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fxus61 kokx 142028 

Area forecast discussion
National Weather Service New York New York
428 PM EDT Mon Oct 14 2019

a dry cold frontal passage this evening will be followed by
building high pressure through Tuesday. A frontal system will
approach on Wednesday, with a rapidly intensifying coastal low
tracking just southeast of the area Wednesday night, and into
the Canadian Maritimes Thursday into Thursday night. High
pressure builds in for next weekend. Another frontal system
approaches for early next week.


Near term /until 6 am Tuesday morning/...
shortwave energy rounding the base of an upper low over eastern
Canada will send a cold front through the area dry this evening.
High pressure over the Ohio Valley then builds east through the

Expect few if any clouds with SW winds veering around to the northwest
at less than 10 mph.

Overnight lows will be right around normal, generally in the
40s, except around 50 for the NYC Metro.


Short term /6 am Tuesday morning through Tuesday night/...
shortwave ridging between one departing upper low over eastern
Canada and an amplifying trough over the upper Midwest into the
Great Lakes, will result in dry, seasonably cool conditions. Any
clouds will be on the increase late Tuesday night as a frontal
system approaches from the west.

A light northerly flow in the morning will become onshore in
the afternoon as surface high pressure works offshore.

Highs on Tuesday will top out in the lower 60s. Lows Tuesday
night will likely vary considerably due to good radiational
cooling, from the lower 50s in Metro NY, to the mid 30s to
lower 40s elsewhere. With a light onshore flow and increasing
low-level moisture, fog may be a possibility as well as frost.
Guidance still showing dew point depressions significant enough
to leave mention of fog out at this time.


Long term /Wednesday through Monday/...
main story during this period will be a strong frontal
system/developing coastal low affecting the region late Wednesday
into Thursday.

Main features will be a strongly amplifying northern stream
shortwave digging through the US/Canada border of The Rockies this
afternoon. This feature will develop a closed upper low that slides
into the upper Great Lakes Tue/Tue night, then phases with the
southern stream Wednesday morning. The phasing and deepening closed
low will approach the region Wednesday, and then pivoting through
the area Wed night into Thu morning and up the New England coast
into the Canadian Maritimes Thu afternoon thru Thu night. At the
surface, low pressure associated with the northern stream closed low
will track east through the Great Lakes Tue into Wed, with its
associated strong cold front pushing towards the region late
Wednesday. At the same time, phasing jet energy will begin to
intensify a southern wave of low pressure tracking NE ahead of the
front off the mid-Atlantic coast; tracking just southeast of Li Wed night.
This will become the primary intense low pressure by Thursday
morning as it tracks up the New England coast.

There is good general model agreement in the above scenario, but
still some spread on intensity of the developing coastal low as it
tracks se of Li and into New England, and to a lesser extent spread
in how close or over the area the low tracks. The sensitivity of
this appear to be with evolution of a central Pacific closed low, and
downstream amplification of West Coast ridging and northern stream
shortwave, and then the eventual phasing with southern stream. The
main implication for our area would be modest, in terms of
amount/axis of rain and strength of winds ahead and behind system.
This should come into better focus over the next 24-48 hrs.

Strong deep layer forcing with this system and a deep subtropical
Pacific and Gulf moisture connection (+1 1/2-2 std pwats) point towards
a heavy rain event late Wed through Wed night. Strong forcing,
closed low/vort energy moving through aloft, and weak surface
instability point to potential for some deeper convection and
embedded thunder. This bring likelihood for 1 to 2 inches of rain,
with locally 2-3" inches of rain. Rain should quickly taper off late
Wed night as trough axis pivots east. Deep cyclonic flow on Thursday
will result in considerable cloud cover with scattered
showers/sprinkles, particularly interior. Can't even rule out a wet
snow flake or two across the far Northwest Hills in any heavier showers as
cold pool moves through aloft and coolest airmass of the season
works in.

