Area forecast discussion
National Weather Service Binghamton New York
133 PM EDT sun may 19 2013
Synopsis...
high pressure off the New England coast and a weak system over the
middle Atlantic will bring the chance for showers through Monday. On
Monday, there is also the chance for thunderstorms as a weak
surface trough approaches the region. Unsettled weather will
continue into the middle of the week.
&&
Near term /until 6 PM this evening/...
125 PM update...
made adjustments downward with afternoon highs especially outside
of the western Finger Lakes where any amount of sunshine looks
doubtful and we have seen temperatures really struggle to climb at all.
With that said in a narrow area along our border with kbuf we are
already into the 70s so will once again have a wide range of temperatures
this afternoon with 70s over the far northwest and 50s to near 60
over the higher terrain of the southeast.
Other adjustment was to lower probability of precipitation dramatically area wide. Our
forecast models continue to suggest chance probability of precipitation and light quantitative precipitation forecast over
the far southeast but it just doesn't appear to be happening. On
closer inspection the models are likely overdoing quantitative precipitation forecast based on the
moist profiles we are seeing and the southeast flow being
overly enhanced by terrain. With that in mind the two main focus
areas for precipitation will be the next hour or two over the far
northeast with our departing boundary from this morning. Then
later today abundant sunshine over western New York combined with
extensive cloud cover farther east will be enough to set up a nice
differential heating boundary. This may be enough along with any
lake breeze boundaries for some isolated convection over the
western Finger Lakes. The RUC does show convective available potential energy above 500 j/kg but
without any significant trigger...kept it isolated at best. As
this dies down this evening expect dry weather across the County Warning Area
until near midnight. By this time I do believe the models in that
a moist southeast flow combined with the right time of the day
(nighttime) will be enough to produce patchy drizzle over the
southeastern third of the County Warning Area. As usual the most likely suspects
will be across the higher terrain. The previous afd is below.
950 PM update... an area of showers stretching from just
west of Utica southeast through Madison...Otsego...Delaware...and
Sullivan counties continues to March eastward. This area will
remain the focus of light showers and/or sprinkles through 1 PM
with the rest of the area remaining dry. Blended with the previous
forecast of ramping probability of precipitation back into the chance range later this
afternoon. Fairly wide range of temperatures today with highs barely
getting into the 60s over most of the area with thick cloud cover.
Warmest temperatures will still be in the northwestern Finger Lakes
through ksyr where we have the best shot at some sunshine. The
previous afd is below...
Radar shows isld rain showers working through c New York and far
northestern PA in assctn with a weak short wave. This acvty will work through
ec New York and the Poconos/Catskills by middle morning as more isld-scattered
rain showers acvty works eastward from from southern ont. There is also a batch
of light rain showers across much of central and southern New Jersey which will continue to
slowly work northeast today and develop back to the northwest as
per model guidc. NAM...GFS...Euro and CMC all show light precipitation
working nwrd today reaching across NE PA and into c New York. The
dynamical set up was as follows: the above mentioned upper level
trough will move slow enough off the NE coast that continual small
short waves/jet streaks will increase the upper confluence during
the day today. This will strengthen the surface hi off the East Coast
and increase the southeasterly flow into eastern New York and eastern PA. The ll ageo
winds show this really well with a southeasterly ageo wind up through New Jersey into
NE PA and ec New York. This will lead to a S-southeasterly low level jet that will advect
significant low-level moisture nwrd today and spread isld- scattered
light rain showers to the region. Thus have increased probability of precipitation to the
north and west during the day today with isld in the far northwest to chance probability of precipitation in
the southeastern zones. The clouds will be thinnest in the upper Finger
Lakes to central southern tier of New York...hence maxes will be higher in
these areas vs points to the S and east.
&&
Short term /6 PM this evening through Tuesday night/...
for tonight a short wave tracks across southeastern Canada and passes NE of
the region. With the passage of this wave the low-level flow will
turn from S-southeasterly to southwesterly and decelerate. Light rain showers should wind
down from west-east overnight tonight so will drop probability of precipitation gradually.
