000
FXUS61 KOKX 201623
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1223 PM EDT Sat Apr 20 2019
.SYNOPSIS...
Low pressure slowly approaches from the west this afternoon and
tonight. This slow moving system does not exit until the
beginning of next week. A cold frontal passage is expected
during the middle of next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
Tracking band of showers extending from central and eastern CT
southward over the western Atlantic. Expect this band to
continue to move slowly east, and possibly weaken as it shifts
away from upper weakening low and as llj moves east this
afternoon. Will maintain the Flash Flood Watch for eastern
locations, but cancel across the western half of the CWA. Cannot
rule out a few showers over western zones, drier air should
preclude any heavy or prolonged rain.
Temps rise through the 60s, but any breaks could result in
higher readings into the 70s away from the coast, and onshore
flow (mainly west of the Hudson River).
Although there could be some lingering showers tngt,
particularly ern LI and CT, the core of the lljet will be e of
the area, taking the flood threat with it. No changes to the
timing of the watch have been made as a result.
&&
.SHORT TERM /SUNDAY/...
The upr low will be making a slow approach on Easter. With the
lljet pcpn east of the cwa, this could allow for a dry mrng. As
temps rise thru the day however, lapse rates will increase,
particularly west of the coastal areas. This could allow for
some isold-sct shwrs to develop. There is a high amount of
uncertainty though even at this short of a time range, as the
upr low track and embedded waves will be capable of producing
pcpn at any time if the dynamics are strong enough. As a result,
chance pops have been retained in the fcst. The Superblend was
used for temps.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Early in the period the upper level portion of the storm that
impacts the region in the near and short term portion of the
forecast will be over the region. Looking for a general shower
chance to begin the period with a closed upper level feature which
is progged to gradually fill, weaken, and lift out by Monday night.
Until then thought it best to keep general shower chance across much
of the CWA. With the upper level low over the area and some
instability present cannot rule out an isolated thunderstorm later
in the day on Monday, especially with any breaks of sun. In the wake
of the departing upper level system a brief period of soft ridging
will attempt to work in for late Monday night and into the day on
Tuesday. The thinking for Tuesday is to keep the region generally
dry with good agreement among the global models on timing.
The next system is progged to approach during Tuesday night and
early Wednesday. There could be enough energy aloft and enough low
level moisture to at least bring a period of chance showers to the
region for Tuesday night into Wednesday morning. There may be enough
instability depending on timing / time of day on Wednesday that a
thunderstorm or thundershower cannot be ruled out. Most of the
modeling has been consistent with the timing of this feature, with
the German ICON model having a few runs with precip hanging in for a
part of Thursday. This is at odds for the most part with the other
global deterministic models and mass fields, therefore will keep
Thursday dry for now with high pressure building in. WPC discussion
does however point out uncertainty next week with individual
shortwaves tracking across the Midwest into the Northeast. This has
lead to variability among the various global ensemble suites. So
confidence is lower than desired for later next week. For now have
leaned towards high pressure being in control by late Wednesday or
Wednesday night through much of Friday as the NAEFS 500 mb forecast
suggests an increase in progression with the northern branch.
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
Low pressure slowly approaches from the west through this
evening. Widespread IFR/MVFR ceilings and low-level wind shear
will continue into the early afternoon. Some improvement to VFR
is still anticipated this afternoon, but could be delayed a few
hours from forecast.
A strong low-level jet across the area will result in LLWS with
winds of 45 to 65 kt at 1500-2000 ft, strongest NYC and east. S
winds at the surface of 15-20kt with G25-35kt. Gusts may be less
frequent away from the coast.
Band of showers has pushed east of NYC terminals and will
continue moving across Long Island and southern Connecticut
through early afternoon. This band of rain should be east of the
entire area by 21z, but few showers cannot be ruled out at any
location this afternoon and evening.
.OUTLOOK FOR 12Z SUNDAY THROUGH WEDNESDAY...
.Sunday-Monday...MVFR or lower in a chance of showers.
.Tuesday...VFR. Slight chance of showers late in the afternoon.
.Wednesday...MVFR or lower possible in showers.
&&
.MARINE...
As showers weaken, and llj moves east, expect any lingering gale
gusts to be too infrequent to continue the Gale Warning. All
waters have been converted to SCA, with ocean waters extended
through Sunday night, mainly for seas. Non ocean waters will
only see 25 kt or SCA criteria gusts this afternoon.
Southerly flow diminishes tonight into Sunday as low pressure
weakens as it approaches the waters. With the diminished flow with
low pressure over the coastal waters a period of patchy fog may
occur for late tonight into early Sunday morning. Seas will remain
up on the ocean waters due to a south to southeasterly swell,
therefore SCA conditions will continue through the weekend and into
early next week on the ocean waters. Meanwhile, sub SCA conditions
are expected for the non-ocean waters through the early part of next
week. Sub SCA conditions may finally return by Tuesday afternoon on
the ocean waters as seas subside below 5 ft.
&&
.HYDROLOGY...
Rain continues to weaken and shift east. Flash Flood Watch only
remains in effect from New Haven CT east, and Suffolk County NY.
Otherwise, no hydrologic impacts are expected for the second
half of the weekend into the end of next week.
&&
.TIDES/COASTAL FLOODING...
Based on latest trends and guidance, only expect tides to
approach or reach minor coastal thresholds for the vulnerable
locations of southern Nassau and southern Queens, the western S
shore back bays. Persistent swell and rough seas along with SE
winds should continue to pile water into these bays. Issued a
coastal flood statement for this upcoming high tide.
&&
.EQUIPMENT...
NYC NOAA Weather Radio Station KWO35 (162.55 MHz) remains off
the air.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Flash Flood Watch until 8 PM EDT this evening for CTZ006>008-
010>012.
NY...Flash Flood Watch until 8 PM EDT this evening for NYZ078>081.
NJ...None.
MARINE...Small Craft Advisory until 6 PM EDT this evening for ANZ330-
335-338-340-345.
Small Craft Advisory until 6 AM EDT Monday for ANZ350-353-355.
&&
$$
SYNOPSIS...12/PW
NEAR TERM...12/PW
SHORT TERM...12
LONG TERM...JE
AVIATION...BC/DS
MARINE...BC/PW
HYDROLOGY...12
TIDES/COASTAL FLOODING...PW
EQUIPMENT...
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