Area Forecast Discussion
Issued by NWS Cleveland, OH
FXUS61 KCLE 241353
Area Forecast Discussion
National Weather Service Cleveland OH
953 AM EDT WED AUG 24 2016
High pressure will linger over the eastern seaboard through
Thursday. A cold front will move east across the area Thursday
evening. High pressure will build east into the northern Great
Lakes by Tuesday. The high will move slowly east to Maine by
Sunday. A warm front will lift north across the area Sunday
afternoon as low pressure moves northeast into the Great Lakes.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
With the retreat of the surface high pressure to the east, the
southwesterly flow on the backside of the high is advecting warmer
and more humid air back into the region. Satellite imagery this
morning shows clouds streaming into the region from the west.
Radar mosaics shows convection from MKE to CMI with some progress
towards the region but for the most part cloud tops are warming as
the associated trough moves east.
For this afternoon we can expected increasing humidity with
temperatures rising to slightly above normal. the convection to
the west will likely weaken further for a few more hours but more
convection may develop in the late afternoon from DTX to southeast
Indiana and then spread into northwest Ohio. Will keep the current
max temperature and pop forecast the same.
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
Weak upper level trough will swing east across the area tonight
with associated potent area of positive vorticity advection. This
feature will have some fairly deep moisture associated with it and
will spread at least a chance for showers and thunderstorms into
the forecast area overnight. Strong warm air advection will be
taking place overnight as well as low level flow is out of the
southwest into the area from the Gulf of Mexico. This will aid in
supplying moisture into the area early on in the period.
Just ahead of the cold front Thursday, a slug of drier air will
begin to push northeast toward the area by Thursday afternoon.
This in combination with a weak cap should help taper off shower
and thunderstorm threat Thursday afternoon. All of the models are
in agreement with this scenario so will back off on mid afternoon
POPs. But, due to the instability and weak cap, will keep at least
a chance for a few pop ups of convection.
Models are considerably faster in bringing the cold front trough
the area around 00z Friday compared to 24 hours ago. As front
pushes through, likelihood for showers and thunderstorms will
increase and will therefore go with likely POPs around 00z Friday.
As cold front pushes through during the night, threat for showers
and thunderstorms will diminish. This will be slow to take place
as cold front is expected to slow in forward motion once it
reaches the forecast area.
Surface high pressure and broad upper level ridge build into the
forecast area Friday through Saturday Night. This will bring an
end to the precipitation and also bring in drier air to the
Temperatures will begin to climb well into the 80s again for
Thursday in the warm sector. Even after frontal passage Thursday
night, air mass behind the front not all that strong so
temperatures should recover nicely Friday and Saturday as well.
.LONG TERM /SUNDAY THROUGH TUESDAY/...
The long term begins Sunday with models showing an upper high over
the Mid Atlantic Coast while a short waves moves across the central
Great Lakes. By Monday the trough is east of the area while the
upper high shifts west becoming lost in more of a broad upper ridge
covering much of the nation. Both models suggest enough moisture
will be in place for a few afternoon/evening thunderstorms but
wouldnt expect more than that at this point. The ridge lasts through
Tuesday after which upper heights fall as the pattern
flattens...turning into a trough over the lakes by Thursday. For now
will have slight chance to low chance pops through the period. Highs
low to mid 80s.
.AVIATION /12Z Wednesday THROUGH Sunday/...
Not much change from the overnight package. Showers and lower
level ceilings around 5 kft are developing in Indiana so moved up
potential for showers just a couple hours west. Made no changes
to precip timing further east but did bring in the lower broken
deck a couple hours earlier. Overnight no washout expected but do
expect lingering showers and/or fog with a decent chance of MVFR
conditions in places across the area.
OUTLOOK...Non-VFR possible in showers and thunderstorms Thursday
and Thursday night.
High pressure over the Mid Atlantic Coast will weaken and
drift east tonight and Thursday. This will allow a cold front to
sweep across the lake Thursday night. Thermal packing suggests
possibly a secondary push on Friday as well. Friday night and
Saturday high pressure will build back in. Winds will be from the
south to southwest today through Thursday night ahead of the front.
By Friday morning winds will be west-northwest turning northeast on
Saturday. Winds will remain generally light through today through
Sunday with speeds mostly 10 to 15 knots or less. Sunday look for
light south to southwest flow to return. No headlines expected.