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Area forecast discussion 
National Weather Service New York New York
336 PM EDT Monday Apr 27 2015

Synopsis...
a series of lows near the Canadian Maritimes will move south through
Tuesday night before consolidating into one low pressure system well
east of New England by Wednesday. At the same time...weakening high
pressure over the middle section of the country slowly builds in from
the west. A weak trough moves across the region on
Wednesday...and then low pressure slowly passes south and east of
Long Island through the end of the work week. High pressure builds
east for Saturday...and then a weak cold front may impact the area
on Sunday.

&&

Near term /until 6 am Tuesday morning/...
a closed upper low near Nova Scotia with a trough and vorticity maximum
extending west into southern New England and upstate New York will
move south tonight as the trough axis moves south of the region
early this evening. Radar still picking up light showers or
sprinkles associated with the upper trough and shortwave. Will
continue with the slight chance probability of precipitation through 01z...as the
shortwave moves south of the area and any surface based
instability is weakened with the loss of heating.

Cyclonic flow will remain through the night with some residual middle
level moisture and scattered to broken cloud cover expected.

&&

Short term /6 am Tuesday morning through Tuesday night/...
cyclonic flow remains Tuesday through Tuesday night as the upper low
slowly weakens and moves East. Heights will be rising through the
period as upper ridging builds east from the Midwest. No
precipitation is expected with near zero probability of precipitation as only a weak vorticity
rotates around the low Tuesday. This vorticity and daytime heating will
be enough for a few clouds to develop. The airmass continues to
modify and warm advection does set up during the day. So have
leaned toward the warmer met guidance for highs.

&&

Long term /Wednesday through Monday/...
weak surface trough moves across the region on Wednesday...but with a
lack of upper level support and limited low-level moisture...not
expecting much beyond some middle and high level clouds. With west to
northwest winds...expecting downsloping flow to warm temperatures into the
70s for most areas west of the Hudson River and highs in the middle to
upper 60s most elsewhere. If the flow is weak enough...afternoon sea
breezes are possible...and that would result in cooler afternoon
temperatures for coastal areas.

For Thursday through Friday...closed low over the Great Lakes dives
into the southeast U.S. Surface low then develops over the Gulf Coast
and tracks towards the Carolinas. Weak high pressure will build over the
northeast and depart during this time...and this high should be
strong enough to keep the low from tracking too far to the north as
it tracks well south of Long Island...and south of the 40/70
benchmark...Friday through Saturday. Will carry mainly low chance
probability of precipitation during this time as some wrap-around precipitation could impact the
local area. Due to the cloud cover and onshore flow...can expect
below normal temperatures with highs in the low 60s on Thursday and in the
50s on Friday. Any precipitation that falls will be light.

By Saturday...the low moves into the western Atlantic and ridging at
the surface and aloft builds west of the region. With rising
heights...can expect improving conds from west to east...and temperatures
moderating back into the low-middle 60s.

Weak cold front then tries to push across the region on Sunday.
Mainly expecting dry conds...but with westerly flow
increasing...temperatures look to warm up through the 60s and back into the
70s.

&&

Aviation /20z Monday through Saturday/...
weak high pressure remains in control.

VFR. Isolated-scattered showers mainly east of the city this aftn/eve...but
coverage too low to include in tafs. Brief MVFR possible in any rain.

Northwest winds with gusts around 20kt. Direction mostly north of 310
magnetic.

... 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: moderate to high confidence that winds favor
north of 310 magnetic rest of the day.

Klga fcster comments: moderate to high confidence that winds favor
north of 310 magnetic rest of the day.

Kewr fcster comments: moderate to high confidence that winds favor
north of 310 magnetic rest of the day.

Kteb fcster comments: no unscheduled amendments expected.

Khpn fcster comments: no unscheduled amendments expected.

Kisp fcster comments: no unscheduled amendments expected.

Outlook for 18z Tuesday through Sat...
Tuesday PM...VFR. Northwest g20kt.
Wednesday...VFR.
Thursday...VFR. East g15-20kt PM.
Friday...chance sub-VFR/rain. Chance NE g25kt.
Sat...VFR.

&&

Marine...
a series of lows near the Canadian maritime continue to
rotate through the maritime before moving east Tuesday night as
weakening high builds slowly east. A northwest to west flow will
persist across the forecast waters. Winds and seas are expected to
remain below Small Craft Advisory levels tonight through Tuesday
night. However...there could be occasional near shore gusts that
approach 25 knots tonight into Tuesday...mainly along the South Shore
of Long Island with better mixing over the land.

Easterly pressure gradient tightens on Thursday and Friday as low pressure
passes south of Long Island. Small Craft Advisory level winds/waves likely for the
ocean waters...and Small Craft Advisory winds possible for the South Shore bays.
Gradient slackens for the weekend...but lingering swells will keep
ocean seas above Small Craft Advisory levels.

&&

Hydrology...
significant precipitation is not expected through Wednesday.

Light precipitation is possible as low pressure passes south of Long Island
late in the week.

&&

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

&&

$$
Synopsis...mps/met
near term...met
short term...met
long term...mps
aviation...jc
marine...mps/met
hydrology...mps/met

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