047
FXUS61 KCLE 181332
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
932 AM EDT Sat May 18 2024

.SYNOPSIS...
Weak low pressure will meander across the region today before a
ridge builds over the forecast area this evening into Sunday.
The ridge will continue to influence the area through Tuesday
afternoon, but expect the next system to approach Tuesday night
and cross the local area Wednesday.

&&

.NEAR TERM /THROUGH SUNDAY/...
9:30 AM Update:
Was able to get the Dense Fog Advisory off the board around 9 AM
due to improving visibilites per observations and webcams.
Otherwise, did tweak POPs this afternoon to get slight chance
wording in along and west of I-75 as a few hi-res models develop
a bit of convection along a lake-aided boundary this afternoon.
The remainder of the forecast is on track and unchanged, with
slight chances for showers or thunder well inland from the lake
this afternoon.

Previous Discussion...
Advection fog and low stratus have developed across the area
early this morning. Fog started off patchy with more low
stratus, but starting to see a transition to dense fog and
expect this trend to continue through daybreak. The Dense Fog
Advisory has been expanded west to include Ottawa and Sandusky
counties due to dense fog being reported at KPCW (Port Clinton)
and shown on nearby traffic cams. Guidance suggests that the
dense fog could expand as far west as the Toledo area this
morning, so will need to keep an eye on visibilities over the
next few hours. Would not be surprised if the Dense Fog Advisory
needed to be expanded westward by the 630 AM update. Locations
outside of the advisory will likely have patchy dense fog before
daybreak this morning, primarily in low- lying areas. Fog
should begin to dissipate as diurnal mixing kicks in by mid-
morning, however some fog may linger along the immediate
lakeshore since fog will likely persist over the lake through
much of today.

Outside of the morning fog, the forecast will be relatively
quiet for most of the area today. A few showers or
thunderstorms may develop in the southern reaches of the CWA
this afternoon, but coverage should be low given weak forcing.
Any showers/storms that develop may move slowly due to weak
steering flow, but PWAT values will be lower than Friday so the
flooding risk is low. Today will be warm and still a touch muggy
with highs in mid to upper 70s to lower 80s. Locations along
the immediate lakeshore may be a few degrees cooler in the upper
60s to lower 70s. Another round of patchy fog (possibly dense
in spots) is likely tonight as skies clear and winds remain
light and overnight lows will fall into the mid to upper 50s.
Dry weather is expected for most of Sunday as a ridge builds
east over the area, but a shortwave cresting the ridge may allow
a few showers/thunderstorms to sneak close to the I-75 corridor
by late Sunday afternoon. Sunday will be even warmer and expect
widespread highs in the upper 70s to lower 80s. Locations near
the I-75 corridor are expected to see high temps in the mid 80s.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
An upper ridge and surface high pressure will be across the area on
Sunday night into Monday. This will keep a quiet forecast for the
first part of the short term forecast period. Return flow across the
region along with a weakening mid-level shortwave trough will enter
through the day on Monday and could allow for some isolated to
scattered rain chances on Monday night into Tuesday. The upper ridge
over the region will be quite strong and believe that any rain will
be very limited and have just some low PoPs, mostly confined to the
western half of the forecast area. A larger upper trough will enter
the central CONUS on Tuesday and advance east toward the forecast
area, breaking down the upper ridge into the region. Some scattered
convection may develop and move into the area on Tuesday and Tuesday
night and have some chance PoPs to reflect this. Temperatures
through the period will be warm for the 3rd week of May with 80s
expected, which may only grow in magnitude, if rain doesn`t
materialize.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
The full pattern breakdown will occur on Wednesday as the main upper
trough enters the area with a pair of stronger shortwaves moving
through the upper flow on Wednesday late morning and again on
Wednesday night. A cold front will also enter the region and this
feature will likely help focus in a larger shower and storm threat
and have likely PoPs still reflected into the forecast. The
environment for an organized severe threat on Wednesday is looking a
touch better with plenty of moisture and instability to work with
and good jet energy aloft. This will be a day to continue to monitor
into next week. Continued upper troughiness across the region on
Thursday, along with some consideration for the pattern to slow,
will allow for slight chance to chance PoPs to continue in the
forecast for Thursday. Some brief upper ridging will return for
Friday to allow for a quiet window but there is some disparity in
the extend guidance to know how long this may persist for the area.
Temperatures will start warm on Wednesday in the 80s ahead of the
cold front. Temperatures will return closer to normal for Thursday
and Friday.

&&

.AVIATION /12Z Saturday THROUGH Wednesday/...
Widespread IFR and LIFR with fog and low stratus will improve to
VFR by mid to late morning and VFR should prevail through at
least tonight. Can`t rule out a few showers or thunderstorms
south of a line from roughly KFDY to KCAK, but the chances are
very low. Additional fog and low stratus will likely develop
overnight, likely ushering non-VFR conditions to at least the
eastern half of the area after about 06-09Z.

Winds will be variable and 5 knots or less through the entire
TAF period.

Outlook...Non-VFR possible with periodic showers and
thunderstorms Tuesday and Wednesday.

&&

.MARINE...
A highly saturated air mass over Lake Erie this morning has allowed
for fog and low stratus to develop over the lake. These poor
visibility conditions will persist through the day today with light
flow and have a Dense Fog Advisory through 4 PM this afternoon. Fog
should still be around the region tonight into Sunday and can see an
extension in the fog headline. Other than the visibility over the
next 24 or so hours, the forecast for Lake Erie through the first
half of next week is very quiet with limited weather of note. High
pressure will return for the weekend 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. This low pressure system will deepen
considerably over the region on Wednesday, as it moves across Lake
Superior. This feature will extend a cold front across the lake on
Wednesday afternoon and evening and flow will veer to the
southwest.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
NY...None.
MARINE...Dense Fog Advisory until 4 PM EDT this afternoon for
     LEZ142>149-162>169.

&&

$$

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