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Area forecast discussion 
National Weather Service New York New York
756 am EDT Monday Jul 25 2016

Synopsis...
a cold front approaches today and moves through the region tonight.
High pressure builds to the west Tuesday and moves off the southeast
coast Wednesday into Thursday. A weak cold front approaches the
region Friday and may linger into the weekend.

&&

Near term /through tonight/...
lead shortwave moving through the region this morning with warm
front lifting north through the region. Convective complex moving
off the central/southern New Jersey coast will remain over the open
waters. Otherwise...iso to sct showers associated with the
shortwave will continue to translate east through Li /CT this
morning.

Shearing northern stream shortwave then approaches late today with
pre-frontal trough approaching the region late this afternoon
crossing the region this evening. Trailing cold front crosses
tonight.

Morning convection and cloud cover complicates the temperature and
instability forecast for today. With subsidence in wake of lead
shortwave...warm front lifting north...and quite a bit of clearing
noted on infrared over eastern PA...expecting a period of partly to
mostly sunny skies filtered by cirrus late morning into early
afternoon. This should allow for temps to rapidly heat up late
this morning into early afternoon. Temperatures away from the
south coasts should be able to climb into the lower to mid
90s...with dewpoints rising into the lower 70s. Heat indices of
100 to 104 expected across NYC/New Jersey Metro...with potential for 105+
if dewpoints advecting NE from southern New Jersey/se PA don't mix out.
For most of the remainder of the region...heat indices peaking
around 100 degrees. The exception will be southern and eastern
coastal areas limited to the mid to upper 80s due to morning cloud
cover and onshore flow. Despite this...heat indices could still
peak in the mid to upper 90s as dewpoints should surge into the
lower to mid 70s.

In terms of convection...would expect subsidence in wake of lead
shortwave to limit convective potential late morning into early
afternoon. Can't rule out an isolated storm developing along
the developing pre-frontal/Lee trough and tracking eastward into
NE New Jersey /lower hud during this time. Better chance for organized
shra/tsra development will be late afternoon into this evening as
shra/tsra likely develop/maintain across central New York/PA along
early morning convective outflow/pre-frontal trough and approach
the region...supported by lift from approaching shortwave energy
and right rear quad of jet streak. This forcing in combination
with marginal to locally moderate instability...thanks to a subtle
elevated mixed layer...in a very moist environment should support
scattered to numerous showers and thunderstorms
developing/maintaining west/northwest of NYC Metro late this afternoon and
then translating eastward through lower hud/NE New Jersey/SW CT and NYC
Metro and towards the western coastal areas late today into this
evening.

Strengthening Uni-directional deep layer shear and tstm coverage
should support storm organization into strong to severe storms
line segments affecting NYC/NJ/Li Metro and points N/NW/W.
Damaging winds from wet Micro/macro bursts looks like the main
threat based on Uni-directional wind fields...deep moisture...and
inverted v soundings. Relatively quick storm motions should
localize flash flood threat to areas with training tstms.

Convection should become elevated and weaken this evening as it
translates farther east across Li/southern CT as it runs into a
deeper marine stable layer. Convection should push offshore by
around midnight as shortwave axis moves across.

Drier air slowly advects in late tonight with weak cold frontal
passage. Areas of fog possible across outlying areas in warm and
muggy airmass.

There is a low risk of rip current development this
morning...becoming moderate late this afternoon into evening as
southerly wind waves increase to around 3 ft.

&&

Short term /Tuesday/...
shortwave axis slides offshore Tuesday...with deep west-northwest flow on
Tuesday. With 850 hpa temps still running in the high
teens...deep mixing...downslope flow and full sunshine...expect
temps to quickly rise into the mid 90s for much of the coastal
plain. Lower 90s for NW hills...and potential for a few upper 90s
for NYC/New Jersey Metro. Noticeably lower dewpoints should keep heat
indices close to air temps...but close to heat advisory criteria
for NYC Metro. Sea breezes should be limited to late day and
immediate south coasts...if at all.

