Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service New York New York
1102 am EDT Thursday Oct 2 2014

an upper level low will slowly move high pressure
moves in behind it through Friday. A cold front approaches from
the west Friday night...then crosses the tri-state on Saturday. High
pressure then builds in to our south and east through Monday night.
Weak low pressure will affect the region on Tuesday...with a weak
cold frontal passage Tuesday night. High pressure will return on


Near term /until 6 PM this evening/...
latest mesoscale-scale guidance seems to be handling rain and drizzle
fairly taper off from west to east through 1 PM.

NE flow will keep a fairly moist lower level in place this
afternoon...but generally thinking the loss of forcing aloft as
upper low slowly drifts NE...will minimize the precipitation chances.

A cloudy sky and persistent NE flow will keep temperatures on the
slightly cooler side. So sided more with the mav guidance to
reflect this possibility.


Short term /6 PM this evening through 6 PM Friday/...
any lingering precipitation by this evening should be offshore south of
Long Island with dry weather then on tap through Friday. A sliver of
high pressure briefly builds south from Canada tonight/Friday
before retreating once again ahead of an approaching low pressure
system for the weekend. Upper level ridging builds in as well
during this time...with the ridge axis shifting through the
northeast during the day Friday. Plenty of subsidence
should see clearing for a short period late tonight/Friday
morning before high level clouds begin streaming in ahead of the
low. With drier air moving in with the high as well...not
anticipating much in the form of fog development tonight.

Have more of a handle on temperatures for tonight/Friday...using
generally a blend of the met/mav guidance. Temperatures tonight expected
to be right around normal to slightly above. With a mostly sunny
sky on Friday and warm air advection...should see highs a few degrees warmer
than today.


Long term /Friday night through Wednesday/...
all nwp guidance remains very consistent with a cold frontal passage on
Saturday. Precipitation moves in from west to east in the morning and exits in
the afternoon with clearing quickly developing by Saturday evening.

Have cut previous forecast quantitative precipitation forecast in coordination with river forecast
centers. Expecting around 1/2 inch with 3/4 inch up in the lower
Hudson Valley. No Hydro issues expected.

High pressure for Sunday and Monday. Clouds start increasing late
Monday with warm air advection. Over-running pattern continues on Tuesday with chance
probability of precipitation for light rain. Weak and diffuse cold frontal passage passage early Wednesday
morning with high pressure building in. Have made it dry on
Wednesday with timing of cold frontal passage.

Lowered temperatures and made for non-diurnal pattern on Saturday with the
precipitation. Below normal temperatures on Sunday...but we quickly return to normal
on Monday and then a bit above normal for Tuesday and Wednesday.

No hazards foreseen through Wednesday.


Aviation /15z Thursday through Monday/...
low pressure well east of Cape Cod will remain nearly stationary
today...with high pressure building over the terminals tonight.

MVFR ceilings will be widespread today...not lifting to VFR until
19z-22z from west to east. Some -dz is possible across Long
Island and southern Connecticut terminals through 16z.

North-NE flow 10-15 knots will continue into this afternoon...then diminish
to under 10 knots this evening.

..NY 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: timing of improvement to VFR could be off by
+/- one to two hours. An occasional gust up to 20 knots is possible
through the late afternoon.

Klga fcster comments: timing of improvement to VFR could be off by
+/- one to two hours. An occasional gust up to 20 knots is possible
through the late afternoon.

Kewr fcster comments: timing of improvement to VFR could be off by
+/- one to two hours. An occasional gust up to 20 knots is possible
through the late afternoon.

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

Kteb fcster comments: timing of improvement to VFR could be off by
+/- one to two hours.

Khpn fcster comments: ceilings may fluctuate between MVFR and VFR this

Kisp fcster comments: timing of improvement to VFR could be off by
+/- one to two hours. An occasional gust up to 20 knots is possible
through the late afternoon.

Outlook for 12z Friday through Monday...


Friday night...MVFR conditions possible late at the NYC metropolitan and
lower Hudson Valley terminals.

Sat...rain with IFR conditions and southeast winds 15-20g25kt. Cold
frontal passage middle to late afternoon at the NYC metropolitan and lower
Hudson Valley terminals...followed by VFR conditions and west wind

Sat night...rain with IFR conditions early at the CT/Long Island
terminals...then cold frontal passage with improvement to VFR. Post-frontal
west winds g25kt.

Sunday...VFR. West winds g20kt.



minor changes this update to reflect the latest trends in
observations and guidance. Forecast appears on track.

Small Craft Advisory remains in effect for all the waters less the Great South
Bay...New York Harbor and the western sound as NE flow increases between
the low offshore and the high digging down from the north. Gusts
between 23 to 28 knots expected during the day today...then
diminishing tonight as the pressure gradient weakens with high
building further over the waters. Seas build today with the
strengthening flow...with 5-9 feet possible on the ocean waters.

Occasional gusts up to 25 knots will be possible this evening/early
overnight for the bays and Long Island Sound. Though confidence is
not enough to extend the Small Craft Advisory at this time over those waters. Still
expecting gusts to 25 knots and seas above 5 feet on the ocean...and
in fact expecting the 5 feet seas to continue so extended the Small Craft Advisory
over the ocean for Friday.

On the ocean...Small Craft Advisory conditions can be expected through next
Wednesday...with perhaps a brief respite for portions of Monday.
Elsewhere...25kt winds possible Sat-sun both ahead of and behind a
cold front. Otherwise they will generally be in the 10-20kt range.


no significant precipitation is expected through Friday evening.
Expecting around 1/2 inch with 3/4 up in the lower Hudson Valley
during the day on Saturday. Light rain is possible for Tuesday.


Okx watches/warnings/advisories...
New York...none.
New Jersey...none.
Marine...Small Craft Advisory until 6 PM EDT Friday for anz350-353-355.
Small Craft Advisory until 6 PM EDT this evening for anz330-



near term...maloit/tongue/Sears
short term...Sears
long term...tongue

National Weather Service Glossary of Abbreviations