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Area forecast discussion 
National Weather Service New York New York
755 PM EDT Tuesday Sep 2 2014

Synopsis...
a cold front will move across the tri-state area tonight into the
early morning hours Wednesday. High pressure over the Ohio Valley
then builds east for the second half of the week. Another cold
front will approach Friday night and move across the area Saturday
and Saturday night. High pressure builds in for the end of the
weekend into the beginning of the new work week.

&&

Near term /until 6 am Wednesday morning/...
a cold front over central PA early this evening will advance quickly
east and still expected to reach the lower Hudson Valley by around
8 PM...crossing NYC metropolitan between 10 PM to midnight...and eastern
Li/southeast CT 2 to 5 am.

There will be a gradual increase in both the deep and low- level
shear as shortwave energy and cold front approach...however
instability levels are expected to continue to fall to marginal
levels over the next couple of hours due to the loss of daytime
heating. Stronger instability will remain well south of the
region. In addition...dynamics associated with the rrq of the
upper jet and shortwave pass mainly northwest of the area...perhaps
clipping northwest portions of the lower Hudson Valley. Thus...better
locations for severe thunderstorm maintenance into this evening look to
be north and south of the region. But with low level jet maintaining
marginal instability and convergence along the cold
front...isolated to scattered convection expected to translate
east this evening through around 2 am.

A strong storm or two is possible...but severe threat looks to be
low for our region. Brief heavy rainfall and gusty winds look to
be the main threats...particularly from NYC/New Jersey metropolitan and points
n&w. Convection should become elevated and deteriorate as it tracks
east into Li/CT as it gets farther away from middle/upper level
forcing and better shear.

Warm...muggy conditions will continue up until frontal passage
with lows in the middle to upper 60s in the suburbs...to around 70 NYC
metropolitan.

&&

Short term /6 am Wednesday morning through 6 PM Wednesday/...
warm...but much drier conditions will be featured on Wednesday as high
pressure builds east from the Ohio Valley. Northwest winds will be
accompanied by highs in the middle 80s with dew points falling off
into the 50s.

Lows Wednesday night will return to seasonable levels with clear skies
and diminishing winds.

There is a moderate risk of rip current formation at Atlantic
beaches on Wednesday due to residual onshore swells.

&&

Long term /Wednesday night through Tuesday/...
high pressure at the surface for Thursday into Friday...allowing for
dry conditions. Zonal flow aloft on Thursday will transition to some
weak ridging Thursday night into Friday which will help to slow the
forward movement of the next cold front that approaches Friday
night. The center of high pressure pushes off the East Coast
Thursday into Thursday night. Return flow on Friday will allow for
an increase in humidity levels as dewpoints rise into the upper 60s.
Some lower 70s dewpoints are not out of the question Friday night
into Saturday .

Models are in fairly good agreement with the front moving
through Saturday into Saturday night. There are differences with low
pressure developing along the frontal boundary as it passes
through...leading to differences in rainfall amounts. At this time
though...flooding is not expected.

Precipitation will taper off Sunday...ending sometime Sunday night.
High pressure then builds in behind the front. A Continental polar
airmass builds in behind the front. Cold air advection will keep
temperatures at or below normal Sunday through Tuesday...in the
70s...while dewpoints will be well in the 50s.

&&

Aviation /23z Tuesday through Sunday/...
a cold front passes through tonight with isolated/scattered thunderstorms with brief
MVFR/IFR conditions and gusty winds possible. Most likely though
in the general time window of 0130-0330z for the city
terminals...khpn and kswf where there is a one hour tempo for
thunderstorms and rain...02-03z. Otherwise VFR conditions with a S-SW flow around
10 knots with some gusts 15-20 knots into early evening becomes more west-northwest
late tonight behind the cold front with the same sustained speeds.
West-northwest flow prevails through Wednesday morning with some backing of
flow to west-SW late in the afternoon.

New York metropolitan enhanced aviation weather support...

Detailed information...including hourly taf wind component forecasts can
be found at: http:/www.Erh.NOAA.Gov/zny/n90 (lower case)

Kjfk fcster comments: timing of -tsra could differ +/- 1 hour
from taf and could last an extra hour than in taf. Timing of SW
wind shift Wednesday could be off by 1-2 hours.

Klga fcster comments: timing of -tsra could differ +/- 1 hour
from taf and could last an extra hour than in taf. Amendments
possible for winds on Wednesday afternoon.

Kewr fcster comments: timing of -tsra could differ +/- 1 hour
from taf and could last an extra hour than in taf. Amendments
possible for winds on Wednesday afternoon.

Kteb fcster comments: timing of -tsra could differ +/- 1 hour
from taf and could last an extra hour than in taf. Amendments
possible for winds on Wednesday afternoon.

Khpn fcster comments: timing of -tsra could differ +/- 1 hour
from taf and could last an extra hour than in taf. Amendments
possible for winds on Wednesday afternoon.

Kisp fcster comments: future amendments could include a one hour
tempo for -tsra depending on how they evolve over next 2-3 hours.
Winds could become more west-SW Wednesday afternoon. Amendments
possible Wednesday afternoon.

Outlook for 00z Thursday through sun...
Wednesday night-Friday night...VFR.
Sat-sun...sub-VFR possible in scattered shra/tsra.

&&

Marine...
southerly winds just ahead of and northwest winds behind the cold front
tonight into Wednesday will remain just below Small Craft Advisory criteria for the ocean
waters. Undercut wavewatch guidance by about a foot on the ocean
tonight...keeping seas at 2 to 4 feet. High pressure then follows
for the second half of the week with tranquil conditions on all
waters.

Sub-Small Craft Advisory conditions expected through the long term period...with dry
conditions through Friday. A front approaches late Friday moving
through Saturday into Saturday night...with showers and
thunderstorms possible through Sunday.

&&

Hydrology...
no hydrologic issues expected Wednesday through the weekend.

&&

Okx watches/warnings/advisories...
CT...none.
New York...none.
New Jersey...none.
Marine...none.

&&

$$
Synopsis...jp/dw
near term...NV/dw
short term...dw
long term...jp
aviation...jc/jm
marine...jp/dw
hydrology...jp/dw

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