Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Cleveland Ohio
740 PM EDT sun Aug 2 2015
low pressure will move through the central Great Lakes overnight
and reach Quebec on Monday. A trailing cold front will drop across
the area early Monday. A second cold front will follow on Tuesday.
Tuesday evening and Wednesday high pressure will build back into
the Ohio Valley.
Near term /until 6 am Monday morning/...
cap still keeping
convection from firing over or near the County Warning Area. Late this evening...
models show a strong short wave dropping southeast into the area
which will also serve to increase moisture and synoptic lift
supporting elevated convection. While the strongest convection
appears to continue mainly east...models show a weakening line of
showers and thunderstorms dropping southeast across the area mainly
after 05z eventually affecting most of the area by morning. Best
chance to remain dry will be the southeast counties. Mav guidance
temperatures look fine in the middle 60s to near 70 for one more night in the
Short term /6 am Monday morning through Wednesday night/...
cold front should be across northwestern Ohio by 12z with showers and
possibly a few thunderstorms ongoing across the eastern and
southern counties. While the western counties dry through the late
morning and afternoon the nam12 continues to show sufficient
moisture for at least chance probability of precipitation into the afternoon. Also a
fairly strong short wave will be rotating through the base of the
trough which will be just to our north. In all...will only slowly
decrease probability of precipitation east through the day. Monday night the NAM and GFS
both show drying moving in from the west although deep moisture
associated with the upper low over the Great Lakes will be just to
our north. The NAM is drier than the GFS here but will side more
toward the NAM and go with a dry forecast most areas. Will keep a
low chance pop northwestern PA and far northestern Ohio as the wrap around
moisture should catch that area first. Tuesday another short wave
rotating through the base of the upper low will likely allow some
of this wrap around moisture to drop into at least the northestern portion
of the area. Will bring clouds into the NE for the day along with
chance probability of precipitation. Continued dry and pc remainder of the area. Wednesday
the upper low tries to shift east. Models differ of the character
of the day however as the NAM shows a dry slot across the area
with subsidence and a surface high. The GFS is more progressive
quickly moving the dry air east and moving in a short wave and
deep moisture out of the Midwest. The European model (ecmwf) has this feature as
well however it remains further west. For now will only bring a
low chance pop to the far southwest during the afternoon and
continue dry elsewhere. Will expand the chance probability of precipitation a bit
Long term /Thursday through Sunday/...
the ridge across the western U.S. And the trough
across the east will continue through the weekend. This will keep
temperatures running below normal for early August...low/mid 70s
only. Shortwave energy will be moving out of the plains and to the
lower Ohio Valley. A surface low will track along the Ohio Valley
Thursday and to the East Coast by Friday. Canadian high pressure
will settle more firmly across the lower Great Lakes for the
weekend. There will be timing and track adjustments that will need
to be made with this system.
Aviation /00z Monday through Friday/...
a line of storms from eastern WI across lower Michigan continues
to move east-southeast toward the local area. Timing of this precipitation puts it over
ktol around 04z and to kcle between 06 and 07z. These two sites are
the only ones that have a legitimate shot for thunder as the line
is expected to weaken after sunset. Expect the precipitation to make it
to kmfd and kcak before breaking up. Only small chances for
precipitation exist at kyng and Keri overnight. The surface cold front
will move through Monday morning. It is possible some
redevelopment could occur during the afternoon and have given kcak
and kyng a small mention. Expect the other taf sites to be dry.
Gusty S to SW flow will continue overnight. Peak gusts should drop
to around 20 knots after sunset. Expect the flow to become
westerly behind the surface front. Some patches of MVFR ceilings are
possible behind the front. Do not think this condition will
persist very long.
Outlook...there will be a few opportunities for non VFR weather
Wednesday through Friday.
it will be a rather breezy period on the lake from this
evening through Tuesday. A cold front will cross the lake early
Monday morning. Ahead of it a couple rounds of showers/thunderstorms
possible. Some thunderstorms may make it into the western basin by
6pm and they may be on the strong side. Otherwise the bulk of the
storms will arrive overnight. Southwest winds will increase this
evening to 25 knots...shifting to the west on Monday morning and
early afternoon and decreasing some. Have extended the Small Craft
Advisory eastward starting later this evening. Winds will back to
the southwest as a secondary trough approaches for Tuesday. Winds
will peak at 10 to 20 knots with this trough. Finally by Wednesday
high pressure will be building across the region and wind/waves will
calm down. For the second half of the week winds will come around to
the northeast as low pressure tracks across the Ohio Valley to the
virginias to end the work week.
Marine...Small Craft Advisory until 4 PM EDT Monday for lez147>149.
Small Craft Advisory until 4 am EDT Monday for lez142-143.
Small Craft Advisory until 10 am EDT Monday for lez144>146.