Дискусии на предсказва
fxus61 kokx 222349
Area forecast discussion
National Weather Service New York New York
749 PM EDT sun Jul 22 2018
low pressure will persist to the west early this week, while
offshore high pressure builds slowly westward. An associated
frontal boundary will remain to the west through much of the
week, with an extended period of unsettled weather with the
chance of showers and thunderstorms each day. A prolonged period
of southerly flow will also result in high humidity.
Near term /until 6 am Monday morning/...
main updates this evening to reflect current temperature trends,
and to adjust precipitation chances based on radar/satellite
observations. Although precipitable water values remain high, modest flow has
led to fairly quick moving storms that are limiting overall
While air mass does have sfc-based instability, most of that
instability is above h8, so without an organized source of lift
coverage should be limited through the rest of the daylight hrs.
Do expect that to change tonight, especially out east, as
heights rise aloft over the western Atlantic and push rain
band and associated mid level forcing back westward from the
Atlantic. It will remain very muggy with temps and dewpoints
in the 70s.
A high risk of rip currents continues at the ocean beaches into
this evening due to large breaking waves of 4-7 ft in the surf
Short term /6 am Monday morning through Monday night/...
an unsettled pattern will be in place the next few days as the
region remains sandwiched between a deep upper trough over the
eastern US and downstream high pressure stationed offshore and
building slowly westward. This setup will result in deep
tropical moisture and uncomfortably high dewpoints.
Periods of showers and thunderstorms are expected into Monday
night. Main areas of activity should be across eastern CT/Long
Island, also from NYC north/west, during Monday afternoon, where
instability looks to be maximized at least into early afternoon,
and as multiple bands of enhanced mid level cyclonic vorticity
pivot counterclockwise around the offshore upper high to
provide some lift.
Precip chances should start to diminish later Mon afternoon into
Mon night as the offshore high continues to build westward.
Temperatures will be near seasonable but with very muggy conditions.
A high risk of rip currents will continue on Monday.
Long term /Tuesday through Sunday/...
an unsettled pattern is expected to continue with an Omega block in
place, keeping a large scale upper ridge over the southwestern US
and western Atlantic, and a large scale upper trough between. As a
result, broad southwest flow will continue to advect moisture into
our region, while both large scale forcing for ascent and a series
of short waves maintain a chance of rain through at least late week.
Although thunderstorms will be possible, the largely tropical air
mass and weak, wet adiabatic lapse rates may act to temper more
widespread coverage. Regardless, periods of heavy rainfall will be
likely, though the timing and placement of these showers will be
uncertain for any given day. There is some indication that a cold
front may approach or even move through by late week, but with
little change in the large scale pattern expect a quick return to
Daytime temperatures will remain a few degrees below climatological
normals due to cloud cover and onshore flow, while overnight
temperatures will be above normal. Humidity levels will remain
uncomfortable with dew points in the lower to mid 70s.
Aviation /00z Monday through Friday/...
the area remains between the low pressure to the west and high
pressure offshore. The high begins to move west late Monday
Mainly MVFR ceilings early this evening with areas of IFR
ceilings, with scattered showers. Scattered showers become more
numerous and coverage increases tonight and Monday, so included
in forecast. There is also a low chance that a few of the
showers may produce lightning and thunder tonight into Monday.
Widespread IFR, to even LIFR at times, conditions develop this
evening and continue overnight.
Ceilings improve to MVFR Monday morning, and then remain
through the forecast period. There may be a brief period of VFR
ceilings in the afternoon.
Winds will remain from the southeast through the period with any gusts
ending this evening. Gusts will return Monday.
Outlook for 00z Tuesday through Friday...
Monday night-Thursday...MVFR/VFR with periods of rain showers and a
chance of tstms. S gusts 20-25 kt during the day.
Friday...MVFR/VFR in possible showers/thunderstorms, with
Small Craft Advisory continues for the ocean waters, with 10-ft seas at the
coastal buoys, and the the Great South Bay where S winds have
been gusting up to 25 kt.
Winds may increase slightly into tonight on the ocean, with
some gusts up to 25 kt as well, and could again approach 25 kt
on the Great South Bay Mon late morning and afternoon.
Prolonged, steady onshore flow should allow ocean seas to
continue at or above 5 ft into late week. Additionally, a
period of Small Craft Advisory-level gusts may be possible on all waters
Wednesday into Thursday as the pressure gradient strengthens
between high pressure to the east, and low pressure to the west.
an unsettled period of weather continues into late week, with
several inches of rainfall possible. The main threat will be
minor urban and poor draining flooding, though isolated flash
flooding may be possible in any heavier showers and
thunderstorms that develop.
NYC National oceanic and atmospheric administration weather radio station kwo-35 (162.55 mhz) remains off
the air for an extended period of time.
New York...high rip current risk until 10 PM EDT this evening for nyz075-
High rip current risk from 6 am EDT Monday through Monday
evening for nyz075-080-081-178-179.
Marine...Small Craft Advisory until 6 PM EDT Tuesday for anz350-353-355.
Small Craft Advisory until 9 PM EDT this evening for anz345.