000
FXUS61 KBGM 240047
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
847 PM EDT Sat Jun 23 2018

.SYNOPSIS...
A slow moving storm will move into southeast Ontario this
weekend. Showers and a few thunderstorms are forecast for
the rest of today and Sunday, before a cold front brings drier
air into the region Sunday night and Monday.

&&

.NEAR TERM /THROUGH SUNDAY NIGHT/...

830 pm update...

A weakening upper level wave is moving across Western NY at
this time. The shower/t`storm activity that was over west-
central PA and southwest NY earlier this evening is struggling
to make it into our forecast area. Therefore, lowered PoPs over
the next few hours...indicating mainly isolated to scattered
showers...left a small area of likely PoPs for showers over the
western Finger Lakes, closer to the remnant circulation. Also
removed mention of thunder from the forecast for much of the
area...as things seem to be stabilizing as we lose the daytime
heating. For the overnight hours continued with just isolated
showers, but did add in some patchy fog toward morning as much
of the latest guidance was hinting at this potential.

On Sunday, another frontal boundary slowly moves south across
the forecast area. This front looks to have plenty of moisture
associated with it, as PWATS remain near 1.5 inches. Bumped up
PoPs a bit, into the categorical range across the southern tier
of NY and northern tier of PA. Skies should remain mostly
cloudy through the day, which should act to limit the amount of
atmospheric instability. However, with that said, across the
southern Tier of NY and especially NE PA any breaks of sun will
help to boost MLCAPE values toward 800 J/KG in the afternoon.
Thus, did feel mentioning thunderstorms in the forecast was the
right way to go for this part of the area...again, mainly during
the afternoon hours. Deep layer shear values around 35-40 kts
could allow for an isolated stronger thunderstorm to develop...but
the cloud cover and lower instability should be limiting factors.
Along and north of the NY Thruway do not see much if any instability
...so only went with a slight chance of a thunderstorm there.
High temperatures look to reach 70-75 for our NY zones, with mid
to upper 70s across NE PA. West-southwest winds 4 to 8 mph in
the morning, shift out of the west-northwest by afternoon;
increasing to 6-12 mph, with a few higher gusts possible.

Not much change for Sunday night, as scattered showers linger
into the evening hours. Overnight, should see a gradual drying
trend, with just a few light showers or drizzle around. The
flow turns north-northwest which should allow cloud cover to
linger in the favored upslope areas of central NY and NE PA much
of the night. Overnight lows hold in the 50s to near 60.

230 pm update...

A low level southeast flow of moist air under an inversion has
kept clouds over the area. Some slow lifting and thinning of the
clouds as the flow shifts south. Convection in central PA is
moving NE into the area this afternoon ahead of a weak surface
boundary and decent upper level wave. Thunderstorms are not
expected to be severe with shear of 30kts and cape under a 1k.
Timing with some heating will be late afternoon Scranton to Penn
Yan but then weakening as it moves further east into cooler air
where more clouds have been. With high pwats thunderstorms could
drop a quick inch of rain. This shouldn`t be a problem given the
recent dryness.

Late tonight fairly quiet with isolated showers and clouds
filling back in and lowering. Forcing will have lifted to the
northeast. Lows around 60 with light fog.

Sunday a slow improvement in sky conditions but with a short
wave trough and surface low convection will be common again
during the afternoon. Again weak instability and winds, so
thunderstorms should be weak. With more sun highs in the 70s,
but mid level cooling weak so lapse rates remain low.

Sunday night the rain moves out quickly as high pressure moves
in. Most of the showers will be in the evening and light. Lows
again near the dewpoints from the mid 50s to around 60 south.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
Period should be dry as a trof and surface front depart to the
east early Monday, and high pressure over the GReat Lakes builds
in. There is a small chance that a light shower could pop up
over the Catskills which is under the western edge of the upper
cold pool, but the possibility is below the chance threshold so
will blend with the surrounding offices and keep them out.

Tuesday morning will be quite chilly under Canadian high
pressure and light winds.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Upper wave and surface low tracks north of the region Wednesday,
with a trailing cold front well down into the mid Atlantic.
Even the EURO is quite robust with the pops and QPF but a bit
slower with the advance of the system. In any event, likely pops
seem reasonable for 12Z Wednesday through 12Z Thursday, with
lingering chance pops into Thursday afternoon with some
leftover instability in the cool air advection. High pressure at
the surface and aloft slowly builds in through the end of the
period. Northwest flow will continue to keep a chance or slight
chance of showers, especially over the northern zones, before
the ridge caps things for the weekend.

&&

.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
Isolated and weak rain showers are possible early this evening,
with currently VFR conditions becoming MVFR after 04Z and
ceilings dropping to IFR after 08Z with light MVFR vsby fog
possible. Conditions are expected to slowly improve to fuel
alternate after 15Z...and then to MVFR after 18Z with a few
showers or possibly a passing thunderstorms for KITH, KELM, KBGM
and/or KAVP after 20Z.

South southeast winds 5 to 10 kts this evening. Late tonight
light and variable winds. Midday Sunday west winds around 6
kts...becoming NW 5 to 10 kt in the afternoon.

Outlook...

Sunday night...Showers and restrictive conditions are possible.

Monday through Tuesday...VFR.

Wednesday through Thursday...Restrictions possible in showers
and storms.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.

&&

$$
SYNOPSIS...TAC
NEAR TERM...MJM/TAC
SHORT TERM...DGM
LONG TERM...DGM
AVIATION...BJT/TAC

NWS BGM Office Area Forecast Discussion

Random Fact

Weather Terms

Lake Effect Snow Warning - Lake effect snowfall of 6 inches or more in 12 hours or less, or 8 inches or more in 24 hours or less.