Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Cleveland Ohio
820 PM EST Sat Dec 20 2014
a weak ridge of high pressure will dominate the region through
Sunday night. A warm front will lift north across the area Monday as
low pressure moves east into Lake Superior by Tuesday evening.
Another low pressure system will move northeast to the western Great
Lakes by Wednesday evening forcing a cold front east through the
region to the Appalachian Mountains by Thursday morning. The low
pressure system will gradually lift northeast of the region by
Near term /until 6 am Sunday morning/...
plenty of low level moisture will remain trapped under the inversion
and surface high pressure overnight. This will result in continued
cloudiness during the night. The high will gradually shift east
overnight allowing winds to diminish to calm. Temperatures have
moved little throughout the day and with high pressure in place and
calm winds...expecting lows to dip a bit further into the 20s.
Have compromised between guidance and last nights lows for
tonight. Have added the brief mention of flurries to the rest of
the area with this middle evening update...shifting it east with a weak
upper disturbance. A few ASOS sites have report -sn with only
Short term /6 am Sunday morning through Tuesday night/...
nearly zonal flow aloft with small perturbations moving quickly east
in the mean flow will give way to another deep digging trough by middle
week. Upper level trough will develop over the central United States
Monday and Tuesday and evolve into an upper level low pressure
system. The low will become vertically stacked with a reflection at
the surface as they move northeast across the region by Tuesday.
In the mean time...surface high pressure will remain dominant Sunday
through Monday and eventually pull out to the east. A warm front
will lift north across the region on Monday but at this time should
pass through dry. Moisture with the front is limited at best.
As warm air advection takes place Monday night into
Tuesday...moisture will begin to stream northeast toward the region.
Models are hinting at a slower progression of the moisture so will
drop back on timing by about 6 hours and reduce probability of precipitation in the east
Tuesday to chance. Moisture surge pushes forward Tuesday night and
will bring in strong warm air advection and a threat for showers.
Due to the warm air advection taking place...may see temperatures
remain nearly steady overnight or even rise a few degrees in advance
of the low pressure system. Winds in advance of the storm system on
Tuesday and Tuesday night not expected to get out of hand until
Temperatures should remain fairly mild through the forecast period
as warm air advection develops.
Long term /Wednesday through Saturday/...
low pressure will be over the central Great Lakes on Wednesday with
periods of rain expected into Wednesday evening. Gusty southwest to
west winds may end up being the main story with gusts in the 35 to
45 miles per hour range possible. It will slowly become cooler Wednesday night
with an eventual change over to snow from west to east. The better
chances of snow look to be over extreme NE Ohio into northwest PA on
Christmas day. At this point it appears that we will remain below
advisory levels but we will continue to monitor this over the next
few days. This low and its gusty winds will be move northeastward to
near Hudson Bay by Thursday night with a brief period of high
pressure ridging into the region from the southeastern US. The next
storm system should approach the region by next Saturday.
Temperatures around 50 degrees will be common Wednesday morning but
will drop into the middle 30s by 06z Thursday. Highs Thursday will all
hinge on any peaks of sunshine but we anticipate that it will remain
in the 30s. Fridays temperatures will be warmer and may reach the
40s but the increased wind speeds will still make it feel like it is
in the lower to middle 30s.
Aviation /00z Sunday through Thursday/...
moisture trapped below an inversion will allow MVFR ceilings to
persist through the night and into Sunday morning. Also...for this
evening and early tonight models show a short wave moving across
central Ohio which has resulted in some minimal radar return
across northwest and north central Ohio. Brought in the possibility
of light snow showers with the potential for MVFR visibilities.
Sunday an upper ridge builds over the area and low level flow will
turn southerly as high pressure moves east. Thinking this could
help to break the inversion through the middle/late afternoon
allowing for breaks and possibly VFR conditions.
Outlook...non VFR late Monday into Thursday.
the lake will be quiet the next 24 hours as high pressure over the
region slowly weakens and slides eastward. This will allow low
pressure over the northern plains to move into the western Great
Lakes. However the main story for the week will be low pressure that
develops over the Southern Plains late Monday and then deepens as it
rotates up into the central Great Lakes Wednesday into Thursday.
This storm system will bring increased southerly winds Tuesday into
Tuesday night. As the low moves into the central Great Lakes on
Wednesday winds will eventually become southwest to west and
significantly increase. The strongest winds will likely move over
Lake Erie Wednesday night into Thursday with gales beginning to look
like a good bet. Since the winds will be from the southwest and west
the water will likely begin to pile up on the east end of the lake
toward Buffalo and should result in lower water levels for shipping
across the western basin. Will continue to mention the chances for
gales in the severe weather potential statement for now but we may go with a gale watch by the
Monday afternoon forecast package.