Severe Thunderstorm Warning 105, NWS Cleveland, OH

Area Forecast Discussion
National Weather Service Cleveland OH
147 PM EDT Sun Jul 19 2020

...18z Aviation Forecast Update...

.SYNOPSIS...
A cold front will move southeast across the area
tonight and become nearly stationary across the Ohio Valley through
Monday. The stationary front will lift north as a warm front on
Tuesday. Another cold front will move east across the area on
Wednesday.

&&

.NEAR TERM /THROUGH MONDAY/...
930 am update...
No significant changes were made to the ongoing forecast for
this afternoon. High res short guidance indicate strong to
severe convection will begin moving into the area between 18z
and 20z.

Previous discussion...
MCS complex still ongoing across portions of the Upper
Midwest/northern MI. It remains unclear of the evolution of this
complex as it tracks southeast this morning, though expectation
is for it to begin to decay over the next couple of hours as it
enters a mostly capped thermodynamic environment.

Remnant MCV noted on the Nighttime Microphysics satellite this
morning across the eastern basin of Lake Erie. Otherwise, dry
and mostly quiet weather is expected through the morning hours.
The two big weather stories today will be the heat and the
chance for severe weather later this afternoon into the evening
hours.

Regarding the heat -

A heat advisory remains in effect from noon to 8 pm across the
entire Ohio portion of the CWA with the recent additions of
Ashtabula/Trumbull/Mahoning Counties. Temperatures will quickly rise
into the lower 90s by noon across the area with southwesterly flow
transporting abundant moisture across the area throughout the day
today. Low to mid 70 dew points are already present across the
Midwest with a plume of PWATs in excess of 2 inches across the Upper
Midwest, evident in the GOES-derived PWAT product. The main question
is how long these surface 70 dew points will remain given afternoon
boundary layer mixing and how high our temperatures can get before
shower/thunderstorm initiation and any cloud debris from residual
overnight thunderstorm complexes to our west. Still thinking much of
the area will reach and maintain 100+ heat indices for at least 2
hours with the exception of NW PA, though the Erie lakeshore will be
close.

Regarding the severe/heavy rain threat -

There remains considerable differences between hi-res models on
timing and location of thunderstorm initiation. The 1730 SPC update
from yesterday remains unchanged with a slight risk across the
entire CWA, mainly for the damaging wind threat. It appears the HRRR
has a relatively good handle on ongoing upstream convection across
portions of the Upper Midwest and Upper Great lakes this morning.
This solution would bring a decaying MCS across central/northern MI,
laying outflow boundaries across southern MI into northern IN. Thus,
initiation would be somewhere around 20-21Z across SE MI/NE IN/NW OH
and propagate east/southeastward into the evening hours.

Not much has changed in the way of the background thermodynamic
environment with 2000 to 3000 J/kg of MLCAPE, modest mid-level lapse
rates of about 6 to 7 C/km, and 20 to 25 knots of effective
shear. Several models are now picking up on a subtle piece of
jet energy that appears to break off from the main flow which
could enhanced storms that develop across NW OH and along the
lakeshore. Appears the main hazard will be damaging winds up to
60 mph as bulk shear vectors align parallel to the initiating
boundary, suggesting organized multicell clusters and/or bowing
segments. The threat for large hail up to quarters appears low
with unfavorable wet-bulb zero heights and high RH throughout
the column, though is a possibility in the first couple of hours
as storm initiate and remain more discrete. SPC has removed the
2% threat for tornadoes and tend to agree given the overall
unidirectional flow from the west and 0-3 km bulk shear vectors
less than 30 knots.

The threat for heavy rain is also apparent with the WPC outlooking
our entire CWA in a marginal risk of excessive rain. Aforementioned
PWATs in excess of 2 inches across the Upper Midwest will propagate
east across MI, arriving into our area this afternoon, though they
appear to be closer to around 1.8 to 2.0 inches. Warm cloud depths
in excess of 10 kft will be present across the area, owing to heavy
bursts of rain with any convection. The one caveat will be the
relatively fast motion of the storms with cloud layer winds around
30 knots. Would need training of storms for any appreciable flooding
threat. However, this could certainly be a possibility as the front
begins to flatten in more of a west/east orientation as we head into
the evening hours.

