Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service New York New York
425 am EST Sat Nov 28 2015

a cold front will move across the area this morning from north to
south. The front will then move slowly farther south towards the
middle-Atlantic this afternoon into tonight. The front will further
slow down on Sunday. By Sunday night...the next strong area of
high pressure will build in from the north and east. This will
continue to build in through Monday. A low pressure system will
impact the region Tuesday into the middle of the week. High
pressure returns for the end of the week.


Near term /until 6 PM this evening/...
an upper level zonal jet streak is helping push a cold front across
the region this morning. Behind the front...850mb temperatures do
not respond as fast. They will lower a few degrees but with the
limited vertical mixing forecast...and more of a westerly surface
flow...expecting another mild day with high temperatures in the
middle 50s to close to 60 degrees...mainly across the coastal

With the front within close proximity of the region during the
day...there will be a chance of showers. Models are not very
conspicuous with the shower activity as quantitative precipitation forecast fields are rather low.


Short term /6 PM this evening through Monday night/...
behind the cold front...high pressure will be slow to move in with
the cold front slowly moving south of Long Island. Zonal jet
remains aloft with another jet streak moving in on Sunday and at
the surface there will be a weak wave of low pressure moving along
the cold front. Therefore...showers will remain in the forecast
tonight into early Sunday before drying out thereafter.

The jet weakens Sunday night into Monday and is suppressed with
its southern branch to the southwest of the region. The left front
quadrant of this jet moves in Tuesday into Wednesday. Another area of
high pressure at the surface builds in from the north and east
Sunday night through Monday before moving southeast of Nova Scotia
into Tuesday. Dry weather prevails Sunday night through Monday. There
will then be some warm air advection aloft with a warm front
approaching. Dry weather remains Monday night but there will be a
low chance of precipitation going into early Tuesday which for
interior areas blocked from the relatively warmer southeast
flow...could present some possible sleet or freezing rain with
plain rain closer to the coast.

Temperatures through the period will be on a gradual decline as
the airmass transitions to a cool maritime type of airmass with
cold air advection increasing Sunday and more onshore flow for


Long term /Tuesday through Friday/...
weak upper level ridging begins Monday night and the surface high
pressure moves into the Gulf of Maine. This will allow a warm
front to approach on Tuesday...pushing north of the region into
Tuesday night as low pressure over the middle of the country moves
into the western Great Lakes region and becomes vertically
stacked. A weak low pressure develops along the warm front Tuesday
night into Wednesday. There may be a round of some moderate
precipitation depending on the track of this low.

Associated cold front approaches and moves through Wednesday. There
are some timing differences between the 00z European model (ecmwf)...12z GFS...and
12z CMC. The GFS is more progressive while the European model (ecmwf) is about 6
hours behind. However...the new 12z European model (ecmwf) is now very similar to the
12z CMC...developing a weak low pressure along the cold front over
Maryland...then heading northeast and tracking in the vicinity of
the tri-state Wednesday night into Thursday. Although this low is could spell out more in the way of quantitative precipitation forecast if it verifies.
High pressure builds in through the end of the week with a return to
dry conditions.

Temperatures will warm into the 50s for a majority of the area on
Wednesday in association with warm air advection with the warm front...then will
come back down to near normal behind the cold front for the end of
the week.


Aviation /09z Saturday through Wednesday/...
a cold front will move across this morning with VFR conds to
start...then MVFR ceilings should develop by early afternoon. Scattered
showers are also possible throughout this afternoon/evening as the
front passes to the south...then mainly across NYC metropolitan and Long
Island this evening.

SW winds under 10 knots will shift northwest and then veer north after frontal passage
during the day Saturday.

Outlook for 06z Sunday through Wednesday...
late Sat night...MVFR conds with scattered showers.
Sunday...MVFR ceilings in the morning...otherwise VFR.
Tuesday...rain/fog with IFR conds. Precipitation could begin at kswf as
freezing rain.
Wednesday...MVFR or IFR conds possible in the morning. Rain ending.


swells at the ocean buoys are at 6 feet...with wavewatch holding onto
5-feet swells through about midnight tonight...and 18z nwps into
Sunday morning. Decided to split the difference...and extended Small Craft Advisory
for hazardous seas through tonight.

Next chance of Small Craft Advisory conds will come Sunday strong high
pressure building from Ontario and Quebec tightens the pressure
gradient...with gusts up to 25 knots and seas building to 5-7 feet on the
ocean waters. Sub-Small Craft Advisory conds will follow for Monday night-Tuesday as the
high builds into New England.

Small Craft Advisory conds are also possible on the ocean Tuesday night into Wednesday night
with the approach and passage of a frontal system.


rainfall amounts through tonight will be light and less than a
tenth of an inch.

Low pressure could bring about 1/2 to 3/4 inch of rain Tuesday into


Okx watches/warnings/advisories...
New York...none.
New Jersey...none.
Marine...Small Craft Advisory for hazardous seas until 6 am EST Sunday
for anz350-353-355.



National Weather Service Glossary of Abbreviations