&&

Long term /Tuesday night through Sunday/...
high pressure builds across the area on Tuesday night then moves
offshore on Thursday. A stalled frontal boundary south of the area
will remain through the weekend. Showers and thunderstorms are
possible during the afternoon and evenings Thursday and through the
weekend, as waves of low pressure begin to ride along this frontal
boundary.

Temperatures on Wednesday and Thursday will be above normal with
highs in the upper 80s to lower 90s and returning to normal levels
on Friday and through the weekend with highs in the low to mid
80s.

&&

Aviation /12z Monday through Friday/...
large area of convection continues to move off the southern New Jersey
coast. Little impacts to knyc terminals. Some brief light rain
showers may develop as weak shortwave passes through the region.
Cannot rule out a rumble of thunder through 15z.

Primarily a VFR forecast through this afternoon. MVFR vsbys possible
in haze for knyc terminals from late morning through early afternoon.

Cold front approaches this afternoon. Convection will fire up west
of the region and looks to impact western terminals from around
20z-02z.

SW flow less than 10 knots will give way to afternoon sea breezes at
coastal terminals 10-15 knots.

Gusty winds and heavy rain possible in convection.

VFR conditions expected tonight, but it is possible that outlying
terminals, such as khpn and kgon could have MVFR or lower vsbys in
fog late tonight.

... Metro enhanced aviation weather support...

Detailed information, including hourly taf wind component forecasts,
can be found at: http://www.Weather.Gov/zny/n90

Kjfk taf comments: reduced vsbys possible in haze from late morning
through early afternoon. Afternoon sea breezes likely this
afternoon. Convection likely this afternoon and evening.

Klga taf comments: reduced vsbys possible in haze from late morning
through early afternoon. Afternoon sea breezes likely this
afternoon. Convection likely this afternoon and evening.

Kewr taf comments: reduced vsbys possible in haze from late morning
through early afternoon. Convection likely this afternoon and
evening.

The afternoon kewr haze potential forecast is yellow...which
implies slant range visibility 4-6sm outside of cloud.

Kteb taf comments: convection likely this afternoon and evening.

Khpn taf comments: convection likely this afternoon and evening.

Kisp taf comments: afternoon sea breezes likely this afternoon.
Convection possible late this afternoon and into this evening.

Outlook for 12z Tuesday through Friday...
Tuesday-Wednesday night...VFR.
Thursday-Thursday night...mainly VFR, except MVFR or lower
possible in isolated to scattered showers and thunderstorms,
mainly late in the day and at night.
Friday...chance of MVFR or lower in scattered showers and
thunderstorms.

&&

Marine...
sub sca conditions expected through Tuesday. S/SW winds gusts to
20 kt possible for most waters this afternoon...with nearshore northwest
winds gusts to 20 kt possible Tuesday afternoon. Occasional
nearshore gusts to 25 kt possible. Ocean seas should remain in the
2 to 4 ft range.

Slight tstm threat on the water this morning with greater chance late
today through this evening.

Below small advisory conditions expected across the area waters from
Tuesday through Friday.

&&

Hydrology...
there is the potential for 1/4 to 1/2 inch of rainfall, with locally
higher amounts, possibly 2+ inches, as numerous showers and
thunderstorms track across the region late this afternoon into
this evening. This presents a localized flash flood
threat...mainly across NYC/NJ Metro and interior with any training
cells.

There is the potential for scattered showers and thunderstorms,
across the area during the afternoons and evenings Thursday through
next weekend.

&&

Okx watches/warnings/advisories...
CT...heat advisory from noon today to 8 PM EDT this evening for
ctz005>007-009-010.
New York...heat advisory from noon today to 8 PM EDT this evening for
nyz067>075-078-080-176>179.
New Jersey...heat advisory from noon today to 8 PM EDT this evening for
njz002-004-006-103>108.
Marine...none.

&&

$$
Synopsis...fig/NV
near term...Nevada
short term...Nevada
long term...figure
aviation...mps
marine...fig/NV
hydrology...fig/NV

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