977
FXUS61 KOKX 191437
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1037 AM EDT Mon May 19 2025
.SYNOPSIS...
Low pressure continues to slowly move off the northern New England
Coast today and sends a surface trough through the area. High
pressure noses in from the north thereafter and remains in control
through Tuesday evening. Deepening low pressure passes south of
the area Wednesday into Thursday. The low then moves northeast
and into the Canadian Maritimes Thursday night through Saturday.
High pressure builds in Saturday night and Sunday.
&&
.NEAR TERM /THROUGH TONIGHT/...
Vertically stacked slow moving low pressure continues to exit the
northern New England Coast today. In the upper levels, a quick
moving shortwave will swing through along with a surface
trough. Not expecting any notable weather from these features.
The pressure gradient weakens slightly today, but with daytime
mixing expecting gusty northwest winds again. The winds aloft
have lowered slightly so gusts will peak out a few mph lower
than yesterday, mainly 25 to 35 mph. Despite ample sunshine, the
cooler pattern we are still in will result in highs in the
upper 60s to mid 70s again.
Skies remain clear tonight as high pressure noses in from the
north. Thinking winds still stay up just enough to limit the
effects of radiational cooling. Current low forecast is lower
40s across the interior and upper 40s to lower 50s elsewhere. If
winds end up lighter than forecast, thinking worst case for the
interior is dropping to the upper 30s, so for now not expecting
any frost formation.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
Winds become light and variable on Tuesday with a weak pressure
gradient over the area. There once again may be a weak shortwave and
surface trough that moves through the area, but not expecting
anything other than some clouds out of this.
Tuesday will be the last dry day before a frontal system brings
several days of unsettled weather to the area. There is still a
decent amount of uncertainty as the models try to resolve two areas
of low pressure and how they interact. Low pressure moves into the
Ohio River Valley Tuesday night and another low forms off the Mid-
Atlantic Coast Wednesday. The question is how these interact as some
guidance shows the two low centers remaining separate and
others have one being absorbed. Regardless plenty of clouds and
rain can be expected. PoPs start after midnight Tuesday night
and become likely by 8am Wednesday. Through the short term
period, the rain will be more light to locally moderate.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Key Messages:
* A frontal system impacts the region Wednesday through Saturday.
* Most rainfall, with periods of moderate intensity, will occur
Wednesday into Thursday. Potential for local urban and poor drainage
flooding.
* An upper-level trough, along with a surface trough from the
departing low, leads to continued clouds and chances of showers
Thursday night through Saturday.
Once again the forecast remains rather consistent from previous
forecasts with the approach of a frontal system impacting the region
mainly Wednesday night into Thursday night, with continued chances
of showers into Saturday.
An upper level trough deepens across the upper midwest and into the
Great Lakes region Wednesday night and Thursday with a closed low
developing. The upper low will be slow to depart to the northeast as
pieces of energy rotate through the low through Saturday. The upper
trough begins to weaken and move northeast late Friday night into
Saturday. Meanwhile, at the surface low pressure moves out of the
Great Lakes and into the region by Wednesday night. A deepening low
along the southeastern coast Wednesday night and Thursday becomes
the primary low, that then passes northeast of the region Thursday
night. A developing low level jet and increased Atlantic moisture
entraining into the low, with precipitable water values increasing
to around 1 inch, will lead to periods of moderate rainfall by late
Wednesday night and continuing into Thursday morning. This will
bring the potential for urban and poor drainage flooding. See the
Hydrology section for more information.
Thursday night, the low moves northeast of the area with the
precipitation beginning to taper off as winds to turn back N/NW,
bringing in somewhat drier air and slight cold air advection aloft.
With a lingering upper and surface trough, chances of precipitation
remains into Saturday. Confidence in this is low, given it`s
possible that dry air and weak cold air advection aloft could be
enough to hinder any showers from developing.
Saturday night into Sunday, the upper level trough finally departs
the region to the east, leading to dry and mostly clear conditions.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
Low pressure slowly moves away into the Canadian Maritimes
today. High pressure builds in from the north tonight.
VFR.
NW winds 15-20kt with gusts mainly 25-30kt, with occasionally
higher gusts, into the afternoon. Late day winds become more
NNW. Winds and gusts diminish this evening, before ending 03Z
to around 06Z. Once gusts end winds become northerly.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
No unscheduled amendments.
.OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY...
Tuesday: VFR.
Wednesday: MVFR or lower with showers likely, especially in the
afternoon into the night. E wind gusts 15-25kt.
Thursday: MVFR to IFR in showers. E/NE winds G20-30kt, highest
across southeastern Connecticut and eastern Long Island.
Friday: MVFR possible, especially in the morning. Chance of showers.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
The Small Craft Advisory has been extended until midnight
tonight for all waters as 25 kt gusts may linger. Today, expect
25 to 30 kt gusts. Sub-SCA conditions then expected the rest of
tonight through early Wednesday.
With the approach of a frontal system during Wednesday, an easterly
flow will be increasing, and by late day SCA conditions are likely
to develop on the ocean waters. With the increased and persistent
east flow Wednesday night SCA conditions become likely across all
the forecast waters Wednesday night and continue into Thursday.
The is a chance that gusts reach gale force on the ocean waters east
of Fire Island Inlet late Wednesday night into Thursday morning
depending on the strength and track of a developing low along the
coast.
As the low tracks northeast of the area Thursday night, and begins
to weaken, a northerly flow develops and winds diminish west to
east, falling below advisory levels Thursday night. However, ocean
seas are likely to remain elevated through Friday.
Winds and seas across the forecast waters will remain below advisory
levels Friday night through Saturday night as low pressure continues
to weaken and track to the northeast and high pressure builds to the
west.
&&
.HYDROLOGY...
Periods of moderate rainfall are possible from late Wednesday into
Thursday. There is the potential for 1 to 1.5 inches of rainfall
with locally higher amounts. The area is in a marginal risk for
excessive rainfall with the main threat local poor drainage and
urban flooding.
&&
.TIDES/COASTAL FLOODING...
A strengthening and persistent E/NE flow Wednesday through Thursday
could bring widespread minor coastal flooding to the area. The two
high tide cycles of concern as of now are the Wednesday
night/Thursday morning cycle and the Thursday afternoon cycle. There
is a bit higher confidence with the first cycle, as winds for the
second cycle may be northerly enough to give some coastal areas
a more offshore flow.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until midnight EDT tonight for ANZ331-332-
335-338-340-345-350-353-355.
&&
$$
SYNOPSIS...MET/JT
NEAR TERM...JT
SHORT TERM...JT
LONG TERM...MET
AVIATION...JMC/MET
MARINE...MET/JT
HYDROLOGY...MET/JT
TIDES/COASTAL FLOODING...