Severe Thunderstorm Warning 107, NWS Cleveland, OH

Area Forecast Discussion
National Weather Service Cleveland OH
219 PM EDT Sat Aug 20 2022

.SYNOPSIS...
A slow moving low pressure system will bring an unsettled and wet
weather pattern across the Upper Ohio River Valley region this
weekend. This low pressure system will linger over the area
through Monday before it move eastward and away from our region
Monday night. High pressure will start to build in on Tuesday
through mid week with a drier weather pattern.

&&

.NEAR TERM /THROUGH SUNDAY/...
Daytime heating with partly sunny skies has been effective at
continuing to build the instability both overhead and upstream
of the local area to 1000-2000 J/kg of ML CAPE. A swath of 70
degree dewpoints extends from western Kentucky into SW Ohio and
is expanding north this afternoon. With that said, we continue
to see an expansion of showers and thunderstorms developing
across central and western Ohio with the better organized
activity moving east out of Indiana. The Storm Prediction Center
has added our southwestern counties into a slight risk for
severe weather this afternoon and will continue to monitor
storms with the potential for either a severe thunderstorm watch
or warnings this afternoon.

Previous discussion... The nicest weather this weekend will
occur this morning through about early to mid afternoon. Then,
our weather will become somewhat unsettled and wetter with
periodic chances or waves of showers and thunderstorms starting
to move in late this afternoon. Our rain chances will ramp up
even more going into Sunday and lasting through Monday thanks to
a slow moving upper level low pressure system which will impact
our region.

The center of the upper level low shows up nicely on the
IR and water vapor satellite imagery this morning over central
Iowa. The skies over northern Ohio and northwest PA are
generally mostly clear this morning but will see a gradual
increase of high and mid level cloudiness move in from west to
east today. Partly sunny skies will help daytime high temps
reach the lower to middle 80s today. We will begin to see the
influence of the low pressure system advancing starting later
today. MLCAPE values will reach a modest 1500 to 2000 J/KG. PW
values will eventually climb up to 1.5" with a very moist
atmosphere ahead of this approaching system. Shear values will
be limited on the order of 25 to 35 knots. Slightly better shear
will be available on Sunday as the system is closer to Ohio.

We anticipate a broken line of showers and storms to develop
near the western border of Ohio by mid afternoon and track
eastward across our area through the late afternoon and evening
hours. This window between 4 pm and 9 pm will be roughly our
best time frame to see any potential for isolated stronger to
marginally severe convection developing. Storm modes will be
multi-cellular and clusters. But there could be a couple storms
that briefly tap into the limited thermodynamics over the area
and become organized enough to produce isolated damaging wind
gusts. Regardless, any of the general thunderstorms later today
will likely have some gusty winds as well as lightning and
localized heavy downpours. Some small hail could be possible
with any stronger storm but the mid lapse rates and freezing
level doesn't appear to be enough to have much of a larger hail
hail threat.

We will likely see a lull in the shower and storm chances
tonight after the initial wave moves through later this
evening. CAMs and other forecast models indicate another wave of
showers and isolated storms may track through around daybreak
through the morning hours on Sunday. The center of the system
will be near Fort Wayne, Indiana by late Sunday afternoon which
will place our local area in a very favorable area and
environment for numerous showers and storms midday Sunday
through the evening. Again thermodynamics will be limited but
maybe just enough to have an isolated damaging wind gust threat
on Sunday with any of the strongest convection. These storms
will be efficient rainfall makers. So any storms that line up
and track over the same areas could produce some localized heavy
rainfall over the next few days. We don't have any hydro
concerns yet but it will be something to watch as we see will
see multiple rounds of rainfall.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
The first half of the period will be influenced by a weak,
positively tilted mid/upper trough. The axis of this trough will
slowly drift from the southern Great Lakes Sunday night into central
New York early Tuesday before becoming absorbed into the large scale
longwave trough over the eastern CONUS by Tuesday night, leaving
broad NW flow in place in its wake with surface high pressure
sliding from the western Great Lakes into the Ohio Valley.

