000
FXUS61 KOKX 082045
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
345 PM EST Mon Jan 8 2024
.SYNOPSIS...
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High pressure over the area tonight will move offshore Tuesday
morning. Intensifying low pressure will track from the Central
States to the Great Lakes Tuesday into Tuesday night. This will
send a strong frontal system across the area Tuesday night into
Wednesday. High pressure briefly builds in Wednesday night through
Thursday night. Another strong low pressure system could bring
heavy rain and high winds to the area late Friday through
Saturday. Weak high pressure returns Sunday into Monday.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
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A brief period of tranquil weather will continue tonight.
High pressure over the area will lead to mostly clear skies,
light to calm winds, and dry air. Some high clouds will begin to
move in towards day break, but this should not impact
temperatures too much. Lows will drop into to the lower 20s
across the interior and middle to upper 20s for most other
locations. The NYC metro should only fall into the lower 30s.-- End Changed Discussion --
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
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**Major storm system to impact the area late Tuesday through Early
Wednesday with heavy rainfall and potential flooding and
strong to damaging winds**
No changes have been made to the Flood Watch.
A High Wind Warning is now in effect from 6pm Tuesday through
6am Wednesday for Staten Island, Brooklyn, Queens, Long Island,
coastal Connecticut along the I-95 corridor, and northern New
London County. The high wind watch is no longer in effect.
A Wind Advisory is now in effect from 6pm Tuesday thorough
6am Wednesday for Manhattan, Bronx, NE NJ, Lower Hudson Valley,
northern Fairfield, northern New Haven, and northern Middlesex
counties.
Tuesday will start out dry with increasing clouds as high
pressure moves offshore. The storm system will continue
intensifying as it begins to move towards the midwest and
southeast. The associated upper trough will amplify and begin
going negatively tilted allowing for anomalous feed of
subtropical moisture along the eastern seaboard. The intense
parent low will track towards the Great Lakes through the day
which sends a strong frontal system towards the region. The
frontal system will then sweep across Tuesday night and should
be offshore by day break Wednesday.
Models have continued to speed up the timing of both the
rainfall and strongest winds over the last 24 hours. Rain
should begin developing from west to east by afternoon becoming
widespread by mid to late afternoon. Initially the rain will be
light to moderate. The rain will become moderate late afternoon
into the evening with locally heavy rainfall. The precip may
briefly mix with some wet snow well inland at the onset, but
warmer air should change any snow over to rain quickly. No
accumulation expected. A more widespread heavy rainfall is
expected Tuesday night with the peak of the rainfall likely
occurring between 00 and 09z. PWATs peak around 1.2-1.3 inches
which is near the top of the observed values on the SPC Sounding
Climatology for OKX for January 7. The latest 12z HREF shows
fairly high probabilities of seeing hourly rainfall rates of
around 0.50 per hour. Rates could be briefly locally higher at
times, especially if the CAMs projections of a squall
line/narrow cold frontal rainband move through along or ahead of
the main windshift/cold front. If this band materilizes,
rainfall rates could briefly touch an inch an hour, but the line
will be moving quickly from west to east so that rainfall rate
should not last for an actual hour. An isolated rumble of
thunder cannot be ruled out. A general consensus of the modeling
indicates the rain should begin tapering off west of the city
midnight to 3am, in the NYC metro 2am to 4am, and east of the
city 3am to 6am.
The forecast average rainfall amounts for the event range from
2 to around 3 inches with locally higher amounts possible. This
rainfall may lead to flooding with some of the main stem rivers
reaching moderate to locally major flood stages. Snow melt,
runoff, and higher than normal soil moisture will only add to
the threat of flooding.
There is a chance for some flash flooding, but widespread urban
flooding appears more likely given the average hourly rates of
about 0.50 inches per hour.
SE winds will increase through the day Tuesday with the
strongest winds expected Tuesday night. The low level jet that
is modeled is concerning with around 95-100 kt between about 4-5
kft. These winds are well above an inversion, but winds around
1-2ft are quite strong around 50-70kt when the jet peaks
overhead. A model consensus has the peak of the low level jet
and winds over the area between 03-09z from west to east. The
highest winds are still expected near the coast with gusts
around 60 mph (in the High Wind Warning). Gusts 45- 55 mph are
expected in the wind advisory area away from the immediate
coast. Sustained winds could reach 25-35 mph at times Tuesday
night. The peak of the winds may occur in just a few hours
coinciding with the passage of the low level jet, 10pm-1am north
and west of the city, 11pm-2am in the NYC metro, 12am-4am Long
Island and Southern CT. Once the front and winds shift more to
the S and SW, winds should weaken, which is expected to occur
before day break Wednesday. It will then remain breezy on
Wednesday with gusts 25-35 mph possible.
