Scientific Forecaster Discussion
Area forecast discussion
National Weather Service New York New York
447 PM EDT Tuesday Jun 30 2015
a warm front just to the south will linger nearby into Wednesday
morning...the lift to the northeast by Wednesday afternoon. A cold
front will move across Wednesday night. Canadian high pressure
will build across the area from Thursday into Friday. Waves of
low pressure will traverse a stationary front to the south through
the weekend. A warm front will lift through on Monday...with a
cold front approaching Monday night into Tuesday.
Near term /until 6 am Wednesday morning/...
Severe Thunderstorm Watch 372 locally extended to include Essex and Union
counties in NE New Jersey. Surface-based instability decreases dramatically as
you go from interior northern New Jersey to NYC via onshore flow of
maritime air with lower dewpoints...but given structure of some
storms to the west decided to go one tier of counties farther east
for dying gasps and/or leftover outflows of storms to the west as
they approach. Do not expect much if any of this activity to make
it into Long Island or southern CT given stable low level maritime
environment in place.
Expect this activity to die down late this evening into the first
part of the overnight...then an approaching shortwave in tandem
with the lingering warm front should help regenerate showers and
thunderstorms late...with likely pop for all of NYC metropolitan and chance
Lows will be near 70 in NYC...and in the 60s elsewhere.
There is a moderate risk for rip currents at ocean beaches through
Short term /6 am Wednesday morning through Wednesday night/...
expect likely to Cat pop for showers and scattered thunderstorms Wednesday morning as
the warm front and associated upper level forcing move across.
Cannot rule out locally heavy rain and gusty winds with the
strongest of this activity.
In the wake of the warm front...best moisture axis appears to
slide east of the region. So uncertainty for afternoon convection
in terms of amount destabilization before afternoon shortwave
passage. Scattered afternoon showers/thunderstorms are possible ahead of
the cold front well inland...with isolated activity elsewhere. Still
a marginal conditional threat for a few strong to severe storms
in the early to middle afternoon.
Setup does not look favorable for widespread convection late in the
afternoon into evening as shortwave looks to be pivoting east of
the region. Coverage may be more isolated along the lagging cold
front as it passes through...with a diminished severe threat due
to subsidence and a drying air mass.
Highs on Wednesday will be from the upper 70s along the coast...to
lower 80s most elsewhere...to middle/upper 80s in NYC and NE New Jersey.
Lows Wednesday night will be slightly cooler than those of tonight...at
least outside of NYC...with some upper 50s possible well inland.
There is a moderate risk for rip currents at ocean beaches on
Long term /Thursday through Tuesday/...
a frontal system settles south of the area on Thursday...as high
pressure builds across the area through the end of the week. On
Saturday...latest models have trended farther south with
precipitation...there is still some chance of moisture triggering
some scattered showers/thunderstorms...but will lower probability of precipitation for most
of the area Saturday afternoon and evening. Temperatures on Saturday
should be in the upper 70s to lower 80s. Dry weather is then
expected on Sunday...with chance for thunderstorms in for Monday
night as a warm front is predicted to lift through the area. A cold
front is then expected to approach the area Monday night into
Temperatures are expected to be near seasonable levels through the
Aviation /21z Tuesday through Sunday/...
low pressure and a warm front will approach from the
VFR most terminals into the evening. The only exception would be
rain showers/thunderstorm at kswf late this afternoon. Kewr and kteb may be impacted
Stratus develops tonight...mainly after midnight. Low end MVFR or
even IFR conditions are possible from 6-14z. Showers are possible as
Improvement to VFR is expected Wednesday morning after 14-15z.
Gusty south to southeast winds diminish this evening. Winds back to
the east/southeast tonight before veering again Wednesday morning to the S.
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: gusts become less frequent by evening.
Klga fcster comments: gusts become less frequent by evening.
Kewr fcster comments: showers and thunderstorms should stay just to
the west of the Airport through 00z...or would weaken as they
approach. Gusts become less frequent by evening.
Kteb fcster comments: a few upstream showers and thunderstorms may
approach the Airport late this afternoon. Gusts become less frequent
Khpn fcster comments: gusts become less frequent by evening.
Kisp fcster comments: no unscheduled amendments are expected through
the early evening.
Outlook for 18z Wednesday through Saturday...
Wednesday afternoon...mainly VFR but thunderstorms are possible.
Wednesday night-Sunday...generally VFR expected. Isolated thunder
though cannot be ruled out through much of the period. As such...sub
VFR conditions remain possible from time to time.
near shore winds in the New York bight and Harbor continue to gust into
the lower 20s.
Ocean seas will gradually build on Wednesday ahead of a cold front.
Potential for marginal Small Craft Advisory seas by Wednesday evening. Otherwise quiet
winds/seas expected outside of any thunderstorms.
potential for scattered thunderstorms to produce locally heavy
rainfall in NE New Jersey early this evening...and throughout from late
tonight into Wednesday morning. Basin average of rain is around a half
inch...but locally 1 inch or more is possible. Most likely threat
will be for minor urban flooding...but there is a low threat of
flash flooding with any training convection.
with approaching full moon...tidal departures of only 3/4 to 1 1/2
feet are needed for minor coastal flooding benchmarks to be reached
during the late evening/night high tides the next few days. Minor
benchmarks could be touched across the most vulnerable
areas...particularly along the South Shore bays of Nassau
County and western Li sound...middle to late week.