Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Cleveland Ohio
400 am EDT sun Aug 30 2015
weak surface low pressure over the middle Mississippi Valley will
dissipate as a weak tough aloft slides east across the area today.
Bermuda high pressure along the East Coast will remain nearly
stationary through much of the week.
Near term /until 6 PM this evening/...
well most but not all have seen a few drops of rain overnight.
About a third of the area received more than a tenth of an inch
and a few rumbles of thunder. The upper trough will increasingly
become sheared today and some of the better moisture will shift
out of the area. Expecting current showers/isolated thunderstorms
on radar to shift east this morning followed by a relative lull. A
few new showers/ts will pop up again this afternoon inland but
again their coverage will be limited. Have worded the forecast as
scattered with precipitation chances no higher than 30 to 50 percent.
Western areas may break out into some sun by later in the
afternoon. Will cluster close to guidance for high temperatures
today...which are not too far off from saturdays highs.
Short term /6 PM this evening through Wednesday night/...
shower/ts activity late in the afternoon will diminish with the
loss of daytime heating this evening and expect the overnight
hours to be dry.
The trend from Monday through Wednesday is for the ridge to build
over the region which will likely continue the primarily dry
weather. Although cannot rule out a stray shower/ts chances with
the strong ridge aloft and no feature to focus convection will not
have much in the way of precipitation mentioned. Models hint at either a
stronger lake breeze or a weak trough to push inland Monday. May
this be enough to trigger a shower/ts? The ridge weakens ever so
slightly Tuesday into Wednesday. Again precipitation chances not high
enough to mention...at or below 20 percent. Temperatures will be
mild though...with middle and upper 80s common. Night lows will be
in the 60s.
Long term /Thursday through Saturday/...
a weak frontal boundary may sag into the region Wednesday night into
Thursday but with 500 mb heights so high it will be tough to get any
convection to develop. Did allow for a slight chance mention in the
grids Thursday afternoon across the southeastern portion of the
County Warning Area. Cant completely rule out an isolated storm or
two along the lake breeze Friday into Saturday but that potential
seems too low to mention at this point.
Otherwise temperatures will be well above average with highs into
the middle and upper 80s. Several locations will likely make a run
at 90 degrees.
Aviation /06z Sunday through Thursday/...
scattered showers and thunderstorms will continue through the
remainder of the night as an upper level trough passes. There may
be a brief period of IFR conditions in the heaviest thunderstorms.
Fog will likely become an issue toward sunrise...especially where
it has rained. Best chances for IFR fog will be across the west.
After the fog dissipates we will then need to monitor an area near
and south of a line from Marion to Meadville for redevelopment of
isolated convection this afternoon. Confidence is low in this
potential but have mentioned vicinity thunder at kcak and kyng.
Outlook...non VFR possible into Monday with isolated showers and
thunderstorms. Areas of non VFR in morning fog.
high pressure will increase its influence over Lake Erie after an
upper level trough passes today. The high will wobble across the
eastern US through next week. A weak cold front may sag onto the
lake Wednesday night into Thursday but even if it does the surface
pressure gradient will remain weak. Wind speeds through the next
week will likely be in the 5 to 10 knot range. However slightly
stronger onshore winds may occur each afternoon as a lake breeze
nudges winds to around 12 knots.