See Tides/Coastal flooding section for coastal/shoreline impacts.
The main axis of moisture and lift will be well offshore on
Wednesday. The intense low will lift towards northeast New
England and the Maritimes by late in the day with the upper low
moving over New England. Instability clouds may remain with the
cold pocket aloft. There could be an isolated shower, but for
now have gone with a mainly dry forecast in the afternoon. Highs
Wednesday range from the upper 40s inland to the lower 50s near
the coast.-- End Changed Discussion --
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
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Another southern stream trough will be moving onshore of the
Pacific northwest midweek and tracks quickly to the east coast
by Friday night. Before the arrival of another strong low late
Friday a weak upper ridge and weak surface high will be across
portions of the northeast and Mid Atlantic regions.
The upper trough and surface low will be tracking well inland
Friday night into Saturday with an occluded low tracking
through the area Saturday. With a low level jet of 60-70kt
developing Friday night and the low level low over the region,
along with precipitable water increasing to 1 to 1.25 inches,
another round of moderate to heavy rainfall is becoming more
likely Friday night into Saturday morning. Also, with the strong
low level and upper dynamics, and elevated CAPE up to 300 J/kg,
isolated thunder is becoming more likely during the same
timeframe as the heavy rainfall. The is the potential for
another flooding event as WPC have placed all the area in at
least a marginal risk for excessive rainfall, with an inland
portion in a slight risk. Finally, with the strong winds anther
high wind event is also becoming more likely.
The low tracks northward through Eastern Canada late Saturday
through Sunday with a strong westerly flow developing across
the region as the precipitation comes to an end. Some wrap
around moisture may move into the northwest portions Saturday
night into Sunday with snow showers, or flurries possible.
However, with the westerly flow drying will be likely and
precipitation may not make it too far toward the coast.
There is a chance of yet another low tracking toward the area
for next Monday.
The NBM looked reasonable for all parameters Wednesday night
through Monday.-- End Changed Discussion --
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
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High pressure shifts offshore tonight ahead of an incoming storm
system that approaches on Tuesday.
Mainly VFR thru 12Z Tue. MVFR cigs develop late Tuesday morning,
becoming IFR or lower in the afternoon with a steady rain falling
through the TAF period.
NW flow around 10 kt with gusts up to 20 kt thru this afternoon
diminishes by early evening. Light and vrb winds tonight, increasing
after 12Z Tue out of the SE. Gusts up to 40 kt possible toward 00Z
Wed. LLWS develops after 21Z Tue.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Gusts may only be occasional at times today.
Timing of category changes on Tuesday may be off by a couple of
hours.
OUTLOOK FOR 18Z TUESDAY THROUGH SATURDAY...
Tuesday PM: IFR or lower. Rain, locally heavy at times. ESE/SE winds
15-20kt gusts 25-30kt in the afternoon. SE winds increasing Tuesday
night to 25-35kt, gusting 40-50kt, highest winds along the coast.
LLWS at night with SE-S winds at 2 kft of 70-80kt.
Wednesday: MVFR or lower with rain early in the the morning. Rain
ending by noon with conditions improving. S-SW wind 20-25kt gusting
30-40kt. Gusts decrease afternoon into the night.
Thursday: VFR. WSW winds 10-15kt with gusts near 20kt.
Friday: VFR early, becoming MVFR or lower with rain. Increasing SE
winds late.
Saturday: MVFR or lower with rain. SE winds 15-25kt G30-35 kt early
in the day.
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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Conditions will remain below SCA levels tonight into
Tuesday morning. Winds will start to ramp up in the afternoon
ahead of an approaching storm system. The system will bring a
fairly quick increase in winds to the waters late Tuesday
afternoon and evening. The strongest winds are likely to occur
overnight into early Wednesday morning. The Storm Watch has been
converted to a Storm Warning. Have also started the Warning at
4pm for the ocean and NY Harbor as winds start to increase into
gales and then storm force by evening. The warning is in effect
elsewhere from 6pm Tue to 6am Wed. Dangerous seas are expected
on the ocean, generally 15-20 ft Tuesday night into early
Wednesday. Waves on the LI Sound look to reach 5- 8ft, highest
east of the Mouth of the CT Ricer. Winds weaken Wednesday
morning, but gales are possible into the afternoon on the ocean,
eastern LI Bays, and eastern LI Sound, with SCA conditions
elsewhere.
On-going gales on the ocean waters diminish to SCA levels
Wednesday night, meanwhile SCA conditions will remain on the
non-ocean waters Wednesday night, falling below by Thursday
morning. On the ocean SCA conditions remain into Friday. The sub
advisory conditions will be shortlived as a strong low pressure
system will be affecting the waters late Friday into Saturday,
Gales will be developing on all the waters Friday night with the
potential for storm force gusts on the ocean waters late Friday
night into Saturday morning. SCA and gale conditions will then
region Saturday night through Sunday.-- End Changed Discussion --
&&
.HYDROLOGY...
