Scientific Forecaster Discussion

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Area forecast discussion 
National Weather Service New York New York
642 PM EDT Thursday Apr 24 2014

Synopsis...
high pressure will build in through tonight...and move east on
Friday. A frontal system will approach Friday night...with low
pressure developing over the middle Atlantic region and passing over
or just south of the region late at night. High pressure will
build into the region this weekend into Monday. Unsettled and
cool weather is forecast to return Tuesday and last through
Thursday.

&&

Near term /until 6 am Friday morning/...
winds should drop off quickly this evening while skies remain
mostly clear. Excellent radiational cooling conditions are
anticipated later on as low levels remain dry...skies remain clear
and winds lighten. Undercut guidance temperatures by a couple of
degree...so converted previous freeze watch to a warning across the
interior...and added parts of NE New Jersey and eastern Long Island to the
warning as well. With isolated near freezing temperatures also possible in
western Suffolk County especially as you go farther east...issued a
frost advisory there.

&&

Short term /6 am Friday morning through Friday night/...
clouds will then gradually lower and thicken during Friday...but
more noticeably in the afternoon. Given the previously dry air mass
and subsidence from high pressure shifting through the area...
moistening ahead of the next system will be slow. As such...
little precipitation is expected during the afternoon.
By evening...light rain will develop from west to east...becoming
steadier overnight and quickly moving offshore by
Saturday morning.

&&

Long term /Saturday through Thursday/...
as a low pressure system moves east of the area Saturday...high
pressure will build into the region behind the front on Sunday and
Monday. With upper troughing lingering on Sat and an upper low
with very cold temperatures aloft expected to pass through...kept chance
pop through the day on Sat and slight chance for Sat night.
Would not be surprised to see thunderstorms with gusty winds and small
hail late day Sat into Sat evening as the upper low passes across.

High temperatures on Saturday should be above normal for
this time of year with highs in the middle to upper 60s. On Sunday
and Monday temperatures drop to below normal after the frontal
passage...with highs in the upper 50s to around 60.

Unsettled and cool weather is forecast to return Tuesday through
Thursday...with highs in the middle to upper 50s and lows in the middle
40s.

&&

Aviation /00z Friday through Tuesday/...
a gusty northwest flow will continue this evening with deepening low pressure
tracking into the North Atlantic. A high pressure ridge builds over the
region early Friday...and offshore Friday afternoon.

VFR through the taf period.

Northwest winds with gusts to around 30kt gradually diminish through 00z.
Winds should remain right of 310 magnetic. Winds continue to
diminish tonight with speeds at or below 10 knots by 4-6z. Winds veer to the southeast
Friday morning with speeds generally blw 10 knots. Southerly flow 10-15 knots in the
extended tafs.

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)

Kewr fcster comments: no unscheduled amendments expected.

Kjfk fcster comments: no unscheduled amendments expected.

Klga fcster comments: no unscheduled amendments expected.

Kteb fcster comments: no unscheduled amendments expected.

Khpn fcster comments: no unscheduled amendments expected.

Kisp fcster comments: no unscheduled amendments expected.

Outlook for 18z Friday through Tuesday...
Friday afternoon...VFR.
Friday night-Sat...MVFR in rain Friday night into Sat. Pockets of MVFR Sat
afternoon possible with rain showers.
Sun-Tue...VFR.

&&

Marine...
Gale Warning has been converted to Small Craft Advisory. However...do expect winds
to diminish rapidly as the evening progresses. Expect sub-Small Craft Advisory
conditions across the area by daybreak Friday as a high pressure
ridge enters the region. Tranquil conditions then prevail through
the day on Friday...with winds increasing from the south late in
the day...but still under 15 knots.

Low pressure developing along an approaching frontal system and
passing over or just south of the waters should lead to Small Craft Advisory conds
beginning late Friday night. The eastern-most sound and ocean waters could
see a brief period of southeast gale force gusts just ahead of the low...but
not of long enough duration to warrant a gale watch.

Small Craft Advisory conds are expected this weekend after the low passes east.
Then...sub-sca conditions return late Sunday into Monday as high
pressure builds over the area. Small craft conditions may return
Tuesday-Wednesday as low pressure moves across.

&&

Fire weather...
red flag warning remains in effect this evening for all areas...and
until midnight in NYC and urban NE New Jersey. Relative humidity in the teens combined
with lingering wind gusts warrant the red flag through the
evening. Slow/gradual improvement is expected tonight as temperatures
cool and winds diminish. Better conds expected Friday via lighter
winds...and higher in developing onshore flow.

&&

Hydrology...
around a half an inch of rain is expected Friday evening into
Saturday morning. However...no hydrologic concerns are expected
through early next week.

&&

Okx watches/warnings/advisories...
CT...red flag warning until 10 PM EDT this evening for ctz005>012.
Freeze warning from 3 am to 9 am EDT Friday for ctz005>012.
New York...red flag warning until 10 PM EDT this evening for nyz067>071-
078>081-177-179.
Freeze warning from 3 am to 9 am EDT Friday for nyz067>070-079-
081.
Red flag warning until midnight EDT tonight for nyz072>075-176-
178.
Frost advisory from 3 am to 9 am EDT Friday for nyz078-080.
New Jersey...red flag warning until 10 PM EDT this evening for njz002>004-
103>105-107.
Freeze warning from 3 am to 9 am EDT Friday for njz002-004-103.
Red flag warning until midnight EDT tonight for njz006-106-108.
Marine...Small Craft Advisory until 10 PM EDT this evening for anz335-
338-345-353-355.
Small Craft Advisory until midnight EDT tonight for anz330-340-
350.

&&

$$
Synopsis...mmd/fig/Goodman
near term...mmd/Goodman/pw
short term...mmd/Goodman
long term...figure
aviation...jmc/met
marine...fig/Goodman/pw
fire weather...precipitable water
hydrology...mmd/fig