000
FXUS61 KOKX 081716
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1216 PM EST Mon Jan 8 2024
.SYNOPSIS...
High pressure builds over the area into tonight and then moves
offshore Tuesday. Deepening low pressure will track from the
Midwest and towards the Great Lakes Tuesday, sending a strong
frontal system through the area Tuesday night into Wednesday.
Another strong low pressure system could bring heavy rain and
high winds to the area late Friday into the weekend.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Forecast on track this afternoon.
High pressure is in control through tonight with dry conditions
over the region. Mostly clear skies are expected with highs in
the lower 40s. High pressure moves offshore tonight. Clouds
increase late into early Tuesday morning. Still enough time
period for efficient radiational cooling with ridging aloft to
start tonight. Vast range of lows from mid 30s for parts of NYC
to upper teens for parts of interior and Pine Barrens of Long
Island.-- End Changed Discussion --
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
Key Points
* A major storm system will impact the region Tuesday night
into Wednesday.
* Heavy rain will cause potential flooding across the region
Tuesday night into Wednesday. Longer timeframe for interior
areas with flooding due to potential for elevated river and
stream flows that will take longer to subside.
* Strongest winds with gusts potentially up to around 60 mph for
Tuesday night along the coast, closer to 50 mph farther
inland.
* Coastal flooding potential with Wednesday morning high tide
but uncertainty on timing of greatest surge.
No additional changes have been made to the Flood Watch and
High Wind Watch from the early morning forecast update.
The flood watch is in effect longer for NE NJ, Lower Hudson
Valley, and Southern CT, which covers any rivers or streams
that will take longer time for subsiding levels. Some rivers and
streams in these locations may remain above their respective
flood stages well after rain ends Wednesday, lingering into the
afternoon hours. Another element with these interior areas is
the added runoff from snowmelt from pre-existing snowpack.
The flood watch is in effect Tuesday evening until noon
Wednesday for the NYC and Long Island region. There is potential
for rapid rainfall accumulations as indicated by some SREF and
GFS ensemble members Tuesday night especially in the mid evening
to overnight hours. A quick 1 to 2 inches potentially in a 3
hour timespan, which approaches flash flood guidance values.
The highest wind potential continues to be across southeastern
portions of NYC metro and Long Island is where there is highest
potential for wind gusts near 60 mph Tuesday night. Farther
north and west, gusts are more limited to near 50 mph. May need
to expand the higher winds into coastal CT.
Deepening trough with strengthening upper level jet picks up Gulf
moisture Tuesday. The upper jets right rear quadrant approaches
getting near the region by early Wednesday.
Mid level trough moves across Wednesday with its associated
vorticity maximum. At the surface, low pressure deepens as it
travels from South Central US to the Great Lakes Tuesday into
Tuesday night. The increasing baroclinic zone will increase
frontogenesis and enhanced lift can be expected across the
region. With layer precipitable waters approaching near 1.3 to
1.4 inches Tuesday night, very heavy rain can be expected.
According to OKX sounding climatology, this is near max and well
above 90th percentile. This is from strong low level southerly
jet and increased low level moisture advection, low level jet
near 90 kt from numerical weather prediction models. Some
elevated instability will allow for an isolated thunderstorm
late Tuesday night.
CAMS depict a squall line amongst other areas of discrete heavy
rain from reflectivity forecasts that move across Tuesday night.
Bulk of rain finishes by early Wednesday morning, but more periodic
rain is forecast for Wednesday until early afternoon. POPs for
the rain Wednesday morning into early afternoon are chance. The
bulk of the rain will have ended early Wednesday morning, so
remainder of the morning into early afternoon, additional rain
will be light. Dry conditions are forecast mid to late Wednesday
afternoon.
Temperatures remain above climatological Tuesday night and
Wednesday.-- End Changed Discussion --
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A gusty, well-mixed but colder airmass builds in Wed ngt and
Thu. Strong subsidence so dry wx is expected. With the breezy
unidirectional flow, the NBM temps seemed reasonable with less
weight given to radiational cooling local climo.
The main focus of the long term will be on yet another deep low
tracking W of the area on Sat. The GFS has a 965 low near Detroit at
12Z Sat. The ECMWF is close at 970. H85 winds in the cwa modeled at
85kt. Another high wind event very possible. In addition, strong
moisture transport should yield a round of hvy rain, and possible a
few embedded tstms, at the onset. There is a significant dry slot
however that is progged to cut the pcpn off after the initial surge.