For Sunday night and Monday, the mid/upper trough and remnant closed
circulation are essentially overhead with a distinct 850 mb low
looking to track from west central Ohio across eastern Ohio and into
PA, but models differ slightly on this exact track with the GFS,
CMC, and ECMWF taking the 850 mb low from western Lake Erie Sunday
night into western New York by Monday night, while the NAM takes it
from west central Ohio through southeast Ohio. Despite these
differences, PVA beneath the upper system, abundant low-level
moisture characterized by seasonably high PWATs averaging 1.50
inches, and increasing low-level convergence as the trailing cold
front slowly progresses from NW to SE Monday and Monday night will
support fairly high coverage of showers and thunderstorms. Coverage
will be highest during peak heating on Monday afternoon, especially
along and east of I-77 where convergence ahead of the front will be
maximized, and models even hint at a mid-level front/deformation
zone wrapping around the backside of the 850 mb low which further
supports a more enhanced band of showers and thunderstorms. However,
still kept at least likely PoPs Sunday night and Monday morning
since the aforementioned forcing and moisture in place will at least
support showers. Upstream radars over the Midwest have shown this
upper low to be active with showers and thunderstorms overnight, so
this also gives confidence in the likely PoPs. There will likely be
too much cloud cover and precip for any severe weather Sunday night
and Monday, but weak to moderate instability, seasonably high PWATs,
and the likelihood for repeated bands wrapping around the system
will support some locally heavy rain. Localized flooding is possible
in areas that see repeated showers and thunderstorms or training.

Monday night will begin the drying trend as the system departs into
central New York, but a trailing surface trough and low level
moisture continuing to wrap around will allow the chance for
scattered showers to persist over NE Ohio and NW PA. It will not be
cool enough for a pure lake response, but NW flow off the lake could
certainly give a slight boost Monday night into Tuesday morning in
these aforementioned areas. The lingering moisture and surface
trough will support diurnal showers and thunderstorms again Tuesday
afternoon, mainly in eastern Ohio and western PA, but coverage will
be far less than Monday. All areas will finally be dry Tuesday night
as the surface high builds in from the west.

Highs Monday will be in the mid 70s to low 80s rebounding a bit into
the upper 70s to mid 80s Tuesday due to increased sunshine. Lows
Sunday night and Monday night will stay in the low/mid 60s with
continued muggy conditions before cooling into the upper 50s to low
60s Tuesday night.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
The surface high will be in control Wednesday through Thursday while
gradually shifting east toward the Mid Atlantic. Broad eastern CONUS
mid/upper troughing will remain in place Wednesday through Thursday
as well, but this trough will lift out briefly Thursday night into
Friday as the high departs ahead of another shortwave and associated
cold front dropping through the Great Lakes. This front looks to
stall in northern Ohio or across the lower Great Lakes, but guidance
is flip flopping on how far south it pushes. This pattern will
support dry conditions Wednesday through Thursday night followed by
a chance for showers/thunderstorms Friday, along with near normal
temperatures Wednesday rebounding to slightly above normal Thursday
and Friday as heights rise.

&&

.AVIATION /18Z Saturday THROUGH Thursday/...
Showers and thunderstorms will continue to expand across western
and central Ohio this afternoon as instability builds across
the region. Scattered thunderstorms are developing ahead of a
more organized line of storms moving into NW Ohio. Have tried to
time these into most terminals reaching TOL/FDY as early as 19Z,
CLE closer to 23Z, and rain reaching ERI towards 04Z.
Adjustments will be needed to timing and could potentially see
a few stronger wind gusts to 40 knots or more with the stronger
storms. MVFR conditions are also expected with thunderstorms.
Otherwise expecting to remain primarily VFR through about 8Z
with the potential for a few pockets of MVFR ceilings or
visibilities if skies clear out and locations had received rain
this evening. Predictability was generally to low to include
but do expect to see an expansion of clouds in the 3-4K range
after 12Z Sunday. Additional scattered showers will be possible
both overnight and on Sunday with thunderstorms increasing in
coverage after 16Z Sunday. Winds will generally be light out of
south or southwest except with thunderstorms.

