and
thunderstorms. A cooler airmass will then settle into the Great
Lakes and Ohio Valley through mid week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Through sunrise, a weak cold front will lay out west to east
along/near the Ohio River. Some river valley fog will be found
in our eastern/southern zones. High clouds will filter in from
the west, blowing off from upstream convection across the
Plains.

For today, convective complexes occurring across IA/KS/MO early
this morning were being aided by a mid level s/wv. These
complexes will also likely result in the formation of one or
more MCVs. The s/wv and MCVs are forecast to eject east into the
middle Ohio Valley by this afternoon. This energy will couple
with an advancing warm front which will bring a plume of MLCAPE
values of 1000 to 1500 J/kg, occurring within a moderately
sheared environment. As a result, various convection allowing
models develop some type of MCS which will progress
east/northeast through the area during the afternoon. Given
shear and instability, some strong to severe storms will be
possible with damaging wind and large hail being the main severe
weather threats, although a spin up tornado can not be ruled
out given the shear environment. Have gone with categorical
PoPs. There appears that once this system moves through, there
will likely be a period where pcpn chances will decrease
substantially in the wake of this system, along with bringing a
temporary decrease in overall instability due to rain cooled air
and weak subsidence. Will talk about this more in the short
term discussion. It will be humid with highs in the upper 70s to
the lower 80s under a low level southerly flow pattern.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
-- Changed Discussion --
Models continue to advertise a secondary mid level s/wv moving
into the region tonight. This feature will be associated with a
stronger low level jet and stronger wind fields. The key to CAMs
developing another MCS across the region will be how much of
the area can recover with SB/MLCAPES to result in severe weather
versus more convection that is elevated/decoupled from the
surface. Right now, it appears that our southern/southwestern
CWA will have the best chance to at least recover with some
SB/MLCAPEs as thunderstorms develop in the low level convergent
flow. As storms begin to share cold pools, the system will be
pushed forward east/southeast with the 0-3 km shear vector.
Damaging winds would be the main threat with isolated large
hail, as well as isolated/few tornadoes possible on on
individual bowing segments. Again have gone with likely to
categorical PoPs. The airmass will be the most moist tonight
with pwats in the 1.50 to 2.00 inch range. Thus, very heavy rain
may fall in a short period of time which would pose a
flood/flash flood threat. However, this should be limited if
storms move at a steady pace. Will mention all hazards for today
and tonight in the HWO. Pcpn is expected to taper off/diminish
in area coverage late as the complex moves east/southeast. Lows
tonight will fall into the lower to mid 60s.

On Monday, a mean mid level trough will dig east into the Great
Lakes and Ohio Valley. This will push surface low pressure and
a cold front east through the region. Overall forcing appears
weak with the best forcing occurring over the eastern half which
is when the cold front will interact with some diurnal
heating/instability. It will be locally breezy with highs
ranging from the lower 70s northwest to the mid/upper 70s east.
-- End Changed Discussion --

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
A couple of upper level disturbances will keep precipitation in
the forecast at times from Monday night through the day on
Wednesday. Dry conditions are then expected from Wednesday night
through the day on Saturday. Saturday night the next chance for
precipitation will occur.

With the passage of the cold front prior to the long term time
period, temperatures will be cooler. High temperatures in the
60s and 70s are expected with lows in the 40s and 50s.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
For today, mid level energy associated with convective
complexes over IA/KS/MO this morning is forecast to move east
into the middle Ohio Valley by this afternoon. Convection
allowing models differ some on exact timing and strength of this
feature. However, the likelihood of showers and thunderstorms
are expected. Thus, have placed this in all the terminals.
Ceilings will lower into the MVFR category with thunderstorms
with TEMPO IFR or lower visibilities in moderate to locally
heavy rainfall. Outside of thunderstorms, winds will veer from
the east, to the southeast, then to the south, increasing
between 10 and 15 knots with gusts up to 20 knots. There will
likely be a break in pcpn from this first feature as it provides
some temporary stability and lower chances of pcpn in its wake
late this afternoon into early evening.

For tonight, a stronger mid level disturbance is forecast to
move east into the Ohio Valley. An increasing low level jet with
this feature will try to pull instability back to the north
into the region along with decent low level convergence,
resulting in another potential convective complex. Showers and
storms are forecast once again. Since the timing of this system
is still a little more uncertain, have opted to place
predominate SHRA with VCTS/CB in the terminals. Again, lower
conditions can be expected with storms (MVFR ceilings, IFR or
lower visibilities). As the pcpn decreases in areal coverage
overnight as the complex moves east, predominate MVFR ceilings
should develop with some pockets of IFR ceilings possible.

OUTLOOK...MVFR ceilings likely with IFR ceilings possible
Monday morning. Thunderstorms possible Monday. MVFR conditions
possible Tuesday afternoon into Tuesday night.
-- End Changed Discussion --

&&

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

&&

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