286 
FXUS61 KCLE 141928
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
328 PM EDT Sun Jul 14 2024

.SYNOPSIS...
A frontal boundary will settle across the Great Lakes through
Tuesday before pushing southeast across the area as a cold front
Tuesday night into early Wednesday. High pressure will build in
from the west Wednesday night through the end of the week.

&&

.NEAR TERM /THROUGH MONDAY NIGHT/...
Scattered showers have developed across NE OH and NW PA and 
ahead of an MCS that is approaching the CWA from the west. The 
strongest convection associated with the MCS is following the 
instability gradient and will miss the local area to the 
southwest, but it's possible that the developing convection to 
the north congeals into the line and scrapes southwestern zones 
that are currently in a Severe Thunderstorm Watch and a Slight 
Risk for severe weather. A boundary is currently lifting 
northeast across the watch area, which could serve as a focus 
for convergence and convective initiation as the MCS tracks 
eastward this afternoon into this evening.

Additional scattered convection may develop through early this 
evening, as already evident in Lucas County. The big question 
is how widespread the convection will be and how much eastern 
locations destabilize over the next few hours - if 
destabilization occurs, there's potential for more widespread 
and stronger thunderstorms since there will be boundaries in 
place. As of now, however, there is quite a bit of CIN and 
destabilization is struggling. Unfortunately, CAMs are not 
handling the current situation well, so will need to rely 
heavily on mesoanalysis, radar, and satellite trends and adjust 
the forecast as necessary.

While the best instability will be in western zones, there will
be sufficient buoyancy and moisture for damaging winds and 
heavy downpours within any thunderstorms that develop. Shear is
a bit marginal (20-30 knots) but there is just enough for a 
low-end tornado and hail threat.

It's safe to say that the forecast for overnight and through the
remainder of the near term period also remains uncertain and 
will depend on how things shake out this afternoon and evening.
Another MCS will likely approach the area from the northwest
late tonight into early Monday morning with another round of
convection possible Monday night. How much each line holds 
together as it crosses into the CWA will depend on instability 
and any boundaries left behind from previous storms. Can't rule
out strong to severe thunderstorms and heavy rainfall with any
storms through Monday night. A Marginal Risk for severe weather
is in place for the entire area Monday with a Slight Risk
clipping the I-75 corridor.  

It will be quite warm and humid throughout the period, although
maximum temps Monday will depend on cloud cover and
precipitation. Highs may reach the upper 80s to lower 90s with
dew points in the low to mid 70s expected. Heat indices may very
briefly touch 100 degrees, but not confident enough to do a heat
headline since any cloud cover or showers/storms will result in
cooler temps/heat indices. Overnight lows will be in the lower
70s each night.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
Active weather pattern will continue to impact the area through the 
short term period as a northwest flow pattern remains established 
with areas of shortwave upper level energy advecting along the broad 
upper level trough. Initially Tuesday morning, remnants of an 
overnight MCS may continue to bring showers and thunderstorms to the 
area, although with limited instability at that time, right now only 
expecting some gusty winds and heavy rainfall. As stated a plethora 
of times in previous discussions, there is a potential for this 
forecast to change/evolve and will be highly dependent on how 
mesoscale features develop upstream and the strength of the system 
when it arrives to northern Ohio. 

By Tuesday afternoon, a cold front will approach the area from the 
northwest with stronger synoptic forcing arriving as well. A mid-
level shortwave and LLJ of 40-50 knots will act to enhance storm 
development. High instability, increasing shear, and a very moist 
airmass with dewpoints in the 70s will aid in enhancement from the 
mesoscale aspect, especially by mid to late afternoon ahead of the 
front. In addition to the potential for storm development, PWAT 
values in excess of 2", deep warm cloud layers, and nearly parallel 
storm motion to the boundary will create very heavy and efficient 
rainfall. This may lead to localized flooding concerns, especially 
in urban areas and where training storms develop. Maintained the 
heavy rain wording for the forecast on Tuesday and Tuesday night to 
account for this threat. To highlight these risks on Tuesday and 
into Tuesday night, SPC has issued a Day 3 Marginal Risk for severe 
weather with strong, damaging winds the greatest threat. WPC has 
issued a Slight Risk ERO for the entire area. 

