000
FXUS61 KOKX 061449
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
949 AM EST Wed Mar 6 2024
.SYNOPSIS...
A frontal system and associated low pressure moves through later
today and tonight. The low will linger just east of the area through
Thursday night. High pressure will briefly nudge down from the north
on Friday. Another storm system will impact the region late Saturday
into Sunday. High pressure slowly builds back early next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
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No changes for this update as the forecast is on track. Will be
waiting for more 12Z guidance to come out before deciding on
any alterations to the rainfall forecast.
Look for a mainly dry morning, but with some spots experiencing
some fog perhaps for the next couple of hours with light winds
and a moist ground and moist low levels. A closed mid level low
swings up from the south for the afternoon and into this
evening. Ahead of it much of the morning looks to be dry, with
the next slug of higher PWATs / moisture pushing up from the
south for the afternoon and evening. Rain should break out
mostly from the S and SW, to the N and NE through the afternoon,
with far No. CT zones seeing the rain very late in the day.
Looking at the latest HREF PMM rain amounts and rates look
rather impressive where the moisture / heavy rain axis can set
up. Other than the ECMWF, the other global guidance by and large
has the higher IVT and PWATs values perhaps being just a bit
further to the east compared to the higher majority of the
higher resolution HREF members. The ECMWF and NAEFS Situational
Awareness Tables (ESATs) have 3 to 4 standardized anomalies with
respect to the moisture plume moving into the area. This is
based on the climatology for the time of year, and March is not
typically a favored time of year for impactful heavy rain.
However the higher resolution guidance cannot be dismissed, thus
continuing with the Flood Watch for the area. There still
remains questions with the degree of instability, however there
should be enough warm rain processes to drive rain rates of up
to a half inch to one inch per hour in the heaviest rain. The
best chance of this occurring will be towards 22z through about
06 to 08z across far E and NE sections. The guidance does not
appear to have the rain train for long over the same areas, and
it does move out quickly with most of the guidance. Current
consensus thinking with respect to the various NWP points to a
slug of 4 to 6 hours of moderate to heavy rain. The relatively
bigger concern is for eastern and northeastern portions of the
CWA from Central LI, N and NE into Central and Eastern CT. The
duration of heavy rainfall could be a couple of hours longer,
perhaps closer to 6 hours and would result in locally higher
amounts of 3 to 4 inches. Otherwise, most rainfall totals will
fall in the 1 to 3 inch range. Antecedent conditions remain
rather saturated from previous rainfall, with antecedent
conditions only worsening / getting more saturated going forward
in time with each subsequent rain event. Thus WPC continues
with the marginal to slight risk across our area today and
tonight, with the slight risk portion expanded slightly to the
west over the past couple of excessive rainfall product
iterations. With respect to the best thermal forcing driven by
the LLJ of around 40 kts at 850 mb, it appears to be further
east over the less flood prone areas. However the western edge
of the heavy rain axis will be right around the NYC metro and
portions of NE NJ and the eastern portion of the Lower Hudson
Valley. The HREF PMM appears more bullish on this potential, but
may be a bit overdone with respect to the heavy rainfall
duration across the area by a couple of hours. Temperatures will
run well above normal today with mainly 50s region wide despite
the clouds and the onshore flow.
The lower level jet and better mid level forcing gets further east
and north later tonight and into early Thursday morning. Look for
the rain to taper by the late evening, probably just before midnight
further west, but to the far east and northeast closer to 8-9z.
Temperatures will average around 10 degrees above normal, perhaps up
to 15 degrees in some locations tonight.-- End Changed Discussion --
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
On Thursday look for a purely stratiform rain with the winds having
more of a northerly component as low pressure attempts to redevelop
just to the south and southeast. Rainfall on Thursday will be on the
lighter side, and there is the chance that rain may completely shut
off for western areas late in the day. Have gone with consensus PoPs
on Thursday into Thursday night with the relatively higher PoPs
further east, especially earlier on. Temperatures will continue to
average above normal despite a good deal of clouds with mainly lower
and middle 50s for daytime maxes. For Thursday night the clouds
break up late in the evening, with clearing from west to east later
at night with a drier north breeze. Cooler air does arrive with
temperatures still a few degrees above average, but noticeably cooler
late at night.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
Confidence continues to increase in unsettled weather returning for
the upcoming weekend. The weather pattern looks quieter for the
first half of next week.
*Key Points*
*Low pressure slowly departs to the east Friday with dry conditions
through Saturday morning.
*The next storm system approaches Saturday, impacting the area late
in the day through Sunday.
*Another period of moderate to locally heavy rainfall is possible
with the weekend system, but specific impacts are unknown at this
time and may be related to where the heaviest rain falls with the
Wednesday/Wednesday night system.
*Dry weather returns the first half of next week.
Broad low pressure will be situated off the east coast Thursday,
with the associated upper level trough over the northeast.
