Scientific Forecaster Discussion
Area forecast discussion
National Weather Service New York New York
141 PM EDT Monday Aug 31 2015
a trough of low pressure will be followed by a weak cold front tonight.
High pressure otherwise strengthens over the middle-Atlantic through
Thursday. A cold front will move through Thursday night followed
by high pressure through the weekend.
Near term /until 6 PM this evening/...
forecast update to keep broken middle and upper level clouds in
longer this afternoon. As a result...have lowered maximum temperatures
today a few degrees. Still looking at highs in the upper 80s and
low 90s. With the highest temperatures in and around the NYC metropolitan
Also...a few showers have started to develop...mainly north and
west of NYC. Will carry a 20 pop for isolated activity.
There is a moderate risk for rip currents at ocean beaches today.
Short term /6 PM this evening through Tuesday night/...
back door cold front passes through the region tonight. With
minimal upper level support...not expecting shra/tsra...so will
carry a dry forecast. Light northerly winds develop behind the
passage of the front...and surface dewpoints will drop a bit...
generally from the middle to upper 60s to the low to middle 60s. With
light winds and high relative humidity levels...some patchy fog
will develop across the interior and across eastern Long Island
late tonight and through daybreak Tuesday.
High pressure strengthens over the mid-Atlantic. Temperatures drop a bit on
Tuesday as compared to today...but will still top off in the upper
80s to around 90 with surface dewpoints in the low to middle 60s. Better
chance for sea breeze development at the coasts on Tuesday as surface
winds will be light during the day. The heat index should remain
below 95 on Tuesday in NYC.
Long term /Wednesday through Sunday/...
late Summer heat and humidity will be replaced by cooler temperatures
Friday through Sunday.
Wednesday through early Thursday...late Summer heat and humidity
will continue as air quality decreases under a stagnant dome of
high pressure. Temperatures will average at least 10 degrees
above normal. Although not in the latest forecast...can not rule out an
isolated thunderstorm Wednesday afternoon and evening with the development of a day time
Day time highs will be in the lower 90s both Wednesday and Thursday with heat
index values approaching 95 degrees across NYC and urban NE New Jersey.
Late Thursday-early Friday...a stronger back door cold front is forecast
to provide some relief initially in the form of widely scattered thunderstorms
mainly Thursday afternoon - evening. Forecast a pop of 20 percent...which may need to be
increased in later forecasts.
Late Friday through Sunday...maritime polar air on east winds replaces
the maritime tropical air mass with cooler temperatures.
Drought will continue to develop region wide...but especially
across Long Island and southern CT through the period with no
significant widespread rainfall in the forecast.
Aviation /18z Monday through Saturday/...
a weak trough of low pressure remains in the vicinity of the
terminals into this evening. A few showers will be possible across
the lower Hudson Valley through 00z. A back door cold front moves
through the terminals 06z to 11z...then moves northeast as a warm
front Tuesday morning.
VFR conditions through the forecast. A brief period of MVFR fog is
possible at kswf late tonight.
This afternoon into early this evening wind will be from the west to
southwest...around 10 knots. Occasional gusts into the upper teens are
possible at the NYC terminals.
Afterward the wind forecast becomes more uncertain with the timing
of the back door cold front...and the shift to the north. Wind could
even be light and variable. Sea breeze development likely Tuesday by
... 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 confidence in wind forecast. Sea
breeze likely remains south. Occasional gusts up to 20 knots this
Klga fcster comments: no unscheduled amendments expected. Occasional
gusts up to 20 knots this afternoon.
Kewr fcster comments: no unscheduled amendments expected. Occasional
gusts up to 20 knots this afternoon.
The afternoon kewr haze potential forecast is green...which implies
slant range visibility 7sm or greater outside of cloud.
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 Saturday...
Tuesday afternoon-Wednesday night...VFR. Afternoon sea breezes
Thursday-Thursday night...VFR. Isolated showers/thunderstorms
possible. Afternoon sea breezes probable.
Friday...VFR. East-northeast winds g15-20kt.
SW pressure gradient tightens today between an approaching back door
cold front and surface high pressure off the mid-Atlantic. Winds and seas
should remain below Small Craft Advisory/Small Craft Advisory levels on all
waters... but seas may briefly build to 5 feet on the central and
eastern ocean waters this afternoon.
Otherwise...conds will remain below Small Craft Advisory conds through Thursday.
Late Thursday-Thursday night...widely scattered thunderstorms possible ahead of an
approaching cold front.
Friday...the next chance for Small Craft Advisory level winds and
seas will occur as winds shift from the east at 15-20 knots following
the passage of a cold front as high pressure moves east across New
Thursday afternoon-early Friday...widely scattered thunderstorms possible ahead of
approaching cold front with less than 1/4 inch rain.
No widespread significant rainfall is forecast through next
near term...British Columbia