Late Tuesday into Wednesday, models suggest the cold front moving 
across the area will begin to slow. Uncertainty in how much it will 
slow and overall timing remains, so opted to increase PoPs across 
the eastern tier of counties throughout the day on Wednesday. Giving 
the weakened environment, not thinking much will remain severe, but 
opted to maintain chance thunder at this time. Overnight on 
Wednesday, the front should settle to the southeast of the area, 
allowing high pressure to build in, breaking the active weather 
trend and allowing for dry conditions to return. 

Temperatures on Tuesday will be quite warm and muggy with highs 
climbing into the upper 80s to low 90s with dewpoints in the 70s. 
This will result in heat index values climbing into the mid to upper 
90s. As the front slow meanders southeast, overnight temperatures on 
Tuesday night will be a bit milder in the northwestern counties, 
dropping into the mid 60s, but elsewhere they will likely only fall 
into the upper 60s to low 70s again. A cool off is expected 
Wednesday when highs only climb into the low 80s during the day and 
lows fall into the upper 50s to low 60s overnight.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
For the entire long term period, high pressure will be the dominant 
driving force of weather across the region, resulting in another 
prolonged period without rainfall with cooler temperatures. Highs on 
Thursday and Friday will only climb into the upper 70s to low 80s, 
before warming back into the mid to upper 80s for this weekend. 

&&

.AVIATION /18Z Sunday THROUGH Friday/...
Quite a tricky TAF forecast with potential for several rounds of
convection possible through 18Z Monday. The main area of 
concern is associated with an MCS currently within the vicinity 
of KFDY, however the strongest activity within that complex will
likely miss the forecast area to the southwest. However, 
scattered showers and thunderstorms may develop across the
entire area this afternoon into this evening. There's still 
some uncertainty in how much the atmosphere destabilizes this 
afternoon, especially as the boundary associated with the MCS 
moves through the area, which will affect the coverage and 
placement of thunderstorms through this evening. Have showers 
and thunderstorms at terminals where confidence in 
shower/thunderstorm chances is highest with VCSH/VCTS elsewhere 
(there will likely be amendments as the afternoon unfolds). 

There will likely be a lull in shower and thunderstorm activity
later this evening before another MCS approaches from the 
northwest overnight. There's a decent chance of more widespread
showers, but any thunderstorm potential will depend on recovery
and any boundaries left over by earlier convection.

To sum things up, there will be multiple opportunities for
convection over the next 24 hours and the forecast will be 
driven by mesoscale features that have yet to materialize. Any 
showers/thunderstorms that move directly over terminals could 
produce torrential rainfall resulting non-VFR conditions and 
brief erratic, gusty winds. Amendments will most likely be 
needed throughout the period as confidence increases.

Outside of thunderstorms, expect VFR conditions and winds out 
of the south/southwest at 6 to 12 knots.

Outlook...Mainly VFR outside of occasional thunderstorms through
Tuesday evening.

&&

.MARINE...
Southwest flow of 10-15 knots is expected to persist through 
Tuesday. Winds may occasionally approach 20 knots on Tuesday as a 
cold front approaches from the east. Timing of the onset of these 
winds remains uncertain given the overall uncertainty with the 
progression of the system the next few days. With that being said, 
cannot rule out a potential short fused Small Craft Advisory being 
needed for Tuesday. Late Tuesday into Wednesday, a cold front will 
move south of the lake, shifting winds to west-northwest at 5-10 
knots behind the boundary as high pressure builds east. These winds 
will persist through at least Friday before becoming more 
northeasterly this weekend. 

It is worth noting the potential for multiple rounds of strong to 
severe storms today through Tuesday. Where these storms do develop, 
strong, damaging wind gusts are the primary threat. In areas 
impacted by these storms, winds and waves may locally increase and 
briefly cause hazardous marine conditions. 

&&

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

&&

$$

SYNOPSIS...Maines
NEAR TERM...Maines
SHORT TERM...Campbell
LONG TERM...Campbell
AVIATION...Maines
MARINE...Campbell