000
FXUS61 KOKX 201947
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
347 PM EDT Sat May 20 2023
.SYNOPSIS...
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Low pressure approaches along the coast and passes through the
region this evening. Meanwhile, a cold front approaches from
the west and moves through tonight. High pressure builds to the
west Sunday. A pair of cold fronts swings through from the
northwest on Monday and late Wednesday into early Thursday,
otherwise high pressure will be in control through the week.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
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A coastal low will push a weak warm front north across the area
through this evening. PWAT values up around 2 inches will
result in periods of moderate to heavy rainfall, mostly across
NYC and east. Rainfall rates are expected to be 1/2 to 3/4
inches per hour, however, there may be brief periods when rates
could be near 1 inch per hour this evening.
Meanwhile a cold front draped across western PA will approach the
western areas by 00Z Sunday, then cross the area by 06Z Sunday. As
the front and weak coastal low slowly shift east through
tonight rain chances decrease with the moderate and heavy rain
coming to an end from west to east. By 12Z Sunday the
precipitation should be east of the area as the cold front
passes to the east.
Temperatures tonight will be in the low to mid 50s.-- End Changed Discussion --
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
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A large scale upper trough will remain over the northeast and
eastern Canada Sunday and Sunday night as surface high pressure
builds to the west, with the center of high pressure to the
north. Clearing is expected as weak subsidence increases.
High temperatures Sunday will be near seasonal levels, in the
lower 70s.-- End Changed Discussion --
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
A cold front should be getting offshore on Monday, with high
pressure in control for much of the upcoming week. A second cold
front is progged to come down from the northwest towards Wed night.
At this time it appears there will be no sensible wx with this
feature as well with shower activity likely staying north of the
area. High pressure will follow once again for the late week period.
Went with a consensus approach with regard to temps throughout. A
pair of dry cP air masses with fairly low dew points should lead to
a strong diurnal curve throughout. Night time temps are expected to
be around normal, with day time temps anticipated to be near to
slightly above normal. Inland locations will experience warmer
temperatures overall compared to coastal locations, in line with the
time of year. The question is whether temps may actually be cooler
than currently progged for Thursday and Thursday night behind a cold
front. Current thinking has the air mass modifying quite a bit as it
presses south, therefore stayed close to the NBM with the NBM
deterministic being on the lower end of the member spread.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
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Low pressure along the Mid Atlantic coast slowly moves
northward along the eastern seaboard today. The low and its
associated coastal front will move across the area, followed by
a cold frontal passage tonight. High pressure starts to build in
from the west on Sunday.
LIFR to IFR conditions in areas of rain. Some of the rain may be
locally heavy at times. An isolated thunderstorm is possible, mainly
east of NYC, during the evening hours, however confidence is too low
to include in the TAF. Coastal terminals could see some visibilities
fall to a half mile or less. Conditions improve to VFR tonight after
06z from west to east with the passage of a cold front.
E/SE winds this gradually veer towards the south then southwest and
eventually become northwest behind the cold front overnight. Winds
speeds will generally remain 10kt or less, however tomorrow
afternoon, some of the terminals could see some higher winds, closer
to 12-14kt, with some gusts into the upper teens. LLWS remains a
possibility at KGON for late this afternoon and evening.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
High confidence of IFR or lower conditions through 06z.
Amendments possible for changing wind directions.
Low chance of a thunderstorm this afternoon and early this
evening.
OUTLOOK FOR 18Z SUNDAY THROUGH THURSDAY...
Sunday afternoon through Thursday: VFR.
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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SCA levels across the ocean waters as a weak low pressure along
the coast approaches and moves through the area. Seas levels
will be slow to subside and do not fall below 5 feet until
Sunday evening. The non ocean waters will remain below advisory
levels through Sunday night.
Sub small craft conditions are anticipated with ocean seas running
at 3 to 4 ft much of the time through mid week. High pressure to the
north is expected to result in a relatively weak pressure gradient
for the first half of next week with only a residual east to
northeast wind much of the time.-- End Changed Discussion --
&&
.HYDROLOGY...
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Storm total through late this afternoon across southern
Connecticut and into Long Island are between 1 to 2 inches, with
an additional one inch to an inch and a half, possibly nearing
4 inches at a few locations by this evening. Outside of the
axis of heavies rain totals will about 1 to 2 inches. A flash
flooding has been issued. However, any flooding that does occur
will more likely be of the minor/nuisance type.
No hydrologic impacts are anticipated in the extended timeframe
with another period of dry weather taking place.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...Flood Watch until midnight EDT tonight for CTZ009.
NY...Flood Watch until midnight EDT tonight for NYZ069>075-176>179.
NJ...Flood Watch until midnight EDT tonight for NJZ006-104-106-108.
MARINE...Small Craft Advisory until 6 PM EDT Sunday for ANZ350-353-355.-- End Changed Discussion --
&&
$$