Special Weather Statement, NWS Cleveland, OH

Area Forecast Discussion
National Weather Service Cleveland OH
915 PM EDT Mon Jul 10 2017

.SYNOPSIS...
Low pressure will drift east across the southern Great Lakes
through tonight, as a frontal boundary washes out across the
region. Another low pressure system will track from the Plains
into the Great Lakes Wednesday and Wednesday night, lifting a
warm front northeast through the area. As the low tracks into
New England Thursday into Friday, a cold front will push south
through the region.

&&

.NEAR TERM /THROUGH TUESDAY/...
Few changes for the 930 update. Thunderstorms rolling along the
warm frontal boundary across NRN IL and IN. Still expect the
storms to clip the SWRN portion of the forecast area and then
push to the SE.

Original discussion...
MCV currently across the southwest part of the forecast area will
continue to move east across Ohio through the evening. Convection
along/ahead of this feature will impact mainly the eastern half of
the forecast area through 00Z, with some scattered showers/storms
elsewhere. The best window for severe storms this afternoon is
closing quickly, and is confined to the far southeastern periphery
of the forecast area. Heavy rainfall is likely with this storms,
with rates in excess of 2" per hour at times. The threat for flash
flooding through 00Z is lowered by the progressive nature of the
convection, but localized flooding is possible.

A bit of a lull is expected with the precip early this
evening, but attention turns to additional storms developing after
00Z. Confidence is still low on the exact placement of the storms,
however hi-res guidance trends are starting to become more
consistent, with development upstream in northeast Indiana
propagating east/southeast from roughly a Findlay to Mansfield line
from the 00Z-06Z time frame. Trended the forecast after the last few
HRRR/RAP runs. Concern for the overnight is more of a flash flooding
threat vs. a severe threat. Low level jet will re-intensify and nose
into the region, which should be the focus of convective
initiation. Modest MUCAPE values of 1000-1500 j/kg with a
long/skinny CAPE sounding profile, PWATS from 1.7-2.0", warm
cloud depths of 11- 13kft, lower deep layer shear, and strong
925-850mb moisture transport all support extremely efficient
rainfall processes which will increase the potential for flash
flooding. Thinking the best threat will be from Findlay to
Mansfield and south, with rainfall rates of 2-4" per hour or
more at times. Was close to issuing a flash flood watch for a
short time tonight, however confidence at this forecast issuance
just too low due to the uncertainties of the thunderstorm
development area.

Modified/washed-out surface boundary/reinforced outflow will
translate southward across the area tonight. The boundary will
settle across the southern part of the area on Tuesday, with low
chances of showers/storms, however most of the area should be dry
for a good bulk of the day.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
Winds will shift back from the south and southwest on Tuesday
night as the next wave begins to track across the upper midwest
and the front begins to move back north as a warm front. Not a
lot of confidence as to whether there will be much in the way of
new convection. We may be able to get through most of the night
rainfree, especially across extreme northeast OH and northwest
PA. Will have a "chance" pop developing across the western
counties shifting northeast across the forecast area on
Wednesday. Temperatures are tricky on Wednesday. With 850 mb
temps progged to range from 17C across NW PA to 20C around FDY,
it could very warm (and humid) where the sun comes out. Highs
could be anywhere from 81 to 93F and will split the difference
shading more toward the warm side given the impact.

New convection will likely develop across the Great Lakes late
Wednesday and Wednesday night as the next short wave tracks
eastward. The convection would seem destined to drop across Lake
Erie Wednesday night. Not sure how that will play out on Thursday.
Will continue with the higher pops in the east and southeastern
counties on Thursday. There is a better chance of cloudiness on
Thursday and forecast high temperatures will be a few degrees cooler
than Wednesday.

Cold fronts can take longer than one would think this time of year
with shallow troughs and weak wind fields and it may take until
sometime Friday to get the front south of the area. Will keep a
small pop on Friday. Dew points will gradually begin to drop.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
The long term begins on Saturday with surface high pressure and
drier air building into the area from the Upper Midwest. An
upper trough will be exiting the region and may help to hold
onto clouds in northeast Ohio and nwrn PA early but for now will
just go with a partly cloudy forecast. A cold front will move
south from the northern lakes to the central lakes. Sunday
another upper trough drops across the Great Lakes in the
northwest flow aloft. The cold front across the central lakes
will move south across the region as upper heights fall and
surface high pressure builds in to the western lakes. Most
forcing with this should remain well north/northeast of the area
but will have slight chance pops late Saturday night through
Sunday morning based on current frontal timing. Monday high
pressure and dry air build in from the northwest. Highs each day
near normal.

