Damaging Winds in Ohio, August 20, 2019

Area Forecast Discussion
National Weather Service Cleveland OH
358 PM EDT Tue Aug 20 2019

.SYNOPSIS...
A cold front will move southeast across the local area Wednesday
evening. A ridge of high pressure will build southeast across
the area Thursday. High pressure will be centered over the local
area Friday night. Below average temperatures are expected for
the end of the week and weekend.

&&

.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
Focus of the near term forecast is thunderstorm potential this
afternoon evening, as thunderstorms begin to develop in west
central Ohio ahead of a long lived but somewhat decaying MCS
tracking through Indiana. Surface destabilization has continued
through the afternoon across the local area, with 2-3k j/kg
MLCAPE centered across western Ohio. Mid level lapse rates
steepen ahead of the MCS, which will influence the area in the
next several hours. Shear remains marginal, with effective bulk
shear values of 20-25 kts across the area through early evening,
which should limit overall organization of storm activity.
However, dry air above 700mb and resultant DCAPE values of
1000-1300 j/kg across the area, coupled with steep low level
lapse rates, will enhance the risk for damaging winds with the
stronger thunderstorms across the area. SPC has expanded the Day
1 slight risk northward into the southwest part of the forecast
area, with a marginal risk for the rest of the area. The best
severe thunderstorm potential will be from 4 PM through 10 PM
across the area.

The associated MCV will slowly shear out/weaken across the area
this evening and push east of the area by Wednesday morning.
Precip chances will be on the downtrend after midnight, but held
onto chance pops east/slight chance pops elsewhere with the
disturbance across the area and ample boundary layer moisture
and perhaps residual outflow boundaries as a focus of surface
forcing. A synoptic cold front will slowly sink south towards
the area Wednesday and into the area Wednesday night. Surface
forcing is marginal with the boundary, and weak destabilization
may limit widespread precipitation development across the area
during the day, especially with the better mid level forcing
displaced north and southwest of the area. Have kept pops in the
chance range on Wednesday, with MLCAPE values up to 1000 j/kg as
much drier air in the 850-700mb layer moves into the area from
the north. High temperatures rise into the mid/upper 80s across
the area. Forecast pops diminish to slight chance range
Wednesday night as the front slides south across the area, with
the loss of daytime heating inhibiting much fuel for precip
development. Pops may linger across the south and southwest
parts of the forecast area after midnight into early Thursday
morning as upstream convectively induced disturbances propagate
eastward along the front, although much of the guidance favors
precip placement just south of the area.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
Weak cold front will start off across our southern counties on
Thursday. A deepening upper level trough will push south across Lake
Michigan on Thursday, maintaining a southwest flow aloft. This may
delay the southward movement of the front and will hold onto a low
chance of showers and possibly a thunderstorm across the south on
Thursday. A noticeable change in airmass will be felt with
highs dropping below normal into the 70s where they will remain
heading into the weekend. High pressure will strengthen across
the Great Lakes Thursday night into Friday, finally pushing the
front south of the area.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Upper level trough shifts east across New England allowing a ridge
to build overhead. Some weak troughing will also be in place across
the southeastern states with moisture focused across the Tennessee
Valley and Mid-Atlantic. The 12Z GFS is the fastest in trying to
pull moisture back north into the area on Sunday but given the
strength of the surface high will continue with a dry forecast.
Finally by Monday the next upper trough will approach from the
northwest with low pops returning to our western counties
Monday, increasing and expanding Monday night into Tuesday.

&&

.AVIATION /18Z Tuesday THROUGH Sunday/...
Showers and TSRA are expected across the area this afternoon
through the evening, although coverage/confidence at this
juncture only warrants TEMPO mention at any given TAF site.
Higher confidence in TSRA impacts are at KFDY, KCLE, KMFD and
KCAK between 22Z and 04Z, with reductions to IFR possible in the
heaviest TSRA. Shower/TSRA coverage will diminish after 06Z,
with lingering VFR clouds possible. Some reductions to MVFR
ceilings possible towards 12Z in the wake of the precipitation,
but will improve to VFR towards the end of the period. Mainly
south to southwest winds will prevail through the period,
although a lake breeze early in the period may keep things more
variable at KERI, and to a lesser extent KCLE.

OUTLOOK...Intervals of non-VFR possible primarily with
thunderstorms possible Wednesday.

&&

.MARINE...
Southerly flow of 10-15 knots will develop on Lake Erie tonight and
increase into the 10-20 knot range on Wednesday ahead of an
approaching cold front. Winds will shift to the north with the
passage of the front Wednesday night and a Small Craft Advisory will
likely be needed east of the Lake Erie Islands. Winds will drop off
fairly quickly on Thursday as high pressure expands south over the
Great Lakes Region. Northeast to east winds of 5-15 knots will
maintain a little bit of a chop on Lake Erie on Friday and Saturday
with flow becoming more east/southeast on Sunday.

&&

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

&&

SYNOPSIS...Greenawalt
NEAR TERM...Greenawalt
SHORT TERM...KEC
LONG TERM...KEC
AVIATION...Greenawalt
MARINE...KEC

Hazardous Weather Outlook...CORRECTED
National Weather Service Cleveland OH
725 AM EDT Tue Aug 20 2019

LEZ061-142>149-162>169-OHZ003-006>014-017>023-027>033-036>038-047-
089-PAZ001>003-210730-
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-
725 AM EDT Tue Aug 20 2019

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

.DAY ONE...Today and tonight.

A few strong to severe thunderstorms may be possible this afternoon
and evening. The main threat will be damaging wind gusts up to 65 mph
and large hail up to quarter size. The best potential will be across
western and central Ohio.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.