Scientific Forecaster Discussion
Area forecast discussion
National Weather Service New York New York
1036 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/...
ml MUCAPES beginning to increase over western zones...but most of
the initial showers/thunderstorms tapering off. Area of showers/thunderstorms
impacted western Orange County with estimated rainfall totals
around 1 inch...and a second wave of showers/thunderstorms currently
spreading over western Orange County. Have issued a Flood Advisory
there through late this evening as an additional inch or so of
rain is possible.
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 elsewhere.
Lows will be near 70 in NYC...and in the 60s elsewhere.
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 /02z Wednesday through Sunday/...
a warm front will approach from the south tonight and lift northeast
of the terminals Wednesday morning. A cold front approaches late
Low confidence forecast regarding flight category tonight. MVFR
has developed at kteb...khpn and kswf...with IFR at kewr.
Stratus may develop earlier than forecast at other terminals.
Higher confidence in low end MVFR ceilings at all terminals after
midnight...with potential for IFR...especially between 8-12z.
Showers are possible as well 8-12z...but most likely 12-15z. Isolated
thunder cannot be ruled out.
Improvement to VFR is expected Wednesday morning after 14-15z. Isolated
shower or storm possible...especially north and west of city
terminals late Wednesday afternoon.
S-southeast winds will continue to diminish this evening. Winds back to the
east/southeast overnight before veering again Wednesday morning to the SW.
Gusts 20-25 knots expected across city terminals in the afternoon.
Outlook for 00z Thursday through Saturday...
Wednesday night-Friday...generally VFR expected.
Saturday...mainly VFR...isolated rain showers/thunderstorms and rain cannot be ruled out.
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 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.