Scientific Forecaster Discussion
fxus61 kokx 222107 cca
Area forecast discussion...corrected
National Weather Service New York New York
507 PM EDT Fri Sep 22 2017
Post tropical cyclone Jose will meander and weaken to the southeast
of Long Island through Saturday night as high pressure remains
centered over the eastern Great Lakes, and extends into the
northeast, into the beginning of next week. Meanwhile,
Hurricane Maria tracks well offshore of the East Coast. A cold
front passes through the region Wednesday night into Thursday.
High pressure builds to the northwest next Friday. Please refer
to National Hurricane Center products for more details on Jose
Near term /until 6 am Saturday morning/...
upper levels still exhibit the persistent pattern of a strong
high amplitude ridge across the eastern US. Upper jet remains
displaced well north into interior southeast Canada.
For tonight, the weakening Post tropical cyclone Jose will keep
clouds and some occasional light showers across parts of Long
Island and southeast Connecticut. Otherwise, mainly dry
conditions are expected. Northerly winds will still be gusty at
times through the evening and just remain gusty at the coast
A combination of mav/met/nam12/gmos was used for min
temperatures tonight. Lowered an extra degree for far western
parts of the region, interior northeast New Jersey and western parts of
lower Hudson Valley and increased an extra degree for eastern
Long Island and southeast Connecticut. Looking at a range from
the upper 50s to upper 60s.
Short term /6 am Saturday morning through Saturday night/...
upper levels still exhibit the persistent pattern of a strong
high amplitude ridge across the eastern US Saturday and Saturday
night. Upper jet remains displaced well north into interior southeast
For Saturday, high pressure will approach closer to the region
and along with it, bring an increase in subsidence. Jose is
forecast to further weaken.
A dry day is forecast with more sun as clouds will be less than
the prior day. The pressure gradient will further decrease
across the area. Northerly winds will lower as a result.
The warmer mav was preferred for temperatures due to recent
better performance. A combination of mav and gmos was used for
Max temperatures, yielding a range from the upper 70s to upper
For Saturday night, high pressure builds in a little more with
continued subsidence. Further weakening of Jose will create an
even weaker pressure gradient with winds likewise diminishing.
Radiational cooling will result in lower minimum temperatures
Saturday night. Used relatively cooler met guidance for Saturday
Long term /Sunday through Friday/...
the longwave pattern will continue to be highly amplified with a
strong upper ridge over the eastern states, with a trough across the
western states, that will remain in place through the beginning of
next week with dry conditions and temperatures above seasonal
normals. There is a possibility of tying or breaking record highs
for Sunday. See the climate section for more information. Meanwhile,
Hurricane Maria will track slowly North, East of the eastern
Seaboard, then northeast through most of the upcoming week as Post
tropical Jose remains southeast of Cape Cod and dissipates Sunday.
Refer to the latest advisories from the National Hurricane Center
for the latest forecast information on Jose and Maria.
The longwave pattern will transition mid to late next week as a
trough digs into the northern plains and Great Lakes region and then
moves east as the eastern ridge weakens. This will bring an end to
the above normal temperatures. A cold front is expected to cross the
area Wednesday night into Thursday. There is some uncertainty with
the timing of the digging trough and the cold front crossing the
area. However, there will be little moisture accompanying the front
and portions of the region may be brushed with the outer bands of
showers from Maria late in the week. So, will have mainly slight
chance probabilities Wednesday night into Thursday.
Weak ridging begins to build to the west Thursday into next Friday.
Due to long period swells from both Jose and Maria, there will be a
prolonged period of rough surf at the ocean beaches, with the
likelihood of a high risk of rip currents.
Aviation /20z Friday through Wednesday/...
Jose will meander off the southern New England coast thru Sat.
Generally VFR thru the taf period. Pockets of MVFR at kgon thru 10-
12z with cigs around 2000 ft at times.
North winds thru the taf period. Gusts will diminish tngt, especially
away from the shore. Winds on Sat in the 10-20 kt range.
..NY Metro enhanced aviation weather support...
Detailed information, including hourly taf wind component forecasts,
can be found at: http:/www.Weather.Gov/zny/n90
Kjfk taf comments: no unscheduled amendments are expected.
Klga taf comments: no unscheduled amendments are expected.
Kewr taf comments: winds could back to around 330-340 true at times
Kteb taf comments: gusts may only be ocnl thru 00z.
Khpn taf comments: no unscheduled amendments are expected.
Kisp taf comments: a stray sprinkle is possible thru 00z.
Outlook for 18z Saturday through Wednesday...
rest of Sat...VFR with N flow.
Sun...VFR with N flow.
Mon...VFR with NE flow.
Tue-Wed...MVFR possible with E flow.
Small Craft Advisory conditions remain on all waters except the western Long
Island Sound and New York Harbor through 6pm. Then, Small Craft Advisory conditions
will be primarily across the ocean and eastern Long Island Sound
and eastern Long Island bays for tonight. Small Craft Advisory conditions
gradually trend down after tonight with just the ocean having
Small Craft Advisory conditions Saturday. By Saturday night, ocean still has Small Craft Advisory
but at during that time, it is primarily due to seas being
mostly dependent on the long period swell. Winds gradually
diminish Saturday and Saturday night with the decrease in
Long period swells are expected to remain on the ocean waters Sunday
through the upcoming week, and a Small Craft Advisory will likely be
needed through the period. Across the remainder of the waters winds
and gusts are expected to remain below advisory levels Sunday
through Wednesday night. Gusts behind a cold front late Thursday and
Thursday night may reach small craft levels across all the forecast
no hydrologic problems anticipated through the end of next week.
Post tropical cyclone Jose will remain nearly stationary a
couple hundred miles southeast of eastern Long Island, with ekman
forcing keeping elevated water levels along the coast despite
Water levels should gradually drop tonight into the weekend.
Historically, guidance is too fast to bring down water levels
in the Back Shore bays when there is a persistent onshore long
period swell, so have continued the coastal flood advisory from
Brooklyn through southwest Suffolk County through tonights high
tide. There is some potential that there could be some very ,
localized minor flooding at the most vulnerable South Shore Bay
locales Saturday morning. This threat can be addressed with a
coastal flood statement if it looks like this threat will be
Rough surf will also continue into the weekend, but dune
erosion from this point on should be localized.
the following are record high temperatures for Sunday
September 24, 2017 along with the forecast high temperature.
Record high temperature forecast high temperature
Central Park........89 (1959) 89
LaGuardia...........89 (1959) 88
Kennedy.............88 (1970) 87
Islip...............83 (2009) 86
Newark..............92 (1959) 90
Bridgeport..........87 (1959) 84
The following are record maximum minimum temperatures for Sunday
September 24, 2017 along with the forecast minimum temperature.
Record Max minimum temperature forecast minimum temperature
Central Park........74 (1970) 70
LaGuardia...........73 (1970) 71
Kennedy.............71 (1970) 69
Islip...............69 (1970) 65
Newark..............74 (1970) 68
Bridgeport..........71 (2011) 66
New York...high rip current risk until 7 PM EDT this evening for nyz075-
Coastal flood advisory until 4 am EDT Saturday for nyz075-080-
Marine...Small Craft Advisory until 6 am EDT Saturday for anz330-340.
Small Craft Advisory until 6 am EDT Sunday for anz350-353-355.
Small Craft Advisory until 6 PM EDT this evening for anz345.