&&

.AVIATION /00Z Tuesday THROUGH Saturday/...
Convection related to upper level short wave has moved east of
the forecast area. Scattered convection developing across NRN IL
and NRN IN ahead of surface low NW IL. Expect convection to
spread east this evening and then track to the SE. Best chance
for convection tonight will be the southern counties. Expect
stratus deck to develop overnight ifr/low mvfr range.

OUTLOOK...Non-VFR on and off through Friday morning in
showers and thunderstorms.

&&

.MARINE...
A southwest flow will continue on Lake Erie ahead of a weak cold
front through mid week. A strong low level jet across the lower
Great Lakes will contribute to the wind. The marine forecast should
be used with caution since several rounds of thunderstorms will
cross Lake Erie through Thursday, and each cluster of thunderstorms
will disrupt the prevailing wind flow.

South to southwest winds tonight will increase to 20 knots or
so, especially on the open waters, then likely diminish by
daybreak. Given the stronger winds offshore and the SSW direction,
will not issue a small craft advisory.

The weak cold front may sag across the lake briefly on Tuesday with
a wind shift to west northwest, then return north as a warm front by
Wednesday, then drop across the lake again by Friday. High pressure
will build across the Great Lakes by the weekend.

&&

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

&&

SYNOPSIS...Greenawalt
NEAR TERM...DJB/Greenawalt
SHORT TERM...Kosarik
LONG TERM...TK
AVIATION...DJB
MARINE...Kosarik

Hazardous Weather Outlook
National Weather Service Cleveland OH
356 AM EDT Mon Jul 10 2017

LEZ061-142>149-162>169-OHZ003-006>014-017>023-027>033-036>038-047-
089-PAZ001>003-110800-
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-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-
356 AM EDT Mon Jul 10 2017

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

.DAY ONE...Today and Tonight.

There is a slight risk for severe thunderstorms today. The main
threat will be large hail and damaging wind gusts in the
thunderstorms.

There is also the possibility that thunderstorms could produce
locally heavy rain, especially where thunderstorms continue to
redevelop and move over the same area. Some isolated reports of
localized flooding over the land areas is possible today into the
evening in the heaviest rainfall.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed.

Lombardy

Special Weather Statement
National Weather Service Cleveland OH
933 PM EDT MON JUL 10 2017

OHZ027-110215-
Wyandot-
933 PM EDT MON JUL 10 2017

...A STRONG THUNDERSTORM WILL AFFECT WYANDOT COUNTY...

At 933 PM EDT, a strong thunderstorm was located near Forest, or 7
miles west of Upper Sandusky, moving east at 20 mph.

Winds in excess of 40 mph and half inch hail are possible with this
storm.

Locations impacted include...
Upper Sandusky, Forest, Sycamore, Carey, Nevada, Wharton, Harpster
and Kirby.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

To report severe weather, contact your nearest law enforcement
agency. They can relay your report to the National Weather Service
office in Cleveland.

LAT...LON 4091 8351 4091 8348 4095 8348 4096 8345
      4099 8311 4072 8312 4078 8350 4081 8350
      4082 8352
TIME...MOT...LOC 0133Z 271DEG 18KT 4087 8342

Sefcovic

Special Weather Statement
National Weather Service Cleveland OH
936 PM EDT MON JUL 10 2017

OHZ017-110200-
Hancock-
936 PM EDT MON JUL 10 2017

...A STRONG THUNDERSTORM WILL AFFECT NORTHERN HANCOCK COUNTY...

At 936 PM EDT, a strong thunderstorm was located over Van Buren, or
near Findlay, moving east at 35 mph.

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

Locations impacted include...
Findlay, Fostoria, North Baltimore, McComb, Arcadia, Vanlue, Van
Buren, Bloomdale, Benton Ridge and Bairdstown.

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

To report severe weather, contact your nearest law enforcement
agency. They can relay your report to the National Weather Service
office in Cleveland.

LAT...LON 4117 8358 4116 8342 4109 8341 4100 8342
      4099 8346 4097 8346 4101 8388 4117 8388
TIME...MOT...LOC 0136Z 273DEG 28KT 4111 8368

Sefcovic

Special Weather Statement
National Weather Service Cleveland OH
1102 PM EDT MON JUL 10 2017

OHZ028-110345-
Crawford-
1102 PM EDT MON JUL 10 2017

...A STRONG THUNDERSTORM WILL AFFECT CRAWFORD COUNTY...

At 1102 PM EDT, a strong thunderstorm was located near Bucyrus,
moving east at 20 mph.

Winds in excess of 40 mph and dime size hail are possible with this
storm.

Locations impacted include...
Bucyrus, Crestline, New Washington, Chatfield, Benton, Tiro, North
Robinson, Oceola and Sulpher Springs.

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

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 4080 8311 4087 8312 4099 8311 4100 8291
      4099 8273 4080 8272 4075 8301
TIME...MOT...LOC 0302Z 261DEG 17KT 4085 8302

Sefcovic