Scientific Forecaster Discussion
fxus61 kokx 211141
Area forecast discussion
National Weather Service New York New York
741 am 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 then approaches from the
west on Monday and moves through Monday night. High pressure
returns for the remainder of next week.
Near term /until 6 PM this evening/...
a high amplitude ridge across the eastern half of the country
will result in a dry, unseasonably warm weekend.
Outside of some thin high clouds, expect a sunny day. A weak
west/SW flow this morning will become onshore late this morning
into this afternoon due to seabreeze development.
Highs will top out in the lower to mid 80s, but slightly cooler
along the immediate coastline.
There is a high risk of rip currents at the Atlantic Ocean
beaches today. The highest surf will be in the morning,
gradually subsiding in the afternoon as the long period swells
Short term /6 PM this evening through Monday night/...
both the upper ridge and surface high will gradually work
offshore tonight into Sunday, while an amplifying upper trough
approaches from the Great Lakes. The latter of which will send a
cold front into the area late Monday into Monday night.
Between the departing high and approaching cold front, a SW
flow will gradually strengthen, becoming strongest Monday
afternoon with gusts up to 25 mph. Highest gusts will be near
It will also remain unseasonably warm, with highs generally in
the low to mid 80s with lows moderating from the mid 50s to mid
60s Sunday morning, to the mid and upper 60s Monday morning.
There is a chance of showers with an isolated thunderstorm
Monday afternoon/night with the cold front. While there is
strengthening of the vertical wind profile as heights fall with
the incoming upper trough, instability remains weak.
There is a moderate risk of rip currents at the Atlantic Ocean
beaches on Sunday.
Long term /Tuesday through Friday/...
high pressure then keeps US dry Tuesday and Wednesday along
with high temperatures closer to normal. A cold front
associated with low pressure tracking through southern Canada
then approaches on Thursday. The upper flow is progged to be
more zonal than cyclonic, so the front therefore weakens as it
approaches US. Have maintained a slight chance of showers with
this front for Thursday. High pressure builds back in on Friday
with dry weather.
Aviation /12z Saturday through Wednesday/...
high pressure remains over the terminals through the taf
period. VFR conditions are expected to continue.
Light and variable winds will become more of a SW flow with sea
breezes for the coastal terminals late this morning into this
afternoon. Wind speeds increase to 5-10 kts this afternoon.
Winds subside to 5kts or less tonight for all terminals and
become variable in direction once again outside of NYC terminals.
Forecast timing of sea breeze could be off by 1-2 hours for
Outlook for 12z Sunday through Wednesday...
Monday...MVFR possible. Chance of showers afternoon into night
with a slight chance of thunderstorms. SW gusts 15-20kt day
into early evening.
easterly swell will gradually diminish today with sub-Small Craft Advisory
conditions forecast by afternoon.
As high pressure gradually works offshore southerly winds will
gradually increase through the time period with Small Craft Advisory conditions
likely to return to the ocean waters Sunday night into Monday.
Marginal Small Craft Advisory conditions will be possible for eastern Li sound
and all of the bays surrounding Li.
Winds and seas then diminish on Tuesday, with all waters below
advisory criteria by Tuesday night. Relatively tranquil conditions
then continue through Wednesday with a weak pressure gradient and
lack of significant swell.
no significant hydrologic impacts are expected through next
NYC National oceanic and atmospheric administration weather radio station kwo35 (162.55 mhz) remains off
New York...high rip current risk through this evening for nyz075-080-081-
Marine...Small Craft Advisory for hazardous seas until noon EDT today