000
FXUS61 KOKX 091256 CCA
AFDOKX
Area Forecast Discussion...CORRECTED
National Weather Service New York NY
756 AM EST Tue Jan 9 2024
.SYNOPSIS...
High pressure over the region departs to the east today. A
strengthening frontal system approaches from the south today
into this evening. Associated strong low pressure moves across
late tonight and moves northeast of the region Wednesday. Low
pressure slowly moves within Southeast Canada Wednesday night
into early Thursday. Another strong low pressure system will
likely bring heavy rain and high winds to the area Friday night
and Saturday. Windy and colder on Sunday.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Strong parent low approaches the Great Lakes today, with
secondary low pressure developing along the Appalachians. An
associated warm front approaches the region from the south.
Synoptic factors are coming into place including, a tightening
pressure gradient, increasing vertical depth of omega, low level
warm advection increasing with increasing SE winds. The rates of
these parameters increase further this afternoon.
Chances for rain and snow mainly north and west of NYC in the
morning and then by the early afternoon the rain is expected to
have moved into NYC and locations north and west. Far interior
some snow may linger before transitioning to rain. Little to no
snow accumulation is expected for the interior with a warming
boundary layer.
The rain spreads east through the remainder of the forecast
region by mid to late this afternoon.
Temperature trend slowly warmer and SE winds will become
increasingly gusty especially by mid to late afternoon.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
-- Changed Discussion --
HIGH IMPACT EVENT WITH HIGH WINDS TONIGHT, POTENTIAL FOR
FLOODING FOR TONIGHT INTO WEDNESDAY.
- High wind warning in effect for all coastal areas including
all of NYC and Long Island. Southern Westchester NY and Hudson
NJ are now included as well.
- Wind advisory remains in effect for inland areas.
- Storm warning for all forecast waters.
- Flood watch remains in effect for the entire region.
Highest winds expected along the coast. Flooding potential for
the entire forecast region.
Flooding threat remains for inland areas Wednesday after the
bulk of rain ends due to forecast of elevated rivers and streams
above respective flood stages. The NYC and Long Island part of
the flood watch only goes until Noon on Wednesday but for the
rest of the region goes until 6PM Wednesday evening.
In addition, coastal flooding is expected for tonight and
Wednesday morning high tides. The highest of the total water
levels is expected to be Wednesday morning. Coastal flood
warnings, advisories and statements are in effect.
For details with flooding, see hydrology section.
For details with coastal flooding, see tides/coastal flooding
section.
For details with storm warning, see marine section.
The reasoning behind the high wind warning and wind advisory. The
main key feature is a low level jet maximum of near 100 kt that
develops this evening at a height of around 4-8 kft. Model sounding
BUFKIT profiles do not depict a strong inversion, as the thermal
profiles appear to be close to isothermal. Winds just 1-2kft above
the surface are shown to reach 50-60 kt according to multiple
model BUFKIT soundings across the coastal areas and with the
heavy rain and aforementioned thermal profiles, much of this
should get mixed down to the surface through downward momentum
transport. The timeframe for this generally after 02Z Wednesday
and before 09Z Wednesday for Western Long Island and New Haven
CT west. The timeframe for this for Eastern Long Island and the
rest of Southern CT to the east is generally after 03Z
Wednesday and before 10Z Wednesday.
Also, coinciding with this timeframe will be tremendous increase
vertically with omega and the total southerly flow extending
throughout the troposphere will increase the PWATS to well above
90th percentile climatology values. Models still conveying PWAT
values near 1.4 inches maximum overnight into the coastal parts
of the region. Large scale of PWATS and upper and low level
jets depict moisture transport from the Gulf of Mexico, Western
Atlantic, and Pacific.
In addition, elevated instability develops late tonight across
eastern parts of the region. Models indicate near zero Showalter
Indices so put in isolated thunderstorms across eastern sections
of the region overnight. CAMs depict a consolidating squall line
that seems to get more organized as it makes it way farther east
within the region overnight.
