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Area forecast discussion 
National Weather Service New York New York
419 am EST sun Nov 29 2015

a cold front will continue to move south of Long Island with a
weak surface low moving along it today. High pressure builds in
later today and tonight...continuing to build in through Monday.
Low pressure traveling west of the region will bring a warm front
near Tuesday with a cold front following on Wednesday. Then...high
pressure builds for the end of the week into next weekend.


Near term /until 6 PM this evening/...
a northerly flow continues behind the cold front. A wave of low
pressure along the front due to a jet streak moving in aloft will
enhance lift. A lot of models are keeping the rain south of Long
Island but due to the region being near the left front quadrant of the
jet streak...added in a slight chance of light rain for southernmost
portions of the region through this morning.

Another note this morning...especially before 8am...if clouds
scatter out and temperatures drop several more degrees across the
interior...due to residual moisture...there could be some patchy
black ice that forms.

Clouds lower this afternoon...move farther south with the southward
progress of the front when the high center moves into Quebec. Still
a northerly flow which will continue the low level cold air
advection. Highs will be lower due to limited vertical mixing...only
to near or just below 950mb...with the decrease in pressure gradient
as the day progresses. Cold air advection evident within the
forecast BUFKIT profiles conveying the backing of winds with height
from low to middle levels.

GFS has been verifying recently a little better compared to the NAM
so used a combo of mav/gmos for highs.


Short term /6 PM this evening through 6 PM Monday/...
for tonight...high pressure continues to build in from the north
but its center will be moving towards Maine. This will shift winds
locally at the surface to more of an easterly component. This will
act to moderate temperatures along the coast with more onshore
flow...preventing efficient radiational cooling. The interior will
be remarkably colder with winds being more light and variable
there so there will be more optimal radiational cooling. The mav
guidance was used for lows.

For Monday...the high center moves into the Gulf of Maine with
winds gaining more of an easterly component. With the center of
the high within close proximity...the pressure gradient will be
weak with winds speeds remaining lighter as a result.
However...with temperatures decreasing a few degrees aloft near
the top of the estimated mixing layer...which again will only be
to around 950mb...maximum temperatures are forecast to be
approximately five degrees colder than the previous day. A mav/met/gmos
combo was used for maximum temperatures Monday.


Long term /Monday night through Saturday/...
aloft...brief ridging Monday night through Tuesday with a
deepening trough approaching from the west for the midweek
period. The deep trough pushes south of the region Wednesday

For Monday night and Tuesday...high pressure will start to weaken
as the high center moves farther southeast of Nova Scotia. The
next low pressure area will be moving into Minnesota/wisconsinregion
with its associated warm front approaching the local region. Here
residual subsidence initially will give mostly clear sky
conditions but clouds will move in later that night with warm air
advection aloft...particularly between 800 and 1000mb. Precipitation
starting time will be crucial and contingent on what precipitation types
will be in the forecast ahead of the warm front. The mav/met/gmos
was used for min temperatures Monday night and maximum temperatures

The lifting is also conveyed from isoentropic lift late Monday
night into daybreak Tuesday. This is more conspicuous within the
GFS model isoentropic surfaces compared to the NAM. European model (ecmwf) and the
Canadian models also are the first models to bring in
precipitation...showing some light quantitative precipitation forecast extending through northeast New Jersey
into NYC between 06z Tuesday and 12z Tuesday. The warm front
continues to slowly approach as a low develops along it. The
prolonged southeasterly winds will continue with rain becoming
more continuous across the region.

For Tuesday night through Wednesday night...the rain continues
Tuesday night with the wave of low pressure passing south of Long
Island. Once the low exits east of the region...more of a
southerly wind will result. The warm front will be slow to lift
north across the region but is forecast to do so by the overnight
period. The associated cold front will move across early Wednesday
with high pressure building in from the west thereafter. The rain
continues into Wednesday before starting to decrease Wednesday
night. European model (ecmwf) and Canadian are also showing anafrontal
characteristics with some rainfall lingering after winds shift to
more westerly direction Wednesday night. The prolonged rain will
be favorable due to synoptic lift as diagnosed by positive
vorticity advection aloft as well as another left front quadrant of
the trough associated jet streak moving across the local region.

There is a consensus amongst the different models of mainly
conditions resuming late Wednesday night. Used gmos for
temperatures Tuesday night and Wednesday...and a combo of gmos/wpc
for temperatures Wednesday night.

Thursday-Saturday...shortwave trough lifts to our NE on Thursday
with upper ridging taking shape overhead. High pressure builds in at
the surface Thursday...and will remain in control through Saturday.
Some differences noted aloft between the latest models...but overall
these differences will have minimal impact on sensible weather. Dry
conditions during this period with temperatures averaging near


Aviation /09z Sunday through Thursday/...
strong high pressure will build southeast from Ontario into upstate
New York and New England tonight.

Still have some lingering MVFR ceilings at kewr/kgon...which should
scatter out at 10z and 12z respectively. Otherwise VFR conds.

High confidence in north flow 8-12 knots into early this evening. Winds
should veer toward the NE later tonight...with g15-20kt also
possible in NYC metropolitan and along the coast.

Outlook for 06z Monday through Thursday...
late tonight...VFR.
Monday...VFR. NE-east winds g15-20kt possible until around midday.
Monday night...VFR.
Tuesday-Wednesday morning...rain likely with IFR conds. LIFR and southeast winds
g20kt both possible Tuesday night.
Wednesday afternoon-Thu...VFR. West-northwest winds g20-25kt.


NE flow will strengthen tonight between high pressure building into
upstate New York and New England...and a weak low off the southern middle
Atlantic coast. This should bring Small Craft Advisory conds to the ocean waters
tonight into Monday afternoon. Conds should briefly abate Monday
night...then another round of Small Craft Advisory conds is likely for the ocean
waters Tuesday-Thursday both ahead of and behind a passing frontal system.
Small Craft Advisory conds are also likely for all waters in Post-frontal west-northwest flow
Wednesday night...and gusts on the eastern ocean waters may approach minimal
gale force.


any rain early today will only be a few hundredths of an inch or
less. Approximately one inch of rain will be possible with the low
pressure system Tuesday through Wednesday night with locally lower
and higher amounts.


Okx watches/warnings/advisories...
New York...none.
New Jersey...none.
Marine...Small Craft Advisory from 9 PM this evening to 6 PM EST Monday
for anz350-353-355.



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