000
FXUS61 KOKX 301937
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
337 PM EDT Sun Apr 30 2023
.SYNOPSIS...
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Deepening low pressure to the south moves over the area tonight. The
low then meanders over the Great Lakes Monday before slowing moving
over the northeast through the middle of the week. An upper level
trough then lingers over the area through the end of the week. High
pressure begins to build in over the weekend.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
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Widespread rain over much of the area continues through this evening
as a deepening low pressure system moves up the East Coast and over
the area through tonight. The intensity of the rain is expected to
increase late this afternoon and into this evening as the center of
the low pressure approaches and provides stronger lift over the
area. Cooling in the mid-levels will likely allow for elevated
instability to develop as well which will result in the potential
for embedded thunderstorms in widespread moderate rain.
The bulk of rain is expected to moves through in the 6PM to midnight
timeframe which may bring a half inch per hour rainfall rates at
times. A Flood Watch remains in effect for NE NJ as well as Orange
and Rockland Counties in the Lower Hudson Valley for the potential
of flash flooding this evening with flash flood guidance values of
only 1-2 inches per 3 hours. Any area not in the Flood Watch is
expecting mainly nuisance or minor street flooding but a flash flood
is not completely ruled out. An additional 1 to 1.5 inches of
rainfall is expected tonight but locally up to 2 inches is possible
in any area with more persistent heavier rainfall.
The low pressure pushes the precipitation north of the area with the
center of the low moving over the area after midnight. Much of
the area will dry out by 2-5AM.-- End Changed Discussion --
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
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The low pressure that impacts the area moves north and becomes
absorbed in a larger low pressure over the Great Lakes which
continues to spin over the area on Monday. Much of Monday morning
and early afternoon is expected to be fairly dry as we remain dry
slotted by the main low. With cooler mid-levels, instability showers
may develop into the afternoon, especially for areas to the west.
Highs on Monday are expected to be in the upper 50s to near 60.
As waves of energy spin around the backside of the low pressure,
another round of rain showers is possible for the area into Monday
evening and overnight, though coverage and timing are uncertain at
this time.-- End Changed Discussion --
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
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No significant changes were made to the extended period. Large and
anomalous upper closed low will move over the northeast on Tuesday.
Showers should be ongoing to start the day on Tuesday as more
organized energy and positive vorticity advection occur as the upper
low settles overhead. There may also be some afternoon and early
evening shower development if any breaks in the clouds can form.
This would steepen lapse rates and could support some low topped
convection with perhaps some small hail. NBM probabilities for
thunder are under 15 percent for Tuesday afternoon. Have continued
to leave out mention of thunder, but would not be surprised to see a
trend upward in thunder probabilities if more heating is realized.
Freezing levels are also quite low around 5 kft Tuesday afternoon.
Highs on Tuesday will only be in the 50s, several degrees below
normal for this time of year.
Little change is expected with the upper low on Wednesday as it is
progged to meander over the northeast. Showers and potentially low
topped convection should develop in the afternoon with steepening
lapse rates with the cold pool aloft. Any enhanced convection could
produce some thunder and perhaps some small hail. Subsequent
forecasts may need to add a chance of thunder if probabilities
increase. Highs again will only be in the 50s.
The upper low moves off the New England coast on Thursday, but upper
level troughing and low heights remain into the end of the week.
While probabilities are lower, a few showers remain possible,
especially in the afternoon each day. Temperatures may be slightly
higher to end the week, but still below normal in the upper 50s to
near 60 degrees.
High pressure then attempts to build in from the west over the
weekend as ridging builds over the Midwest. This should result in
drier conditions, and a warming trend. NBM temperatures on Sunday
have the region reaching 65-70 for highs.-- End Changed Discussion --
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
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Deepening low pressure over the mid Atlantic moves northeast,
passing over the terminals this evening, and then tracking to the
north late tonight. The low remains to the northwest through Monday.
IFR, and locally LIFR, continues into late tonight, before improving
to MVFR, and then becoming VFR Monday morning. Timing of the
improvements will be dependent on the track of low pressure through
the region.
Light rain, with periods of moderate to locally heavy rainfall
late afternoon into the early evening, continues into late
tonight, ending as low pressure tracks north. Isolated
thunderstorms are still possible, and may be an hour or two
later than currently in the forecast, and confidence is low with
areal coverage and timing.
Winds remain NE to E, briefly becoming SE to S early this
evening along the coast before becoming W to SW with the passage
of the low. Inland wind switch to NW to N, and then NW late
tonight. There will be a brief period of lighter winds as the
center of the low moves over the terminals. Monday winds will
be SW gusting 20-25kt. A brief period of LLWS is possible at
KGON 22Z to 00Z as a low level jet tracks near southeastern
Connecticut.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
High confidence of IFR conditions into late tonight, with low
confidence on the timing and coverage of any convection that
will be possible 22Z to 04Z. Occasional gusts to around 20 kt
possible through early evening.
OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
Monday afternoon and night: VFR. Chance of showers, local MVFR
possible.
Tuesday - Thursday: VFR. Chance of showers, MVFR at times.
Friday: VFR in the morning. Chance of afternoon showers with
MVFR, IFR possible.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
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Small craft conditions are expected for all waters through
Monday morning with gusty E winds tonight to 25-30 kt shifting
to SW by Monday morning. These winds slowly subside below SCA
thresholds by early Monday afternoon. Wave heights will remain
elevated for the ocean and the far Eastern Long Island Sound
where SCAs continue through the evening and into the overnight
Monday Night.
Lingering swells on the ocean will keep seas elevated above 5 ft
Tuesday into Tuesday night. Seas subside on Wednesday with
conditions remaining below SCA levels into the end of the week.-- End Changed Discussion --
&&
.HYDROLOGY...
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A widespread 1.5 to 3 inches of rain that has fallen over the last
few days. An additional 1 to 1.5 inches of rainfall is expected
tonight for much of the area with locally up to 2 inches possible.
This will bring the potential for localized flash flooding in more
susceptible urban areas of NE NJ and portions of the Lower
Hudson Valley. Minor nuisance and street flooding remains
possible elsewhere through this evening and into the first half
of the night.
No hydrologic impacts are expected Monday through next weekend.-- End Changed Discussion --
&&
.TIDES/COASTAL FLOODING...
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No changes to the current coastal flood statements. Any coastal
flooding looks isolated and mainly across the south shore back bays
and SW CT coast along the Western LI Sound. Astronomical tides are
low and a 2 to 3 ft surge is needed for minor coastal flooding.
There may be a timing offset with the strongest winds and higher
surge with deepening low pressure this evening, which will help keep
tides from going over minor flooding levels. Elsewhere, water levels
should remain below minor flooding during the evening high tide.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
NY...Flood Watch until midnight EDT tonight for NYZ067-069.
NJ...Flood Watch until midnight EDT tonight for NJZ002-004-006-
103>108.
MARINE...Small Craft Advisory until noon EDT Monday for ANZ331-335-338-
340-345.
Small Craft Advisory until 8 PM EDT Monday for ANZ332.
Small Craft Advisory until 7 AM EDT Tuesday for ANZ350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...DS/MW
NEAR TERM...MW
SHORT TERM...MW
LONG TERM...DS
AVIATION...MET
MARINE...DS/MW
HYDROLOGY...DS/MW
TIDES/COASTAL FLOODING...