000
FXUS61 KOKX 281737
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1237 PM EST Wed Feb 28 2024
.SYNOPSIS...
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.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
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 cold front passage will be accompanied by a line of
moderate to heavy showers with isolated thunderstorms.
A strong frontal system moves across the region through this
evening. Occasional showers will continue to move across the
region through the rest of the afternoon. A rumble of thunder
cannot be ruled out as there is some elevated CAPE, but radar
trends would favor activity remaining light to moderate showers.
There may be a brief lull in the showers late this afternoon
before a line of showers with isolated thunderstorms move across
the region. The system is progressive which will negate any
flooding threat other than some ponding or minor urban flooding
at worst.
The cold front should move 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 shower 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. Winds have been running weaker than forecast so far
despite the strong winds aloft. Think winds will reach advisory
criteria everywhere with the cold front passage as strong cold
advection and mixing takes place. This is when 45 to 50 mph
gusts are likely around 7pm to 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.
&&
.SHORT TERM /6 AM THURSDAY MORNING 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 WEDNESDAY/...
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 /18Z WEDNESDAY THROUGH MONDAY/...
-- Changed Discussion --
The area remains in the warm sector of a frontal system. A
strong cold front approaches this afternoon and moves through
the terminals this evening into the first half of the overnight.
Conditions vary from MVFR to LIFR across the area. Some isolated
and brief spots of VFR are possible early this afternoon. A
drop back to IFR is expected later this afternoon into this
evening ahead of the cold frontal passage.
Rain showers today with a period of more steady and moderate
rain immediately ahead of the cold front late this afternoon
and early this evening. 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, into the afternoon. KTEB and KEWR will
see wind shear this afternoon and not as strong, with winds at
2000 ft at around 40-50 kt.
Otherwise, strong and potentially gusty southerly winds
continue through this afternoon, 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 early this afternoon
before becoming more frequent in the later afternoon.
The timing for the frontal passage, abrupt wind shift to the
west, and the strongest wind gusts up to 40-45kt is:
00-02Z for KSWF, KTEB, KEWR, KLGA, KJFK, and KHPN.
01-03Z for KBDR and KISP.
02-04Z for KGON.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Unscheduled AMD likely for timing of changing flight categories
into the evening. LLWS may be stronger that forecast with a low
level jet of 65 to 75 kt. Gusts may be more occasional this
afternoon before picking up in frequency closer to this evening.
OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...
Thursday Afternoon: VFR. NW winds diminishing to 15-20G25-30kt 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.
Monday: 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...
Additional rainfall around 0.75 to 1.25 inch is forecast through
this evening. 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...MW
MARINE...JM/JP
HYDROLOGY...JM/JP