Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Cleveland Ohio
348 PM EDT Monday may 25 2015
high pressure off the East Coast of the US will continue to
increase moisture levels from the Gulf of Mexico through the
middle of the week. Several pieces of jet energy will move across
the region through the week bringing increased chances of showers
and thunderstorms. A weak cold front will move across the lower
Great Lakes Wednesday night.
Near term /until 6 am Tuesday morning/...
middle level showers continue to drift across the region but have
generally produced trace amounts of rainfall. This is in response
to an increase in the low level moisture and lift from a 850 mb
jet that is sliding eastward across the region. So far there have
not been enough breaks in the cloud cover to increase the heating
which will decrease the thunder threat. However we did still
mention an isolated thunder chance through the evening...mainly
across the east.
The evening showers...maybe a rumble of thunder...will dissipate with
the setting sun. We will then await another surge of moisture and
ripple of jet energy that will move into the region from the south
after 06z. This may end up being some more middle level showers
that develop over the eastern County Warning Area.
It will be another warm night with lows only dipping back into the
Short term /6 am Tuesday morning through Thursday night/...
the morning showers and possible rumble of thunder should drift
eastward or dissipate with the morning mix. The approaching wave
from the Midwest should help to increase the lift late afternoon
into the evening hours. The increased lift and continued flow of
moisture into the region should generate thunderstorms over
Indiana/Northwest Ohio and possibly across the eastern County Warning
Area Tuesday afternoon. The western convection will have a chance
to sweep across the County Warning Area Tuesday evening. At this
point confidence is high enough to mention likely probability of precipitation. There
should be a lull in the thunder for a few hours Wednesday morning
but a weak frontal boundary will move across the region during the
afternoon. This should be a focus for thunderstorms Wednesday
afternoon into the evening hours. Slightly drier air returns on
Thursday with the upper level ridge attempting to increase slightly.
Of note through the week is the fact that upper level heights will
be rather high. This may end up limiting the coverage of
thunderstorms each afternoon and evening.
Temperatures will continue to be above seasonal averages through
the week with highs generally in the lower 80s. Lows will be in
Long term /Friday through Monday/...
the long term begins Friday with the models showing high pressure
across the southeast coast...low pressure across Quebec and a
frontal system southwest from the low across the Central Lakes to
Texas. This frontal system will eventually get into the area but for
Friday there will be a general lack of forcing. With that said will
have slight chance probability of precipitation for mainly diurnal shower or thunderstorm.
Models a bit better on timing today with both the GFS an European model (ecmwf)
bringing the front through on Saturday. The front will stall in the
Tennessee or lower Ohio Valley Sunday before likely moving back
north on Monday. The front will bring its own moisture with it but
will also get an influx of glfmx moisture as it waffles through the
area during the weekend. This of course if a fairly wet pattern
suggesting high chance to likely probability of precipitation will be needed Saturday
through Sunday with chance probability of precipitation continuing Monday. Above normal
temperatures Friday and near normal Saturday through Monday.
Aviation /18z Monday through Saturday/...
a few showers reaching the ground west but much is not. Conditions
across the area remain VFR early this afternoon. Moisture will
continue to stream into the area from the south-southwest this
afternoon although not a lot of forcing expected. This should
continue the development of scattered showers this afternoon through
the area with western terminals possibly dropping to MVFR ceilings as
they move in from the west. Overnight models indicate some drier
air moves in at first followed by another impulse from the south
after 06-09z. Will begin the evening VFR with conditions dropping
to MVFR in fog/mist with scattered showers mainly east half. Winds
will continue from the south-southwest this afternoon gusting to near 30 kts
at times. This evening winds should diminish quickly.
Outlook...non VFR possible Tuesday afternoon through Wednesday
in scattered rain showers and thunderstorms and rain.
will continue with a Small Craft Advisory primarily for winds west
third. Winds should decrease further off shore given stabilizing
effects of the cooler water but close to shore winds should continue
gusting into the middle 20 knot range into early evening. No headlines
expected through the remainder of the forecast. Winds will remain
primarily from the south to southwest at 10 to 20 knots or less
through Wednesday night. Thursday and Friday winds will become light
and variable. Best chance for thunderstorms will come Tuesday and
Marine...Small Craft Advisory until 10 PM EDT this evening for