Outlook...Non-VFR possible with scattered rain showers and
thunderstorms Sunday through Tuesday, with the best chance
Saturday afternoon through Monday.

&&

.MARINE...
Periods of showers and thunderstorms will affect the lake late today
through Tuesday, with the greatest chances coming Sunday and Monday,
but outside of any thunderstorms, quiet conditions are expected on
Lake Erie over the next 5 days. Light easterly winds of 5-10 knots
today become more southerly tonight through Sunday night before
becoming west and eventually northwest Monday. NNW winds of 10-15
knots are then expected behind a cold front Monday night into
Tuesday before backing more westerly and decreasing late Tuesday
into Wednesday. This will keep waves generally under 1 foot through
the period, except 1-2 feet Monday night into Tuesday.

The International Centre for Waterspout Research (ICWR) shows a risk
Sunday night into early Monday and again Monday night into early
Tuesday. The lake surface to 850 mb delta T's will only be 9 to 10
C, but low LCL heights and light winds adding some south shore
convergence could support a waterspout or two. Not confident enough
to put in the marine forecast products at this time though given the
lacking delta T's.

&&

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

&&

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

Hazardous Weather Outlook
National Weather Service Cleveland OH
323 AM EDT Sat Aug 20 2022

LEZ061-142>149-162>169-OHZ003-006>014-017>023-027>033-036>038-047-
089-PAZ001>003-210730-
Ripley to Buffalo NY extending from 5NM off shoreline to US-
Canadian border-Maumee Bay to Reno Beach OH-
Reno Beach to The Islands OH-The Islands to Vermilion OH-
Vermilion to Avon Point OH-Avon Point to Willowick OH-
Willowick to Geneva-on-the Lake OH-Geneva-on-the-Lake to Conneaut OH-
Conneaut OH to Ripley NY-
Detroit River Lt. to Maumee Bay OH to Reno Beach OH beyond 5NM
offshoreline to US-Canadian border-
Reno Beach to The Islands OH beyond 5NM off shoreline to US-
Canadian border-
The Islands to Vermilion OH beyond 5 nm off shoreline to US-
Canadian border-
Vermilion to Avon Point OH beyond 5 nm off shoreline to US-
Canadian border-
Avon Point to Willowick OH beyond 5 nm off shoreline to US-
Canadian border-Willowick to Geneva-on-the-
Lake OH beyond 5NM off shoreline to US-Canadian border-Geneva-on-the-
Lake to Conneaut OH beyond 5 nm off shoreline to US-Canadian border-
Conneaut OH to Ripley NY beyond 5 nm off shoreline to US-
Canadian border-Lucas-Wood-Ottawa-Sandusky-Erie-Lorain-Cuyahoga-Lake-
Geauga-Ashtabula Inland-Hancock-Seneca-Huron-Medina-Summit-Portage-
Trumbull-Wyandot-Crawford-Richland-Ashland-Wayne-Stark-Mahoning-
Marion-Morrow-Holmes-Knox-Ashtabula Lakeshore-Northern Erie-
Southern Erie-
323 AM EDT Sat Aug 20 2022

This Hazardous Weather Outlook is for Lake Erie, north central
Ohio, northeast Ohio, northwest Ohio and northwest Pennsylvania.

.DAY ONE...Today and tonight.

A couple isolated strong to marginally severe thunderstorms are
possible late this afternoon into evening. There is a very limited
risk for isolated damaging wind gusts of 50 to maybe 60 mph with the
strongest and more organized storms. Localized heavy rainfall will
be possible with storms that train over the same area.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

Isolated strong to marginally severe thunderstorms will be possible
again Sunday afternoon and evening. The main threat will again be for
isolated damaging wind gusts of 50 to maybe 60 mph with the
strongest and more organized storms. Localized heavy rainfall will be
possible with storms that train over the same area.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

Special Weather Statement
National Weather Service Cleveland OH
422 PM EDT Sat Aug 20 2022

OHZ008-018-019-202100-
Seneca OH-Huron OH-Sandusky OH-
422 PM EDT Sat Aug 20 2022

...A strong thunderstorm will impact portions of northwestern Huron,
Seneca and southeastern Sandusky Counties through 500 PM EDT...