Storm system shifts northeast of the region Wednesday into
Wednesday night. Upper level trough with vorticity maximum moves
across in the area Wednesday and then northeast of the region
Wednesday night. Some rain showers may occur from time to time
Wednesday with dry conditions expected Wednesday night. Pressure
gradient will still be tight Wednesday and will begin to relax
Wednesday night. Gusty westerly flow on Wednesday will be below
advisory thresholds but a localized isolated gust or two to
near 45 to 50 mph cannot be ruled out. Most gusts are expected
on Wednesday to be in the range of near 30 to 40 mph. Gusts
decrease more Wednesday night.-- End Changed Discussion --
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
The main focus remains on the storm sys for late Fri into Sat, with
winds on the back side lingering thru Sun.
There were no notable changes with the 00Z modeling. Timing of the
hvy rain is in the Fri ngt thru Sat time period, and h85 winds are
still coming in at around 90kt. This time around, the ECMWF is the
deeper low, getting into the 960s invof Detroit. The GFS keeps it in
the 970s. The track is remarkably similar to the system we will be
getting tngt and Wed.
The rainfall with this storm does seem to be a quick hitter, with
the dry surge cutting things off quickly, so this could be a
limiting factor wrt the flood threat. Winds still on track for
another high wind event based on the pattern. The GFS has around 50
kt at 1500ft Sat ngt into Sat mrng.
This storm is several days out, so the details still have some time
to be worked out. The low will transition into an occluded wind
machine on Sunday, producing windy/breezy conditions across the cwa.
Winds could be close to advy lvls early in the day. Otherwise, the
gusty wly winds and colder airmass will keep wind chills in the 20s
or lower thru the day. Sat ngt wind chills in the single digits and
teens.
For the rest of the long term:
Thu into Fri mrng are dry ahead of the storm. Temps abv climo, and
the NBM was followed.
There is another low pres sys possible Mon or Tue. There will be a
cold airmass in place as this potential low takes shape, and the
modeling indicates a track near the coast or offshore possible. This
will be one to watch for potential winter storm impacts, but it is
way too far out to have any confidence in the track or details.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
Deep low pres tracks thru the Midwest today, and into on Wed.
MVFR cigs develop 14-16Z, becoming IFR in the late afternoon.
A steady rain developing into the evening push. Moderate to
heavy rain likely prevails after 00Z. Visibilities drop to 1 to
2SM in +RA. FG is also a possibility (especially for KSWF), but
confidence is lower with respect to fog development for the city
and coastal terminals due to the wind.
Light and vrb winds increasing out of the SE this mrng. Gusts
up to 40 kt possible toward 00Z, with city and coastal terminals
having gusts up to 50 kt towards 04-06z. LLWS develops towards
the eve push and continues overnight. Winds become wly around
12-14Z Wed.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of MVFR onset may need to be adjusted thru 15Z.
Additional amendments likely thru the TAF period for CIGS and
VIS.
OUTLOOK FOR 12Z WEDNESDAY THROUGH SATURDAY...
Wednesday: MVFR or lower with sct showers in the morning, then
improvement to VFR. SW wind around 20kt gusting 30-35kt. Gusts
gradually decrease at 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 20-30kt G30-40 kt.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
Current sub-SCA conditions on the waters will ramp up quickly by
mid to late afternoon with gales and then storm force wind gusts
for tonight. Ocean seas build to 14 to 20 ft tonight into early
Wednesday.
Gales are likely Wednesday into Wednesday night, eventually
subsiding to SCA level wind gusts late Wednesday night. Ocean
seas will remain elevated well above SCA thresholds Wednesday
through Wednesday night.
Decreasing winds late Thu, with all areas likely blw 25kt by Fri
mrng. Seas on the ocean will remain at sca lvls thru Thu ngt,
subsiding by the end of the day Fri. Winds will then rapidly
increase with the next storm Fri ngt, with gale to storm force winds
possible late Fri ngt into Sat. Gales are likely behind the low on
Sun.
&&
.HYDROLOGY...
No hydrologic impacts are expected through this morning.
Flood watch remains in effect for the entire forecast region
from 6PM tonight to 6PM Wednesday for NE NJ, Lower Hudson Valley
and Southern CT. Flood watch remains in effect for NYC and Long
Island 6PM tonight until 12PM Wednesday.
WPC has moderate risk for much of the area for Northeast NJ,
Lower Hudson Valley and Southern CT with NYC and Long Island in
a slight risk for excessive rain for this afternoon through
tonight.
