Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Pittsburgh PA
1012 am EST Sat Feb 13 2016
Arctic air will provide snow showers for the area today. Much
colder temperatures and dangerous wind chills expected through
Near term /until 6 PM this evening/...
will continue to See Lake enhanced snow across the northern
counties this afternoon...with coverage in the ridges affected by
upslope flow as well. Hi- res models hint that the most favored
band locations will edge northeastward with time...so tried to
trend the probability of precipitation in this direction. Expect to see scattered shsn
begin to bloom in other areas as well with steep low level lapse
rates providing some instability. Activity will begin to wind down
during the late afternoon/evening with loss of heating. Snow rates
will continue to become less efficient with time as the dendritic
growth zone reaches the surface. Temperatures are in good shape
overall. A portion of the Wind Chill Advisory expires at 16z and
expect to allow that to occur.
Short term /6 PM this evening through Monday/...
Lake effect snow showers will taper off and shift northward as a
surface ridge builds overhead tonight and Sunday. High pressure...
weakening winds...and a snow pack will provide a scenario where
temperatures fall close to or below zero by early Sunday morning.
Temperatures will moderate somewhat on Sunday...with a return of
southerly flow and a scattering of the clouds.
Shortwave moving east across the Great Lakes will bring warm
advection along with an increase in deeper moisture Sunday night
into Monday. This will give a period of snow especially south of
Pittsburgh with some accumulation possible. Temperatures look to
rise later Sunday night and will push to near the seasonal
Long term /Monday night through Friday/...
by Monday night and through Tuesday a strong southern stream
shortwave will induce low pressure along the Gulf Coast which will
quickly move across the Middle Atlantic States. Models still have not
landed on an exact track or strength of the developing low...but
the system will cross the southern Appalachians and move toward
New England by Tuesday night. With so much uncertainty...the long
term will be created using the superblend.
Aviation /15z Saturday through Wednesday/...
multi-lake fetch lake effect snow bands will be moving across the
area this morning. The strongest amongst them will likely waffle
near kfkl through the morning hours...while activity over other
sites should be less organized and persistent. Generally MVFR ceilings
will be common through the day...however due to the highly
convective nature of the bands...periods of VFR conditions will
certainly be possible as well. Winds will continue to gust from
the north-northwest through the period. Fries
Outlook.../Saturday night through Wednesday/...
low pressure systems will bring widespread restrictions later
Sunday night through Wednesday.
Maryland...Wind Chill Advisory until 9 am EST Sunday for mdz001.
Winter Weather Advisory until 7 PM EST this evening for mdz001.
Ohio...Wind Chill Advisory until 11 am EST this morning for ohz039-
Wind Chill Advisory until 9 am EST Sunday for ohz040-041-050.
PA...Wind Chill Advisory until 9 am EST Sunday for paz007>009-
Winter Weather Advisory until 7 PM EST this evening for paz074-
Lake effect Snow Advisory until 7 PM EST this evening for
WV...Wind Chill Advisory until 11 am EST this morning for wvz003-
Wind Chill Advisory until 9 am EST Sunday for wvz001-002-021-
Winter Weather Advisory until 7 PM EST this evening for wvz510-