Convection should begin to wane in the late evening/overnight hours
as the nocturnal boundary layer begins to stabilize and any upper
forcing moves away from the complex. Monday will feature quiet and
dry weather with slightly less humid conditions with temperatures
reaching the upper 80s and dew points in the lower 60s.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
Upper level pattern will switch to a more zonal flow with high
pressure at the surface Monday night. The cooler and drier airmass
will keep showers at bay during the overnight, but attention will
turn to the next shortwave approaching from the west. There is some
indication of upstream mcs development overnight that could trek
eastward bringing increased vorticity over the local area by Tuesday
afternoon. Should this feature materialize than there will be
enhanced shear combined with return flow/increased moisture to
support strong to severe storms and heavy rain. This set up is
conditional on the feature upstream. Should this complex not
materialize than the risk for strong storms lessens. However,
convection will still develop with the presence of the warm front
timed with diurnal heating in the afternoon. The surface low will
move east over Lake Huron Wednesday, dragging a cold front in its
wake. This will support the best chances for shower and thunderstorm
coverage in the forecast period. Temperatures will remain a few
degrees above normal Tuesday and Wednesday with high thicknesses
over the area, despite increased cloud coverage and shower activity.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
For late week the pattern will favor northwest flow aloft with a
trough over the northeast. Multiple weak shortwaves expected to
rotate over the lower lakes late week. These features combined with
diurnally driven pop up convection make it difficult to rule out
shower/storm activity at any time late in the forecast despite
surface high pressure building south on Friday. Surface temperatures
will remain at to slightly above normal temperatures and dewpoints
will be in the 60s. With elevated instability during the overnight
hours could see ongoing showers and thunderstorms, though coverage
will lessen after dark. Ridging starts to edge east into the area
over the weekend which should support gradually warming.

&&

.AVIATION /18Z Sunday THROUGH Friday/...
Mainly VFR conditions are expected with the exception for this
afternoon and evening in and around scattered strong to severe
convection. We have mentioned this potential in a TEMPO groups
between 20z and 02z from northwest to southeast across the area.
Ceilings and visibilities may drop briefly to MVFR. All
convection will decrease and move out of the area later tonight.
VFR is expected for tomorrow. Winds will be southwesterly and
gusty this afternoon 10 to 15 knots. Gusts will be higher at
around 20 knots. Higher gusts of 30 to 45 knots could be
possible in and near thunderstorms this afternoon and evening.
Winds will relax from the west tonight and tomorrow around 5 to
10 knots.

Outlook...Occasional non-VFR possible with scattered showers
and thunderstorms on Tuesday and Wednesday.

&&

.MARINE...
Have added headlines for all nearshore waters today into this
evening mainly for gusts. Southwest flow will increase today as a
shortwave approaches from the upper lakes. The lakes will remain
more stable than the inland locations, however believe enough mixing
will still occur over the water to bring down frequent gusts over
20kt into this evening. With the front approaching tonight could see
a period of sustained small craft winds mainly in the east for an
hour or two. Waves are projected to reach 4' mainly across the
central and eastern basin. Winds will diminish overnight with
improved conditions under high pressure on Monday.  Otherwise,
several more rounds of showers/storms will impact the nearshore
waters through Tuesday and Wednesday.

&&

.CLIMATE...
ERI and CLE have a chance to tie or exceed previous record daily
high temperatures later today. The forecast high temperature at
ERI is 92 degrees while the record is 93 degrees set in 1946.
The forecast high temperature at CLE is 95 degrees while the
record record is 95 degrees set in 1930.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...Heat Advisory until 8 PM EDT this evening for OHZ003-006>014-
     017>023-027>033-036>038-047-089.
PA...None.
MARINE...Small Craft Advisory until midnight EDT tonight for LEZ147>149.
     Small Craft Advisory until 10 PM EDT this evening for
     LEZ142>146.

&&

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

Hazardous Weather Outlook
National Weather Service Cleveland OH
252 PM EDT Sun Jul 19 2020

LEZ061-142>149-162>169-201900-
Lake Erie open waters from Ripley to Buffalo NY-
Lake Erie nearshore waters from Maumee Bay to Reno Beach OH-
Lake Erie nearshore waters from Reno Beach to The Islands OH-
Lake Erie nearshore waters from The Islands to Vermilion OH-
Lake Erie nearshore waters from Vermilion to Avon Point OH-
Lake Erie nearshore waters from Avon Point to Willowick OH-
Lake Erie nearshore waters from Willowick to Geneva-on-the Lake OH-
Lake Erie nearshore waters from Geneva-on-the-Lake to Conneaut OH-
Lake Erie nearshore waters from Conneaut OH to Ripley NY-
Lake Erie open waters from Maumee Bay to Reno Beach OH-
Lake Erie open waters from Reno Beach to The Islands OH-
Lake Erie open waters from The Islands to Vermilion OH-
Lake Erie open waters from Vermilion to Avon Point OH-
Lake Erie open waters from Avon Point to Willowick OH-
Lake Erie open waters from Willowick to Geneva-on-the-Lake OH-
Lake Erie open waters from Geneva-on-the-Lake to Conneaut OH-
Lake Erie open waters from Conneaut OH to Ripley NY-
252 PM EDT Sun Jul 19 2020

This Hazardous Weather Outlook is for central Lake Erie, eastern
Lake Erie and western Lake Erie.

