Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus61 kokx 242014 
afdokx

Area forecast discussion
National Weather Service New York New York
414 PM EDT Sat Jun 24 2017

Synopsis...
a series of weak low pressure troughs forming over land each
day will move offshore each night through Tuesday night, while
strong high pressure remains well to the southwest. The high
will eventually build in on Wednesday. A warm front will
approach on Thursday and move through at night. A cold front
approaching from the north on Friday will stall nearby into the
Holiday weekend, with unsettled weather.

&&

Near term /until 6 am Sunday morning/...
a mostly clear night expected after transverse bands of
cirrocumulus drift across late today. Gusty winds will diminish
toward/after sunset, then a weak boundary should move through
late tonight, with light northwest-north winds. Lows tonight should range
from the mid 50s inland/Long Island Pine barrens, to the mid 60s
invof NYC.

A high surf advy and high rip current risk continue into this
evening via incoming long period S swell (6-7 ft/9 sec).

&&

Short term /6 am Sunday morning through Sunday night/...
Sunday should be another mostly sunny and pleasantly warm day,
with highs 75-80. Another weak inland trough/pseudo-cold front
should set up over land, and move offshore at night. As this
takes place, an afternoon sea breeze should give way to stronger
west winds for a while from late day into the evening. Low temps
will be just a touch cooler than those fcst for tonight, ranging
from the lower 50s inland, to lower 60s in/just outside NYC.

&&

Long term /Monday through Saturday/...
looks fairly dry with comfortable humidity and slightly below normal
temperature though mid week. A warm front approaches on Thursday as
low pressure passes across southern Canada. In its wake, a cold
front sags south into New York state on Friday. The front becomes
stationary near the region into the weekend - which appears will
be "unsettled."

Region is in the right rear entrance to a strong 120+ knots polar jet
streak along with surface trof over the Hudson Valley on Monday
afternoon. Fortunately, instability is limited to below 500 hpa -
at least based on sref and GFS. Nwp quantitative precipitation forecast is near zero and have thus
confined any pop to extreme northwest area.

Similar situation on Tuesday with perhaps a tad more instability and
pseudo cold frontal passage. Have a 20 pop for the afternoon.

Wednesday is dry and then warm advection starts in on Thursday.
Frontal boundary in the region, or just north, on Friday and have
pops in for thunderstorms and rain. Looks to remain unsettled through the Holiday
weekend at this time.

Temps come back to near seasonable on Thursday and then go above
Friday into the weekend. No heat issues foreseen though.

&&

Aviation /20z Saturday through Thursday/...
a cold front pushes east of the terminals today. High pressure
builds into the region tonight and Sunday.

All the precipitation has ended across the terminals. VFR for
the remainder of the taf period. Main headline will be the gusty
winds this afternoon. West-northwest winds will gust to 20-25
kt, with some occasional higher gusts possible until 00z or so.
Winds diminish tonight with many locations becoming light and
variable. Seabreezes are expected to develop Sunday late
morning/afternoon.

Outlook for 18z Sunday through Thursday...
Sunday afternoon-Sunday night...VFR. Afternoon sea breezes
expected.
Monday...VFR. Coastal sea breezes expected.
Tuesday...VFR. Isolated thunderstorms and rain north and west of NYC.
Wednesday...VFR.
Thursday...VFR.

&&

Marine...
rough ocean conditions expected into tonight, with northwest near shore
winds gusting to 20-25 kt. The stronger winds appear confined to
around New York Harbor, to the Small Craft Advisory there remains in effect til 8 PM.

Ocean seas running 7-9 ft at the offshore buoys are 1-2 ft above
both wavewatch and nwps, so have extended the Small Craft Advisory there into
Sunday. There could be a brief lull in seas Sunday afternoon
before a tighter pressure gradient ahead of an approaching
trough possibly brings them back to 5 ft. Have held off on
extending Small Craft Advisory that far out in time to see if the 1-2 ft anomaly
between observed and model forecast seas continues into Sunday.

For the longer term...tranquil on Monday and continuing through
Thursday morning. Ocean seas will likely build to Small Craft Advisory criteria
late Thursday and continue as such on Friday.

&&

Hydrology...
see public information statement for area rainfall reports from
this morning's heavy rain.

No hydrologic impacts expected Sunday and through at least the
end of next week.

&&

Tides/coastal flooding...
astronomical tides are running very high, especially during the
evening high tide cycles.

Northwest flow has pushed enough water away from most susceptible
locations to keep water levels tonight below flood benchmarks.
This does not look for the be the case however for the Nassau
South Shore bays, where water levels should briefly touch or
barely exceed minor thresholds early this evening, from 8-10 PM.

&&

Equipment...

* the kokx Doppler weather radar (wsr-88d) remains unavailable
due to required maintenance. The radar could return to
service as early as Sunday.

* Surface observations from kfrg (farmingdale, ny) are not
available. Observations from khpn (white plains, New York and khvn
(new Haven,ct) are being disseminated through backup methods.
All is due to an FAA communication line outage. Return to
service time is unknown.

&&

Okx watches/warnings/advisories...
CT...none.
New York...high rip current risk until 9 PM EDT this evening for nyz080-
081.
High surf advisory until 9 PM EDT this evening for nyz080-081.
New Jersey...none.
Marine...Small Craft Advisory until 8 PM EDT this evening for anz338.
Small Craft Advisory until 6 am EDT Sunday for anz355.
Small Craft Advisory until 2 PM EDT Sunday for anz350.
Small Craft Advisory until 11 am EDT Sunday for anz353.

&&

$$
Synopsis...Goodman/tongue
near term...Goodman
short term...Goodman
long term...tongue
aviation...British Columbia

National Weather Service Glossary of Abbreviations