703
FXUS61 KILN 260559
AFDILN

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

.SYNOPSIS...
Widespread showers and thunderstorms are expected Sunday
afternoon into Sunday night as a warm front lifts north across
the Ohio Valley. This will be followed by a cold front on
Monday, leading to a continued chance for showers and
thunderstorms. A cooler airmass will then settle into the Ohio
Valley through mid week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Slow moving weak cold front moving thru the eastern portion of
ILN/s FA will continue to sag slowly southeast and stall out
near the Ohio River overnight. Isolated thunderstorms have
developed along this front in the moderate instability field.
These storms will come to an end by midnight as they move off to
the east.

Skies will become mostly clear tonight and as the front stalls
out across southeast portions of our area, winds will become
light and variable. These conditions could lead to some some
areas of fog, especially in the river valleys across the south
and east.

Lows tonight will range from the mid 50s northwest to the
low/mid 60s southeast.

&&

.SHORT TERM /MONDAY/...
The frontal boundary draped along the Ohio River early Sunday
morning will lift back to the north as a warm front through the
day on Sunday. Models appear to be in fairly good agreement that
an ongoing convective complex off to our west Sunday morning
will track eastward along the boundary and overspread our area
through mid to late afternoon. However, there remains some
uncertainty with the amount of instability that will be present
ahead of this and as a result how well this initial shot of pcpn
will maintain itself as it outruns the better forcing.
Therefore, the severe threat also remains somewhat uncertain
with this initial activity through mid to late afternoon, but
the the highest threat would likely be for areas along and west
of I-75. Damaging winds would be the main severe weather threat
with this initial line of storms.

How the initial wave of pcpn plays out will impact how well we
are able to recover through Sunday evening. If we are able to
recover enough, a more widespread severe weather event will be
possible later Sunday evening into Sunday night, most likely in
the 9 PM to 2 AM timeframe. This would be accompanied by more
favorable wind/shear profiles, leading to the threat for
damaging winds, large hail and a few tornadoes. In addition
heavy rainfall would be possible with these storms along with
the potential for localized flash flooding.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Some lingering showers, potentially thunderstorms may be found
in the southeast half of the CWA Monday morning. Additionally,
more showers and a few thunderstorms will occur ahead of an
afternoon frontal passage, noted primarily by a westerly turn in
winds and notable speed increase. The frontal passage is more
an airmass change in humidity and wind direction versus
temperature. This front occurs as upper level shortwave energy
moves east during the day with a mean westerly flow found behind
it, lasting through Tuesday afternoon. Late Tuesday into the
evening will see the upper level trough axis pass across our
area to the east with winds becoming slightly more northwest
behind it. Showers will precede the trough in the afternoon,
affecting northern CWA a little earlier and limiting high
temperatures here. South and west of metro Cincy is expected to
be the rain/no rain transition for Tuesday.

On Wednesday, a strong shortwave will dive southeast and weaken
as it crosses the CWA. Showers should accompany its passage
during the day with the most likely occurrence found in the
north/northeast. This feature turns the mean flow to the north,
which will last through Friday. Thursday night will see surface
high pressure centering over eastern OH, with notable height
increases west of the CWA. The upper ridge axis lingers over the
Ohio Valley through early Saturday, then southwest flow kicks
back in during the day.

Steady drop in high temps through Wed (near 70), a slow rebound
Thurs/Fri and warmer Sat. Lows follow suit and bottom out Fri
morning (45-50), rebounding for the weekend. More detail in
temps/pattern relationships follow:

Temperatures will naturally follow these patterns. Showers and
the westerly wind shift on Monday will drop highs to the 70s,
about a 5- 6 degree drop from Sunday`s highs. Drier air will
push lows below 60 for the first time in a while ~ 57-58, about
an 8 degree drop in overnight lows from the previous night.

Tuesday showers moving nnw-sse in the late day will inhibit
high temperatures in the south to remain similar to Monday,
while northern CWA should see a 3-4 degree drop topping out in
the lower 70s. Decreasing cloud cover behind this feature with a
continued wnw flow will push another 4 degree drop with
Wednesday morning lows in the lower 50s.

On Wednesday, cloud cover and showers found with the strong but
decaying s/w energy will drop highs another 4-5 degrees,
landing northern half of the CWA 70 or a touch below, lower 70s
south of the Ohio River. North flow and building high pressure
in a dry airmass will result in overnight lows in the upper 40s
to near 50. A negligible 2-3 degree bump in highs Thursday will
result from sunshine and cold advection cancelling each other
out. One last 1-2 degree drop in low temps will result in the
coolest night of the forecast ranging from 45-50, coolest in the
northeast, and likely the last night of any readings in the
40s. Sunshine overcomes the weakening cold advection on Friday
with highs in the upper 70s, a 3- 5 degree bump from Thursday.
Saturday morning lows will be in the low-mid 50s. The continued
and building high with a return to southerly flow will mark a
more notable warming with highs reaching within a degree or two
of 80.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
Through sunrise, a weak cold front will lay out west to east
near the Ohio River. VFR conditions will prevail except in
southern/eastern river valleys where some MVFR/IFR visibilities
will occur.

For today, mid level energy associated with convective
complexes over NE/IA/KS/MO early 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 forecast. 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 some pockets of IFR ceilings possible.

OUTLOOK...MVFR/IFR ceilings likely Monday morning. Thunderstorms
possible Monday. MVFR conditions possible Tuesday afternoon
into Tuesday night.

&&

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

&&

$$
SYNOPSIS...JGL
NEAR TERM...AR
SHORT TERM...JGL
LONG TERM...Franks
AVIATION...Hickman