741
FXUS61 KCLE 160521
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
121 AM EDT Thu May 16 2024

.SYNOPSIS...
Low pressure over the Ohio Valley departs east to the Mid-
Atlantic Coast tonight. High pressure builds into the area
tonight through Thursday evening. Another low pressure system
will impact the area on Friday and Saturday.

&&

.NEAR TERM /THROUGH TODAY/...
935 PM Update...
No significant forecast changes this evening. Any lingering
convection is largely out of the CWA at this point.

Previous Discussion...
Upper-level low and surface low combination centered over
southern OH/western WV will continue to make eastward progress
this evening. Scattered rain showers with embedded isolated
thunderstorms east of I-75 and away from Lake Erie will
continue through about 00Z this evening before rapidly
dissipating thereafter. Patch to areas of fog will develop late
tonight through tomorrow morning before giving way to partly
sunny skies tomorrow as weak high pressure builds in. The next
low pressure system approaches from the west tomorrow with rain
chances increasing late Thursday night (30-50% range west of
I-77).

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
An upper-level trough with just a weak surface reflection is
expected to be located over the southern Plains and Ozarks Friday
morning. This upper trough is expected to lift east-northeast
through the first half of the weekend while gradually closing off.
Models are trying to key on a couple of pieces of energy working
through Friday morning and again Friday evening/night ahead of the
main closed low, with the main closed low making its closest pass on
Saturday before getting shunned towards the central Appalachians
Saturday night. Broad warm / moist advection and occasional lift
ahead of the approaching closed low will keep the forecast unsettled
for Friday and Saturday. The forcing with a closed off/cut off and
relatively weak low aloft will be diffuse and fairly modest so it
will not rain the entire period, with greater shower and storm
potential likely to be tied to the exact timing / track of the
various pieces of upper energy and daytime heating. POPs start out
fairly similar area-wide Friday morning. From late Friday through
Saturday night, higher POPs are generally focused farther south and
east with lower POPs gradually working in from the northwest. It is
uncertain how quickly we can clear the rain out of parts of our area
during the day Saturday, as the closed low will not be in a hurry to
move through and exit. However, there is currently better agreement
that a more notable drying trend is likely by Saturday night.

It will be slightly above average and on the muggy side for this
period. Expect highs generally in the 70s Friday and Saturday with
dew points pushing towards or into the lower 60s. Overnight lows
will be in the low to mid 60s Friday night, perhaps cooling slightly
more into the upper 50s/lower 60s for Saturday night. There is not
expected to be enough instability or flow aloft for a severe weather
threat Friday or Saturday. A lack of greater organization should
preclude much of a flooding threat, though with weak mean flow any
convective showers or storms could drop isolated heavier rain.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As the closed low from the first half of the weekend exits east,
broad ridging and deep-layer southwest flow will develop. This will
allow for a more substantial warming trend into the first half of
next week. A warm front is expected to develop just to our north on
Monday ahead of low pressure ejecting out of the Plains and towards
the upper Midwest. This means we should be in the open warm sector
until a cold front crosses in the vicinity of Tuesday night or
Wednesday. Mainly dry conditions are expected Sunday and much of
Monday. We will need to monitor for thunderstorms to develop to our
west and make it in at times late Monday through Tuesday afternoon.
Greater shower and storm potential may arrive Tuesday night as the
cold front begins nearing, so have rather low POPs Monday and
Tuesday trending to high chance or likely (40-60%) Tuesday night and
Wednesday. By Tuesday and Wednesday, the combination of steeper mid-
level lapse rates potentially advecting in aloft and above-average
PWATs could yield sufficient instability, when combined with
moderate flow aloft, for more organized thunderstorms. Highs will
range from the mid 70s to low 80s for Sunday, warming more solidly
into the low to perhaps mid 80s for Monday and Tuesday. Highs on
Wednesday will be very dependent on frontal timing. Overnight lows
will generally range from the mid 50s to the mid 60s.

&&

.AVIATION /06Z Thursday THROUGH Monday/...
Primarily VFR conditions will continue through this period,
although patchy fog is possible tonight, especially in areas
where it rained Wednesday. Have opted to include MVFR conditions
at all terminals except KTOL and KFDY primarily due to
visibility reduction, but far eastern terminals could see
lower ceilings push west as well. In addition, opted to lower
KERI to IFR conditions this morning with the chance of fog over
Lake Erie pushing inland. Will continue to monitor over the next
couple hours for a better handling on the extent of the fog. By
late morning, all conditions will rebound to VFR and persist
through the remainder of the period. Winds will generally be
light and variable, but for KCLE and KERI a lake breeze this
afternoon will briefly increase winds to 5-10 knots from the
north.

Outlook...Non-VFR possible with showers and thunderstorms
Friday through Saturday.

&&

.MARINE...
North-northeast flow at 8 to 15 knots will continue through Thursday
morning. High pressure will slide over the lake on Thursday, causing
the winds to become variable but generally onshore with the highest
pressure located over the chilly lake waters. Winds shift east-
southeast Thursday night and Friday at generally 6 to 12 knots with
southeast winds continuing through Friday night. Winds will be
variable but generally light over the weekend. Winds and waves are
expected to remain below headline criteria for the foreseeable
future. Some fog is possible over the chillier waters of the eastern
basin overnight tonight into early Thursday. Isolated thunderstorms
are possible over the lake Friday afternoon through Saturday
evening, though greatest potential should be inland.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
NY...None.
MARINE...None.

&&

$$

SYNOPSIS...Saunders
NEAR TERM...26/Saunders
SHORT TERM...Sullivan
LONG TERM...Sullivan
AVIATION...Campbell
MARINE...Sullivan