There is a good agreement among the modeling that the trough axis
will be slow to depart to the east. While the deepest moisture
should be offshore, there will likely be some lingering lighter rain
in the morning, which becomes scattered in the afternoon. Some of
the latest guidance is hinting at a mostly dry Thursday afternoon
with some lingering low clouds and a few sprinkles. Any impactful
rain with the mid week system is likely to occur through Wednesday
night and no additional significant rain is currently expected
Thursday.
A brief period of dry weather takes place Friday as a ridge returns
aloft and high pressure takes control at the surface. Expect a
mostly sunny day Friday. The ridge axis shifts east Friday night
into Saturday morning ahead of the next storm system. Developing low
pressure across the Plains on Friday shifts towards the Great Lakes
Friday night through Saturday. The low then tracks towards southeast
Canada Saturday night with redevelopment taking place over New
England Sunday morning. The low continues to deepen as it occludes
near Maine later Sunday into Sunday night.
The parent low passing well to our NW and retreating high pressure
support this event being a rain event. The latest model consensus
brings in the steadiest rain Saturday evening through Sunday
morning. Moderate to locally heavy rain could occur with this system
with another 1-2 inches of rain possible. These details are still of
lower confidence given that the event is several days away. It is
also important to note that where the heaviest rain occurs with
today / tonight`s system may result in hydrologic impacts with the
weekend system. The system departs Sunday with the associated upper
low passing through Sunday into into early Monday. There could be
some lingering precip Sunday night with the upper low with a low
potential of a rain/snow mix well inland.
High pressure builds in Monday into Tuesday and will be in control
into the middle of next week. Temperatures will be above normal
Friday in the upper 40s and lower 50s. Near normal highs in the
middle to upper 40s are expected Saturday with highs to slightly
above normal readings Sunday. Temperatures Monday may be below
normal in the lower to middle 40s before a warming trend Tuesday
into Wednesday.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
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Low pressure approaches from the south today, passing over the
area terminals this evening and overnight.
IFR or lower with little improvement today. Terminals likely
decline to LIFR or lower this afternoon as rain moves into the
area after 18Z.
Period of moderate to locally heavy rainfall this evening into the
first half of tonight. Likely a 3-5 hour window of this,
generally between 22z-03z for the NYC terminals, but could
linger several hours thereafter. After 06z, rain will start to
taper off from west to east. Some slow improvement is expected
toward 12z Thursday, with MVFR cigs possible. Return to VFR late
Thu AM or early afternoon.
Light and variable winds this morning take on more of a E to NE
direction as the low approaches from the south. As the low passes
over the area, winds become more northerly tonight. Winds remain
around or less than 10kt through much of the TAF period.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments liekly for changing flight categories.
OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY...
Thursday: MVFR or lower earlier, improving to VFR by afternoon.
Winds N to NE G20- 25kt.
Friday: VFR.
Saturday: MVFR with a chance of rain early, then rain likely late
day and at night.
Sunday: MVFR with rain in the morning. Possibly VFR in the afternoon
with a chance of rain.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Small craft conditions will prevail on the ocean waters with mainly
4 to 6 ft seas today. Seas will climb higher tonight into Thursday.
Small craft gusts will become increasingly likely into Thursday
morning on the non-ocean waters, and could linger into Thursday
night, especially further east. SCA conditions continue on the ocean
Friday. Winds should largely fall below SCA levels Friday except
well east of Moriches Inlet. Seas will remain elevated. A brief
period of sub-SCA conditions are expected Friday night before the
next storm system this weekend. SCA conditions should return late
Saturday and especially Saturday night and Sunday.
&&
.HYDROLOGY...
WPC maintains a slight to marginal risk of excessive rainfall today
and tonight. A flood watch remains in effect. Widespread minor
flooding is expected, with some river flooding as well as more
significant flash flooding possible.
An additional 1 to 2 inches of rain could fall with the storm system
this weekend. Impacts with this event are still somewhat uncertain
as it will depend on where the heaviest rain falls with the
Wednesday/Wednesday night system.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...Flood Watch from 1 PM EST this afternoon through late tonight
for CTZ005>012.
NY...Flood Watch from 1 PM EST this afternoon through late tonight
for NYZ068>075-078>081-176>179.
NJ...Flood Watch from 1 PM EST this afternoon through late tonight
for NJZ002-004-006-103>108.
MARINE...Dense Fog Advisory until 1 PM EST this afternoon for ANZ331-
332-335-338-340-345-350-353-355.
Small Craft Advisory from 10 AM Thursday to midnight EST
Thursday night for ANZ331-335-338-340-345.
Small Craft Advisory from 10 AM Thursday to 6 AM EST Friday
for ANZ332.
Small Craft Advisory until 6 AM EST Friday for ANZ350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...JE/DS
NEAR TERM...JE/BR
SHORT TERM...JE
LONG TERM...DS
AVIATION...BC
MARINE...JE/DS
HYDROLOGY...JE/DS