Area forecast discussion
National Weather Service New York New York
157 PM EDT Wednesday Jun 19 2013
Synopsis...
high pressure builds in from the northwest today and remains in
control through the end of the week. A weak cold front will pass
through the area Sunday night into Monday with high pressure
returning in its wake.
&&
Near term /until 6 PM this evening/...
16z surface analysis shows high pressure building into the tri-
state area. Last several hours of rap analysis at h500 indicate a
shortwave trough and weak vorticity maximum moving through...there will be
little consequence from this feature.
Light north to northeasterly flow will continue into the afternoon
with just a few fair weather clouds. Late afternoon sea breezes
are expected at the coast. Otherwise...mostly sunny with a dry
airmass as surface dewpoints drop into the 40s. Mixing profiles
support highs of mostly 75-80.
There is a moderate risk of rip currents at Atlantic Ocean beaches
today.
&&
Short term /6 PM this evening through Thursday night/...
light to calm winds and a mostly clear sky tonight will allow for
decent radiational cooling outside of the city...with lows 5-10
degrees below normal in most of the suburbs.
High pressure center shifts offshore on Thursday with a return SW-S
flow setting up. Sea breezes are likely as winds remain light
through the first few thousand feet in elevation. Surface dew points
should remain at comfortable levels in spite of this as drier air
from aloft mixes down. Mixing won't be as deep as today due to
subsidence...however temperatures at the top of the mixed layer
should allow for highs of generally 75-80 once again.
Dry weather continues into Thursday night with lows still below
normal...but not as cool as tonight.
&&
Long term /Friday through Wednesday/...
global models in good agreement with the overall pattern in the long
term time frame. Aloft...a mean trough will give way to slightly
rising heights by Saturday and continuing to build through the week.
GFS is slightly more aggressive with the strong ridge moving in
while the European model (ecmwf) tracks a shortwave through Monday and then quickly
rises The Heights.
At the surface... high pressure remains in control through the long
term with a general south-southwest flow. Used a mav/met blend for
temperatures on Friday with a good general agreement for near normal
values. Temperatures will continue to moderate through the week and used
wpc guidance as it seemed reasonable with no major temperature
fluxes. Near to just above normal temperatures are expected.
Models trying to hint at a few showers on Friday but have continued
the dry forecast with little instability or lift. On Saturday...a
cold front will weaken and dissipate by the time it reaches the
western County Warning Area boundary. With some instability in place with afternoon
heating...this boundary could create a few showers...mostly in far
north and west zones. Have left chance probability of precipitation for that area.
Highest chances for showers and thunderstorms will be Sunday night
into Monday as a cold front approaches and possibly remaining
stationary through Monday. European model (ecmwf) also trying to hint at a potential
decaying mesoscale convective system tracking southeast along the front...along the southern side
of an upper jet. Will generally keep chance probability of precipitation in the areas north
and west of NYC and slight chance elsewhere. The northern areas will
have the highest instability during the day and therefore the
greatest precipitation chances.
&&
Aviation /18z Wednesday through Monday/...
hipres builds over the region tonight and offshore on Thursday.
VFR through the taf period.
North winds into this evening except where sea breeze flow develops. Gust
potential will decrease through the day as winds aloft lighten.
Nearly calm overnight with southerly flow developing after 12z Thursday.
Enhanced flow along the S coasts after 17-19z Thursday...with sustained
winds likely to be at or above 15kt at kjfk.
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: variability in prevailing wind direction
possible through 21z as gust frequency decreases. Sea breeze expected
to develop during taf tempo period.
Klga fcster comments: variability in prevailing wind direction
possible through 23z as gust frequency decreases. Sea breeze
expected to develop during taf tempo period.
Kewr fcster comments: variability in prevailing wind direction
possible through 00z as gust frequency decreases. Sea breeze expected
to develop during taf tempo period.
Kteb fcster comments: no unscheduled amendments expected.
Khpn fcster comments: no unscheduled amendments expected.
Kisp fcster comments: variability in prevailing wind direction
possible through 22z as gust frequency decreases. Sea breeze expected
to develop during taf tempo period.
Outlook for 18z Thursday through Monday...
Thu-Fri...VFR. Prevailing SW winds.
Sat-Mon...mainly VFR. Areas of MVFR or lower in the morning. Isolated-scattered
afternoon/evening thunderstorms possible...especially north and west of the city. SW
winds.
&&
Marine...
high pressure builds in over the waters through the day today.
A northerly flow at around 15 knots weakens this afternoon with
local sea breeze directions developing nearshore late in the day.
A light return S to SW flow develops for Thursday as the center of
high pressure shifts offshore. Tranquil conditions therefore
prevail.
Winds and seas are expected to remain below Small Craft Advisory criteria through
early next week as high pressure remains over the area.
&&
Hydrology...
dry weather is expected through at least Sunday morning. Showers and
thunderstorms are possible each afternoon sun-Tuesday but no
widespread significant precipitation is expected.
&&
Okx watches/warnings/advisories...
CT...none.
New York...none.
New Jersey...none.
Marine...none.
&&
$$
Synopsis...jc/ln
near term...ds
short term...jc
long term...line
aviation...jmc
marine...jc/ln
hydrology...jc/ln
