000
FXUS61 KOKX 280917
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
417 AM EST Wed Feb 28 2024
.SYNOPSIS...
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A warm front moves across the region today, followed by a cold front
passage this evening. A secondary cold front moves across Thursday.
High pressure then builds in thereafter going into Thursday night.
This high pressure area moves out into the Atlantic on Friday. An
inverted trough or wave of low pressure could bring a period of
unsettled weather over the weekend into early next week.-- End Changed Discussion --
&&
.NEAR TERM /THROUGH TONIGHT/...
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Main points
* Wind advisory expanded to include entire forecast region. Suffolk
NY and New London CT closest to low level jet max have wind
advisory start this morning and continue through tonight while the
remainder of the region starts at 4PM this afternoon and goes
through tonight.
* The reasoning and details for this wind advisory is that post cold
front this evening into the overnight is when most gusts will be
observed up to near 45 to 50 mph. Heavy rain showers and isolated
thunderstorms will help bring down these higher gusts via downward
momentum transport with deep mixing expected post cold front with
the strong cold air advection which will make for more gusty
strong winds.
For today through tonight, mid level flow remains SW. A mid level
trough approaches from the west today and then crosses into the
region tonight. With its passage through the region tonight will be
an increase in positive vorticity advection. This vort max moves
into western parts of the region the first half of tonight and then
moves across the eastern half of the region overnight. Large scale
models exhibit general coherence and agreement of solutions
regarding 500mb height and vorticity based on 00Z GFS, 00Z NAM, 12Z
ECMWF and 00Z Canadian but the 00Z NAM appears to be faster than the
other aforementioned models.
At the surface, a warm front moves across the region today
with winds picking up thereafter and become more SW. A strong
cold front will be approaching from the west. This front moves
through the region during the evening hours. From the large
scale model depictions of 00Z GFS, 00Z NAM, 12Z ECMWF, and 00Z
Canadian, the models agree with a sharp frontal boundary but
exhibit some differences regarding the speed of the front. GFS
appears fastest, showing the front east of the area by 03Z
Thursday. Otherwise, all other models do agree with front being
east of the region by 06Z Thursday. The HRRR shows the cold
front east of the region by 04Z Thursday.
Regarding the precipitation, most of this will be in the form of
rain with exception of post cold front and possible snow showers
that could develop overnight into early Thursday morning. There will
be strong cold air advection as seen in 00Z GFS, 00Z NAM, 12Z ECMWF
and 00Z Canadian models all depicting a decrease of near 20 to 25
degrees C with 850mb temperatures from early Wednesday morning to
early Thursday morning. The showers late tonight will have
difficulty forming due to strong dry air advection as well as
cold air advection. There will be more limits to the moisture.
Depending on how well winds are at evaporating the leftover
wet grounds, there may be some puddles that freeze over by early
Thursday morning, making for a patchy ice threat and for
slippery conditions.
GFS and NAM models especially within their BUFKIT profiles
indicate weak elevated instability of less than 100 J/kg.
Normally would not think this present enough instability to
warrant mention of thunderstorms but in this case, considering
the vort max and strong cold front moving in, there will be a
lot of dynamical vertical forcing. Therefore going to mention
isolated thunderstorms.
Regarding BUFKIT profiles, the area is inverted with strong low
level jet during the day today and then tonight, the cold air
advection especially right behind the cold front will allow for much
more mixing. While during the day, the highest winds and wind gusts
are forecast only for eastern sections, at night, the entire area
will have higher winds and wind gusts. Winds from the top of the
mixed layer are not expected to mix down but probably will mix from
not too far below. Using wind gusts consensus between the NAM and
GFS and taking the average between the mean mixed wind gusts and top
of the mixed layer wind gusts for the forecast.
Would expect overall, a high likelihood of getting 45 to 50 mph wind
gusts across the entire region in the time window of near 7PM
tonight and before 3AM Thursday. Model BUFKIT profiles convey a
decreasing trend thereafter with winds and the large scale models
show a relative decrease in the tightness of the pressure gradient.
Concerning temperatures, today utilized NBM and tonight
utilized a combination of NBM and CONSRaw.-- End Changed Discussion --
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
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Negatively tilted mid level trough moves east of the region
Thursday. Westerly mid level flow will become more NW. After some
initial positive vorticity advection to start Thursday morning going
into early Thursday afternoon, there is more negative vorticity
advection thereafter. Accompanying this will be more steady height
rises.
These mid level height rises continue through Friday with more of a
ridging pattern taking shape.
