000
FXUS61 KOKX 281449
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
949 AM EST Wed Feb 28 2024
.SYNOPSIS...
-- Changed Discussion --
A strong frontal system moves across the region through 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/...
-- Changed Discussion --
Main points
* Wind advisory remains in effect for the entire area. Suffolk
and New London this morning and rest of area goes into effect
late this afternoon into the evening.
* Periods of showers likely through the afternoon. An isolated
rumble of thunder possible from NYC west.
A strong frontal system moves across the region through this
evening. The region is within the warm sector this morning with
the expectation of occasional showers through the afternoon. The
showers should become widespread this evening as the main cold
front quickly swings through the region. SPC mesoanalysis
indicates some very minimal MUCAPE and there have been several
lightning strikes observed to our west across PA this morning.
Have added in a slight chance of thunder this morning from the
NYC metro on west. Isolated thunderstorms are also possible with
the cold front this evening. The showers will be progressive
which will negate any flooding threat other than some ponding or
minor urban flooding at worst.
The modeling still differs slightly with the timing of the
front, but it appears the front moves through west of the Hudson
River between 6-9pm and then quickly sweeps east across Long
Island and Southern Connecticut 9pm to midnight.
There will be a sharp temperature drop behind the front with a
decrease of near 20-25C at 850 mb. Surface temperatures in the
50s will quickly drop into the 40s and then 30s immediately
behind the front. There could be a brief snow showers as the
precip ends, but think this is very limited as any precip behind
the frontal passage should quickly end an hour or two after.
The area is inverted with strong low level jet through the
afternoon. The strong 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 and a better chance at seeing gusts
45 to 50 mph across the entire region in the time window of
near 7PM tonight and around midnight. The low level winds
decrease thereafter as the pressure gradient relaxes.
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.-- End Changed Discussion --
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
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.
Dry conditions expected Thursday through 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.
Winds diminish Thursday night and with mostly clear sky
conditions, radiational cooling will be more optimized, allowing
for lows to drop into the upper teens to near 30, using 2/3 MOS
consensus and 1/3 NBM. Temperatures moderate Friday with more SW
flow developing. Highs forecast on Friday are back well into the
40s using NBM.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
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.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
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A warm front lifts north this morning. A strong cold front
approaches this afternoon and moves through the western terminals
this evening and eastern terminals tonight.
Conditions vary from MVFR to LIFR across the area, which should
continue through this morning. Marginal improvement to MVFR is
possible for western terminals before a drop back down to IFR is
expected this afternoon into this evening.
Periods of rain showers today. A period of moderate rain with
the cold front passage this evening for the western terminals,
and tonight for the eastern terminals. The rain may be
accompanied by an isolated thunderstorm. Confidence and coverage
was not high enough to include in TAFs.
Low level wind shear will be strong, with 2000 ft southerly winds
50kt to 70kt at KJFK and KLGA terminals and east, and with the
strongest LLWS at KGON, this morning into the afternoon. KTEB
and KEWR will see wind shear a bit later this afternoon and not
as strong, with winds at 2000 ft at around 40-50 kt.
Otherwise, strong and gusty southerly winds continue through today,
quickly shifting to the west and remaining gusty this evening with
the frontal passage. The strongest gusts (35-40 kt) will likely
occur with the line of showers in association with the
aforementioned cold front. Isolated gusts this evening may
approach 45 kt with the frontal passage. Gusts may be more
occasional this morning before becoming more frequent in the
afternoon.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Unscheduled AMD likely for timing of lowering, and changing, flight
categories into the afternoon and evening. LLWS may be stronger
that forecast with a low level jet of 65 to 75 kt. Gusts may be
more occasional this morning before picking up in frequency this
afternoon.
OUTLOOK FOR 15Z THURSDAY THROUGH SUNDAY...
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...
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.
&&
.HYDROLOGY...
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.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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.
&&
$$
SYNOPSIS...JM/JP
NEAR TERM...JM/DS
SHORT TERM...JM
LONG TERM...JP
AVIATION...JP/MW
MARINE...JM/JP
HYDROLOGY...JM/JP