442
FXUS61 KCLE 210143
AFDCLE

Area Forecast Discussion
National Weather Service Cleveland OH
943 PM EDT Mon May 20 2024

.SYNOPSIS...
Low pressure will track northeast across the Plains Tuesday,
extending a cold front east across the area on Wednesday. High
pressure will return for Thursday, followed by another cold front
Thursday night into Friday.

&&

.NEAR TERM /THROUGH TUESDAY NIGHT/...
930 PM Update...
Slight adjustments were made to temperatures that cooled quicker
than previously forecast, but no other changes were needed with
this update.

630 PM Update...
There remains a potential for a few isolated strong
thunderstorms in NW OH where the lake breeze continues to
interact with convection lifting northeast through the area.
Overall threat for severe remains limited, especially with the
sun setting, but will continue to monitor the ongoing
convection. These storms should end over the next couple hours,
leaving the remainder of tonight dry as upstream convection is
not expected to move into the area. Only minor tweaks were made
with this update to highlight the area of greatest potential of
storms this evening, but the remainder of the forecast is
unchanged.

Previous Discussion...
The severe thunderstorm across NW OH has exited land with recent
satellite and radar trends suggesting a weakening trend as it
continues north across Lake Erie. Otherwise, could see
additional isolated to scattered shower/thunderstorm coverage
further east, mainly associated with the lake breeze near the
lakeshore. However, low-level moisture is much more limited
further east and southeast, evident by larger T/Td spreads and
deeper mixing.

Following sunset, dry conditions should primarily exist
overnight and into Tuesday morning, although we`ll need to watch
residual outflow/lingering showers and thunderstorms
approaching from the west overnight. Otherwise, the dynamics
that generated thunderstorms today will be similar for Tuesday
afternoon and evening, largely lake-breeze driven with limited large-
scale forcing evident. However, expecting initiation further
east this time as enhanced low- level moisture pools across
North and Northeast Ohio, coupled with marginal MLCAPE around
1000 J/kg, weak shear less than 20 knots, and steep 0-3 km lapse
rates ranging between 8-9 C/km. Once again, we`ll need to watch
for residual outflow/showers and thunderstorms approaching from
the west Tuesday night.

Near record-highs are possible again for Tuesday across the
area, with temperatures rising into the upper 80s to lower 90s.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
A shortwave trough will move into the western and Upper Great Lakes
Region on Wednesday. The Ohio Valley region will be in a
southwesterly deep-layer flow with an enhanced vorticity maxima
moving along in the flow. A cold front will slowly sag southeastward
through the lower and eastern Great Lakes region Wednesday afternoon
and night. A moist and unstable airmass ahead of the slow moving
frontal boundary will become destabilized on Wednesday into Wednesday
evening. Surface dewpoints will rise into the middle 60s. Modest
midlevel lapse rates will be around 7 C/km. Moderate destabilization
will be possible with MLCAPE up to 2000 J/kg. Vertical shear will be
modest around 35 knots. Scattered showers and thunderstorms will be
likely with a few of them possibly severe with isolated damaging
wind gusts and some hail possible Wednesday afternoon into the
evening. Afternoon high temperatures will max out once again in the
middle to upper 80s Wednesday before convection develops.

The slow moving cold front will reach central and southern Ohio on
Thursday. We will maintain higher POPs for showers and thunderstorms
on Thursday for areas along and south of Highway 30 and lesser
values closer to the lakeshore. Weak high pressure tries to build in
Thursday night with a slight drying trend. High temperatures on
Thursday will be slightly cooler in the middle to upper 70s.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
The extended forecast by next weekend is a little uncertain given
the erratic westerly flow beyond day 5. It appears we may have a weak
area of high pressure over the eastern Great Lakes on Friday with a
fair weather day. High temperature will be in the middle 70s to
around 80 degrees. The Ohio Valley region will remain a psuedo deep
layer southwesterly flow aloft. The next impulse in that flow may
arrive over the weekend of by the later half with the next round of
showers and storms. Temperatures will remain above average for next
weekend.

&&

.AVIATION /00Z Tuesday THROUGH Saturday/...
Widespread VFR conditions are expected to persist through this
TAF period as the area remains in the warm sector of an
approaching system. A few thunderstorms continue to linger over
NW OH, but with how isolated they are opted to not include in
the KTOL TAF as confidence is very low that another storm will
impact the terminal especially given the weakening environment.
Once these showers exit the area the remainder of the overnight
period will be dry as ongoing upstream convection is not
expected to persist far enough east to impact KTOL or KFDY. A
similar pattern will repeat itself tomorrow with another
potential of daytime thunderstorms across the area, some that
may be strong with gusty winds the primary concern. Again opted
to not include in the TAFs due to the scattered nature expected
and low confidence, but the best timing for any convection will
be between 18Z Tuesday to 00Z Wednesday.

Winds will persist from the south-southwest at 4-10 knots
through this period, although KCLE and KERI will likely be
impact by another lake breeze Tuesday afternoon which will shift
the winds to be from the north.

Outlook...Mainly VFR expected outside of any thunderstorms.
Isolated thunderstorms are possible during the afternoon and
early evening hours Tuesday. Scattered to numerous thunderstorms
are more likely Wednesday afternoon into Wednesday night.

&&

.MARINE...
There is a weak lake breeze near the lakeshore this afternoon. This
lake breeze should wash out by sunset this evening. A warm front
will move northward across the lake this evening. A weak low will
pass north of the lake tonight and allow for south to southwest flow
up to 10 knots to return over Lake Erie. A slightly stronger low
pressure system will develop over the Upper Midwest Tuesday and the
pressure gradient will increase across the lake Tuesday night into
Wednesday. Southerly to southwesterly winds will strengthen up to 20
knots. The southwest flow on Wednesday afternoon could mix pretty
well and wind speeds may be close to SCA headline. A slow moving
cold front will extend across the lake on Wednesday night and winds
will shift from the west and then north as high pressure builds over
the lake on Thursday. The surface high will move east of the lake on
Friday and northeast flow will be favored.

&&

.CLIMATE...
High temperatures will approach record values today and Tuesday.

Daily Record High Maximum Temperatures

Date    Toledo         Mansfield      Cleveland      Akron          Youngstown     Erie
05-21   93(1941)       89(1941)       89(1941)       91(1934)       89(1934)       88(1911)

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...Air Quality Alert until midnight EDT Tuesday night for
     OHZ010>014-020>022-089.
PA...None.
NY...None.
MARINE...None.

&&

$$

SYNOPSIS...Kahn
NEAR TERM...Campbell/Kahn
SHORT TERM...Griffin
LONG TERM...Griffin
AVIATION...Campbell
MARINE...Griffin
CLIMATE...