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No hydrologic impacts are expected through Tuesday morning.
A major storm system will bring a total of 2 to around 3 inches
of rain with locally higher amounts Tuesday afternoon into early
Wednesday. The bulk of the heaviest rain will occur Tuesday
night. Widespread urban flooding is possible as runoff from
snowmelt and saturated grounds add to the flooding concerns.
There is also a chance for flash flooding given the antecedent
conditions, but one factor that may inhibit flash flooding is
hourly rainfall rates on average around 0.50 inches.
River flooding is a bigger concern across NE NJ, Lower Hudson
Valley, and interior Southern CT. The runoff from snowmelt,
higher than normal stream flows will combine with the heavy
rainfall to raise several rivers and streams into moderate
flooding. Localized major flooding is possible and current
projections take the Saddle River at Lodi into major flooding
early Wednesday morning. Ramapo River at Mahwah is forecast to
reach moderate flooding Wednesday morning. Tha Yantic River may
also near minor flooding, but a reasonable worst case scenario
is for moderate flooding if higher rainfall amounts occur. Many
other quick responding rivers and stream will likely reach
banfull and could exceed moderate flooding levels.
Hydrologic impacts are possible again Friday night and Saturday
with more moderate to heavy rainfall. The exact magnitude and
extent of the issues are uncertain this far out.-- End Changed Discussion --
&&
.TIDES/COASTAL FLOODING...
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This section will be updated by early this evening.
The potential for a significant coastal flood event with the
Wed AM high tide remains. Potential for SE storm force winds
Tuesday Night into early Wednesday, bringing potential for
widespread moderate to locally major coastal flooding. Early
guidance from Steven`s NYHOPS ensemble is producing surge values
of 3 to 4 ft. This will also coincide with increasing
astronomical tides with a new moon on Jan 11. Along the
oceanfront, potential for 15-20 ft surf causing widespread dune
erosion and scattered overwashes. Localized dune
inundation/breaches possible where dunes have been compromised
by earlier storm events.
Newest guidance shows a decrease in the NYHOPS ensemble for
South Shore Bays with regards to total water level. Because of
this change and uncertainty, feel chances for widespread moderate
coastal flooding are still low enough chance to hold off on
watch issuance.
Coastal flood impacts are possible around the times of high tide
Friday night and Saturday with another deep low tracking west of the
area.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...Flood Watch from Tuesday evening through Wednesday afternoon
for CTZ005>012.
Wind Advisory from 6 PM Tuesday to 6 AM EST Wednesday for
CTZ005>007.
High Wind Warning from 6 PM Tuesday to 6 AM EST Wednesday for
CTZ008>012.
Coastal Flood Advisory from 7 PM Tuesday to noon EST Wednesday
for CTZ009-010.
Coastal Flood Warning from 6 AM to noon EST Wednesday for
CTZ011-012.
NY...Flood Watch from Tuesday evening through Wednesday afternoon
for NYZ067>071.
Wind Advisory from 6 PM Tuesday to 6 AM EST Wednesday for
NYZ067>073.
High Wind Warning from 6 PM Tuesday to 6 AM EST Wednesday for
NYZ074-075-078>081-176>179.
Coastal Flood Advisory from 7 PM Tuesday to noon EST Wednesday
for NYZ071-078-177.
Coastal Flood Advisory from 5 AM to 10 AM EST Wednesday for
NYZ072-074-075.
Flood Watch from Tuesday evening through Wednesday morning for
NYZ072>075-078>081-176>179.
Coastal Flood Warning from 4 PM Tuesday to 1 PM EST Wednesday
for NYZ079>081-179.
Coastal Flood Warning from 5 AM to 9 AM EST Wednesday for
NYZ178.
NJ...Flood Watch from Tuesday evening through Wednesday afternoon
for NJZ002-004-006-103>108.
Wind Advisory from 6 PM Tuesday to 6 AM EST Wednesday for
NJZ002-004-006-103>108.
Coastal Flood Advisory from 5 AM to 10 AM EST Wednesday for
NJZ006-104-106-108.
MARINE...Storm Warning from 6 PM Tuesday to 6 AM EST Wednesday for
ANZ331-332-335-340-345.
Storm Warning from 4 PM Tuesday to 6 AM EST Wednesday for
ANZ338-350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...DS/MET
NEAR TERM...DS
SHORT TERM...DS
LONG TERM...MET
AVIATION...DR
MARINE...DS/MET
HYDROLOGY...DS/MET
TIDES/COASTAL FLOODING...