In terms of winds, ahead of the low a period of east/southeast winds 20 to 25
mph gusts 30-35 mph (peak winds 25-30 gusts to 40 mph possible
across eastern li) likely along the coastal plain Wed
afternoon/evening. Then in the wake of low pressure west/northwest winds of 20
to 30 mph and gusts to 40 to 45 mph likely late Wed night into
Thursday. There is potential for Wind Advisory 30-35 mph and gusts
to 50 mph if stronger low development verifies. Windy
conditions will continue into Thursday night, although gust
potential likely decreases with decreased instability.

Cyclonic flow will be slow to relent through the day Friday. Northwest
winds will be weakening, but still a a breezy day. Another below
seasonable day with sct-bkn afternoon strato-cu.

Then a gradual moderation to seasonable and then above seasonable
temps and fair weather this weekend as upper ridging build in and
high pressure builds to the south of the region.

Next chance of rain looks to be some time early next week, as
another deep trough develops over the central US, with an
increasingly moist and active flow deep SW flow developing into the
eastern US. Indication are a slow moving frontal system or systems
approaching for Monday/Tuesday.


Aviation /21z Monday through Saturday/...
high pressure builds in today, then a cold front passes through this

VFR. West-SW winds 5-10 kt into this evening.

... 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: no unscheduled amendments expected.

Klga taf comments: no unscheduled amendments expected.

Kewr taf comments: no unscheduled amendments expected.

Kteb taf comments: no unscheduled amendments expected.

Khpn taf comments: no unscheduled amendments expected.

Kisp taf comments: no unscheduled amendments expected.

Outlook for 18z Tuesday through Saturday...
Wednesday...lowering to IFR in the aftn with rain. Chc southeast
gusts around 25kt.
Thursday...VFR. Northwest gusts 25-35kt.
Friday...VFR. Northwest gusts 20-25kt mainly am.


the pressure gradient remains relatively weak during the short
term through Tuesday night. Conditions are expected to remain
below Small Craft Advisory across all local waters.

Southeast winds increase across the waters Wednesday ahead of approaching
cold front and developing low pressure. Small Craft Advisory conditions expected
on all the water by early Wed afternoon into evening ahead of
low pressure. A brief period of gales likely on the ocean waters
east of Moriches Inlet as low pressure approaches, and possible
for the rest of the ocean waters and east Li sound/east bays as southeast
llj moves through.

Winds expected to shift to the northwest Wed evening, with west/northwest gales
likely developing on the ocean waters late Wed night, and then
likely all waters for Thursday. Gale conditions should fall to Small Craft Advisory
Thu eve/night, with Small Craft Advisory wind gusts likely subsiding Friday morning
into afternoon. Ocean seas will rapidly build Wed aft/eve, but
should fall below Small Craft Advisory Fri afternoon as winds weaken as they will be
wind wave dominant.


a significant rainfall of 1 to 2 inches is likely Wednesday
afternoon into Wednesday night, with localized swaths of 2 to 3
inches. The bulk of the rainfall is expected in a 6 to 9 hr period
late Wednesday afternoon through Wednesday evening.

Urban, poor drainage, and low lying flooding is expected. There is a
low probability of flash flooding along a few of the fast
responding small rivers and streams in NE New Jersey and lower hud
valley. Additionally, localized flash flooding will also be an
issue for coastal areas if heaviest rain coincides with the Wed
night high tides.


Tides/coastal flooding...
tidal departures of generally 2 to 2 1/2 ft above astronomical
are needed for minor flooding during the times of high tide late
Wed eve into Wed night. There is quite a bit of spread in the
ensemble guidance, partly due to some differences in the
potential strength of low pressure wind fields, and equally so
due to timing of windshift from east/southeast Small Craft Advisory winds to northwest Small Craft Advisory winds.
At this point, model consensus would indicate potential for
minor coastal flooding along much of the coastal plain, with a
low probability for localized moderate impacts where wave
action combines with elevated water levels.

If heaviest rain coincides with the Wed night high tide, more
widespread flooding would be experienced than normally expected
by minor water levels.


NYC National oceanic and atmospheric administration weather radio station kwo35 (162.55 mhz) remains off the


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


near term...dw
short term...dw
long term...Nevada

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