Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Cleveland Ohio
729 PM EST Sat Dec 27 2014
a cold front near the Ohio Indiana border this evening will move
across the forecast area tonight and then off the East Coast on
Sunday. A weak area of high pressure will build over the region
Sunday into early Monday. A cold front will drop south out of
Canada on Monday night.
Near term /until 6 am Sunday morning/...
no major changes for the early evening update. Tried to blend the
hourly pop forecast this evening with the radar trends... the
initial batch of showers was expanding across central Ohio and
spreading across NE Ohio. Eventually the area will fill in across
Northwest Ohio but most of the rain will remain light. Made minor
adjustments to the hourly temperatures early tonight as the actual temperatures
are running a couple of degrees warmer than forecast. No other
Original "tonight" discussion...
a cold front is forecast to move through the forecast area
overnight. Scattered showers are expected to continue to increase
ahead of the front. The models show an increase in low level
moisture from the Ohio River valley moving north which should help
to increase the areal coverage of the precipitation overnight. I
expect the bulk of the precipitation to occur in the 00z-06z time
frame. After 06z the precipitation should begin to move out of the
forecast area. As cold air advection begins after 06z it is
possible some of the precipitation that lingers could fall as a
mix of rain and snow. I expect little or no snow accumulations.
The precipitation will remain light. Temperatures will remain warm
through the evening hours and eventually drop after midnight with
the frontal passage. Winds will shift to the west to northwest and
temperatures should fall into the middle/upper 30s by 12z.
Short term /6 am Sunday morning through Tuesday night/...
a few rain or snow showers may linger over NE Ohio and northwest PA on
Sunday morning as the cold front pushes to the east. Very dry air
will move into the region during the afternoon. This should bring
an end to the precipitation. A weak ridge of high pressure will
build over the region Sunday night and this system should remain in
place through most of Monday. A weak back door front is forecast to
drop south across Lake Erie Monday night into Tuesday. There is
very little moisture with this front and I do not expect much
precipitation with it. However...the current forecast has a slight
chance of snow showers for this time period and I see no reason to
remove it at this time. Temperatures Sunday and Monday will drop to
more seasonal normal values with highs in the 30s and overnight lows
in the 20s.
Long term /Wednesday through Saturday/...
high pressure will dominate the weather picture Wednesday and
Thursday with just a few snow showers for the traditional lake
effect snow belt areas only. Temperatures below normal both days.
By Friday a developing southwestern states low pressure system will
move towards the Ohio Valley region and spread precipitation into
the forecast area southwest to northeast beginning Friday afternoon
or evening. The precipitation could begin as snow or mixed...and
possibly change to rain on Saturday....however we still have
several days to take a closer look at how this system will
materialize. Temperatures on Friday near normal and slightly above
normal on Saturday.
Aviation /00z Sunday through Thursday/...
a cold front will move east across the area tonight. At 00z the
cold front was approaching tol and fdy. By 06z the front will be
near eri. Some showers were ahead of and behind the front. IFR
ceilings will occur near and just behind the front for a few hours
and then ceilings will improve to MVFR and then begin to improve
to VFR starting early Sunday afternoon over Northwest Ohio. Visibilities
will be MVFR in some of the more intense showers.
Outlook...areas of non VFR ceilings Monday night through
Wednesday especially across NE Ohio/northwest PA.
a cold front will Cross Lake Erie tonight resulting in higher
winds and waves strong enough for US to Post a Small Craft
Advisory for the eastern two thirds of the lake through midday
Marine...Small Craft Advisory until 10 am EST Sunday for lez147>149.
long term...British Columbia