Scientific Forecaster Discussion
Area forecast discussion
National Weather Service New York New York
1252 PM EST Friday Mar 7 2014
a high pressure ridge will be in place today through Saturday.
Meanwhile...an area of low pressure approaches from the south and
passes well to the southeast tonight. A cold front then approaches
late in the day Saturday. A series of weak fronts will cross the
region through early next week. A storm system will then approach
from the middle section of the country during the middle of next
Near term /until 6 PM this evening/...
subsidence from high pressure continues to create an inversion
below 900mb...and moisture streaming in from the ocean is getting
trapped beneath it...leading to mostly cloudy skies. The
persistent cloud cover and onshore flow has helped to keep temperatures a
bit cooler...in the lower to middle 30s. Have adjusted temperatures
accordingly for the afternoon.
Weak isentropic lift approaches from the south this afternoon. Chances are
that we remain dry through the day...with only a slight chance of
drizzle over the ocean waters late afternoon.
Short term /6 PM this evening through 6 PM Saturday/...
low pressure well to the south heads northeast. On the outer fringes
of this system ... isentropic lift pushes into the area. Model
consensus has the deepest moisture occurring during the evening
hours...and deep enough only across eastern Long Island for any
chance of precipitation. There will still be relatively dry air in the middle
levels...so anything that falls should be on the light side. There
should however be enough moisture aloft for ice nucleation or seeder
feeder mechanisms. With the boundary layer marginally cold
enough...went with a slight chance of light mixed rain and snow
during the evening hours. Clearing follows during the late night
Weak high pressure will bring a mostly sunny start to the tri state
area on Saturday. Middle to high level clouds will then increase later
in the day ahead of an approaching cold front. The front could be
entering the northwest portion of the forecast area right at the end of the
afternoon. Moisture right ahead of the front is lacking...so will go
with a dry forecast. A mav/NAM MOS blend looked good again for
highs...which will finally climb back up to around normal levels.
Long term /Saturday night through Thursday/...
models in good agreement with a fast weakly trough upper flow over
the NE US through early next week with a series of northern stream
shortwaves and associated clipper systems moving through the NE.
The first of these late Sat night into sun will bring the chance
for a few snow showers. Then another Sunday night into Monday will
bring the chance for light snow showers Sunday night transitioning
to light rain showers on Monday. With polar vortex remaining over
hudsons Bay...not expecting any Arctic intrusions during this
time...with temperatures near seasonable levels.
Uncertainty continues for the middle week period with the interaction
of Pacific short wave energy with the northern branch of the polar jet.
Significant spread continues with the magnitude of phasing and
resultant troughing...with sensitivity lying in Pacific energy entering
the western US late in the weekend/early next week and its
interaction with a northern stream trough digging around a southeast
sinking polar vortex. With the low predictability this far out...no
significant changes to the forecast in this time period. A general
scenario of low pressure developing across across the middle section of
the country Tuesday...and then across Tennessee Valley Wednesday...passing off the
middle Atlantic coast Wednesday night into Thursday. With fairly good agreement in
a polar frontal passage Tuesday night...a cold scenario is
preferred...with the track/intensity of low determining all snow vs
a wintry mix. It is still too early to determine the significance of
this system...but will continue to be monitored.
Zonal upper flow and surface ridging returns for the end of the week
Aviation /18z Friday through Wednesday/...
low pressure passes well south and east of Long Island through
tonight. Weak high pressure briefly builds in for Saturday morning.
Ceilings will remain between 2500-3500 feet all day today. North-
northeast winds today...with speeds between 8-12 knots.
MVFR ceilings return for the first part of tonight.
Ceilings improve to VFR late tonight/early Saturday morning as the low
departs and high pressure briefly builds in. Winds will back to
the northeast. Gusts into the teens Saturday morning/afternoon
may be occasional.
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: ceilings will be right on the MVFR/VFR threshold
Kjfk fcster comments: ceilings will be right on the MVFR/VFR
threshold through 02z.
Klga fcster comments: ceilings will be right on the MVFR/VFR threshold
Kteb fcster comments: ceilings will be right on the MVFR/VFR threshold
Khpn fcster comments: ceilings will be right on the MVFR/VFR threshold
Kisp fcster comments: ceilings will be right on the MVFR/VFR threshold
Outlook for 18z Sat through Wednesday...
Sunday...mainly VFR. Brief light precipitation possible in the morning.
Monday...mainly VFR. Brief light precipitation possible.
Wednesday...VFR early. Sub-VFR late.
east winds pick up today as low pressure well to the south tracks
NE. Gusts to 25 knots expected on the ocean waters. Additionally...seas
should build up to 5 feet by day's end. The low passes to the
southeast tonight...then heads farther out to sea during Saturday.
Although winds eventually subside below Small Craft Advisory levels by Saturday
morning...a lingering east-southeast swell will help keep seas up in spite of a
light to moderate offshore flow. Feel that wavewatch could be at
least a foot too high with its wave height forecast on
Saturday...however...thinking is that seas up to at least 5 feet is
a likely scenario. Overall Small Craft Advisory remains in effect through Saturday.
Marginal Small Craft Advisory conditions are possible in a northwest flow
sun...otherwise sub Small Craft Advisory conds expected into early next week with a
series of weak frontal passages.
no significant widespread precipitation expected through early
There is potential for significant precipitation during the
middle of next week as a storm system emerges from the MS
valley...but uncertainty in the forecast details continues at this
the National oceanic and atmospheric administration weather radio transmitter that serves the New York City
metropolitan area remains out of service due to radio frequency
interference with the U.S Coast Guard transmitter.
For more information see the following public information
statement (all lower case):
Marine...Small Craft Advisory until 6 PM EST Saturday for anz350-353-