Scientific Forecaster Discussion
fxus61 kokx 212054
Area forecast discussion
National Weather Service New York New York
454 PM EDT Sat Sep 21 2019
a large area of high pressure along the East Coast will be slow
to work east this weekend. A cold front will eventually approach
on Monday, and pass through Monday night, followed again by high
pressure from Tuesday into Wednesday night. Another weak cold
frontal passage on Thursday will usher in yet another large high
pressure system for Friday into next weekend.
Near term /until 6 am Sunday morning/...
high pressure over the region starts to slowly move offshore
tonight. Mostly clear skies and light winds will allow temperatures
to fall into the 50s and lower 60s. Lows in the NYC Metro area will
remain in the middle 60s. A mav/met blend was in good agreement and
A high rip current risk will continue at the ocean beaches into
Short term /6 am Sunday morning through Sunday night/...
the upper ridge and surface high will continue to gradually move
offshore Sunday and Sunday night. Meanwhile, an upper level trough
will begin to approach the Great Lakes region.
As the high continues to move offshore, southwest flow will
gradually strengthen both Sunday and Sunday night. This southwest
flow will continue to keep unseasonably warm conditions across the
area on Sunday, as temperatures climb into the lower and middle 80s,
across most of the County Warning Area. The only exception will be across the Twin
Forks of Long Island and eastern coastal Connecticut, where highs
will remain in the upper 70s.
Dry conditions continue into Sunday night, with just some increase
in cloud cover late Sunday night into early Monday morning as trough
well off to the west slowly approaches the area. Lows Sunday night
will remain in the 60s.
There will be a moderate rip current risk at the ocean beaches
into this evening.
Long term /Monday through Saturday/...
this time frame will start off with a northern stream closed
moving slowly across the northern tier of states. An associated
trailing cold front approach Mon afternoon and push through Mon
night, with most of the associated precip late day Mon into Mon
night. With an unseasonably warm air mass in place and dewpoints
well into the 60s, think there will be enough instability for
tstms with the frontal passage.
The front should clear the area by Tue morning, with high
pressure and dry conditions returning via mid level
confluence/low level subsidence after passage of the front and
cutoff low to the north. A more significant northern stream
trough will push another cold front through on Thu, with another
large sfc high pressure system building in for Saturday as
heights rise aloft across the eastern states.
Temps will be above normal through the period, especially on Mon
and Thu ahead of the cold frontal passage, with highs both days
mostly in the lower/mid 80s. The coolest night should be Tue
night, with clear skies/light winds allowing for widespread
40s inland for lows.
Aviation /20z Saturday through Thursday/...
high pressure remains centered off the Carolina coast through
VFR through the forecast period.
Sea breezes have developed, with most terminals with sea breeze
directions. There is some uncertainty as to the timing, and
whether or not, the sea breeze moves through klga and kteb.
Winds in the NYC Metro area become SW again, under 10 kt, as
the sea breezes end early this evening, 23z to 02z. At the
outlying terminals winds become calm to light and variable.
Sunday winds again become southerly with sea breezes, and during
the afternoon gusts to around 15 kt will be likely.
Outlook for 18z Sunday through Thursday...
Sunday...VFR. Gusty southerly wind to around 15 kt in the
Monday...MVFR possible. Chance of showers from late in the
afternoon through the night. There is a slight chance of
thunderstorms in the afternoon and early evening. SW gusts
15-20 kt into early evening.
Tuesday-Thursday...VFR. A slight chance of showers Thursday
sub-Small Craft Advisory conditions tonight as high pressure remains over the
area. As the high gradually slides offshore, S-SW winds will
gradually increase Sunday into Monday, with Small Craft Advisory conditions
expected to return to the ocean waters beginning late Sunday
night. An extended pd of Small Craft Advisory conds is then possible for the
ocean waters even as winds diminish on Tue, especially out
east, as swells from ts Jerry begin to arrive.
rainfall Mon night could total over 1/2 inch across southeast CT and
eastern Long Island. Otherwise, no significant hydrologic
impacts expected through next week.
NYC National oceanic and atmospheric administration weather radio station kwo35 (162.55 mhz) remains off
New York...high rip current risk until 8 PM EDT this evening for nyz075-
near term...British Columbia
short term...British Columbia