A major storm system will bring a total of 2 to 3.5 inches of
rain with locally higher amounts this afternoon into early
Wednesday. The bulk of the heaviest rain will occur tonight.
Some GFS ensemble members indicating possible 4+ inches of
rainfall across some parts of Southern Connecticut.
There will be potential for widespread urban and poor drainage
flooding as well as river and stream flooding. The river and
stream flooding would potentially linger through the day
Wednesday and potentially into Thursday.
Hourly rainfall rates maximum according to HREF look to be more
between a half inch to three quarter of an inch overnight. An
isolated area of 1 inch per hour of rainfall rate is possible
but will be quite brief in duration.
There is forecast moderate to major flooding for some area
rivers especially in NE NJ.
Hydrologic impacts are possible Fri ngt and Sat with another
round of hvy rain possible. The exact magnitude and extent of
the issues are uncertain this far out, but most of the cwa is
under a Slight Risk from WPC.
&&
.TIDES/COASTAL FLOODING...
Significant ocean dunefront damage expected Wednesday.
Widespread minor to moderate coastal flooding with Wed AM high
tide. Localized major coastal flooding will be possible,
especially within the South Shore Bays of Long Island.
NY HOPS Steven Institute surge models actually have went back up
compared to 24 hours ago in terms of the total water level
forecasts.
SE storm force expected tonight into early Wednesday, with a
windshift to west southwest gale likely just before the time of
high tide for most areas. This windshift will likely limit
potential for locally major coastal flooding to just the Great
South Bay of LI. Elsewhere, widespread moderate flooding likely
for southern bays of NYC/LI and eastern bays of LI, and SE CT.
Elsewhere generally minor flooding.
Minor coastal flooding possible for the southern bays of W LI,
and along W LI Sound this evening as E/SE increase towards gale
force.
Along the oceanfront, potential for 15-20 ft surf causing
widespread dune erosion and scattered overwashes Wed AM.
Localized dune inundation/breaches possible where dunes have
been compromised by earlier storm events. 10 to 15 ft breaking
surf expected with Wed PM high tide, and with lower water
levels, expect dune impacts to be lower magnitude and less
widespread.
Coastal flood impacts are possible around the times of high
tide Friday night and Saturday with another deep low tracking
west of the area.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Flood Watch from 6 PM EST this evening through Wednesday
afternoon for CTZ005>012.
Wind Advisory from 6 PM this evening to 6 AM EST Wednesday for
CTZ005>007.
High Wind Warning from 6 PM this evening to 6 AM EST Wednesday
for CTZ008>012.
Coastal Flood Advisory from 7 PM this evening to noon EST
Wednesday for CTZ009-010.
Coastal Flood Warning from 6 AM to noon EST Wednesday for
CTZ011-012.
NY...Flood Watch from 6 PM EST this evening through Wednesday
afternoon for NYZ067>071.
Wind Advisory from 6 PM this evening to 6 AM EST Wednesday for
NYZ067>070.
High Wind Warning from 6 PM this evening to 6 AM EST Wednesday
for NYZ071>075-078>081-176>179.
Coastal Flood Advisory from 7 PM this evening 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 6 PM EST this evening through Wednesday
morning for NYZ072>075-078>081-176>179.
Coastal Flood Warning from 4 PM this afternoon to 1 PM EST
Wednesday for NYZ079>081-179.
Coastal Flood Warning from 4 AM to 10 AM EST Wednesday for
NYZ178.
NJ...Flood Watch from 6 PM EST this evening through Wednesday
afternoon for NJZ002-004-006-103>108.
Wind Advisory from 6 PM this evening to 6 AM EST Wednesday for
NJZ002-004-103>108.
High Wind Warning from 6 PM this evening to 6 AM EST Wednesday
for NJZ006.
Coastal Flood Advisory from 5 AM to 10 AM EST Wednesday for
NJZ006-104-106-108.
MARINE...Storm Warning from 6 PM this evening to 6 AM EST Wednesday for
ANZ331-332-335-340-345.
Storm Warning from 4 PM this afternoon to 6 AM EST Wednesday
for ANZ338-350-353-355.
&&
$$
SYNOPSIS...JMC/JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...JMC
AVIATION...JMC
MARINE...JMC/JM
HYDROLOGY...JMC/JM
TIDES/COASTAL FLOODING...