Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Binghamton New York
1008 am EDT Friday Sep 4 2015
a weak front will slowly move south across the area today and may
spark a few thunderstorms over northeast Pennsylvania. High
pressure will move back into the region late tonight resulting in
dry and warm weather through the weekend.
Near term /through tonight/...
10 am update...
The current forecast is in great shape, so just some minor sky
cover and temperature tweaks are required at this time.
A stubborn area of lower stratus clouds continues to slowly shrink
late this morning, mainly over The Finger lakes and central
southern tier regions of NY, and north-central PA. We expect this
area of cloudiness to be gone by 11 am-12 noon. Thereafter,
another partly to mostly sunny afternoon is on tap.
A moisture gradient is evident from NE to SW across New York and PA
today (drier to the NE and more moisture to the sw), as judged
from blended total precipitable water imagery and mesoscale-analysis
data. Coincident with maximum heating this afternoon, and also
where surface dew points will remain somewhat higher, the air mass
will destabilize to a greater degree over PA, versus New York (potential
mixed-layer cape values of 1000-1500 j/kg). Although deep-layered
shear and overall forcing are weak, the combination of
instability and complex terrain could well be enough to create
isolaed showers and thunderstorms this afternoon across the Pocono
plateau. Our current probability of precipitation grids handle
this scenario quite well.
Especially over central NY, although it will be warm again (highs
in the 80s area-wide) this afternoon, it will feel less humid
than recent days, as surface dew points drop into the 50s and
Another quiet morning is present across central New York and
northeast Pennsylvania as all diurnal convection have dissipated.
The backdoor front that sparked off convection Thursday afternoon
is now draped across NE PA. Patchy dense fog have developed again
this morning across much of the area. Since the airmass have not
changed much in the last few days... expect fog to become dense
again... especially near 9-12z. Expect fog to lift around 14-15z.
After the fog mixes out... expect the rest of the morning to be
quiet. Expect another diurnal cumulus deck to develop tomorrow
afternoon across the area. The front will slowly move south this
afternoon and may create additional showers and thunderstorms.
The activity is expected to develop over NE PA and southward.
Similar to yesterday... these storms will be slow moving and may
produce heavy rainfall.
Temperatures are expected to be above the seasonal norm... rising into the
upper 70s to low 80s.
Short term /Saturday through Sunday night/...
little change was made to the previous forecast. High pressure at
the surface will build southward Friday night and settle over the
region through the weekend. Aloft the ridge will regain control
of the weather pattern and inhibit convection to develop over the
region through the weekend. Ridging aloft and at the surface will
allow temperatures to remain above seasonal averages.
Long term /Monday through Thursday/...
strong upper level ridge will remain over the northeast through
middle week before getting flattened by an upper level wave. Surface high
pressure along the eastern Seaboard will provide dry and hot
conditions through midday Tuesday. Models differ significantly on
the frontal passage timing with the GFS much faster than the European model (ecmwf).
Typically this time of year upper level ridges hang Tuff and delay
the passage of fronts. Will carry chance/slight chance probability of precipitation for
convection Tuesday afternoon through Thursday as a surface cold front
with waves possibly along this boundary makes its way through the
Aviation /14z Friday through Tuesday/...
a very similar story today compared with recent mornings due to
little change in the weather pattern and airmass. Ksyr/kelm will
likely see IFR conditions with kith seeing conditions below
Airport mins continuing until around middle morning. Tricky forecast
for kbgm as conditions have improved...however expect another
period of IFR as valley fog lifts through area. Finally just
looking at MVFR for kavp with krme remaining VFR as slightly drier
air has moved in. Similar to recent mornings, restrictions lift
middle to late morning (13-15z).
After this morning's restrictions, mainly VFR the remainder of the
day. Some isolated storms will be possible over NE PA and there is
the slight risk one could affect kavp with associated restrictions
but chances are low so this is not included in taf.
Restrictions likely again tonight however some indications
fog/mist may not be quite as dense/widespread due to slightly
drier air so confidence in IFR and below not as high for kith/kbgm
so at this point only indicate MVFR visbys. Fairly confident,
however, kelm will see at least IFR restrictions.
Winds remain light through the taf period...generally around 5
knots or less.
Saturday-Monday...mainly VFR is expected. Early morning fog is
possible each day, especially kelm.
Tuesday...restrictions possible as cold front approaches region
with possible shra/tsra.