Area Forecast Discussion
Issued by NWS Upton, NY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
770
FXUS61 KOKX 250938
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
538 AM EDT Thu Apr 25 2019

.SYNOPSIS...
High pressure today gives way to a warm front tonight, and cold
front Friday night. Low pressure departs to the northeast
Saturday as weak high pressure briefly builds into the area.
Weak low pressure passes across the tri state area Sunday and
Sunday night. High pressure briefly builds again Monday before
another frontal system passes through Monday night into Tuesday.
Yet another frontal system impacts the region Wednesday into
Thursday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Weak ridge this morning will give way to approaching northern and
southern stream shortwaves later in the day. High pressure at the
sfc moves east and a warm front approaches this afternoon. Mid and
high level clouds will increase through the day, lowering toward
evening. Could see some light rain develop late, but dry air below 7
kft will be an inhibiting factor.

With increasing clouds and developing onshore flow, temperatures
will remain in the 60s, with higher readings away from the immediate
coast. Will follow a MOS blend between cooler NAM and warmer GFS
numbers.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
Southern stream shortwave approaches, with a sfc low tracking
northeast ahead of it, tracking toward eastern Ohio by Friday
morning. A warm front approaches the area from the south tonight
into Friday morning.

As the northern and southern stream shortwaves begin to phase and
approach, the warm front will likely lift to the north of the area
by late in the day Friday. Parent sfc low should move across the
eastern portions of the Great Lakes Region, with a secondary low
likely developing just to our west and passing nearby Friday night.
The cold/occluded front will then move across the area late at
night, slowing as upper trough becomes negatively tilted.

As for sensible weather, rain chances will increase tonight as the
warm front approaches. Rain will become more widespread by Friday
morning, then may lighten and diminish in coverage as the warm front
lifts through in the afternoon. May just see some spotty light rain
for a time. However, Any breaks in the precip will be short lived as
showers ahead of the secondary low and cold front approach and move
through late in the day and Friday night. Will include thunder
mention later in the day and into the evening as a few hundred
joules per kilogram of Mucape can be expected per various model
projections.

Looking at various ensemble precip plumes, total QPF looks to reside
in the 1/2-1 inch range, with a few members higher, and some lower.

Will follow a MOS blend with little differences noted at night, but
will lean toward cooler NAM numbers during the day Friday based on
expected E/SE flow and plenty of low level moisture.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
The long term period will be characterized by an active pattern that
will bring a series of short waves across the region Sunday through
next Thursday. A closed upper low near the Hudson Bay will remain in
the longwave northern trough across eastern Canada and into the
northern plains and upper midwest. The low and trough persist
through the extended period as the low and trough slowly retrograde.
As mentioned as series of shortwaves, with generally weak surface
lows, move through the area. Brief and weak high pressure will be in
between this systems. There is some uncertainty with the timing and
placement of these systems and changes in the forecast will be
likely, especially in the longer term. For now, the strongest low
will be exiting to the northeast Saturday and leaned toward a slower
exit as both the ECMWF and GFS keep precipitation across the area
Saturday morning and moving out to the northeast Saturday afternoon.
Timing and movement of the low for Sunday has been fairly consistent
from previous guidance, however, still not high enough confidence to
increase probabilities to likely at this time.

Temperatures through the long term will be near seasonal normals and
with no extreme fluctuations with no intrusions of cold air, or
warmth as the northern stream dominates.

&&

.AVIATION /09Z THURSDAY THROUGH MONDAY/...
High pressure moves across the terminals through early today and
then off into the Atlantic through this afternoon. A warm front
approaches tonight into early Friday.

Mainly VFR conditions expected. Showers become likely late
tonight into early Friday. There will be potential for MVFR to
IFR conditions Friday.

Winds will be northerly around 5 kt through early today and
then will become more southerly late morning into the afternoon,
increasing to 5-10 kts.

...NY Metro Enhanced Aviation Weather Support...

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

KJFK TAF Comments: Timing of more SE wind could be off by a few
hours.

The afternoon KJFK haze potential forecast is GREEN, which
implies slant range visibility 4-6SM outside of cloud.

KLGA TAF Comments: Timing of more S wind could be off by a few
hours.

The afternoon KLGA haze potential forecast is YELLOW, which
implies slant range visibility 4-6SM outside of cloud.

KEWR TAF Comments: Timing of more SE-S wind could be off by a
few hours.

The afternoon KEWR haze potential forecast is YELLOW, which
implies slant range visibility 4-6SM outside of cloud.

KTEB TAF Comments: Timing of more SE-S wind could be off by a
few hours.

KHPN TAF Comments: Timing of more S wind could be off by a few
hours.

KISP TAF Comments: Timing of more S wind could be off by a few
hours.

.OUTLOOK FOR 06Z THURSDAY THROUGH MONDAY...
.Late tonight-Friday...MVFR conds and rain developing,
continuing Friday with isolated thunder. IFR possible by Friday
afternoon.
.Saturday...VFR. W to NW gusts up to 30 kt.
.Sunday...A chance of showers with MVFR conditions.
.Monday...VFR.

&&

.MARINE...
Light N/NE winds this morning shift to the S as high pressure
moves east. Then winds back to the E/SE as a warm front
approaches tonight. Wind speeds increase Friday ahead of low
pressure and cold front. The warm front may pass north, and
winds shift to the S/SW, then W behind the low/front Friday
night.

Seas will build Friday and Friday night in response to the increase
in speeds. No headlines though at this time since it is late 3rd
period.

West to northwest winds will increase Saturday morning behind a cold
front and departing low pressure. At this time at least SCA wind
gusts will be likely across all the forecast waters Saturday into
Saturday evening. There is a chance of a few hours of wind gusts
reaching gale force Saturday morning. However, at this time
conditions are marginal and duration is uncertain, so will not issue
a gale watch.

Once wind gusts fall below SCA levels Saturday evening, ocean
seas will remain elevated through Saturday night.

With another frontal system expected to pass through the region
Sunday and Sunday night, a period of SCA wind gusts and ocean
seas will be possible Sunday night into Monday morning.

After Monday morning, winds and seas are expected to remain sub
SCA through Tuesday.

&&

.HYDROLOGY...
Next chance for significant rain of at least a half inch, to
possibly over an inch in spots, will occur late tonight through
Friday night. Quick motion of the cells may limit a more widespread
flooding threat, with nuisance urban/poor draining flooding the main
concerns at this time.

A series of frontal systems will bring a chance of precipitation
Sunday through Wednesday. Significant precipitation is not
expected, with a total of 1/2 inch to 3/4 of an inch through the
period.

&&

.EQUIPMENT...
NYC NOAA Weather Radio Station KWO35 (162.55 MHz) remains off
the air.

&&

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

&&

$$
SYNOPSIS...MET/PW
NEAR TERM...PW
SHORT TERM...PW
LONG TERM...MET
AVIATION...JM
MARINE...MET/PW
HYDROLOGY...MET/PW
EQUIPMENT...



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.