Area Forecast Discussion
Issued by NWS Upton, NY

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FXUS61 KOKX 261611
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1211 PM EDT Tue Mar 26 2024

.SYNOPSIS...
A high pressure ridge over the area will gradually weaken
through tonight. A cold front approaches on Wednesday and
slowly passes through during Wednesday night into Thursday.
Meanwhile, low pressure develops along the Atlantic seaboard,
tracks NE, passing us to the southeast late Thursday night into
Friday morning. The low eventually tracks into the Canadian
Maritimes over the weekend. Another low pressure system may
impact the area early next week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
The forecast is mainly on track. Minor adjustments were made to
hourly temperatures and dewpoints based on the latest trends
with temperatures having to be raised.

Shallow moisture trapped under an inversion keeps us cloudy today.
Weak isentropic lift arriving from the east introduces a slight
chance of light rain or drizzle over LI and southern CT
this morning. Chances of light rain and drizzle then expand
west this afternoon with the help of some isentropic lift. High
temperatures about 5 degrees below normal.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
Light rain and drizzle potential expands farther to the rest of the
area tonight. Moisture then deepens west to east on Wednesday ahead
of a cold front. Threat of rain therefore trends higher towards the
western zones. Also expecting areas of fog starting tonight when the
turbulent mixing potential near the bottom of the low level
inversion lessens. We could be stuck with the fog well into the day
Wednesday with light winds and plenty of low level moisture. Milder
for Wednesday, with highs in the 50s.

A cold front enters the forecast area Wednesday night, bringing an
area of focused moisture convergence with it. Rain is therefore
likely Wednesday night with the deeper moisture and lift along the
front. Models show elevated CAPE Wednesday afternoon and night, but
lift appears to be to weak for a mention of thunder.

The front slows its eastward motion on Thursday as the flow aloft
amplifies and a 500mb trough axis approaches. This will help focus
energy along an elongated area of low pressure toward the Carolina
coast. This deepening low center then tracks NE and approaches not
too far SE of the 40N/70W benchmark late Thursday night. The
combination of the front, frontogenetic forcing on the NW side of
the elongated low, and synoptic upper divergence from a jet streak
continue the likelihood of rain across the area on Thursday, with
rain chances diminishing west to east Thursday night. Cold air wraps
in from the NW as the rain is ending late, but likely too late for
any potential snow (northernmost zones only) to be of any
significance. Will keep out the mention of snow for the time
being.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Low pressure passes east of the region on Friday, as a cold front
slides east of the region. Any left over precipitation Friday
morning is expected to come to an end shortly after daybreak, mainly
across the eastern sections of Long Island and Connecticut. There is
a low end chance that POPs linger into Friday afternoon. There is
some uncertainty with just how strong the low is that passes east of
the area and its exact placement on Friday. The deeper the low is,
the better chance that we could see some snow showers on the back
end of the precipitation Friday morning. Will go with a rain/snow
mix for now. Otherwise, expect a gusty northwest flow, with a
colder/drier airmass working into the region.

Conditions are expected to remain dry at least Friday night and the
first half of Saturday. Some of the forecast guidance is hinting at
a quick moving low pressure system/upper level shortwave to
pass over the area late Saturday into Sunday. This may set off a
few showers/light rain, however the timing and placement of
this feature remains a bit uncertain with low confidence. Will
only carry slight chance POPs for now.

The next chance of rain comes Monday night into Tuesday as yet
another low pressure treks towards the region. With this being a day
7-8 event, will cap POPs at 50 for now.

&&

.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
High pressure over the region slowly weakens through tonight.

MVFR ceilings are expected at all the area terminals through the
day and into the evening. IFR is possible at KGON late this
afternoon and evening. Tonight, conditions are expected to fall
to IFR with low end chance of some terminals falling below IFR.
Areas of fog are forecast late tonight into Wednesday.
Confidence remains low, however where confidence is highest,
have included a TEMPO to cover this threat. Conditions improve
Wednesday morning to MVFR.