.DAY ONE...This afternoon and tonight.

There is a slight risk for strong to severe storms this afternoon and
evening with the primary threat being damaging winds and heavy rain.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to Standard Operating Procedures. Please relay
any information about observed severe weather to the NWS while
following all local, state, and CDC guidelines.

OHZ003-006>014-017>023-027>033-036>038-047-089-201900-
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-
252 PM EDT Sun Jul 19 2020

...HEAT ADVISORY IN EFFECT UNTIL 8 PM EDT THIS EVENING...

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

.DAY ONE...This afternoon and tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Heat Advisory.

There is a slight risk for strong to severe storms this afternoon and
evening with the primary threat being damaging winds and heavy rain.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to Standard Operating Procedures. Please relay
any information about observed severe weather to the NWS while
following all local, state, and CDC guidelines.

PAZ001>003-201900-
Northern Erie-Southern Erie-Crawford-
252 PM EDT Sun Jul 19 2020

This Hazardous Weather Outlook is for northwest Pennsylvania.

.DAY ONE...This afternoon and tonight.

There is a slight risk for strong to severe storms this afternoon and
evening with the primary threat being damaging winds and heavy rain.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to Standard Operating Procedures. Please relay
any information about observed severe weather to the NWS while
following all local, state, and CDC guidelines.

Special Weather Statement
National Weather Service Cleveland OH
157 PM EDT Sun Jul 19 2020

PAZ001-002-191900-
Northern Erie-Southern Erie-
157 PM EDT Sun Jul 19 2020

...A STRONG THUNDERSTORM WILL AFFECT SOUTHWESTERN ERIE COUNTY...

At 157 PM EDT, a strong thunderstorm was located near Albion, or 9
miles east of Conneaut, moving east at 25 mph.

Winds in excess of 40 mph are possible with this storm.

Locations impacted include...
Erie, Edinboro, Girard, Albion, Northwest Harborcreek, Lawrence Park,
Wesleyville, Lake City, Cranesville, Platea, McKean and Avonia.

LAT...LON 4185 8000 4185 8052 4198 8051 4201 8043
      4204 8031 4211 8017 4217 8000
TIME...MOT...LOC 1757Z 278DEG 21KT 4195 8038

Lombardy

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CLEVELAND OH
206 PM EDT SUN JUL 19 2020

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

0140 PM     MARINE TSTM WIND 3 NE AVONIA             42.08N 80.24W
07/19/2020  M41 MPH          LEZ149             PA   PUBLIC

            MEASURED BY MARINA. TIME ESTIMATED VIA
            RADAR.

&&

ANM

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CLEVELAND OH
221 PM EDT SUN JUL 19 2020

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

0148 PM     MARINE TSTM WIND 3 WNW CLEVELAND         41.50N 81.73W
07/19/2020  M55 MPH          LEZ146             OH   MESONET

            MESONET STATION XCLE CLEVELAND - EDGEWATER.

&&

ANM

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CLEVELAND OH
222 PM EDT SUN JUL 19 2020

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

0203 PM     MARINE TSTM WIND 3 N CLEVELAND           41.52N 81.68W
07/19/2020  M43 MPH          CUYAHOGA           OH   ASOS

            ASOS STATION KBKL CLEVELAND.

&&

ANM

Special Weather Statement
National Weather Service Cleveland OH
232 PM EDT Sun Jul 19 2020

PAZ002-191915-
Southern Erie-
232 PM EDT Sun Jul 19 2020

...A STRONG THUNDERSTORM WILL AFFECT SOUTHEASTERN ERIE COUNTY...

At 231 PM EDT, a strong thunderstorm was located over Corry, or 25
miles southwest of Jamestown, moving east at 60 mph.

Wind gusts up to 50 mph are possible with this storm.

Locations impacted include...
Corry, Union City, Wattsburg and Elgin.

Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

LAT...LON 4185 7961 4185 7996 4204 7993 4204 7976
      4200 7975 4200 7962 4199 7961
TIME...MOT...LOC 1831Z 270DEG 51KT 4195 7968

Lombardy