Scientific Forecaster Discussion
Area forecast discussion...corrected
National Weather Service Cleveland Ohio
333 PM EDT Monday Jul 28 2014
a persistent upper level trough over the eastern Great Lakes and
Ohio Valley will keep temperatures well below normal through much
of the week. The trough will also keep the threat of showers and
a few thunderstorms in the forecast as well.
Near term /through tonight/...
short wave which brought rain and thunderstorms to the area last
night and into this morning has now moved east with only a few
lingering showers east. Will cover this with slight chance probability of precipitation
into the evening. Otherwise behind the short wave clouds looking
more diurnal although copious amounts of low level moisture have
resulted in mostly cloudy skies across northwestern Ohio and upstream
across Michigan as well. Through the evening am expecting some
breakup central and west although southeast of the lake across northestern Ohio
and northwestern PA clouds could take a bit longer to break. Guidance lows
in the lower 50s with even a few upper 40s east inland. Both the
mav are in good agreement so will remain close.
Short term /Tuesday through Thursday night/...
upper pattern remain stagnant through 84 hours with the center of
the upper trough moving west by 1 to 2 hundred kilometers or so
(in quebec) to near James Bay. This will continue to pump
cool...fairly moist air across the area through the short term
period. This will result in scattered to locally numerous showers
dominated by diurnal forcing as well as any short waves moving
through the flow. Tuesday morning the models show one such short
waves dropping across the area from the northwest during the
morning and early afternoon. Brought chance probability of precipitation to all of the
area during the day. Another wave drops across the area Tuesday
night and Wednesday so continued chance probability of precipitation north and east
Tuesday night and across the entire area Wednesday. Tapered probability of precipitation
Wednesday night and then brought in chance probability of precipitation for Thursday
afternoon as well. Temperatures in the 70s and 50s.
Long term /Friday through Monday/...
the models show the upper trough camped over the area Friday and Sat
then there is some indication that the upper trough may lift a
little north-northeast for sun and Monday to lessen the threat for rain showers/thunderstorms and rain some.
Temperatures will consistently stay below normal due to The Pocket of cool
air over the region associated with the upper trough so will
generally run below GFS MOS highs through the period.
Aviation /18z Monday through Saturday/...
models show a general decrease in lower level moisture into tonight
and MOS guidance supports this in lifting ceilings well into VFR levels.
Won't fight the overwhelming guidance but will only lift some place
to 3500 feet. The ceilings in the west part of the area will likely
scatter out with sunset and some or all of the east may also have
this happen. Winds gusting 20 to 25 knots will diminish with sunset.
Scattered rain showers around eri and yng will become less numerous into this
evening then a few isolated rain showers may hang around the snowbelt
overnight. A trough dropping southeast into the area will increase the
chance for rain showers from northwest to southeast on Tuesday. Given the latter hours of the
taf period will only mention this rain showers threat with use of vcsh.
Outlook...occasional non VFR in showers Tuesday through Saturday.
Small Craft Advisory conditions will diminish tonight. Conditions remain somewhat
favorable for isolated waterspouts through Tuesday morning. A trough
dropping toward the lake should back the flow to west-southwest Tuesday then turn
back west or west-northwest Wednesday as the trough moves through. High pressure will
spread over Ohio late Wednesday through Thursday and tend to remain in place through
Sat which should keep the winds light.
Marine...Small Craft Advisory until 4 am EDT Tuesday for lez144>149.
Small Craft Advisory until 10 PM EDT this evening for lez142-