Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Binghamton New York
254 PM EDT Sat Aug 23 2014
clouds with scattered showers and sprinkles...will give way to
gradual clearing tonight as high pressure builds into the region.
After early morning fog...a sunny to partly cloudy sky can be
expected Sunday with near normal temperatures. Dry and warm
weather is expected the next few days.
Near term /through Sunday/...
230 PM update...
high pressure currently over Quebec will be backing across our
region the next 24 hours...meaning dry and eventually mostly clear
weather is en Route. However...before that occurs...plenty of
moisture remains trapped below developing subsidence
inversion...which will keep clouds pervasive through this afternoon
thus holding back temperatures to fall-like readings. Also...one
last upper wave is dropping north-northeast to south-southwest this afternoon...a final
gift from the pesky upper low hanging offshore Newfoundland.
Despite lack of heating at the surface due to clouds...we will
still initiate manage scattered showers-sprinkles for a time this
afternoon. Being in the left entrance region of the jet...we do
not have forcing aloft other than simple marginal- at-best
instability via the cold air advection aloft from the wave.
Subsidence at about the 12 kft above ground level level will limit depth of the
saturated layer...and thus any showers will be light...rainfall
rates significantly less compared to the last couple of days.
Because of moisture trapped under subsidence inversion...clouds
may take awhile to erode this evening...northeast to southwest as
dry air feeds in from building high pressure. However...even as
the sky clears...we should have an easy time developing valley
fog...locally dense. So anyone in the valleys tonight may have a
hard time seeing stars as clouds give way to fog. Lows tonight
mainly low to middle 50s.
Surface high pressure in charge Sunday. Not only that...but a
strong ridge will build aloft over the western to central Great
Lakes region...on its way into our region. After morning fog
and/or low clouds burn off...should be a dry nice sunny to partly
cloudy day with temperatures warming up to near climatological
averages...in the middle 70s to low 80s for highs. This will be the
beginning of the warm up courtesy of incoming upper ridge.
Short term /Sunday night through Tuesday/...
230 PM update...
period will be dominated by warm upper ridge...yielding daytime
temperatures right around the warmest readings that we have had
this month. 1000-500mb heights will creep into the lower 570s
decameter range...while 850mb temperatures reach the middle teens
celsius by Tuesday. Highs should manage low 80s Monday...and low-
middle 80s Tuesday as the surface high shifts to the midatlantic
coast and gets US into light southwesterly return flow. Only
caveat is that a small upper wave will translate across the Great
Lakes region to flatten the ridge Tuesday afternoon-
evening...which may spread high thin clouds into at least upstate
A Banner Valley fog night is expected Sunday night with light-calm
wind...clear sky and thus radiational cooling...surface high
pressure...and moist near-surface air due to recent rains. Valley
fog will likely occur Monday night as well with similar
conditions. Other than the early morning fog...and the high thin
clouds mentioned above for late Tuesday...the short term period
looks mainly clear.
Long term /Tuesday night through Friday/...
3 PM update...
Medium range models are not in very good agreement today...
especially with the formation and prediction of any kind of tropical
system in the western Atlantic. There looks to be enough movement to
an upper trough over the East Coast during the middle-late part of the
week to keep a cyclone out to sea...but the effects of moisture
streaming north seem highly plausible. There is some agreement to a
west-east cold front sagging into the region on Wednesday which will
warrant introduction of rain chances from weds-thurs. As weak waves
move east along the boundary...the highest probabilities for rain
seem to be Wednesday night-thurs. Then...the timing of precipitation varies on
the European model (ecmwf)/GFS models into next weekend. GFS would trend precipitation
quicker into and out of the area while holding a simulated tropopause
system closer to coast than European model (ecmwf). Gefs ensembles similar to
operational European model (ecmwf)...so will tend to follow the slower evolution
additional precipitation on Saturday and Sunday. In summary...not looking
too dry of a week ahead.
Temperatures near to slightly cooler than normal.
Aviation /18z Saturday through Thursday/...
Pesky axis of low level moisture convergence...low ceilings and light
rain/drizzle will persist for the southern four terminals into this
evening before sinking air behind slow moving...but still deparing
upper disturbance takes over. Surface high pressure is also expected to
build in tonight. There should be a gradual trend toward VFR for a
time late today and this evening for everyone then...all indications
are for a return to flight restrictions overnight. To what degree is
up in the air and will depend on areas of clear vs cloud cover. We
suspect that elevated terminals will be Sat upon by a developing
stratus layer which could force conditions to be below alternate
minimums if not even Airport mins. The lower elevated stations are
likely to see valley fog and possibly a higher IFR or MVFR stratus
deck. Stations that become more clear this evening will sock in with
fog. At this point...have broad brushed the forecast with fairly
poor ceilings/visibilities after about 08z-13z...but due to high uncertainty on
the details have stopped short of shutting most of the airports
down. The last 6 hours of the forecast on Sunday morning should
feature the typical burn off and lifting of ceilings through MVFR to VFR
Winds under high pressure will be light and variable...or subject to
light prevailing drainage flows as are typical at kith and kavp.
Monday through Wednesday...VFR except restrictions likely in early morning
valley fog mainly at kelm.
Thursday...VFR/MVFR. Chance of showers.