Scientific Forecaster Discussion
fxus61 kokx 222008
Area forecast discussion
National Weather Service New York New York
408 PM EDT sun Sep 22 2019
high pressure continues to move farther into the western
Atlantic through Monday. A cold front approaches from the west
Monday and moves across the region Monday night. High pressure
builds in for the middle of the week. Another cold frontal
passage on Thursday will be followed by yet another large area
of high pressure for Friday and Saturday. A cold front will
approach from the north on Sunday.
Near term /until 6 am Monday morning/...
the sub tropical ridge across the eastern states weakens tonight
as a progressive shortwave approaches. Surface high pressure
continues to move farther into the western Atlantic. Warm
advection continues tonight with an increase in high cloudiness
tonight. Mild, above normal conditions will remain. There may be
some patchy River Valley fog tonight. However, winds will be a
little stronger and this may not occur.
There will also be a moderate rip current risk at the ocean
beaches into this evening.
Short term /6 am Monday morning through Monday night/...
the progressive short wave moves into the region by late Monday
and into the area Monday night, as the upper low closes off. The
upper trough will then linger into late Monday night and
Tuesday. At the surface a weak trough develops ahead of the cold
front. However, there will be little forcing, instability, or
cape, until the cold front moves into the region late in the
afternoon. So will maintain dry weather until after 18z inland
and closer to the coast around 20z. With warm advection
continuing Monday, and a warm and humid airmass already in
place, temperatures will be well above normal. Across portions
of northeastern New Jersey and the lower Hudson Valley
temperatures may be near 90. Temperatures Sunday were above
guidance and went with the higher guidance temperatures Monday.
With little instability and cape from around 20z to 01z, and
across the inland areas only mentioned isolated thunder. Farther
to the east the area will likely remained capped, with a weak
subsidence inversion in place, which does not look like this cap
will be broken looking at BUFKIT soundings. With the progressive
nature precipitation will be exiting the eastern zones by 10z
Tuesday. Temperatures remain above normal Monday night, with the
exception of the far interior where cooler air will be moving in
behind the cold front. In these areas temperatures will be near
There is a high rip current risk at the ocean beaches for
Long term /Tuesday through Sunday/...
a cold front will have passed east to start the day on Tue.
With a lagging upper trough and sfc reflection yet to move
across, could see some afternoon stratocu development
throughout, possibly some sprinkles across the higher terrain of
southern CT. Tue night into Wed night will then be fair and dry
under mid level confluence and low level subsidence in the wake
of this slow moving trough, with sfc high pressure drifting
As another upper trough moves across southern Canada and the
northern tier of states, a cold front should pass through on
Thu. Best dynamics for lift pass mainly to the north, so only
have slight chance pop for daytime Thu, then dry conds expected
Thu night into at least Sat morning as high pressure builds at
the sfc and aloft. A cold front may get close enough to generate
some showers, possibly as early as late day Sat, more so into
Temps through the period will continue above normal, with
daytime highs at least 5-8 deg above the seasonal avg, and as
much as 8-12 deg above avg ahead of the approaching cold fronts
on Thu and Sat.
Aviation /20z Sunday through Friday/...
high pressure over the western Atlantic will continue to slide
eastward. A cold front approaches late Monday.
SW flow this afternoon to near 10 kts for all terminals this
afternoon. NYC terminals may be slightly higher, closer to the
10-15 kt range. Some wind gusts up to 20 kt are expected for
this afternoon. Winds diminish tonight, however increase once
again on Monday, with gusts to near 20 kt.
Mainly VFR conditions are expected through the taf period. There
is a chance some fog returns to outlying terminals tonight if
Outlook for 18z Monday through Friday...
Monday...mainly VFR. Gusty SW winds.
Monday night...MVFR possible in showers and possible
Tuesday-Friday...mainly VFR. A slight chance of showers
a increasing and persistent southwesterly flow ahead high
pressure retreating into the western Atlantic and a cold front
approaching from the west will result in ocean gusts reaching
Small Craft Advisory levels Monday into Monday night. As the cold front moves
into the waters and then passes to the east Monday night, winds
and gusts diminish and shift to the northwest. Wind gusts fall
below Small Craft Advisory levels on the ocean late Monday. However, ocean seas
will remain at Small Craft Advisory levels Monday night with a combination of
wind waves and increasing swell from Tropical Storm Jerry. See
the Tropical Prediction Center for forecasts on Jerry.
Otherwise, winds remain below Small Craft Advisory levels on the non ocean
A Small Craft Advisory is in effect for the ocean waters Monday and Monday night,
and remaining through Tuesday for the waters east of Fire Island
An extended pd of hazardous ocean seas, with long period swells
5-6 ft and hazardous conditions at the inlets, expected from
Tue into Wed evening, especially east of Fire Island Inlet as
swells from distant Tropical Storm Jerry arrive from the S-se.
Ocean seas east of Moriches Inlet could also briefly touch 5 ft Thu
afternoon as west flow increases with a cold frontal passage.
rainfall Monday night will generally be less 1/4 inch with
localized higher amounts possible, especially across
southeastern Connecticut. 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 from Monday morning through Monday
evening for nyz075-080-081-178-179.
Marine...Small Craft Advisory from 6 am Monday to 6 am EDT Tuesday for
Small Craft Advisory from 6 am Monday to 6 PM EDT Tuesday for