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Area forecast discussion 
National Weather Service Binghamton New York
657 PM EDT Monday Jul 6 2015

Synopsis...
a weakening area of low pressure will move northeast across
New York tonight and Tuesday morning. Scattered showers and
isolated thunderstorms will accompany this feature...but most
areas will see only short periods of rain. A stronger cold front
will cross the region Tuesday night and Wednesday with a better
chance for showers and storms. A small area of high pressure will
bring fair weather to the region Wednesday night before another
system brings more precipitation to the region Thursday.

&&

Near term /through Tuesday/...
radar shows scattered to isolated rain showers moving northward into c New York
and northern PA in advance of a weakening upper level low that was
presently centered over eastern Ohio/western PA. The isld to scattered rain showers that
has formed over c New York and northern PA was assctd with ll moisture advection
in the presence of the maximum heating of the day. Storm Prediction Center mesoanalysis
website has much of c New York/NE PA between 500 and 1000 j/kg. Given
that Li/S were also negative a few parcels could get high enough for
thunderstorms and rain so have isld thunderstorms and rain in grids along with rain showers through early
evening. After sunset...we expect this acvty to wane so have probability of precipitation
dropping off for a time between 0 and 6z as the boundary layer
stabilizes. Later tonight as the upper level low tracks into NE
PA/SC New York I expect more rain showers to flare up again so increase probability of precipitation
after 6z. This upper level low will be opening up and there will
be some upper level pv advection across eastern New York clipping our eastern zones Tuesday am
so with increasing heating in the presence of some upper forcing
have probability of precipitation climbing across our eastern zones Tuesday am. Then by afternoon
forcing is weak as region is behind the upper level pv maximum and
next front is still well west of region. Believe there will be a
lull Tuesday PM but still maintain chance probability of precipitation in collaboration with
neighboring weather forecast offices. Given convective available potential energy up to 1000 j/kg there could be a few
thunderstorms and rain pop up with afternoon heating. Confidence is lower here.

Then for Tuesday night...next upper level trough works across the Great
Lakes region to Quebec and pushes a front south into c New York Tuesday night and
by early Wednesday NE PA. Since the main upper level forcing with this
front stays north of the region and the front comes through during the
night we are not expecting any severe weather. However...there could
be locally heavy rains especially Tuesday evening in our western counties
where there will be sufficient instability and strong ll moisture
advection. NAM soundings for kelm Tuesday evening have precipitable waters over 2 inches
with a 40 knots low-level jet from the SW. The highest instability
will be west of our area Tuesday PM so this could lead to back-building
cells. So will continue to mention potential for heavy rain in severe weather potential statement Tuesday
night. Given the uncertainties we will have severe weather potential statement for whole area but
in the wording emphasize the western areas the hardest and mainly in
the evening. The precipitation should weaken as it works into our eastern
and southern zones late Tuesday night.

&&

Short term /Tuesday night through Thursday night/...
models in fairly good agreement through the period allowing for
above average forecast confidence. All models showing the front
pushing through Wednesday morning...decreasing chances for rain
through the morning through the afternoon. Precipitable waters still above 1.5
inches so some moderate to heavy rainfall will be possible as the
showers and thunderstorms exit...with that said the front will
flatten our some across PA with some precipitation possible lingering
across NE PA through the evening. Upper level flow will be zonal
as another wave pushes across the region Thursday with another
shot at precipitation...some models show moisture recovering to levels
with precipitable waters nearing 1.75 to 1.9 inches allowing for heavy rain
again in thunderstorms. Flow becomes more northwest behind the wave as
ridging builds across the MS River Valley...and drier air moves into
the area. Temperatures at or just below seasonal avgs.

&&

Long term /Friday through Monday/...
models in decent agreement with the overall upper level pattern
and just minor surface feature differences...providing better forecast
confidence through this period than the last few days. The models
have been all over the place the last few days with respect to the
long term trends...but today they seem to be gripping onto a
solution and will move the forecast in that direction with the 12z
runs of the GFS and Euro having a very similar look. Northwest flow to
start the period as ridging starts to retro from the MS valley into
The Four Corners region of the Continental U.S.. over most of the weekend
weak surface high will keep the temperatures just above seasonal avgs and
conditions dry...late in the weekend a trough will start to build
across the Great Lakes and eastern Continental U.S....possibly cutting off by
next Monday. It is possible that this cut off low will linger for
awhile and produce a threat for very wet conditions next week as
precipitable waters look to climb. Its well into the future...and things may
change if the position of the cut off significantly changes...but
definitely something to watch.

&&

Aviation /00z Tuesday through Saturday/...
VFR conditions exists all taf sites in c New York and NE PA at this
time. Visible satellite imagery shows a lot of clearing with middle and
higher clouds poised to stream in from PA. All models continue to
show a S to southeast flow of moisture in the low levels streaming
northward into c New York and NE PA overnight through 12z. This moisture is
expected to saturate out to an MVFR layer all taf sites between
02z and 04z across kavp-kelm-kbgm and kith and by 08z in our northern
tafs of ksyr and krme. We expect occasional IFR conditions at kbgm-kith-
kelm and kavp after 8-9z through 12z. This airmass had a lot of IFR
this morning down in Virginia and Maryland and trajectories suggest the same
air mass will be ovhd toward 12z. By 14-15z or so...a wind shift to
the SW will occur in tandem with boundary layer heating and
conditions will improve to VFR in scattered cumulus by afternoon all
taf sites.

Winds will be light south to southeast overnight and south to
southwest 5 to 10 knots Tuesday.

Outlook...

Tuesday night through Thursday night...restrictive conditions
possible in scattered showers/thunderstorms.

Friday/Saturday...VFR.

&&

Bgm watches/warnings/advisories...
PA...none.
New York...none.

&&

$$
Synopsis...djn
near term...djn
short term...abs
long term...abs
aviation...djn

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