The occluded low tracks into Canada late Sat and Sun, leaving
strong wly flow locked into the area. There could be some pockets of
light snow rotating into the area around the deep low, although
downslope will attempt to dry things out before reaching the cwa.
The NBM with local adjustments was used for temps Fri-Sun.
&&
.AVIATION /17Z MONDAY THROUGH FRIDAY/...
High pressure builds in today, sliding offshore tonight ahead of
incoming storm system Tuesday.
Mainly VFR thru 12Z Tue. MVFR cigs develop late Tuesday morning.
NW winds gusting 20-25 kt this morning, then gradually
diminishing this afternoon. Light and vrb winds tonight, then
increasing after 12Z Tue out of the SE.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Gusts may only be occasional at times today.
Direction may hang near or just right of 310 mag into late
afternoon.
Timing of MVFR cigs may be off by a couple of hours.
OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY...
Tuesday: MVFR becoming IFR in the afternoon and night. Rain during
the afternoon and becoming heavy at night. E-ESE winds 15-20kt with
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 2kft 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
35-45kt. Gusts decrease afternoon into the night.
Thursday: VFR. WSW winds 10-15kt with gusts near 20kt.
Friday: Mainly VFR. Chance of MVFR and rain by nighttime.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
-- Changed Discussion --
SCA remains in effect on ocean east of Fire Island Inlet through
early this evening. Sub-SCA conditions briefly thereafter for
tonight.
Tuesday conditions will ramp up quickly late day into the
evening. Brief SCA conditions late Tuesday will escalate to
gales in the evening and then storm force winds potentially late
evening into overnight. There is a storm force watch for all
waters Tuesday night.
Wednesday will likely have residual gales with otherwise
widespread SCA level wind gusts. Forecast leaning towards more
gales for Wednesday.
Gales Wed ngt come down to sca lvl winds on Thu. Winds diminish blw
sca lvls Thu ngt, but seas on the ocean generally remain blw 5 ft.
All waters may be blw sca lvls Fri, then winds ramp up quickly Fri
ngt into Sat with gales to storm force winds possible.-- End Changed Discussion --
&&
.HYDROLOGY...
-- Changed Discussion --
No hydrologic impacts are expected through tonight.
Rain increases Tuesday afternoon into the evening, becoming
moderate. Mostly heavy rain expected Tuesday night. Rain comes
to an end Wednesday morning. Bulk of rain expected Tuesday
night.
A total of 2 to 3 inches with locally higher amounts is
forecast. Runoff from snowmelt and saturated grounds could add
to the flooding concerns.
Whole area has potential for flash flooding Tuesday night.
River flood potential continues across the interior where
elevated river and stream flows will lead to enhanced flood
potential. The river flooding could very well linger into the
day Wednesday with longer residual time for stages to subside
across some rivers and streams.
The Weather Prediction Center Excessive Rainfall Outlook
has much of the interior in a moderate risk. The rest of the
forecast region remains in a slight risk. This is for Tuesday
into early Wednesday morning.
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.-- End Changed Discussion --
&&
.TIDES/COASTAL FLOODING...
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.
Some coastal flood impacts are possible around the times of high
tide Fri ngt and Sat with another deep low tracking W of the
area.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...Flood Watch from Tuesday evening through Wednesday afternoon
for CTZ005>012.
NY...Flood Watch from Tuesday evening through Wednesday afternoon
for NYZ067>071.
Flood Watch from Tuesday evening through Wednesday morning for
NYZ072>075-078>081-176>179.
High Wind Watch from Tuesday evening through late Tuesday
night for NYZ074-075-078>081-176>179.
NJ...Flood Watch from Tuesday evening through Wednesday afternoon
for NJZ002-004-006-103>108.
MARINE...Storm Watch from Tuesday evening through late Tuesday night
for ANZ331-332-335-338-340-345-350-353-355.
Small Craft Advisory until 6 PM EST this evening for ANZ350-
353.-- End Changed Discussion --
&&
$$
SYNOPSIS...JMC/JM
NEAR TERM...JM/DS
SHORT TERM...JM
LONG TERM...JMC
AVIATION...JMC/DR
MARINE...JMC/JM
HYDROLOGY...JMC/JM
TIDES/COASTAL FLOODING...