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Area forecast discussion 
National Weather Service New York New York
1042 PM EDT Mon Oct 24 2016

high pressure slowly builds in from southern Canada through
Wednesday. The high moves east on Wednesday giving way to a
frontal system Thursday into early Friday. Another frontal system
impacts the area this weekend, followed by high pressure Monday.


Near term /until 6 am Tuesday morning/...
a 700-500 hpa shortwave will pass by overnight. At the minimum
will help to keep boundary layer well mixed and winds up. Could
also see some clouds over far northwest zones before low level downslope
takes over farther east.

Temperatures continue to fall of not as fast as forecast in urban
and rural zones. As a result, have tweaked lows up a few degrees
in most places - consistent with latest trends in guidance and
observations. Based on expectation of winds staying up and lows
not quite as cool/cold - plus dewpoints falling off faster than
expected, have removed patchy frost from the forecast overnight.


Short term /6 am Tuesday morning through Tuesday night/...
upper trough over northern New England and the Canadian Maritimes
will slowly translate east Tuesday into Tuesday night. Cold
advection will continue with 850 temperatures dropping to -4 to
-6c. A similar subsidence inversion to Monday will likely be present
per BUFKIT soundings around 800 hpa. There appears to be enough
moisture during the day trapped beneath this inversion to help
develop some stratocumulus. Sky conditions start the day partly
cloudy, with the potential to go mostly cloudy at times in the
afternoon. Gusty northwest winds are once again forecast from the strong
pressure gradient between the low to the northeast and building
high to the west. Mixing up to near 800 hpa should allow for
gusts 25 to 30 mph in the afternoon, strongest near the coast.

High temperatures will end up well below normal for this time of
year in the upper 40s and low 50s.

Cold advection continues Tuesday night, but ideal radiational
cooling conditions are not anticipated as winds will remain up.
However, the coldest airmass of the season will be in place and
temperatures should be able to fall to near 30 degrees across the
interior, and middle and upper 30s most elsewhere. Have therefore
issued a freeze watch across all of interior southern CT, the lower
Hudson Valley excluding Orange County where the growing season has
ended, and interior NE New Jersey. Elsewhere, do not think a widespread
frost will occur due to the winds and overall dry airmass in


Long term /Wednesday through Monday/...
trough finally departs, allowing weak ridge to briefly build

Next shortwave tracks across the Great Lakes region Wednesday night,
and slows as it closes off Thursday and Thursday night over the
northeast. The pattern remains progressive as yet another shortwave
follows this weekend.

Some differences in the global models are noted with regard to
timing, and speed of these systems as they move west to east.

At the surface, high pressure builds overhead, then moves east late
Wednesday/Wednesday night. A warm front approaches Wednesday night
from the west as low pressure tracks across the Great Lakes and
across PA/western New York.

The low and associated frontal boundary slows as it moves over the
area Thursday, passing to the east Thursday night into Friday.

High pressure builds to the south as another low moves across the
Great Lakes region Saturday, passing to the north early Sunday. Some
questions arise on Monday with upper levels, and thus surface
features at that time. Could be unsettled.

As for sensible weather, warm air advection showers move in late Wednesday night and
through the day Thursday. Enough cold air ahead of the warm air advection, and time
of day being early morning could result in some snow showers briefly
northwest zones. Some accumulations are possible across higher elevations
before a change to plain rain occurs.

Once this area of showers moves east Thursday night, generally dry
weather is expected ahead of next best chance Saturday ahead of the
upstream shortwave.

After a chilly start to the period Wednesday, temperatures will be
near normal in this progressive pattern, with no large swings in
temperatures expected.


Aviation /03z Tuesday through Saturday/...
VFR as high pressure builds over the region. Northwest flow, with some
gusts up to 25 kt early at kjfk and 20 kt elsewhere at the NYC
metros and kisp, will diminish to around or just under 10 kt and
back west-northwest.

Expect broken VFR cigs on Tuesday, with northwest winds g25-30kt. Some
question as to how soon winds will diminish 22z-00z at outlying
terminals, and like the past couple of nights could stay elevated
until or just after the end of the 00z taf period.

Outlook for 00z Wednesday through Saturday...
Tuesday night...VFR with diminishing northwest winds.
Wednesday...VFR. Northwest-north-northwest g20kt possible near the coast.
Thursday...MVFR conditions likely in rain. IFR conditions possible at
night. Southeast winds 10-20kt.
Friday...VFR. West-northwest winds g25kt.
Sat...VFR. Chance of rain. SW winds g15-20kt.


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

Strong pressure gradient over the waters will continue through
Tuesday with Small Craft Advisory conditions. Winds may briefly weaken on near
shore waters tonight before increasing again during the day on
Tuesday. The Small Craft Advisory remains in effect through Tuesday evening and may
need to be extended into Tuesday night on the ocean waters as
winds are likely to remain around 25 kt.

Gusty northwest winds will diminish Wednesday as high pressure builds.
Winds shift around to the east, then southeast Wednesday night as Thursday
as the high departs, and a warm front and low pressure system

As the low passes by Friday, winds shift back around to the west/NW
and increase behind the departing low. These winds back yet again to
the west/SW ahead of next low pressure system Saturday.

Ocean seas subside and remain well below 5 feet Wednesday, Wednesday
night and into Thursday. Seas build once again ahead of and behind
the low pressure system that impacts the waters later Thursday, and
these rough seas continue Friday night, then subside Saturday.


dry weather is forecast through Wednesday.

Low pressure impacts the area Thursday and Thursday night. Forecast
quantitative precipitation forecast is expected to produce anywhere from 1/2 to 3/4 of an inch of
rainfall. Local amounts over an inch are possible. No hydrologic
impacts expected at this time.


Okx watches/warnings/advisories...
CT...freeze watch from late Tuesday night through Wednesday morning
for ctz005>008.
New York...freeze watch from late Tuesday night through Wednesday morning
for nyz068>070.
New Jersey...freeze watch from late Tuesday night through Wednesday morning
for njz002-004-103-105-107.
Marine...Small Craft Advisory until 6 PM EDT Tuesday for anz330-335-338-


near term...maloit
short term...ds
long term...precipitable water

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