At 422 PM EDT, Doppler radar was tracking a strong thunderstorm over
Tiffin, moving northeast at 50 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Tiffin, Bellevue, Clyde, Green Springs, Bloomville, New Riegel,
Monroeville, Republic, Flat Rock and Vickery.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4140 8294 4134 8284 4129 8284 4129 8276
      4124 8268 4100 8302 4099 8328 4104 8336
TIME...MOT...LOC 2022Z 227DEG 45KT 4112 8318

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

Lombardy

Special Weather Statement
National Weather Service Cleveland OH
436 PM EDT Sat Aug 20 2022

OHZ028-029-036-037-047-202115-
Crawford OH-Marion OH-Richland OH-Morrow OH-Knox OH-
436 PM EDT Sat Aug 20 2022

...Strong thunderstorms will impact portions of western Richland,
northeastern Marion, Morrow, southeastern Crawford and northwestern
Knox Counties through 515 PM EDT...

At 436 PM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from 8 miles southwest of Galion to near Sunbury.
Movement was northeast at 25 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Mansfield, Mount Vernon, Mount Gilead, Galion, Shelby, Ontario,
Lexington, Crestline, Fredericktown, Cardington, Bellville, Plymouth,
Chesterville, Sparta, Waterford, Butler, Caledonia, Edison, Marengo
and Tiro.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4035 8275 4035 8286 4070 8300 4078 8294
      4100 8265 4044 8232 4032 8274
TIME...MOT...LOC 2036Z 240DEG 22KT 4068 8293 4030 8283

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

Lombardy

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CLEVELAND OH
437 PM EDT SAT AUG 20 2022

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0425 PM     FLOOD            MARION                  40.58N 83.12W
08/20/2022                   MARION             OH   911 CALL CENTER

            WIDESPREAD STREET FLOODING IN MARION WITH
            VEHICLES STRANDED. WATER DUE TO SEWER BACKUP
            APPROACHING SOME HOMES AS WELL.

&&

JS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CLEVELAND OH
439 PM EDT SAT AUG 20 2022

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0301 PM     TSTM WND DMG     1 WNW GREEN CAMP        40.54N 83.23W
08/20/2022                   MARION             OH   911 CALL CENTER

            TREE DOWNED ACROSS LARUE-GREEN CAMP ROAD.
            TIME ESTIMATED VIA RADAR.

&&

JS

Special Weather Statement
National Weather Service Cleveland OH
440 PM EDT Sat Aug 20 2022

OHZ007>009-202130-
Erie OH-Ottawa OH-Sandusky OH-
440 PM EDT Sat Aug 20 2022

...A strong thunderstorm will impact portions of Ottawa, Erie and
eastern Sandusky Counties through 530 PM EDT...

At 440 PM EDT, Doppler radar was tracking a strong thunderstorm 7
miles south of Port Clinton, moving northeast at 40 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Sandusky, Fremont, Port Clinton, Clyde, Castalia, Marblehead,
Bloomingville, Sandusky South, Vickery, Fairview Lanes and Whites
Landing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4140 8314 4146 8303 4143 8301 4142 8292
      4147 8281 4144 8276 4146 8271 4150 8274
      4151 8281 4147 8283 4150 8285 4147 8301
      4157 8282 4153 8282 4154 8271 4150 8273
      4142 8262 4139 8252 4140 8242 4126 8303
TIME...MOT...LOC 2040Z 239DEG 34KT 4141 8295

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

Lombardy

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CLEVELAND OH
441 PM EDT SAT AUG 20 2022

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0333 PM     TSTM WND DMG     MARION                  40.58N 83.12W
08/20/2022                   MARION             OH   911 CALL CENTER

            TREE DOWNED INTO A HOUSE. TIME ESTIMATED VIA
            RADAR.

&&

JS