Scientific Forecaster Discussion
fxus61 kbgm 211849
Area forecast discussion
National Weather Service Binghamton New York
249 PM EDT Wed Aug 21 2019
isolated to scattered showers and thunderstorms will dissipate
this evening. A cold front crosses the region on Thursday with
isolated to scattered showers, especially for northeast
Pennsylvania. Dry and cool high pressure builds in behind the
front to end the week and lasts through the weekend.
Near term /through Thursday/...
Short wave continues to push east and is just about exiting our
forecast area as of 1830z. There is an area of convergence at
the surface, where a weak line of convection has developed
between i88 and i90 corridors. However, water vapor shows very
dry air aloft and any updrafts are having a very hard time
punching into this dry air layer, so convection has remained
quite weak. Convection this morning also had hindered
instability this afternoon, as cloud cover limited much surface
heating from occurring. There has been some recovery over the
last hour or two and low level lapse rates are increasing, but the
dry air mentioned above should be enough to limit the vertical
extent of any storms that can get going.
Showers and thunderstorms will dissipate as forcing continues to
push further east this evening and with the loss of heating.
Skies will likely remain partly cloudy overnight, but may see an
increase in clouds by morning with a cold front dropping down
from the North. Valley fog development seems likely with the wet
antecedent conditions from rainfall earlier today and light
winds overnight, but if clouds push into the region sooner than
expected, then this could hinder fog development.
Tomorrow cold front crosses the area, but instability will be
weak, but there could be enough instability realized across NE
PA for a few thunderstorms to develop. A much drier and cooler
airmass pushes in behind the front with high pressure overhead
by early Friday morning.
Short term /Thursday night through Saturday/...
frontal boundary will be just south of the area on Friday
morning and may trigger a few light showers over the extreme
south early in the day. Then, high pressure will build in for
the weekend with much drier air. Closed upper low will drop into
eastern New York and may trigger some instability showers, especially
east of I-81, but coverage will be very limited. Otherwise,
expect below normal temperatures through the period with the
Long term /Saturday night through Wednesday/...
a relatively quiet weather period as an upper low slowly
withdraws from eastern New York into New England on Monday. This may
result in a few instability showers over the eastern zones,
especially with daytime heating. Behind the low, some weak
upper ridging develops. At the surface, ridging noses down from
northern New England as remains in place into Tuesday. So
despite a few light showers due to the upper low, the period
should generally be dry and comfortable with afternoon highs
trending from below to near normal by Tuesday.
Aviation /18z Wednesday through Monday/...
tricky aviation forecast with a couple waves of convection
moving across the terminals. The first will finish carrying
through the area 12z-15z. While isolated to scattered
convection will generally be possible through the day, another
primary time of focus is expected from mid-afternoon northwest
to early evening southeast due to a boundary sweeping through
with newly developing storms from daytime heating. For that
second batch there are currently no thunder groups for kelm-
kith-ksyr-krme due to likelihood of storms only just starting to
form as the boundary passes; but watch for amendments in case
confidence increases. Winds will be variable to light southeast,
will veer southwest to west later today under 8 knots, though
erratic gusts are possible in vicinity of storms. Behind the
front, at least minor ceiling restrictions are expected to
develop later tonight for the New York terminals. Depending on where
heavier rain falls today, lingering moisture tonight could cause
lower restrictions than currently indicated in the tafs.
Thursday...scattered showers and possible brief restrictions as
a front passes, otherwise VFR.
Thursday night through Sunday...VFR, except late night/early
morning fog possible at kelm over the weekend.