700
FXUS61 KCLE 171806
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
206 PM EDT Fri May 17 2024

.SYNOPSIS...
Weak low pressure will influence the region through Saturday
before high pressure returns Saturday night through Monday. The
high will shift east of the area Monday night as the next system
approaches from the west.

&&

.NEAR TERM /THROUGH SATURDAY/...
12:30 PM Update...

Lowered temperatures slightly this afternoon based on the slow
exit of the steadiest showers and clouds. Otherwise, the
forecast remains on track. Weak diurnal instability has
generated some convection in the southeast counties, and with
unseasonably high PWATs, these are producing locally heavy
rainfall. We received a report from Millersburg of 1.75 inches
of rain in the past hour. The heaviest convection will slide
east of the region within the next hour, so not expect any
flooding.

9:30 AM Update...
Showers remain widespread as of 1330Z with abundant moisture and
lift from broad upper diffluence and the right entrance of a
75-85 knot H3 jet streak. The most widespread coverage is along
and east of I-71, but renewed development is taking place in NW
Ohio closer to the aforementioned jet streak, and these will
move east through early this afternoon. With all of this being
said, expanded the likely and categorical PoPs farther west this
morning into mid afternoon to reflect a slower end to the most
widespread showers. Most QPF will be 0.25 inch or less.

630 AM Update...
Showers continue to progress east across the area. Still can`t
rule out some thunder in the heavier pockets of rain. Made a
few adjustments to PoPs based on latest radar trends, but
otherwise no significant changes needed with this update.

Previous Discussion...
Weak troughing will influence the local area today with a
couple of shortwaves lifting across the CWA this morning and
again this afternoon. Showers, currently over the western
portion of the area, will continue to spread east across the
local area through this morning before largely exiting to the
east by early afternoon. There`s a little bit of instability in
place this morning, so can`t rule out a few rumbles of thunder
within more convective showers. Instability increases during
peak diurnal heating this afternoon and there will be plenty of
moisture in place so scattered showers and thunderstorms could
develop this afternoon before diminishing this evening. While
showers will be progressive this morning, unseasonably high
PWATs in addition to very weak steering flow will could result
in slow-moving showers/storms and potential for locally heavy
rainfall. With that being said, the scattered nature of
precipitation will keep the flash flooding potential relatively
low. The severe weather threat is also low given weak shear.

Patchy fog will likely develop tonight due to residual low level
moisture and light and variable surface winds; moisture from
today`s precipitation will likely add additional moisture that
could lead to patchy dense fog.

Shower and thunderstorm chances continue into Saturday as weak
low pressure meanders into the Ohio Valley. PoPs should largely
be influenced by terrain, so the highest chance PoPs are largely
confined to the southern half of the CWA. Similar to today,
slow-moving showers/storms are possible due to high PWAT values
and weak steering flow.

Highs will be in the 70s today with the warmest temps in the
upper 70s expected near the I-75 corridor and lower 70s more
likely across NE OH and NW PA. Tonight`s lows will fall into the
upper 50s to lower 60s with Saturday`s maximum temps climbing
into the mid to upper 70s (NE OH/NW PA) to lower 80s (NW OH).

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
The short term forecast period for much of the weekend into Monday
will be quiet. An upper ridge will build into the eastern CONUS with
a trough being subverted south into the Southeast United States. The
ridge across the region will allow for high pressure to build front
the northeast and hold firm across the area through Monday. The
surface high will move east on Monday and allow for a warm front to
lift north across the region. A shortwave will try to ripple through
the upper trough on Monday night, but this energy may hit a wall
with the ridge and trends are drier for Monday night. Temperatures
will be above normal for the 3rd weekend of May, as 80s are becoming
increasingly favored. Mid 80s will be favored by Monday with the
warm front through the area.

&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...
The dry pattern with the upper ridge across the region will
breakdown for the middle of next week. However, the trends for this
pattern evolution continue to be slower with the wettest day landing
firmly on Wednesday for now. A deep upper trough will enter the
central US on Tuesday and progress east with several waves through
the week. One wave will start to break down the ridge on Tuesday and
nudge it eastward with the main wave entering on Wednesday with the
main trough axis crossing the region by Wednesday night. Have PoPs
increasing through the period with the highest PoPs on Wednesday.
The PoPs on Tuesday may be a bit high as the first wave may not do
much for generating convection in the forecast area. A more
progressive region will set up for the end of the week and have
residual chance PoPs through the end of the period. All in all,
temperatures will be above normal for any time period ahead of the
trough axis, or Tuesday and Wednesday for now. Temperatures will
return toward normal for the end of the week.

&&

.AVIATION /18Z Friday THROUGH Wednesday/...
Drier air is slowly working into western and northern areas this
afternoon allowing KTOL, KFDY, and KCLE to mainly become VFR,
but steadier showers continue farther south and east where MVFR
remains prevalent at KCAK, KMFD, KYNG, and KERI. Expect the
steadiest showers to continue to exit this afternoon, but
scattered showers and a few pockets of thunder will redevelop,
so carried VCSH at all sites into this evening before gradually
ending from NW to SE. The theme should be better cigs and vis
late this afternoon and evening with much more scattered shower
coverage compared to this morning.

Moving into tonight, confidence continues to increase on
impactful fog since most areas saw rainfall today, and there
will be plenty of lingering low-level moisture and
light/variable winds. Think mist will start lowering
visibilities after 04Z, but the biggest risk for dense fog will
be between 08 and 12Z, so used TEMPO groups. The fog and
mist/low clouds should improve rather quickly Saturday morning.

SW winds of 5-10 knots this afternoon will become light and
variable tonight into Saturday morning.


Outlook...Non-VFR possible with showers and thunderstorms
Saturday and again on Tuesday.

&&

.MARINE...
The forecast for Lake Erie through the first days of next week is
very quiet with limited weather of note. Today will likely be the
most active day on the lake with light southeast flow and a window
for showers and thunderstorms with a weak system moving through the
region. High pressure will return for Saturday and Sunday and light,
generally northeast flow will be favored across the area for the
weekend. A warm front will cross the lake for Monday and southeast
flow will return to the lake. Southerly flow will continue into
Tuesday and increase ahead of a low pressure system that will move
through the Northwest Great Lakes for the middle of the week. No
marine headlines are expected at this time.

&&

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

&&

$$

SYNOPSIS...Maines
NEAR TERM...Garuckas/Maines
SHORT TERM...Sefcovic
LONG TERM...Sefcovic
AVIATION...Garuckas
MARINE...Sefcovic