Scientific Forecaster Discussion
Area forecast discussion
National Weather Service New York New York
1055 am EST Thursday Dec 5 2013
a warm front crosses the area today followed by a cold front Friday
afternoon. High pressure builds in behind the departing front and
remains over the region through most of the weekend. A storm
system will affect the area Sunday night and Monday...followed by
a return of high pressure by the middle of next week.
Near term /until 6 PM this evening/...
update...dense fog advisory has been issued for the entire County Warning Area
until noon. Widespread fog is being observed with visibilities at
or below a quarter of a mile. Across Long Island...visibilities
have not yet fallen to a quarter of a mile...however it is
expected visibilities will fall within the hour.
Just some scattered drizzle/light rain expected this
morning...especially across CT. Temperatures will slowly rise
through the day.
Otherwise...weak high pressure continues to slide offshore
early today. A warm front...located in central New Jersey...is expected
to move through by 12-18z. With warm advection already occurring
and cloudy skies...temperatures are expected to steadily rise through the
morning and maximum out at about 10 degrees above normal.
Guidance is backing off on the coverage of measurable precipitation
today with the highest chance this morning as a 500-700mb
vorticity maximum passes through. Into the afternoon...seems much of
the forcing is focused more north and west of NYC until the cold
frontal precipitation approaches. With the low levels moist and the warm
front in the vicinity...light rain or drizzle is really possible
at any time through the day. Low level moisture looks fairly
shallow today so will therefore keep sprinkles/drizzle in the
forecast for the morning then chance probability of precipitation and light rain showers
for the afternoon into the evening.
Short term /6 PM this evening through 6 PM Friday/...
behind the warm front...temperatures stay nearly steady with
southwesterly winds in place. Lows tonight will only drop to the
middle 40s to lower 50s in response. Cold frontal passage is then
expected Friday morning which will turn winds northwesterly and
begin filtering in much cooler air. Temperatures on Friday will still be
able to reach above normal values...and only a few degrees warmer
than the lows...before the cold air filters in.
With dew points in the upper 40s to lower 50s...expect patchy fog
across the area overnight as well.
As for the rain...sprinkles/drizzle will prevail through the
evening. The band of rain associated with the cold front approaches
by 06z and passes through during the morning hours with likely probability of precipitation
in the forecast. The cold front will then stall near to just south
of the area Friday. The first wave of precipitation just mentioned is
associated with the initial front and a piece of 700mb energy.
Behind that...breaks in the rain are possible briefly Friday
Long term /Friday night through Wednesday/...
with the cold front aligned with the flow aloft...Post-frontal
precipitation is expected during Friday night. Cold air filters in...and
BUFKIT forecast soundings show sleet and snow mixing in with the
rain during the evening hours north and west of the
city...eventually ending as all snow well north and west. For the
city...adjacent zones and Long Island...rain with a slight chance
of a wintry mix right as precipitation ends...but will keep it as all
rain in the grids for now. Snow/sleet accumulation of up to 2
inches expected for the inland zones.
High pressure keeps the region dry Saturday through much of Sunday
with below-normal temperatures.
For late-day Sunday through Monday night...models in decent
agreement that low pressure shifts in from the south and
west...bringing precipitation mainly Sunday night through Monday afternoon.
Right now it looks like a snow/sleet mix at the onset as wet-bulbing
would probably occur...then a changeover to rain likely by midnight
Sunday night for the city and coastal areas. For inland spots...a
wintry mix...but will leave out any mention of freezing rain at this
point. All areas probably seeing precipitation type of rain by noon on Monday
with a decent east to southeast flow.
The system heads out to sea on Monday night with a chance of
lingering precipitation...otherwise dry Tuesday and Wednesday with high
pressure slowly building back in.
Aviation /16z Thursday through Monday/...
a warm front over the region resulting in very low conditions
through tonight. A cold front approaches from the west late
Confidence increasing on some improvements for afternoon. We
could even break briefly to marginal visibility and VFR
ceilings...especially kewr/kteb. Still expecting a return to LIFR this
evening...especially for the coast with minimums possible.
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: high uncertainty in timing and amount of
improvement this afternoon. Thinking we could be better than forecast with
visibility possibly reach 3-5sm and bkn002 going scattered for a few
Confident in wind forecast and that speeds remain below 10 knots.
The afternoon kewr haze potential forecast is yellow...which implies
slant range visibility 4-6sm or greater outside of cloud.
Kjfk fcster comments: high uncertainty in timing and amount of
improvement this afternoon. Thinking we could be slightly better than
forecast with visibility possibly reaching 2-3sm and even the bkn002 going
scattered for a few hours.
Minimums possible again tonight.
Klga fcster comments: high uncertainty in timing and amount of
improvement this afternoon. Thinking we could be better than forecast with
visibility possibly reaching 3sm and bkn002 going scattered for a few
Confident in south wind for this afternoon...though shift may occur
sooner than forecast.
Kteb fcster comments: high uncertainty in timing and amount of
improvement this afternoon.
Khpn fcster comments: high uncertainty in timing and amount of
improvement...if any...this afternoon.
Kisp fcster comments: high uncertainty in timing and amount of
improvement this afternoon. Ceiling could scatter to VFR and visibility could
Minimums possible tonight.
Outlook for 12z Friday through Monday...
Friday-Friday night...sub VFR likely...especially in periods of rain.
Sun...MVFR or lower late in the day. Chance -sn/pl...especially away
from the immediate coast.
Monday...sub VFR likely in rain.
dense fog advisory has been issued for all of the area waters
until midnight with visibilities falling to 1 nm or less.
Winds remain fairly light through the morning with winds turning
southerly and increasing in the afternoon behind a warm front. As
a cold front approaches and a 30-40kt low level jet
develops...gusts to 25kt on the ocean waters are possible. Seas
will also increase in response and be above 5 feet tonight.
Therefore...have issued a Small Craft Advisory for tonight through Friday. Winds
and seas on the other waters will remain below criteria...10-15kt
gusts and 1-3ft seas.
After a brief lull...Small Craft Advisory conditions will be possible once again late
Friday night into Saturday over the ocean waters. Sub-Small Craft Advisory probable
on Sunday...then winds and seas increase with an approaching storm
Sunday night and Monday. Small Craft Advisory conditions expected with this storm.
precipitation is expected today through Saturday with around an inch
of mostly rain expected.
Another storm system could bring a liquid equivalent precipitation
amount of a half inch to an inch from Sunday afternoon through
due to interference issues with the U.S. Coast Guard
emergency broadcast channel...the New York City National oceanic and atmospheric administration all hazards
weather radio station kwo35 remains out of service. The National
Weather Service is working with several U.S. Government agencies
to isolate and resolve this technical problem.
During this time...the transmitter may be returned to service
intermittently for use of the National oceanic and atmospheric administration all hazards weather radio
during potentially dangerous weather situations...for routine
weekly tests of the warning system...and to determine if the
interference issue has been resolved.
CT...dense fog advisory until noon EST today for ctz005>012.
New York...dense fog advisory until noon EST today for nyz067>075-078>081-
New Jersey...dense fog advisory until noon EST today for njz002-004-006-
Marine...dense fog advisory until midnight EST tonight for anz330-335-
Small Craft Advisory from 6 PM this evening to 6 PM EST Friday