000
FXUS61 KOKX 211836
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
236 PM EDT Wed Jun 21 2023
.SYNOPSIS...
High pressure remains over New England today before shifting
east into the Atlantic on Thursday ahead of an incoming warm
front. A weak frontal system over the Ohio Valley and the Mid
Atlantic tracks slowly northward Friday and then remains in the
area through the weekend. Another, deeper, frontal system
approaches from the Great Lakes Monday with a cold front passing
through the area Tuesday.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Strong ridging over the Upper Midwest begins to build east
today, with a 1028 mb surface high remaining situated over
northern New England. Meanwhile, a cutoff low continues to
meander over the Southeast, with the local region sandwiched in
between these features.
Breezy conditions today as the easterly flow increases between
the New England high and approaching mid Atlantic low pressure
wave. A modest 15-20 mph with gusts 25-30 mph. The strongest
winds will be along the coast where a few gusts up to 35 mph are
possible.
Increasing high and mid cloud cover from south to north can be
expected as the frontal wave begins to track northward into the
Mid Atlantic this evening. The high pressure both aloft and the
surface will create subsidence and prevent any precipitation
from making it this far north today. Clouds thicken further
tonight ahead of an approaching warm front, with showers
developing for southern areas by daybreak or so Thursday.
Highs will continue below normal for this time of year in the
low to mid 70s. Lows tonight will range from the lower 50s
inland, to around 60 in the urban metro.-- End Changed Discussion --
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
Surface high pressure shifts farther east into the Atlantic on
Thursday as a warm front lifts north toward the region.
Hi-res CAMs indicate a band of rain developing ahead of this and
eventually overspreading the region from south to north. The
departing high and ridging aloft will try to impede this however,
slowing its progression as the rain runs into a much drier and
more stable environment. Significant mid level dry air will
have to be overcome, which may take into the afternoon hours for
parts of the northern interior to saturate. While the rain is
expected to weaken, if not dissipate as it moves farther inland,
guidance indicates additional shortwave energy moving around
the cutoff low Thursday night, potentially bringing another
round of showers.
The 00z HREF paints a general 0.25" to 0.75" across NYC and Long
Island through Thursday night, with less than a quarter inch into
interior CT and the Lower Hudson Valley. Fortunately, rates do
not appear to rise to a level of concern, though some brief
minor flooding may be possible in any locally heavy downpours.
The rain and clouds will limit surface heating on Thursday, with
little diurnal variation in temperatures expected. Highs for most
top out in the upper 60s, about 10 to 15 degrees below normal, and
remain in the 60s overnight into Friday morning. With subtle
adjustments, followed a combination of national blended guidance
and the super blend for this update.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
The long term will continue to be characterized by a nearly blocked
pattern, atypical of mid-June for this part of the country, as an
upper ridge remains over the western Atlantic.
A cutoff low over the Southeast US will be opening into a longwave
trough Friday and then moves slowly through the region through
Sunday. Another upper rough moves out of Canada into the Great Lakes
region for the beginning of next week. Weak surface low pressure to
the south of the region Thursday will move into the area Friday and
remain into the weekend. Then another, deeper, surface low moves
slowly through the Great Lakes with a cold front moving through
Tuesday. A portion of northeastern New Jersey and the lower HUdson
Valley are in a marginal risk for excessive rainfall Friday and
Saturday with periods of moderate rainfall possible with warm cloud
processes dominating. However, there is uncertainty if flash flood
guidance will be exceeded as the NBM is indicating low chances for
rainfall rates exceeding 2 to 3 inches in 3 and 6 hours.
Temperatures Friday into the beginning of next week will be near
normal levels as a warm and humid airmass remains, with dew points
in the mid 60s, and at times near 70 across inland locations.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
-- Changed Discussion --
High pressure anchored off the New England coast will drift
eastward as low pressure and an attendant warm front lift
northward into the Mid Atlantic region.
In between these two systems, E winds have increased to 15-20
kt with infrequent gusts to 20-25 kt at terminals closest to the
coast, while inland terminals are mostly sustained 10-15 kt
with gusts mostly just under 20 kt. Winds should diminish a
little toward evening, then back more to the NE and increase
again to these same values late tonight and continue into Thu
morning, with gusts more frequent than has been the case today
so far.
Rain will be moving in late tonight into Thu morning as well,
reaching the NYC metros and Long Island some time between
06Z-09Z, and KSWF/CT terminals by 12Z-13Z. MVFR cond should hold
off for a couple of hours, mostly not coming in til daybreak. An
axis of heavier rainfall may develop and bring IFR cond to KISP/KBDR
by afternoon.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
No unscheduled AMD expected.
OUTLOOK FOR 18Z THURSDAY THROUGH SUNDAY...
Thursday afternoon: Showers. MVFR expected, IFR possible. E
winds G15-25kt along the coast.
Friday through Monday: Showers/MVFR likely, with chance of
tstms/IFR. Best chance for tstms will be from the NYC metros
north/west each afternoon and evening.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
SCA gusts expected to continue on all waters today, and likely
into Thursday morning, with tight easterly gradient between mid
Atlantic low and slowly departing New England high. SCA was
expanded to all water this morning. Ideal fetch for seas to
build to 3 to 5 on LI Sound and 6 to 9 ft on the ocean. Winds
gradually subside below SCA late Thu into Thu night, with ocean
seas gradually following suit.
Winds and seas are expected to remain below SCA levels Friday and
Saturday as weak low pressure remains in the vicinity. Ocean seas
may be near or over SCA levels Sunday into Monday evening with a
persistent southerly flow that increases Monday, and in addition
long period SE swells will be affecting the waters.
&&
.HYDROLOGY...
No hydrologic concerns through Thursday night.
The Weather Prediction Center has placed western sections of the
forecast area (the Lower Hudson Valley and northeastern New Jersey)
in a marginal risk of excessive rainfall for Friday and Saturday. As
a more humid air mass moves into the region precipitable waters
values will be increasing to around 1.75 to just over 2 inches.
There is a chance that areas in the marginal risk could see up to
2.00" of rainfall in a short period of time as warm cloud processes
dominate. However, there is a great deal of uncertainty with the
movement of the upper and surface lows that will affect rainfall
rates. Even if flash flooding does not occur, widespread nuisance
flooding remains possible with flooding of urban areas and low lying
and poor drainage areas.
&&
.TIDES/COASTAL FLOODING...
There is a high risk of rip current development for all ocean
beaches today and Thursday with building easterly wind swell.
Breaking surf likely builds to 5 to 7 ft with a strong e to w
longshore component, which will likely also enhance beach
erosion.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None.
NY...High Rip Current Risk through Thursday evening for NYZ075-080-
081-178-179.
NJ...None.
MARINE...Small Craft Advisory until 8 PM EDT Thursday for ANZ331-332-
335-338-340-345.
Small Craft Advisory until 8 AM EDT Friday for ANZ350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...DR/MET
NEAR TERM...NV
SHORT TERM...DR
LONG TERM...MET
AVIATION...BG
MARINE...NV
HYDROLOGY...DR/MET
TIDES/COASTAL FLOODING...