At the surface, large scale models signaling a secondary cold front
that moves through Thursday which will is expected to be a dry
frontal passage. This will be followed by high pressure building in
Thursday night. This high pressure area shifts east and offshore
into the Atlantic on Friday.
With models generally agreeing on 850mb temperatures Thursday
near -12 to -15 degrees C, would expect temperatures to stay
well below normal. Highs stay range from near 30 to 40 across
the region.-- End Changed Discussion --
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
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Friday night begins an extended period when there will be a chance
of rain. A wave of low pressure tries to develop to our south along
a trough. The wave potentially meanders somewhere in the vicinity
between the Mid-Atlantic coast and 40N/70W benchmark through the
middle of next week. Stuck closely to NBM PoPs (which are limited to
chance) from Friday night onward due to the uncertainty. Precip type
should be rain. The only exception would be a low chance that
freezing rain occurs over parts of the far NW fringe of the forecast
area if precip were to occur late Friday night/early Saturday
morning. Temperatures Saturday through Tuesday are expected to
be above normal.-- End Changed Discussion --
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
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A warm front continues moving northward overnight. Another warm
front lifts north this morning. A strong cold front approaches this
afternoon and moves through the terminals this evening west and
tonight east.
Conditions vary from MVFR to LIFR across the area, which should
continue through early this morning. By mid to late morning there
may be a period of brief improvement to MVFR, especially inland as
the area becomes warm sectored as a warm front lifts north of the
area.
Periods of drizzle expected overnight, with a low chance of rain. An
isolated thunderstorm may move through KSWF through 10Z, however
confidence too low to include in the forecast, but included VCTS.
Additional periods of rain move in this morning, and continue until
the cold front passage this evening west, and tonight east.
Low level wind shear will be strong, with 2000 ft southerly winds
50kt to 70kt at the NYC terminals and east, and with the strongest
LLWS at KGON, this morning into the afternoon.
Otherwise, strong and gusty southerly winds continue through today,
quickly shifting to the west and remaining gusty this evening with
the frontal passage. Gusts in some terminals may not materialize
until later this morning, with occasional gusts until then.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Unscheduled AMD likely for timing of lowering, and changing, flight
categories overnight and into Wednesday morning. LLWS may be
stronger that forecast with a low level jet of 65 to 75 kt.
Occasional gusts at KEWR and KTEB of around 20 kt until 12Z with
gusts becoming more prevailing thereafter.
OUTLOOK FOR 06Z THURSDAY THROUGH SUNDAY...
Late tonight: VFR, KGON may be MVFR early, then. West to northwest
winds G30-40kt.
Thursday: VFR. NW winds 20-25G30-35kt in the morning, diminishing to
15-20G25kt late in the afternoon.
Friday: VFR. S winds G15-20kt along the coast.
Saturday: Chance of rain. MVFR cond possible.
Sunday: Slight chance of rain. Mainly VFR.
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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Gales expected to develop today on all waters but may be more
occasional in frequency for some waters. Gales expected to be
frequent tonight during and after cold front passage. Winds trend
down late tonight into early Thursday morning but pick back up
during the day with more gales forecast. The gale warning goes
until 1PM Thursday afternoon.
Winds thereafter trend lower, into SCA range for the rest of
Thursday afternoon, lingering into the evening before dropping below
SCA levels overnight Thursday night. The winds remain below SCA
thresholds on Friday.
Ocean seas remain above SCA thresholds through Thursday evening and
then lower below SCA thresholds late Thursday night with ocean seas
remaining below SCA thresholds on Friday.
Oceans seas build with a swell Saturday night into Sunday as a wave
of low pressure tries to take shape off the Mid-Atlantic coast.-- End Changed Discussion --
&&
.HYDROLOGY...
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Most of the rainfall today through tonight will amount to between
0.75 to 1.25 inch of rain with some locally higher amounts that
could reach up to near 2 inches.
Other than brief minor nuisance flooding of urban and poor drainage
areas, no other significant hydrologic impacts are expected.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...Wind Advisory from 4 PM this afternoon to 7 AM EST Thursday
for CTZ005>007-009>011.
Wind Advisory until 7 AM EST Thursday for CTZ008-012.
NY...Wind Advisory from 4 PM this afternoon to 7 AM EST Thursday
for NYZ067>075-176>179.
Wind Advisory until 7 AM EST Thursday for NYZ078>081.
NJ...Wind Advisory from 4 PM this afternoon to 7 AM EST Thursday
for NJZ002-004-006-103>108.
MARINE...Gale Warning until 1 PM EST Thursday for ANZ331-332-335-338-
340-345-350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...JM/JP
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...JP
AVIATION...JP
MARINE...JM/JP
HYDROLOGY...JM/JP