Area forecast discussion 
National Weather Service New York New York 
1236 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 huors 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 Tuesday/... 
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/... 
high pressure builds in from the Great Lakes through tonight. 


VFR through the taf period. Middle and high clouds gradually 
continue to dissipate through the day...then sky clear tonight. 


North-north-northeast around 10 knots through at least early afternoon with isolated 
gusts 15-20 knots...except at kewr which likely will have more 
frequent gusts from midday into early afternoon. Sea breeze likely 
middle-late afternoon/early evening kbdr/kgon/kjfk/kisp/klga/kewr. 
Winds become light and variable at all terminals this evening. 


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: moderate-high confidence in seabreeze - low 
confidence in exact timing. Could be off +/- 2 hours. Isolated 
gusts to 15-20 knots possible through early afternoon. High 
confidence in winds to the right of 300 true through early 
afternoon. 


Klga fcster comments: moderate confidence in seabreeze - low 
confidence in exact timing. Could be off +/- 2-3 hours. Isolated 
gusts to 15-20 knots possible through early afternoon. High 
confidence in winds to the right of 300 true through early 
afternoon. 


Kewr fcster comments: moderate confidence in seabreeze - low 
confidence in exact timing. Could be off +/- 2-3 hours. Isolated 
gusts to 15-20 knots possible through midday...then moderate 
confidence in more frequent gusts around 16-20z. High confidence 
in winds to the right of 300 true through early afternoon. 


The afternoon kewr haze potential forecast is green...which 
implies slant range visibility 7sm or greater outside of cloud. 


Kteb fcster comments: low-moderate confidence in seabreeze - low 
confidence in exact timing. Could be off +/- 2-3 hours. Isolated 
gusts to 15-20 knots possible through early afternoon. 


Khpn fcster comments: very low chance of seabreeze late this 
afternoon/early this evening. Isolated gusts to 15-20 knots 
possible through early afternoon. 


Kisp fcster comments: moderate-high confidence in seabreeze - low 
confidence in exact timing. Could be off +/- 2 hours. Isolated 
gusts to 15-20 knots possible through early afternoon. 


Outlook for 12z Thursday through Sunday... 
Thursday-Saturday morning...VFR. 
Saturday afternoon/night. Mainly VFR...except MVFR or lower 
possible in isolated-scattered rain showers/thunderstorms and rain mainly to the north/west of city 
terminals in the afternoon/evening. 
Sunday...MVFR or lower possible. 


&& 


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/maloit 
marine...jc/ln/ds 
hydrology...jc/ln