Scientific Forecaster Discussion
Area forecast discussion
National Weather Service New York New York
440 am EDT sun Mar 9 2014
high pressure will briefly build into the region today. A series
of clipper systems will track north of the region tonight through
Tuesday. A storm system will then approach from the middle section of
the country during the middle of next week. High pressure returns
for the end of the week.
Near term /until 6 PM this evening/...
shortwave slides east this morning...with west-northwest upper flow for today.
Surface ridging briefly buildings in today.
Light rain showers over southern portions of the region will
continue to push south early this morning...perhaps mixing with snow
before ending. Skies clear from west to east towards daybreak in wake of
shortwave. This should provide a sunny morning...with increasing
high clouds late in the day ahead of an approaching series of weak
A gusty northwest flow expected today with temperatures much cooler than
yesterday...generally lower 40s city/coast and upper 30s interior.
Short term /6 PM this evening through Monday night/...
models in good agreement with a fast but weakly troughed upper flow
over the NE US for early next week with a series of weak northern
stream shortwaves and associated clipper waves moving through
southern Canada into New England through Tuesday morning.
The first of the shortwaves and associated weakening clipper rides
through New England Sunday night into Monday. Overrunning setup and
thermal profiles would support a brief period of light snow late
Sunday night into Monday morning...mainly northern zones...as this
disturbance passes through. A very light snow accumulate is possible
across northern zones.
The second of these shortwaves and a stronger clipper systems tracks
through the same general area Monday night/Tuesday morning. With it
taking a track well to the north...and region in the warm sector of
this system...not expecting much more than a few rain showers with
cold frontal passage Monday night/early Tuesday morning.
Long term /Tuesday through Saturday/...
uncertainty continues for the middle week period with the interaction
of Pacific short wave energy with the northern branch of the polar jet.
Spread continues with the strength of the northern and southern
stream energies...their degree of phasing...and resultant strength
of trough as it reaches the East Coast Wednesday night/Thu.
Although models have been consistent in signaling a midweek system
affecting the region...there has been significant run to run
inconsistency with operational models on track and intensity of low
due to the above uncertainties and therefore quantitative precipitation forecast amounts and p-type.
The main areas of sensitivity have been the strength of northern
stream shortwave energy rotating around the polar vortex and
interaction with Pacific energy. The 12z and 00z runs...as well as 12z
gefs/European model (ecmwf) ensembles...have been leaning towards shortwave energy
rotating around the polar vortex being a bit weaker...keeping Arctic
high/airmass locked up a bit farther north...leading to a farther
north track and warmer scenario for the region. The hope is for
increasingly better model initialization of the second piece of the
puzzle...the Pacific energy interaction...from Monday on as it enters
the western US coast. This piece of energy...and degrees of
phasing...will play a strong role in the intensity of the low.
12z operational models indicated a warmer solution for the majority of
the storm...with the potential for snow on the backside. The 00z
operational models are in a similar Camp with low pressure
developing over the Central Plains Tuesday...tracking eastward
through the Ohio/Tennessee River valleys Tuesday night/Wed...and then
over or just south of the region Wednesday night. Main forecast
adjustments were to increase probability of precipitation to high likely Wednesday into Wednesday night
and adjust temperatures to portray a storm track along the coastline
(warmest southeast coast and colder northwest interior). Along the coast this
would lend to mainly rain Wednesday with a transition to snow on backside
late Wednesday night...while across the northwest interior a snow/wintry mix to
rain to snow scenario. As explained above there is still uncertainty
on the track and intensity of the low...so not enough predictability
yet to venture on any rain/snow amounts.
Cold and breezy as the storm pulls out at the end of the week with
Canadian high pressure building in. Another cold front is then forecast to
move across Friday night or Sat.
Temperatures Tuesday will be above normal levels. Temperatures on Wednesday will be
predicated by low track...and then below normal temperatures return
during the latter half of the week.
Aviation /09z Sunday through Thursday/...
high pressure builds in from the west today.
VFR. MVFR ceilings at kisp possible until around 0930-10z.
Northwest flow expected today. Speeds generally 10-15 knots with gusts 15 to
20 kts. For the NYC metropolitan terminals...winds favoring north of 310
magnetic until around 17-18z...then equal chances of being north or
south of it thereafter.
Winds diminish toward evening...after 20z...then turn toward the
west during the evening hours.
Outlook for 06z Monday through Thursday...
Monday...VFR. SW g25kt
Monday night...sub VFR possible.
Wednesday-Wednesday night...VFR early. Sub-VFR likely in snow and/or rain.
Thursday...improving to VFR early. Northwest g25-30kt.
latest buoy observation show that the entire ocean waters have likely
subsided below 5 feet. With an offshore flow today...not expecting
seas to build. However...cold advection this morning will probably
kick up winds/gusts after sunrise. With collaboration from the
surrounding offices...have decided to extend the Small Craft Advisory on the ocean
through this morning. The pressure gradient relaxes a little this
afternoon with weaker cold advection...but an occasional gust to 25
knots is still not out of the question. Sub-Small Craft Advisory conditions then likely
through Monday night. Gusts and seas could reach advisory criteria
over the eastern ocean waters on Tuesday as a clipper system moves
through northern New England.
Low pressure moves through the middle Atlantic on Wednesday and emerges
off the New Jersey coast late in the day/evening hours. Expect seas to
build...with a moderate onshore flow backing to the northwest
Wednesday night and Thursday. There is a chance of gale force winds
on the ocean on Thursday with the back side of the storm...but Small Craft Advisory
conditions across all waters is the more likely scenario.
no significant widespread precipitation expected through early
There is potential for a significant precipitation during the middle
of next week as a storm system tracks near the region...but
uncertainty in the forecast details continues at this time.
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 noon EDT today for anz350-353-355.