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Area forecast discussion 
National Weather Service New York New York
657 am EST Thursday Dec 25 2014

Synopsis...
a cold front crosses the area early this morning...with its
associated low tracking into Quebec today. High pressure then
builds to the south of Long Island through Saturday. A cold front
approaches from the northwest Saturday night...crosses the tri-
state on Sunday. This front stalls out well to the south of Long
Island...with waves of low pressure riding along it...into the
middle of next week...as Canadian high pressure builds in from the
west.

&&

Near term /until 6 PM this evening/...
the surface cold front was into central CT and Long Island at
11z...with an area of showers behind it. The cold front should
exit to the east by 13z...with the showers trailing behind it by
about a couple of hours.

The cold front has also scoured out the dense fog ahead of
it...so have cancelled the remainder of the dense fog advisory.

700-500 hpa trough axis crosses this morning...with clearing in
its wake for this afternoon.

Main story for this Christmas is well above normal temperatures
and gusty winds.

Daytime highs should run around 15 degrees above normal...with
temperatures remaining fairly steady this morning immediately behind
the cold front...then fall off into the 40s by middle-late afternoon.

Winds should gust to 30-40 miles per hour by this afternoon...with strongest
gusts near the coast and in higher elevations across the interior.

&&

Short term /6 PM this evening through Saturday night/...
gusty winds last into early this evening...then fairly rapidly
diminish through the remainder of the evening.

Deep layered ridging begins to build in Thursday night...with its
axis building over the area on Saturday...then sliding off to the
east Saturday night. Associated subsidence under the ridge should
keep things dry from Thursday night-Saturday night...with minimal
cloud cover through Saturday...then increasing middle-high clouds
ahead of a cold front Saturday night.

For lows tonight...used a blend of ecs/mav/met guidance with NAM
2-meter temperatures...with values forecast to be around 10
degrees above normal. A blend of mav/met/ecs guidance with NAM
2-meter temperatures and a mix down from 975-950 hpa per BUFKIT
soundings was used for highs on Friday...with readings expected to
be 5-10 degrees above normal.

For lows Friday night a blend of mav/met guidance was used...with
values around 10-15 degrees above normal. For highs Saturday a
blend of mav/met guidance with NAM 2-meter temperatures and a mix
down from 975 hpa per BUFKIT soundings was used. Highs should be
around 10 degrees above normal. A blend of mex/men/ekd/ecm/ece/wpc
guidance with NAM 2-meter temperatures was used for lows Saturday
night...with values forecast to be 10-15 degrees above normal.

&&

Long term /Sunday through Wednesday/...
with exception of CMC - models have in general come into fairly
good agreement with the idea that the cold front that passes
through the area Sunday...ends up stalling out to far to the south
for waves of low pressure passing along it to have much if any
impact on the area. Two possible exceptions are with the initial
wave of low pressure and secondary cold frontal passage Sunday
night...and another wave of low pressure on Tuesday.

For now...have slight chance to chance probability of precipitation with the cold frontal
passage...then slight chance probability of precipitation across southern zones with the
passage of the first wave. For now it appears the boundary layer
should be warm enough to support only rain in this time frame.

The region remains in between a closed upper low to the north and
ridging off the Florida coast through at least Tuesday night...with the
timing and placement of shortwave troughs embedded in the flow
between the two determining the exact track/strength of waves of
low pressure along the stalled cold front. For now appears
strongest shortwave will pass on Tuesday...so have slight chance
probability of precipitation across southern areas Monday night/Tuesday...otherwise have
gone dry over land Monday- Tuesday night. Likely will be cold
enough in the lowest layers to support mainly snow...except for
maybe at the immediate coast. For now though any precipitation is
expected to be light...as the area should be in the northern
periphery of the system.

Wednesday should be dry with northern stream ridging passing over
the area.

For temperatures Sunday-Wednesday a blend of
mex/men/ekd/ece/ecm/wpc guidance was used. After above normal
temperatures on Sunday...below normal temperatures are forecast
Monday-Wednesday.

&&

Aviation /12z Thursday through Monday/...
a cold front now just west of NYC will continue to move through
the terminals through about 13z-14z.

Conditions have quickly improved to VFR in the city and some
surrounding terminals. Expect all the terminals to improve to VFR
by 14z-15z and the rain the be east of kgon by 15z.

Winds become westerly and increase behind the front. Expect 15 to
20 knots speeds with gusts 30 to 35 knots. Low probability of gusts 35-40 knots.

Winds and gusts gradually diminish this evening and tonight.

..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: generally high confidence forecast after
15z with VFR conditions and gusty west winds. May see an
occasional wind gusts higher than forecast possible.

Klga fcster comments: generally high confidence forecast after
15z with VFR conditions and gusty west winds. May see an
occasional wind gusts higher than forecast possible.

Kewr fcster comments: generally high confidence forecast after
15z with VFR conditions and gusty west winds. May see an
occasional wind gusts higher than forecast possible.

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

Kteb fcster comments: generally high confidence forecast after
15z with VFR conditions and gusty west winds. May see an
occasional wind gusts higher than forecast possible.

Khpn fcster comments: generally high confidence forecast after
15z with VFR conditions and gusty west winds. May see an
occasional wind gusts higher than forecast possible.

Kisp fcster comments: generally high confidence forecast after
15z with VFR conditions and gusty west winds. May see an
occasional wind gusts higher than forecast possible.

Outlook for 12z Friday through Monday...
Fri-Sat...VFR.
Sun...marginal VFR. Chance of rain.
Monday...VFR.

&&

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

A cold front will move across the area waters early this morning
winds increasing to gale force behind the front. Therefore...have
cancelled the small craft and gone straight to gales today.

Small Craft Advisory gusts then expected for the remainder of the evening...tapering
off to below Small Craft Advisory levels after midnight tonight. Latest guidance
indicting that gusts will come to an end rather quickly.

Sub-Small Craft Advisory conditions are anticipated on Friday into next week
though there is uncertainty in how far south the stalled frontal
boundary will remain next week.

&&

Hydrology...
up to a 1/4-1/2 an inch of additional rainfall is expected...with
locally higher amounts possible...before precipitation comes to an
end shortly after sunrise. It should then be dry through Saturday
night.

No significant precipitation is expected from Sunday-Wednesday at
this time.

&&

Climate...
record maximum minimums for Christmas day...

Location.......record/year
Newark.............47/1979
bdridgeport........45/1964
Central Park.......50/1979
LaGuardia..........48/1964
JFK Airport........46/1987
Islip Airport......45/1987

These records likely will not fall as temperatures are currently
forecast to fall to the upper 30s to around 40 degrees at or
before 11:59 PM this evening.

&&

Okx watches/warnings/advisories...
CT...none.
New York...none.
New Jersey...none.
Marine...Gale Warning until 6 PM EST this evening for anz330-335-338-
340-345-350-353-355.

&&

$$
Synopsis...maloit
near term...maloit
short term...maloit
long term...maloit
aviation...British Columbia
marine...British Columbia
hydrology...maloit
climate...

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