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Area forecast discussion 
National Weather Service New York New York
1001 am EDT Friday Jul 31 2015

Synopsis...
weak high pressure builds across the area through tonight. The
high pressure departs early Saturday. A series of weak frontal
boundaries will then impact the area over the rest of the weekend
and into the new week. In between....weak high pressure will
prevail across the area.

&&

Near term /until 6 PM this evening/...
minor tweaks based on latest guidance...otherwise...no other
remarkable changes made to forecast database.

Despite a negative height tendency in the middle to upper
levels...weak high pressure builds in at the surface from the
southwest. The surface westerly flow behind a cold front will
promote drier conditions. Quick diurnal warming underway.

The dewpoints will be lower during the time of maximum heating...in
the middle 50s to lower 60s for most locations...making for less
humid conditions. The temperatures however...will be a few degrees
warmer than the previous day...with many locations in the upper
80s to around 90. The subsidence from the weak high will allow for
less clouds.

There is a moderate risk of rip current development at Atlantic
Ocean beaches today.

&&

Short term /6 PM this evening through 6 PM Saturday/...
for tonight...high pressure continues to build in for the first
half...then slightly shifts away overnight into Saturday. The
clouds will be minimal to start but will increase overnight with
the decreasing subsidence. This factor will lead to relative
warmer low temperatures at night in addition to the return
southerly flow. Lows forecast will be ranging from the lower 60s
to lower 70s for the majority of the forecast region with the
warmer values near NYC and across Long Island as well as across
parts of the Connecticut coast.

For Saturday...a cold front approaches from the west. Daytime
trough development is indicated in the models. A stronger
southerly flow will allow for moderation of the airmass with
slightly cooler readings with the maritime influence. Still it
will be very warm with highs in the middle to upper 80s for most
locations and lower 90s for parts of NYC and urban New Jersey. In
addition...the humidity will be back on the rise with the onshore
flow as dewpoints increase to the upper 50s to middle 60s. Some
models are indicating some convection for the afternoon hours but
without much coherency between model solutions...went with slight
chance for time being.

&&

Long term /Saturday night through Thursday/...
a broad upper trough from central Canada southeast into the northeast quarter
of the nation will be in control of the weather during this time
period.

For the most part...mainly tranquil conds on tap for the region
during this period. A series of weak cold fronts will move across
the region starting Saturday night and continuing through the middle
of next week. For now...expecting widely scattered showers/thunderstorms Saturday
evening...then dry conds prevail until the next cold front Monday
night into Tuesday. Not expecting much in the way of precipitation with
each front...and in between...weak high pressure will rule. A stronger
cold front moves though on Wednesday and looks to stall just south of the
region with a wave of low pressure tracking across the Middle Atlantic
States. There are some timing issues amongst the global models.
Forecast area looks to be on the northern periphery of the system.
For now...will just have a low chance for showers.

At the onset...temperatures during the period will be near to slightly
above normal with highs generally in the 80s to around 90. Humidity
levels will be low Sunday...and then will start to creep up early in
the week before another cold front moves through Monday night into Tuesday
with another shot of drier air for the middle week. Temperatures return to
nearly seasonable levels for Wednesday and Thursday.

&&

Aviation /14z Friday through Tuesday/...
a weak surface trough develops this afternoon resulting in backing of
northwest winds to the west. Gusts up to 20kt in the afternoon...mainly city/coastal
terminals.

Late day seabreeze development likely at kjfk as synoptic flow
in the lowest 4k feet will be around 10kt through the afternoon then
weaken during the evening. SW flow should predominate at kbdr/kgon.
Low probability of S seabreeze it making it to kisp...but SW flow
expected in the afternoon.

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: winds right of 310 magnetic through this
morning. Timing of winds backing to the left of 310 could be +/-
1-2 hours from forecast. Moderate confidence in seabreeze between
19z and 21z.

Klga fcster comments: winds right of 310 magnetic through this
morning. Timing of winds backing to the left of 310 could be +/-
1-2 hours from forecast. Low probability of seabreeze(aft 22-23z).

Kewr fcster comments: equal chances of winds on either side of 310
magnetic this morning. Timing of winds backing to the left of 310
could be 1-2 hours earlier than forecast.

The afternoon kewr haze potential forecast is green...which
implies
slant range visibility 7sm or greater outside of cloud.

Kteb fcster comments: timing of winds backing to the west could be
+/- 1-2 hours from forecast.

Khpn fcster comments: timing of winds backing to the west could be
+/- 1-2 hours from forecast.

Kisp fcster comments: timing of winds backing to the west could be
+/- 1-2 hours from forecast. Seabreeze possible after 20z.

Outlook for 12z Sat through Tuesday...
Sat-sun...VFR.
Monday...increasing S flow with a chance of thunderstorms.
Tuesday...chance thunderstorms. Winds shifting to the west.

&&

Marine...
a weak pressure gradient across the waters will keep conditions
below Small Craft Advisory through tonight as high pressure builds. On
Saturday...the southerly flow will allow for an increase in winds
and seas as high pressure moves away from the region. Small Craft Advisory will be
possible but confidence is not high enough in this timeframe to
warrant any issuance of Small Craft Advisory at this time.

Thereafter...a series of frontal boundaries will impact the
waters over the rest of the weekend and into the new week. Ocean
seas may build to 5 feet during this time due to a prevailing S/SW
flow.

&&

Hydrology...
no significant widespread rain expected.

&&

Okx watches/warnings/advisories...
CT...none.
New York...none.
New Jersey...none.
Marine...none.

&&

$$
Synopsis...jm
near term...jm/pw
short term...jm
long term...dw
aviation...24/NV
marine...jm/dw/pw
hydrology...jm/dw

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