For Monday...the NAM...GFS and CMC all show a weak front dropping
southward in the wake of the above mentioned Canadian short wave.
The shift in the ll flow tonight to more southwesterly will allow for significant
ll moisture advection with models forecasting dewpoints to rise to at or above
60f across much of the forecast area Monday. This will occur prior to
the weak frontal boundary dropping southward Monday PM. Hence the NAM and
GFS both show convective available potential energy approaching 1000 j/kg Monday PM. The upper level
forcing will be weak as New York and PA will be just downstream from the
upper level ridge axis. Ystda/S 12z Euro run never drops the front
southward Monday as the short wave tracking in southeastern Canada stays
farther north. With weak forcing...yet decent cape and some
uncertainties will go with generic chance/S for rain showers and thunderstorms and rain
following previous shifts and other surrounding offices Monday into
Monday evening. Timing of the convection will be tricky this far out so
will not be very specific yet.
For Monday night...instability wanes to some extent...especially in the
eastern 1/2 of the County Warning Area. In the west across western New York to NC PA some cape
remains through the night. Will drop probability of precipitation Monday night...with the highest
lingering in the west and lowest to the east by Tuesday am.
Tuesday and Tuesday night look unsettled as the main cyclone and
assctd upper trough move eastward and accelerate the ll winds from the
SW into New York and PA. In addtn...there will be a lead short wave that
will enhance large lifting Tuesday night. Dewpoints will be well into the
60s and with significant moisture advection...and cape I see rain showers
and thunderstorms and rain both Tuesday and Tuesday night. The 0-6 km shear looks marginal for
severe at this time so not expecting any significant severe weather this far
east. Model qpfs were running generally under an inch so not
expecting any Hydro issues either.
&&
Long term /Wednesday through Saturday/...
330 am update...
beginning of extended features stalled frontal boundary stretched from
the Midwest into the northeast. Gom will be wide open as srly flow will
be prevalent between low to the west and Bermuda high to the east.
Airmass expected to destabilize on Wednesday, with potential to
continue through 12z Thursday as ul WV approaches from the west. Thus, have
bumped probability of precipitation into the likely range on Wednesday across New York zones closer to
convergence axis. Frontal passage prognosticated to occur Friday morning per GFS and ec.
00z Euro has come more into line with GFS regarding upper level low for
the weekend pulling north into the Canadian Maritimes with hipres
building in at the surface.
Have dropped temperatures slightly after 12z Friday due to frontal passage. Memorial Day
weekend remains up in the air with 00z Euro indicating cloud temperatures moving
out of Canada while 00z GFS brings a surface low up the eastern Seaboard
keeping cold air at Bay. 00z Gem also indicating a dvlpng surface low
over the Carolinas by 00z Saturday, similar to latest GFS. Thus, am
leaning more toward warmer GFS/Gem solution for the end of the week. Have
blended latest warm maximum temperature forecast with cooler wpc values for initial
forecast.
&&
Aviation /18z Sunday through Friday/...
12z update...
MVFR ceilings working north across New York terminals this morning. Higher
elevation site at kbgm sitting at IFR ceilings through 15z. Other
terminals should remain MVFR today. Further to the north at krme
and ksyr VFR conditions will start off the taf period through 15z
and then become MVFR through the end of taf valid time. Low level
moisture will become trapped under the inversion with IFR expected
after 00z at select terminals.
Winds light out of the S-southeast between 5-10kts becoming more
southwesterly late in the taf period.
Outlook...
Monday...MVFR in scattered showers.
Tuesday/Wednesday...MVFR in showers/thunderstorms.
Thursday...MVFR possible in showers/thunderstorms.
&&
Bgm watches/warnings/advisories...
PA...none.
New York...none.
&&
$$
Synopsis...djn
near term...djn/heden
short term...djn
long term...pvn
aviation...pvn
