401 
FXUS61 KCLE 071335
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
935 AM EDT Sun Jul 7 2024

.SYNOPSIS...
High pressure will be over the Ohio Valley today then shift towards 
New England on Monday. Moisture from the remnants of Beryl will 
approach the area towards the middle of the week.

&&

.NEAR TERM /THROUGH MONDAY/...
Surface high pressure will be overhead today then shift towards
New England on Monday. The airmass is sufficiently dry for only
scattered cumulus clouds to develop with no precipitation in 
the forecast through Monday. Temperatures will trend 2 to 4 
degrees warmer today except for locations in NE Ohio and NW 
Pennsylvania where lake breezes will keep areas from Cleveland 
to Erie PA with similar temperatures to Saturday. Upper level 
heights trend upward on Monday in response to the trough 
deepening across the Upper Midwest. With surface winds out of 
the south, temperatures will continue to trend warmer with highs
in the upper 80s to low 90s. Dewpoints will tend to be near or 
just above 60 degrees which is typical of summer and will not 
contribute to noticeable increases to the heat index.

&&

.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
The middle part of the week is starting to look more interesting, 
with increasing odds that the remnants of Beryl will impact the 
region. Of course, details are uncertain at this point given 
differences with how Beryl will interact with a longwave trough 
across the central CONUS, but trends point toward tropical moisture 
at least bringing greater coverage of showers and thunderstorms. 

Now for a little more detail, surface high pressure over the eastern 
Great Lakes Monday night will exit offshore Tuesday as a northern 
stream mid/upper shortwave progresses from the Upper Midwest into 
eastern Canada. This will drag a cold front into the southern Great 
Lakes Tuesday, but guidance is coming into agreement that the 
boundary will stall somewhere near Lake Erie as the dynamics pass 
mostly north of the region. This will result in less in the way of 
forcing, therefore reducing the coverage of showers and 
thunderstorms compared to previous forecasts. There will be some 
synoptic scale lift on the southern fringe of an 80-90 knot upper 
level jet streak, and this combined with at least moderate MLCAPE of 
1000-1500 J/Kg will allow scattered convection to develop in the 
afternoon and evening, but not all areas will see rain. An isolated 
severe storm or two is possible in this pattern, mainly in the form 
of damaging downburst winds and locally heavy rainfall, since weak 
mid-level lapse rates will limit hail production, but the severe 
threat is not looking widespread. 

Things become more interesting starting Tuesday night. As the 
aforementioned shortwave moves out across eastern Canada, broad 
mid/upper troughing over the central CONUS will pick up Tropical 
Cyclone Beryl and lift it from the lower Mississippi Valley into the 
southern or western Great Lakes by Wednesday evening. This could 
spread deeper tropical moisture and anomalously high PWATs over 2 
inches northeastward into the region Tuesday night and Wednesday, 
but the track of the remnant circulation differs in the guidance. 
The latest NAM and deterministic Canadian runs take the circulation 
up through Ohio while the ECMWF takes it up through Indiana, and the 
GFS takes it just east of Chicago. These differences are the result 
of uncertainty regarding the amplitude of the central CONUS trough 
which range from an open trough to somewhat of a closed low. The 
latest QPF forecast from WPC utilizes an ensemble blend which puts 
the steadiest swath of rainfall across Indiana and Michigan, but 
there is still room for this to shift farther west or east in time. 
Regardless, increasing moisture Tuesday night and Wednesday will 
lead to greater coverage of showers and thunderstorms, so have 
increasing PoPs during that period. Coverage should be greatest 
during the day Wednesday as the tropical moisture interacts with 
diurnal heating. It is worth noting that if the track goes across 
Indiana and Michigan, enhanced low-level shear in the eastern 
quadrant could result in low-topped supercells with rotation, so we 
could see a marginal severe threat Wednesday in addition to locally 
heavy rainfall. Coverage of precip should gradually lessen Wednesday 
night as the circulation lifts away from the region.

Highs Tuesday will reach the mid/upper 80s, cooling into the low/mid 
80s Wednesday, but still humid. Lows Monday night and Tuesday night 
will stay in the upper 60s/low 70s, with mid/upper 60s Wednesday 
night.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
There remains some uncertainty with how the upper level pattern will 
evolve late in the week into next weekend behind the remnants of 
Beryl. This is due to a quasi Omega block starting to break down 
allowing the broad longwave trough over the central CONUS to shift 
east, but the speed in which that happens is uncertain. The 
deterministic GFS is the slowest since it has more of a closed low 
over the Upper Midwest compared to a more open trough axis in the 
other guidance. At this time, stayed with NBM PoPs and temperatures 
which has seasonably warm and humid conditions and daily chances for 
scattered showers and thunderstorms as daytime heating interacts 
with the old frontal boundary in the region. Once the trough lifts 
out, higher heat over the Rockies and Plains could attempt to spread 
east later next weekend into the following week, but some form of NW 
mid/upper flow looks to persist keeping the warmest conditions west 
of the region. 

Highs in the upper 70s/low 80s Thursday will warm into the low/mid 
80s Friday and mid/upper 80s Saturday.

&&

.AVIATION /12Z Sunday THROUGH Thursday/...
High pressure will maintain mostly clear skies today and winds
of 10 knots or less through the period. We are seeing a few
sites with MVFR visibilities at TAF issuance but these will
improve through about 1230Z. Otherwise scattered cumulus clouds
are possible this afternoon with mostly clear skies tonight. 
Westerly winds today will veer to northwesterly at CLE/ERI/YNG 
this afternoon with a lake breeze, then east to southeast 
overnight.

Outlook...Non-VFR possible in isolated to scattered showers and
thunderstorms Tuesday through Thursday.

&&

.MARINE...
Mainly quiet conditions will continue on the lake through the 
period. Light and variable winds today and Monday thanks to high 
pressure over the southern Great Lakes will turn S to SW Monday 
night and eventually W late Tuesday with speeds increasing to 10-15 
knots as the high shifts east and a cold front sags into the region. 
Winds will then oscillate between E and NE at 10-15 knots Tuesday 
night and Wednesday as the remnants of Beryl approaching from the 
southwest before turning W to NW by Thursday as the system exits to 
the northeast.

Locally higher winds and waves could occur in and near scattered 
thunderstorms Tuesday and Wednesday.

&&

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

&&

$$

SYNOPSIS...KEC
NEAR TERM...KEC
SHORT TERM...Garuckas
LONG TERM...Garuckas
AVIATION...KEC
MARINE...Garuckas