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Area forecast discussion
National Weather Service New York New York
953 PM EST Thu Feb 23 2017

Synopsis...
a weak cold front approaches tonight and then retreats back to
the north as a warm front on Friday. High pressure will remain
steady over the western Atlantic through Friday night. A
frontal system approaches Saturday and crosses the region
Saturday night. High pressure builds over the area during the
early part of next week. A warm front moves through Tuesday,
with the attendant low and cold front moving through by mid to
late week.

&&

Near term /until 6 am Friday morning/...
with the narre not indicating any reformation of the fog
overnight, and low level winds remaining 20 to 30 kt, along
with clouds overspreading the region in advance of a cold front,
little to indicate that widespread fog develops. Only patchy
fog, more than 3 statue miles, remains across southern
Connecticut. With the cloud cover and weak cold advection not
expecting temperatures inland to fall off to previous lows and
raised overnight lows. Along the coast temperatures will remain
nearly steady or fall a couple of degrees overnight.

A line of isolated showers and embedded thunderstorms extended
from northeastern Pennsylvania to south central Pennsylvania.
There is still some weak surface instability into western
Orange County, along with minimal cape. As the line advances
eastward possible a rumble of thunder could occur into extreme
western Orange County. Otherwise just isolated showers. Adjusted
the probabilities, keeping the best chances mainly across
Connecticut and north of New York City, as cold front is not
expected to push farther south and best forcing will remain in
that areas.

&&

Short term /6 am Friday morning through Friday night/...
weak frontal boundary retreats to the north as a warm front
during the day on Friday. Models have come into better agreement
with this scenario, which is reasonable given a stronger
southerly flow developing ahead of system strong shortwave
across the central states. Low stratus and areas of fog will
start the day with potential for dense fog during the morning
commute, especially near the coast.

The forecast uncertainly lies with how quickly the low stratus
and fog erode. As was the case on Thursday, it will likely
erode away north and west of the coast by early afternoon and
could linger near the coast into much of the afternoon. This
will play a role in high temperatures. With anomalously warm air
in place, highs should have no trouble reaching the middle and
upper 60s north and west of the NYC Metro. These numbers could
be higher dependent on how quickly clouds erode. Further east,
temperatures will likely be held down in the upper 50s and lower
60s due to onshore flow and longer duration of clouds/fog.

Stratus and fog are once again possible Friday night with
conditions remaining unseasonably warm. Some light rain or
drizzle is also possible as a stronger onshore flow develops
ahead of approaching cold front from the west.

&&

Long term /Saturday through Thursday/...
persistent low-level warm/moist advection will maintain a chance of
stratus, patchy fog and drizzle beneath the inversion through
Saturday morning. High temperatures will once again be close to 10
to 20 degrees above climatological normals, though perhaps a few
degrees colder than Friday closer to the coast due to onshore flow.
By Saturday evening, a potent vort Max and attendant cold front
approach the region. At this time it appears a narrow line of
showers and perhaps a few thunderstorms will move through ahead of
the front with a quick 0.25-0.50 inches of rain possible. A few
stronger gusts may mix to the surface as the front passes, given
wind speeds 30-40 kt just above the surface. Temperatures and dew
points will slowly fall Saturday night, though will still remain
above normal as winds remain strong and gusty through the night. The
stronger winds will continue through Sunday, with high temperatures
closer to climatological normals. High pressure will pass to the
south Sunday night into Monday, with increased cloud cover between
the high and an approaching area of low pressure to the west
maintaining mild temperatures across the region. Thereafter,
confidence decreases rapidly, though general consensus indicates a
warm frontal passage Tuesday followed by increasing chances of
precipitation ahead of the associated slowly approaching low
pressure and attendant cold front. However, model differences
are very large, as the systems for early to late week are still
over the data sparse areas of the Pacific, and are not yet
initialized well.

&&

Aviation /03z Friday through Tuesday/...
a cold front stalls north of the city terminals tonight before
shifting back north as a warm front Friday.

Increasing confidence of prevailing VFR through the night into
Friday. Still a chance of at least tempo IFR cigs from roughly
08-13z. -Shra possible at kswf for the next few hours, but
but for now will just go with vcsh there.

Winds will be S-SW under 10 kt for coastal terminals, and light and
variable elsewhere.

For Friday, VFR with S winds increasing to around 10 knots.

Outlook for 00z Saturday through Tuesday...
Friday night-Saturday...sub-VFR possible Friday night into Saturday
morning before improving back to VFR.
Saturday night...MVFR likely with rain.
Sunday...VFR.
Monday...VFR early...becoming MVFR. Chance of rain or snow.
Tuesday...possible MVFR in showers.

&&

Marine...
long period east to southeast swell of around 10 seconds was
across the ocean waters and seas have built to around 4 feet
with seas fluctuating to near 5 feet. With seas periodically
near 5 feet will not issue a Small Craft Advisory at this time.

Otherwise, high pressure over the western Atlantic brings a
persistent southerly flow through Friday night, but winds and
seas will remain below small craft levels.

Winds and seas will increase to Small Craft Advisory levels Saturday
ahead of a cold front, and likely remain elevated through Sunday
following the frontal passage. Winds and waves will gradually
subside Sunday night into Monday as high pressure moves south of the
area. The next chance of Small Craft Advisory conditions will be
Monday night into Tuesday as winds strengthen following a warm
frontal passage. Winds and seas may remain at or near Small Craft
Advisory conditions through late week ahead of a cold front.

&&

Hydrology...
a quarter to one half of an inch of rain is likely Saturday. No
hydrologic impacts are expected through the next week.

&&

Climate...
the following are record high temperatures for Friday February 24,
2017 along with the forecast high temperature.

Record high temperature forecast high temperature
----------------------- -------------------------
Central Park........75 (1985) 64
LaGuardia...........73 (1985) 63
Kennedy.............60 (1984) 60
Islip...............59 (2000) 58
Newark..............73 (1985) 66
Bridgeport..........60 (2016) 58

The following are record maximum minimum temperatures for Friday
February 24, 2017 along with the forecast minimum temperature.

Record Max minimum temperature forecast minimum temperature
------------------------------ ----------------------------
Central Park........54 (1985) 54
LaGuardia...........51 (1985) 54
Kennedy.............47 (1984) 50
Islip...............44 (1984) 49
Newark..............47 (1985) 53
Bridgeport..........39 (1984) 47

The following are record maximum minimum temperatures for Saturday
February 25, 2017 along with the forecast minimum temperature.

Record Max minimum temperature forecast minimum temperature
------------------------------ ----------------------------
Central Park........51 (1930) 48
LaGuardia...........49 (1996) 48
Kennedy.............46 (1996) 47
Islip...............47 (1996) 46
Newark..............47 (1996) 47
Bridgeport..........44 (1996) 46

&&

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

&&

$$
Synopsis...MD/ds
near term...met
short term...ds
long term...Maryland

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