Area Forecast Discussion
Issued by NWS Upton, NY

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FXUS61 KOKX 212253
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
653 PM EDT Sat Apr 21 2018

.SYNOPSIS...
High pressure will be in control through early next week. The
high gives way to low pressure mid week. Another low may impact
the area late in the week.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Quiet and chilly night in store as strong high pressure continues to
build into the region from the northwest. The atmosphere remains
dry, so clear skies anticipated for the night. Evening sea
breezes dissipate and winds lighten.

Low temperatures will range from the low 30s across the interior and
Pine Barrens of Long Island to the upper 30s and lower 40s
elsewhere. Some frost is likely to develop where temperatures drop
into the low-mid 30s with light winds, so have included frost
mention in the grids.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
Tranquil weather will continue Sunday into Sunday night with high
pressure in control. Upper trough over southeast Canada moves
further to the north and east over the North Atlantic. Heights will
gradually rise as an upper ridge over the northern Plains
approaches. One last shortwave dives down the back side of the upper
trough, which may include a weak surface trough passage in the
evening. There will be no discernible change to sensible weather
other than a few fair weather clouds in the afternoon and evening.

The air mass continues to moderate on Sunday, so temperatures should
be several degrees warmer than those on Saturday. Highs will be near
seasonable levels in the lower 60s. Good radiational cooling
conditions expected Sunday night with temperatures falling into the
30s inland and lower to middle 40s elsewhere.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Ridge Monday and Tuesday gives way to approaching shortwave that
slowly lifts northeast and phases with northern stream shortwave by
Wednesday. As this unfolds, sfc low tracks to the east coast, and
passes to the northeast Wednesday/Thursday. Rain chances increase
during this time, mainly from Tuesday night through Wednesday night.

The local area should remain between this departing shortwave, sfc
low and downstream shortwave that approaches late in the week, and
into next weekend, although timing remains in question. As such,
generally dry conditions are expected during this time, with perhaps
spotty showers, low coverage. Then higher probabilities for showers
are expected Friday night or Saturday, again dependent on timing.

As for temperatures, much of the period will feature seasonable
temperatures with the exception of Wednesday, where onshore flow
will keep highs several degrees below normal.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
High pressure will build in through the TAF period.

VFR. NW-WNW winds around 10 kt with gusts 16-20 kt this afternoon
for most terminals except some coastal terminals at WSW-SW. Overall
low confidence regarding which side of 310 magnetic the city
terminals prevail. KLGA has a better chance of prevailing north of
it, with KEWR and KJFK prevailing south of it. A late day/early
evening sea breeze is also anticipated for KJFK, but might not occur.

.OUTLOOK FOR 18Z SUNDAY THROUGH THURSDAY...
.Sunday through Tuesday...VFR.
.Tuesday night through Wednesday...MVFR or lower conditions
increasingly likely with rain. E winds near 10 kt gusting near
15-20 kt Wednesday.
.Thursday...Mostly VFR, chc MVFR in -shra. W gusts around 25 kt.

&&

.MARINE...
Tranquil conditions continue into early next week on the waters with
high pressure in control and a weak pressure gradient.

As high pressure builds, then moves east, tranquil conditions are
expected across the area waters Monday and Tuesday. Increasing
easterly flow ahead of an area of low pressure and warm front should
result in building seas Wednesday. Winds will shift as low pressure
and frontal boundaries pass Wednesday night and Thursday. Seas
should subside some, and Wavewatch III output lowered during this
timeframe.

&&

.HYDROLOGY...
No hydrologic impacts are forecast into early next week.

Rain is likely during the mid week period, but no hydrologic
issues are anticipated at this time.

&&

.EQUIPMENT...
NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) remains off
the air.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.

&&

$$
SYNOPSIS...DS/PW
NEAR TERM...DS/PW
SHORT TERM...DS
LONG TERM...PW
AVIATION...JC
MARINE...DS/PW
HYDROLOGY...DS/PW
EQUIPMENT...



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