NNE-NE winds are expected to continue through much of the day
today, generally 10-15 kt. Wind speeds may begin to fall below
10 kt this evening. Some wind gusts, mainly east of NYC
terminals are forecast today to near 20-25 kt.

     NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

Timing of MVFR to IFR or lower may be off by 1 to 3 hours.

OUTLOOK FOR 12Z WEDNESDAY THROUGH SATURDAY...

Wednesday: MVFR to IFR. Areas of fog as well as light rain or
drizzle possible. Rain becomes likely Wednesday night.

Thursday: IFR with rain, eventually tapering off late at night
except at KGON. NW wind gusts Thursday night to near 20-25 kt.

Friday: MVFR early, becoming VFR in the afternoon. Slight chance
of rain or snow showers early for KISP and KGON. NW wind gusts
20-25 kt.

Saturday: Mainly VFR. W-NW wind gusts 20-25 kt.

Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90

&&

.MARINE...
SCA remain in place on the ocean through Weds afternoon due mainly
to elevated seas from a lingering swell. Gusts to at least 25kt also
expected during the day today, but becoming less likely heading into
the evening. SCA also for eastern LI sound through this afternoon -
again primarily for elevated wave heights. A prolonged period of
winds at or below 10kt is expected from late tonight through
Thursday morning. Winds then increase Thurs afternoon and night from
the N-NW as the pressure gradient tightens over the waters. Advisory
level gusts expected at for all waters by the end of this period.
Could get close to gales on the ocean late Thursday night.

Low pressure passing east of the waters on Friday will result
in at least small craft conditions with both gusty winds and
elevated seas. There is a chance gales will be needed during the
daytime Friday. The small craft conditions are likely to
continue through the first half of the weekend before conditions
subside below SCA levels.

&&

.HYDROLOGY...
Mostly 1-2 inches of rainfall is forecast from Wednesday through
Thursday night. The higher amounts will be focused more toward Long
Island and southern Connecticut. Given the current flash flood
guidance, not anticipating hydrologic impacts, but if the
expected totals ramp up in subsequent forecasts, maybe some
minor flooding could occur over southern Connecticut.

No hydrologic impacts are anticipated for the weekend and into
early next week.

&&

.TIDES/COASTAL FLOODING...
The current forecast is a blend of the previous forecast and NYHOPS
with consideration of the the departure trends seen since the past
high tide cycle.

Advisories remain in effect for today`s high tide cycle for Southern
Nassau County, as well as along western LI Sound from Southern
Fairfield/Northern Nassau on westward. Coastal flood statements,
where flooding is expected to be only isolated and barely reached,
remain across NY Harbor through the rest of Southern Brooklyn/Queens
as well as the south shore back bays of SW Suffolk County.

Winds will be much lighter in the hours leading up to tonight`s high
tide cycle, so not enough confidence to issue advisories/statements
for tonight in spite of the nighttime cycle being higher
astronomically. Perhaps Southern Nassau and Southern Fairfield
counties could need an advisory, but might only need a statement.
Will allow the next shift to assess trends and updated guidance for
further headline considerations.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Coastal Flood Advisory until 3 PM EDT this afternoon for
     CTZ009.
NY...Coastal Flood Advisory until 3 PM EDT this afternoon for
     NYZ071-073-176-177.
     Coastal Flood Advisory until 1 PM EDT this afternoon for
     NYZ179.
NJ...None.
MARINE...Small Craft Advisory until 6 PM EDT this evening for ANZ332.
     Small Craft Advisory until 6 PM EDT Wednesday for ANZ350-353-
     355.

&&

$$

SYNOPSIS...BC/JC
NEAR TERM...JC/BR
SHORT TERM...JC
LONG TERM...BC
AVIATION...BC/JM
MARINE...BC/JC
HYDROLOGY...BC/JC
TIDES/COASTAL FLOODING...


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