Area Forecast Discussion
Issued by NWS Cleveland, OH
FXUS61 KCLE 241941
Area Forecast Discussion
National Weather Service Cleveland OH
341 PM EDT WED AUG 24 2016
High pressure along the mid Atlantic coast will move offshore as
a warm from central Indiana to southern Ohio moves northeast
through the region. On Thursday the region will be in a rather
warm and humid air mass as a weak cold front approaches from the
northwest. The weak front will move through the region Thursday
evening. Weak high pressure with slightly cooler and less humid
air will overspread the region Friday.
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
A diffuse warm front is located from central Indiana to southern
Ohio. The front will move across the region tonight and advect
much more humid air back into the region. Dewpoints will rise into
the 70s in many locations. The return of sultry conditions will be
accompanied by a chance of showers and thunderstorms but diurnal
timing of the front is not optimal for strengthening convection.
Low LCL heights and sufficient 0-1km shear near IND has produced
some impressive rotational signatures on radar. This could be a
concern over the next few hours as the warm frontal boundary lifts
toward the region with high surface dewpoints. Overnight low
temperatures will be elevated given the increase in humidity and
cloud cover. Convective activity that overspreads the region this
evening will diminish after midnight.
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/...
The main forecast problem during this period is assessing the
likelihood of severe weather Thursday afternoon as the cold front
approaches the region from the northwest. The region will have
plenty of MLCAPE(greater than 2000 j/kg) as temperatures rise to
near 90F and dewpoints reach the mid 70s. 0-6km wind shear rises
to the 30-40knots which should help organize and sustain the
convection that is expected to develop over northern Ohio by early
to mid afternoon. We can expect some bowing line segments with
damaging winds being the most likely threat.
Deep tropical moisture will again be in place in this air mass as
PW values reach near 2.0 inches. Intense convection will likely
produce torrential rainfall rates of 3-4" per hour and produce
Heat Indices will reach the upper 90s making it feel quite sultry
near the end of a very warm August.
The front will drop south across the region Thursday evening and
lingering showers and thunderstorms should end near midnight.
Slightly cooler and less humid air will move into the region
behind the front but no quick drying is expected since cold
advection is weak.
For the weekend upper level ridging builds over the mid Atlantic
states which should produce dry stable conditions across the
region will a gradual increase in heat and humidity.
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Little change in the extended period. Sunday will be hot and humid
with temps in the mid to upper 80s. But a weak frontal boundary
will move across the forecast area late Sunday into Monday. For now
will keep low chance pops going...mainly Sunday night into Monday
morning. High pressure builds south over the area Monday and holds
fast into the middle of the work week.
.AVIATION /18Z Wednesday THROUGH Monday/...
Scattered showers/TSRA moving across central Indiana will move
across the forecast area this afternoon/evening. Not sure how far
east TSRA will make it since moving into more stable environment.
Should diminish significantly after sunset.
Warm front...now into SW Indiana...forecast to lift NE over the
area overnight. Expect widespread MVFR with areas of IFR with the
front overnight. Better chance for convection tomorrow afternoon
as we are in the warm sector and capes increase to over 2k j/kg.
OUTLOOK...Non-VFR possible in showers and thunderstorms Thursday
afternoon and evening.
South winds will turn to the southwest overnight as a warm front
across the Mid Mississippi Valley lifts NE of the Lake. Better
chance for convection tomorrow afternoon and evening as capes rise
to above 2000 J/kg. Cold front will move across the lake Thursday
night. Small craft advisory will likely be needed at least in the
east...as winds turn to West at 15 to 20 knots. Lake quiets down
Friday afternoon as high pressure builds over the lake.