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239
FXUS61 KILN 260128
AFDILN

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
928 PM EDT Sat May 25 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 /UNTIL 6 AM THIS MORNING/...
-- Changed Discussion --
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.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM 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 FRIDAY/...
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 /02Z SUNDAY THROUGH THURSDAY/...
Weak cold front east of the TAF sites will stall out near the
Ohio River overnight. Any convective activity associated with
this front will continue pushing off to the east and is not
expected to impact the TAF sites.

Skies will become mostly clear by late evening. With winds
becoming light and variable overnight, some areas of mainly
river valley fog will be possible later tonight into early
Sunday morning.

This will mainly affect the KLUK TAF site where MVFR to IFR
vsby restrictions can be expected. A convective system will
approach from the west through the day on Sunday and this will
affect the TAF sites through mid to late afternoon. Have covered
this threat with a VCTS beginning at 20Z for the western TAF
sites and 22Z for Central Ohio. A second convective complex
looks to affect the area overnight Sunday. There is more
uncertainty with this feature and for now have a mention of VCTS
at 04Z at the 30 hour KCVG TAF sites. Both of these thunderstorm
complexes will have the potential to produce severe weather.


OUTLOOK...Thunderstorms possible at times through Tuesday.

&&

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

&&

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