Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Cleveland Ohio
1242 PM EST Tuesday Feb 9 2016
low pressure over the Great Lakes will move slowly east. Arctic
air over the upper Midwest will gradually spread across the lower
Great Lakes through middle week. High pressure will build across the
Ohio Valley on Thursday. An Arctic cold front will drop across
the area on Friday night.
Near term /until 6 PM this evening/...
band of snow finally starting to reach the forecast area this
afternoon. Snow accumulations will be light with this initial
snow. More light snow will follow from the north later this
afternoon into tonight. Otherwise...made some minor temperature
adjustments with this update.
Short term /6 PM this evening through Thursday/...
we will get on the back side of the upper low tonight into Wednesday
and cold advection will increase. The surface trough that has been
north of the area will swing through on Wednesday. This should
cause a general increase in the snow especially as it crosses Lake
Erie Wednesday morning.
The synoptic snow will transition to lake effect snow in the
snowbelt as 850 mb temperatures are prognosticated to drop to -20c Wednesday
night. The instability remains moderate to extreme off Lake Erie
into Thursday. The combination of enhanced synoptic snow starting
tonight and the lake effect persisting into Thursday will likely
produce snow fall in excess of a foot in some areas of the
snowbelt. The best bet would be inland Erie County PA but the
entire snowbelt is at risk of exceeding warning criteria. Not as
much confidence about the Lakeshore as winds will veer to
northwest on Wednesday which tends to push most of the snow
inland. Will issue a lake effect snow watch starting late tonight
and ending Thursday afternoon for the entire snowbelt.
The snow and snow flurries will taper off elsewhere Wednesday night
as drier Arctic air over spreads the area. Some random flurries off
Lake Michigan may persist into early Thursday. Some sun will peak
out across Northwest Ohio on Thursday. Temperatures near the lower
guidance due to the Arctic air.
Long term /Thursday night through Monday/...
Lake effect snow looks to taper off Thursday night across northwest
PA as winds shift more westerly and moisture levels decrease. There
may still be a few snow showers but the snow accumulations will be
isolated. Snow will increase again by Friday afternoon with all
locations having chances of seeing some light snow ahead of the next
clipper system that will move across the Great Lakes region. Models
indicate that the air in the wake of this clipper will be the
coldest we have seen this winter season. Once again the lake effect
snow will increase for Friday night into Saturday. We will need to
monitor the connection to Lake Huron on Saturday and see which bands
get the boost on the northwest flow. Drier air and lowering
inversion heights should limit or end the lake effect snow on Sunday
but at some point Sunday night the next storm system will move into
the region. Models differ on the track of this low so have gone no
higher than chances probability of precipitation at this time. This low looks like it could
bring accumulating snow to the entire County Warning Area.
Temperatures are expected to be below average through the long term.
In the wake of the clipper Friday night this cold air will drive
temperatures into the teens. Highs on Saturday will likely be in the
single digits to around 10. Saturday night looks to be the coldest
night with lows near or below zero common. The region will warm
Sunday into Monday with highs back to around freezing on Monday.
Aviation /18z Tuesday through Sunday/...
trough dropping southeast across Northern Ohio this afternoon.
Currently is from near the islands southwest to near kfdy.
Area of snow along and ahead of the trough currently affecting
ktol and kfdy and should get into kmfd and kcle early this
afternoon. Area has been shrinking however if it holds together it
should also impact Keri kyng and kcak middle to late afternoon.
Conditions mostly MVFR across the region however expect IFR in
the snow. Models show lift developing aver Lake Erie and spreading
inland across northestern Ohio and northwestern PA this evening and overnight.
Also a short wave will be moving in from the west with another
trough. Expecting snow showers to develop across western terminals
mainly after midnight.
Outlook...non VFR possible through the week in snow and lower
ceilings as a series of clippers move across the area.
southwesterly winds will become more westerly today and increase to
20 to 25 knots. Winds will become more northwesterly on Wednesday
and remain that way into Thursday at 15 to 25 knots. There will be a
lull between storm systems late Thursday into early Friday.
Southwest winds increase ahead of a trough on Friday but as winds
shift to the northwest some of the coldest air of the winter season
will arrive. Winds will be near 30 knots just ahead of the trough
and for a few hours in its wake. Freezing spray may occur Wednesday
night but appears to be a definite thing Friday into the weekend.
Ohio...Lake effect snow watch from late tonight through Thursday
afternoon for ohz012>014-089.
PA...lake effect snow watch from late tonight through Thursday
afternoon for paz001>003.