000
FXUS61 KOKX 181132
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
732 AM EDT Thu May 18 2023
.SYNOPSIS...
High pressure settles over the area today before moving offshore
tonight into Friday. Weak low pressure affects the area Saturday
into Saturday night. A cold front moves through Sunday into
Sunday night. High pressure builds in for the beginning of next
week and remains in place through the middle of next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
Letting the Freeze Warning continue until 8 am for all zones, as a
few zones have been hovering right at 33 degrees or so. It really
doesn`t pay to discontinue at this point as all the zones that have
a Freeze Warning are at least close enough to freezing to warrant it
to continue until 8 AM.
After a rather chilly start temps start to moderate quickly towards
mid morning as high pressure moves overhead. Expect plenty of
sunshine today with synoptic scale sinking motion in place. As the
high builds further east for later this afternoon look for a SE-S
flow to get going. This will keep eastern areas cooler into the
afternoon. Highs should range from primarily the middle 60s inland
to the west, with mainly lower 60s and a few upper 50s for coastal
locations. The southerly flow continues tonight and with mainly
clear skies it will be another chilly night, just not quite as
chilly as this past night. Lows will range mainly in the lower and
middle 40s, with some lower 50s in the NYC metro as this
unseasonably dry air mass moderates.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
During Friday looks for a few more clouds, but skies should still
average out to be mostly to partly sunny. More clouds attempt to
move up from the south late in the day but the daytime should remain
dry. With a deeper return flow as the high gets well offshore look
for temperatures to reach around 70 inland to the west, with mostly
lower and middle 60s elsewhere.
For Friday night moisture begins to move up along the coast, mainly
after midnight. At the same time a cold front transverses the Ohio
Valley. With the area under a return flow mainly out of the south
look for increasing lower level moisture and clouds as per the NAM
and HRWFV3 fx soundings. Towards and after 6z Sat bring in chance
PoPs from south to north across the area. This may be a little fast,
but did not want to totally discount the GFS based solution(s) at
this point.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
An upper trough tracking across the Great Lakes Friday and into the
Northeast on Saturday will send a cold front toward the region. At
the same time, a frontal wave forming along an old coastal front
along the southeast coast on Friday, will track north along the
eastern seaboard ahead of the digging upper trough. Model
differences hinge on how quickly the upper trough closes off. The
GFS is the most progressive and quickest of the global models,
sending the front through much of the area by midnight Saturday. The
Canadian and ECMWF are closer to a frontal passage around daybreak.
This will also impact how far west the axis of heaviest rainfall
tracks with the frontal wave preceding the cold front on Saturday.
The GFS has shifted more west with the frontal wave, more in line
with the ECMWF and Canadian. Right now, staying fairly close to the
NBM/WPC QPF, the heaviest rains look to be across far eastern LI and
SE CT on Saturday, dropping off quickly to the west due to a sharp
gradient. Capped POPs at likely right now. Although there is high
confidence that it will rain Saturday into Saturday night, there
still remain uncertainty in when and where. There will likely be
some west/east shift of this axis over the next couple of days.
Rainfall amounts currently range from a half inch far west suburbs,
to around an inch and a third far east sections.
Following the cold frontal passage, the rain should come to an end
for most areas by daybreak Sunday, except for some lingering showers
in the morning, mainly for eastern areas. Once gain though, this
will depend on any timing changes with the upper trough/closed low.
In addition, there is marginal instability with warm, moist air
being pulled up ahead of the coastal low in a S/SE flow. Thus, there
is low chance for convection, but confidence was not high enough to
put thunder in the forecast.
Thereafter, strong high pressure builds in from the west through
the middle of next week with dry, nearly seasonable weather.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
High pressure builds over the area tonight and slides east today
afternoon through tonight.
VFR.
NE winds this morning quickly shift to the E and then SE before
sea breezes develop by late this morning into early this
afternoon, shifting winds to the S. Winds at a few locations
may even briefly become light and variable before the sea breeze
develops. Moderate confidence with the timing of the sea
breezes. Winds remain southerly through this evening, but
diminish to less than 10 kt by around sunset. Some outlying
terminals may once again become light and variable this evening.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Moderate confidence with the timing of sea breezes moving through
the terminals late morning into the afternoon.
OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
Friday: Mainly VFR. MVFR ceilings possible for KSWF early
Friday morning
Saturday: Chance of MVFR or lower in rain/showers
Sunday: Chance MVFR/showers early, then VFR.
Monday: VFR.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
High pressure settles over the waters today. This yields a light
pressure gradient, at least initially. The high then moves east and
a return flow primarily out of the south begins late today and
continues into tonight and Friday. Some gusts will likely approach
20 kts out on the western ocean and some of the near shore waters
Friday afternoon and early evening, but at this time it appears that
conditions fall short of small craft with respect to winds and seas.
For Friday night a prevailing SE wind should result in marginal
small craft gusts at times.
Waves on the ocean water build in response to a strengthening S to
SE flow ahead of coastal low, with 4-7 ft seas possible by late
Saturday morning into Saturday afternoon. Waves diminish late
Saturday night into Sunday afternoon. Conditions fall below SCA
Sunday night. High pressure builds in from the NW early next week
with sub-SCA conditions.
&&
.HYDROLOGY...
There are no hydrologic concerns through the forecast period.
&&
.CLIMATE...
The following are record low temperatures for Today, May 18th. New
records have been recorded for JFK, BDR, and ISP. Please see the
Record Event Reports (RER) for further details.
Record Minimum Temperatures for Today, May 18th
-------------------------------------------------
Central Park........41 (1973)
LaGuardia...........44 (2002,1973)
Kennedy.............42 (2003,1973)
Islip...............38 (2003,1973)
Newark..............43 (2003,1983,1955)
Bridgeport..........41 (1984,1983)
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Freeze Warning until 8 AM EDT this morning for CTZ005-006-008-
012.
NY...Freeze Warning until 8 AM EDT this morning for NYZ067>070-079-
081.
NJ...Freeze Warning until 8 AM EDT this morning for NJZ002.
MARINE...None.
&&
$$
SYNOPSIS...JE/JP
NEAR TERM...JE
SHORT TERM...JE
LONG TERM...JP
AVIATION...JP
MARINE...JE/JP
HYDROLOGY...JE/JP
CLIMATE...