Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Cleveland Ohio
941 am EDT Tuesday Oct 21 2014
low pressure near Buffalo will move off the southern New England
coast later today and then remain stationary through middle
week...trapped by deepening low pressure aloft across the northeast
portion of the nation. High pressure will move into the central
Great Lakes Tuesday and extend into the upper Midwest through
Near term /through tonight/...
a weak surface cold front/trough has moved east of our forecast area
and now stretches south-southwest through the Pittsburgh area from a
surface low located over western New York. Despite frontal passage
expanded pop coverage west given current surface observations and
analysis of an upper level trough axis bisecting Ohio northeast to
Latest radar analysis shows the rain is more intense/widespread
across the Youngstown- Warren area...or east of this trough axis.
This batch of showers will move into western PA during the next
hour and shower activity will become more scattered and lighter...
with occasional periods of heavier showers through the rest of the
morning and early afternoon. Across the central third of the
forecast area light to moderate rain is falling...and another
round of heavier showers is moving onshore from Lake Erie. Further
west...just a few spotty showers are observed. Again all this
shower activity will generally push east as the upper trough
pivots northeastward across central Ohio this morning.
The current thinking remains that probability of precipitation will decrease from west to
east with passage of the trough axis. Drier air can already be
seen in animated water vapor imagery across western Ohio.
Short term /Wednesday through Friday night/...
upper low drops south across western PA today reaching northern Virginia
tonight before finally moving off the Delaware-Maryland-Virginia coast Wednesday. The
low moves back north into New England for Thursday and Friday.
Basically eastern Ohio and northwestern PA will be within the circulation
of the system tonight through Wednesday with short waves rotating
south across the region. Best rain chances will come tonight
through Tuesday night with only chance probability of precipitation for northwest
Pennsylvania Wednesday as deeper moisture pulls east. Thursday
through Friday expect mainly dry conditions as very dry air
associated with a weakening upper ridge moves across the area.
Temperatures below normal to start...rising to near normal by late week.
Long term /Saturday through Monday/...
model differences in the strength of a cold front clipping the area
Sat or early Sat night is leading to uncertainty. For now will stay
with slight chance probability of precipitation. Temperatures should moderate a little more for
Sat...getting close to normal.
Continue uncertainty for sun due to the model differences. Will keep
the forecast dry with temperatures similar to Sat. More upper ridging for
Monday and a S to SW flow should finally lead to a day of temperatures above
normal. Right now the models keep the better moisture west of the
area so will keep the day dry.
Aviation /12z Tuesday through Saturday/...
mix of IFR/MVFR and local VFR should settle into a more uniform MVFR
by midday. Expect little change late afternoon through 06z. Scattered rain showers
will continue next 24 hours as upper level low stalls just east of
area but should shift into mainly east half of the area. Colder
temperatures will also add some lake enhancement to the rain showers.
Winds gusting to around 20 knots will be likely today then should
gradually decrease early tonight.
Outlook...non VFR should slowly shift east Wednesday through Wednesday night.
think increasing north winds will produce Small Craft Advisory conditions for most of
the lake today that will probably continue into Wednesday night and maybe
even into Thursday evening as the weather pattern shows little change. High
pressure does finally spread up the Ohio Valley Friday and should
decrease the winds enough for waves to be below 4 feet.
The models differ more for Sat so the strength and affects of a cold
front that may cross the lake is in question. Will continue to show
some increase in a SW wind by Sat veering west by the end of the day.
Marine...Small Craft Advisory until 4 am EDT Thursday for lez142>149.