Scientific Forecaster Discussion
fxus61 kbgm 271050
Area forecast discussion
National Weather Service Binghamton New York
650 am EDT Sat may 27 2017
a system moving by to the south may brush northeast Pennsylvania
with a few showers today. Otherwise mostly dry weather is
expected until the next system brings showers and the chance of
thunderstorms late Sunday into Monday. A generally unsettled
pattern will persist through much of next week.
Near term /through Sunday/...
300 am...still some very weak returns being seen on radar with
some light showers being reported around Syracuse. Otherwise
just looking at mostly cloudy skies with low stratus and areas
of light mist and fog.
Heading into early Saturday, any lingering light showers or
drizzle over central New York looks to diminish by morning as the
deeper moisture and lift moves off to the east. Otherwise, do
expect lingering low level moisture to result in continuing
mostly cloudy skies. Also, there will be a dying convective
complex that will move east toward the area however since the
upper level flow turns more NW, this should cause the system to
dive mostly to our south so we only mention low chances of
showers over NE PA and keep most of central New York dry. Temps will
still be on the cool side with highs mostly in the middle to
For Saturday night, weak ridging will briefly move over the area
resulting in skies becoming mainly clear with light winds. This
will result in a good chance for some valley fog to develop by
morning as temps cool to dew points. Lows will be cool...mostly
upper 40s to low 50s.
For Sunday, early morning valley fog quickly Burns off with some
sunshine before clouds thicken up ahead of the next system
approaching from the west. Most of the day should be dry but we
do introduce a chance of showers and the risk of thunder to the
western southern tier by late day. The warm advection pattern
developing ahead of this system will result in 850 mb temps
rising to around 12 c which will result in highs generally
reaching the low to mid 70s.
Short term /Sunday night through Tuesday/...
330 am update...
main concern in the short term is focused around the passage of a
cold front and the increased potential for showers and a few
isolated weak storms...mainly Sunday night and Monday morning. Will
also see a second front move through Tuesday afternoon with more
showers and isolated storms.
Upper level ridging will be shifting to E/NE Sunday evening as the
next upper low drops in from central Canada across the ern Great
Lakes Sunday night and Monday morning. A lead short wave ahead of
the main cutoff low will have a surface front associated with it and
a narrow corridor of deep layer moisture and strong dynamics.
Elevated instability should be sufficient for a few weak storms
through Monday morning. The main threats will be cloud to ground
lightning, brief heavy rain and gusty winds. The heaviest
precip is expected to move in from the west/SW around midnight
along the twin tiers and The Finger lakes...and track to the
E/NE through the morning hours fairly quickly. The deep layer
moisture is expected to move to the east ahead of the front with
a wedge of drier air filtering in on the back side. There will
likely be enough broad large scale lifting going on to keep a
relative abundance of clouds around through the rest of Memorial
Day, and possibly a few isolated rain showers, but the threat
for continuous rain through the Holiday afternoon/evening is
fairly low. A few breaks in the clouds cannot be ruled out, but
given the pattern, not very optimistic. Morning rain is expected
to amount to a quarter to half inch at most.
Weak ridging and a drier air mass Monday night/Tuesday morning will
likely keep weather conditions quiet. Can't rule out a stray
sprinkle or periods of drizzle though. A secondary front will slide
in from the west late Tuesday morning and increase the potential for
a few rain showers through noon. This front will interact with a
gradually destabilizing boundary layer Tue afternoon...bl cape
around 200-500 j/kg, steep lapse rates...to produce a better chance
of scattered showers and storms. Thunderstorms should remain weak.
May see another tenth to quarter of an inch.
Temperatures will remain steady and nearly seasonal with highs in
the 60s and 70s...and lows in the 50s.
Long term /Tuesday night through Friday/...
330 am update...
the parent upper low across Canada will rotate ewd Tuesday night
through Friday and bring a slug of cooler air south across New York and PA
late this week...along with periods of showers and storms. The upper
low will have a series of embedded waves rotate around it as it
tracks through Quebec...which will likely trigger the showers. The
threat for storms is tough to nail down at this point. If an
embedded wave swings through central New York/NE PA during peak heating of
the afternoon, the convective potential will be enhanced with
steeper lapse rates and more instability. The one limiting factor
will be the presence of cooler air within the boundary layer and the
lack of any significant deep layer moisture. So, will continue with
chance pops during the afternoon/evening hours Wednesday and
Thursday and lower slight chc pops during the morning and over night
The upper low begins to lift out of the area Thursday night and
most of the area starts to become under the influence of upper level
ridging and weak warm air advection. Temperatures will slowly warm
back into the lower/mid 70s as the work week comes to an end...and
the potential for rain decreases under weak high pressure.
Aviation /12z Saturday through Wednesday/...
low stratus persists into this morning with IFR likely until 14z
for kbgm while kith/ksyr will continue to fluctuate between
fuel alternate MVFR and IFR until 14z. Conditions are slightly
better at kavp and kelm where fuel alternate MVFR will persist
until mid morning with cigs lifting beyond this time. All sites
are expected to be VFR by 18z.
Skies clear tonight as a ridge briefly moves in and this will
set up favorable conditions for valley fog at kelm with IFR
likely beginning around 8z. Remaining sites stay VFR.
Surface winds will be light (5 kt or less) throughout the
Monday through Wednesday...restrictions possible from scattered
showers and perhaps thunder.