373
FXUS61 KCLE 160907
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
507 AM EDT Tue Jul 16 2024

.SYNOPSIS...
A frontal boundary will settle across the Lower Great Lakes today
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 WEDNESDAY/...
A line of storms west of I-77 continued to move across the area,
producing very isolated strong wind gusts. This activity should
be out of the area by 12Z. Meanwhile, a wake low moving to our
north has been responsible for locally strong winds west of I-71
this morning, with observed gusts of 35kts at KTOL and 33 kts
at KFDY. Should see this activity spread east and may see brief
1-3 hour period of gusty winds before winds gradually diminish
through the day today.

Additional isolated to scattered showers and thunderstorms may
develop this afternoon/evening, though trends do not look very
favorable for severe weather despite most model guidance
forecasting moderate instability (1500-2000 J/kg MUCAPE) paired
with marginal deep layer shear (20-25kts). Subsidence in the
wake of an MCV will likely prevent too many robust updrafts in
our forecast area this afternoon. Additionally, most CAM
modeled reflectivity have an MCS (and possibly another MCV)
developing over Illinois and moving east to the south of our
forecast area by this evening into tonight. If an MCV does
develop to our south, this could potentially be a focus for
additional shower/thunderstorm develop this evening into
tonight. For now, most of the area in a marginal risk for severe
weather (level 1/5) but it`s a pretty low confidence forecast
at this point. Strong winds gusts would be the most likely
weather hazard.

By tomorrow a cold front moves in from the northwest. Most
models have a broken line of showers and thunderstorms
developing along this front during the afternoon hours. There
will be much less instability (~750-1000 J/kg MUCAPE) but
greater deep-layer shear (30-50 kts, depending on the model).
The 06Z HRRR/NAM Nest both have weak updraft helicity tracks but
it seems unlikely for this to happen. Even so, this will be
worth monitoring.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
If you`re tired of the warm and humid weather with low-
predictability convection then this portion of the forecast is for
you. Wednesday`s cold front may still be exiting during the evening
so do linger low chances for showers across our southeast the first
part of Wednesday night. Otherwise, a seasonably deep longwave
trough will be settling into the Great Lakes Wednesday night into
Thursday before shifting east-northeast into Quebec and New England
to end the work week. We may actually get lake effect clouds and a
few sprinkles Thursday morning as the trough digs in amid strong
cold air advection over the lake. Otherwise, strong high pressure
builds in Thursday night and persists through the end of the work-
week bringing mainly clear and refreshingly cooler conditions. Look
for highs in the low to mid 70s on Thursday and in the mid to upper
70s on Friday with dew points falling safely into the 50s by
Thursday afternoon. Overnight lows will likely still be in the low
to mid 60s Wednesday night but should get into the 50s outside of
the immediate lakeshore and denser urban corridors Thursday and
Friday nights. As the prior discussion said, open those windows.

&&

.LONG TERM /SATURDAY THROUGH MONDAY/...
Strong high pressure remains in control through Saturday night as we
remain beneath upper-level confluence on the backside of the
departing longwave trough. High pressure slowly weakens Sunday into
Monday as the trough to our northeast continues to depart, with the
next modest trough deepening across the Mississippi Valley by the
beginning of next week, encouraging broad and light south-
southwesterly flow over our region. High confidence in dry weather
through Saturday night. The weakening high pressure and some
moisture return on Sunday make it a bit harder to completely rule
out any chance for an increase in clouds and perhaps a stray shower
but odds in any one spot are still under 20%, precluding a forecast
mention. No major systems on Monday but gradual return flow
continues, so do begin including some 20% POPs (which does not
garner a forecast mention in our text products that far in the
future). Overall, very low impact weather for this period. Highs
will return to the low to mid 80s through the weekend with overnight
lows ranging from the upper 50s to mid 60s Saturday and Sunday
nights, with low to upper 60s in the forecast for Monday night.

&&

.AVIATION /06Z Tuesday THROUGH Saturday/...
An organized line of thunderstorms located along the IN/OH
continues to progress eastward, with recent reports of 60 mph
wind gusts. However, latest radar structure appears to suggest
that it`s weakening as it approaches the I-75 corridor. Did time
out this line of thunderstorms across all TAF sites, with
greater confidence in timing and impact for our western TAF
sites, and much lower confidence for eastern TAF sites. There
is a possibility that this dissipates quickly enough for little
to not thunderstorms to occur at sites along and east of I-77.
Will continue to monitor though. Brief lower ceilings and
visibilities will be possible within thunderstorms.

Thunderstorms should exit the area by 12Z. Additional scattered
showers and thunderstorms should develop later this afternoon
into early tonight. Timing and areal extent of these storms is
very uncertain though, so started with VCSH/VCTS mentions for
now. MVFR ceilings become

Southwest to west winds 10-12 knots with occasional gusts 18-22
knots will diminish this evening to 5-8 knots while becoming south.
Winds gradually turn southwest to west while increasing to 12-15
knots with gusts to 20-22 knots by mid Tuesday morning/early
afternoon. Winds gradually weaken tonight.

Outlook...Non-VFR possible in isolated to scattered showers and
thunderstorms Tuesday afternoon and evening. Non-VFR possible in
patchy fog Tuesday night into Wednesday morning.

&&

.MARINE...
Similar to yesterday an MCV (small low pressure generated by
thunderstorms) is currently over southeastern Michigan and will move
over or just north of Lake Erie this morning through early this
afternoon. Several hi-res models depict enhanced west-southwest
winds of 20 to perhaps briefly 30 knots moving west-east across the
lake on the south side of the MCV, and are already seeing that
across Northwest OH and the waters off of Toledo. Given that, have
issued a short-fused Small Craft Advisory until noon west of
Vermilion and 4 PM farther east. Otherwise, mainly light winds are
expected on the lake over the next several days. In decent cool air
advection northerly winds will increase to around 15 knots late
Wednesday night into early Thursday which will build some 2-4
footers in the nearshore waters. Will closely monitor that wind
forecast as an uptrend could result in a Small Craft Advisory,
though the current wind/wave forecast is below criteria.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...Beach Hazards Statement until 4 PM EDT this afternoon for
     OHZ011-012-089.
PA...Beach Hazards Statement until 4 PM EDT this afternoon for
     PAZ001.
NY...None.
MARINE...Small Craft Advisory until noon EDT today for LEZ142>144.
     Small Craft Advisory until 4 PM EDT this afternoon for
     LEZ145>149.

&&

$$

SYNOPSIS...Saunders
NEAR TERM...Saunders
SHORT TERM...Sullivan
LONG TERM...Sullivan
AVIATION...Saunders
MARINE...Sullivan