Area Forecast Discussion
Issued by NWS Cleveland, OH
FXUS61 KCLE 231927
Area Forecast Discussion
National Weather Service Cleveland OH
327 PM EDT SAT JUL 23 2016
Weak high pressure over the area will drift into the central
appalachians sunday as a weak cold front moves southeast through
the northern Great Lakes. The cold front will move southeast
across the region monday then high pressure will build over the region
for the middle of next week.
.NEAR TERM /THROUGH TONIGHT/...
A quiet and sultry evening is in store for the region as weak high
pressure remains overhead. MLCAPE near 2000 j/kg is present but
with sufficient MLCIN to inhibit convection especially north of
Route US 30. The region should remain dry but can not rule out an
isolated shower south of US 30 but for now will keep the forecast
dry. Some drier air along with deeper mixing has lowered dew
points in inland nw PA and extreme ne Ohio. This will allow for
slightly cooler overnight lows in the mid 60s. Higher humidity
elsewhere will help keep temperatures from dropping out of the
70s. fair weather cumulus will dissipate toward sun set but high
clouds from distant west convection over WS and IL will likely
spread into the region.
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
No changes are planned for the Heat advisory across the region
into Sunday evening as temperatures and humidity values will be
just high enough to support the advisory over the central and
western portion of the forecast area.
On Sunday the hot air mass will still be in place with 850 mb
temperature from 20-22c across the area. This could easily support
high temperatures in the mid 90s but there is some indication that
a weak impulse will be rippling east along the southern edge of
the westerlies just north of the region across Michigan and Lake
Erie and this may initiate showers and storms mainly in the
afternoon near Lake Erie. The increase in clouds and any
precipitation will help keep temperatures slight cooler than if an
adiabatic to supper adiabatic lapse rate were to develop in the
afternoon over the rather dry ground now in place.
A weak cold front will sag slowly south across the region late
Sunday and Monday and we can expect scattered showers and
thunderstorms to develop. The GFS is faster than the ECMWF and
brings the boundary across the region Monday morning which
diurnally is not a favorable time for convective development. The
Euro is slowly but appears to be even weaker with the front so
again the chances for rain are not overly high. 850 mb
temperatures are still be elevated but increased clouds and some
scattered showers should help keep temperatures down some.
The boundary will settle south of the region Monday night with
perhaps a lingering shower in the southeast counties early. Dry
conditions are expected through Tuesday with slight cooling to
only 17c at 850 mb.
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
The zonal flow aloft is progged to evolve into a shallow trough
aloft as we transition back to a more seasonable weather pattern
toward the end of next week.
High pressure will slide off to the east on Wednesday. The models
are in decent agreement with a warm front returning across the
midwest ahead of a cold front dropping across the Great Lakes by
Thursday. Some of the models develop a surface low on the front on
Thursday and this could be from convective feedback and will keep
pops rather low on Thursday given the uncertainty. There is also
some disagreement on just when the cold front will drop across
the area. The ECMWF is a bit faster with the front by late Friday
while the other models prefer Saturday. The CMC develops a wave
on the front, again another potential result of convective
feedback. Will keep the forecast rather vague at this time with
a chance of showers/storms Thursday night into Saturday.
Temperatures will gradually trend toward normal with some
uncertainty each day depending on the amount of clouds and
.AVIATION /18Z Saturday THROUGH Thursday/...
High pressure sliding by to the north. A very weak front was
dropping south of KMFD and KCAK. A thunderstorm not out of the
question this evening but it should be south of the TAF sites.
Cumulus will dissipate this evening. MVFR fog/haze will develop
toward daybreak Sunday although lower dew points will keep the
fog to a minimum across much of extreme northeast OH and
northwest PA. High and mid clouds will spread across the Great
Lakes later tonight and Sunday morning with a cold front reaching
the western Great Lakes.
OUTLOOK...Non-VFR possible late Sunday into Monday with showers
High pressure over the northern Great Lakes will move off to the
east. Winds will come around from the southeast and then southwest
by Sunday morning ahead of the next cold front. Winds will increase
from the southwest ahead of the front by Sunday night and from the
west behind the front on Monday. Winds and waves will approach small
craft advisory criteria but may stay just below. Thunderstorms will
probably spread across Lake Erie from later Sunday into Monday
morning and small craft operators will have to be alert.
High pressure will spread across the Great Lakes Monday and Tuesday
and shift east on Wednesday. The next cold front will sag across the
Great Lakes Wednesday and will approach Lake Erie Thursday.
OH...Heat Advisory until 8 PM EDT Sunday for OHZ003-006>011-017>021-