000
FXUS61 KOKX 232006
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
406 PM EDT Sun Apr 23 2023
.SYNOPSIS...
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Low pressure heads northeast this afternoon while a secondary cold
front passes through into this evening. High pressure then slowly
begins to build toward the area Monday. The area will be in
between low pressure to the northeast and high pressure to the
southwest on Tuesday. High pressure builds a little more into
the area going into midweek. The high pressure area will move
offshore Wednesday into Wednesday night. A trough of weak low
pressure moves across Wednesday night into Thursday. An area of
low pressure moves south of the region Thursday afternoon into
Thursday night. Another low moving south of the region may
impact the area Friday into next weekend with high pressure
northeast of the region.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
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GOES-16 6.19 micron WV depicting a potent mid/upper low located over
northern MN this afternoon with several shortwaves embedded amongst
the broader cyclonic flow. At the surface, low pressure was located
over eastern Long Island moving east with a cold front to the south,
and a secondary cold front located further to the west, over
eastern PA.
As the aforementioned surface low heads east, westerly winds with a
cooler and drier airmass (dewpoints in the 30s and 40s) were
advecting from the west into the region. Lingering
precipitation from yesterday/last night`s event was noted over
extreme eastern portions of southeastern CT and was slowly
moving east. With westerly flow and clearing behind the low,
temperatures have risen into the low and mid 60s (upper 60s in
NYC per NYC micronet obs), but remain in the 50s where cloud
cover remains slower to move out over eastern areas and is not
likely to recover much this afternoon.
This evening, a potent mid level shortwave trough and secondary
cold front will pass through the region. Along with an increase
in the Cu field, a shower and perhaps an isolated thunderstorm
are again possible for mainly areas north and west of NYC
through early evening. HREF member/CAM soundings are showing
some instability aloft given the proximity to the mid level
shortwave noted earlier. Any activity appears diurnally driven,
and should weaken with the loss of daytime heating.
Under westerly flow, lows tonight will be in the low and mid 40s
across the urban and coastal areas and upper 30s in the interior.
The westerly flow should keep temperatures from bottoming out too
close to the dewpoints, which should be in the low and mid 30s.-- End Changed Discussion --
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
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Surface high pressure builds in from the southwest slowly on Monday
while another mid and upper trough rotates around an upper low over
the Great Lakes. The day looks mostly dry, though will start out
cloudy across eastern portions of the area with lingering
low/mid level moisture. By afternoon, clouds will be on the
increase across the interior, in the vicinity of the upper
trough, with a chance of an isolated shower. Given the very dry
low levels, up to about 700mb, thinking is that it will be tough
for any shower that does develop to reach the surface, so have
left PoPs out of the afternoon forecast.
Highs will be seasonable to slightly below, in the low to mid
60s.-- End Changed Discussion --
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
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A mid level low hovering in Southeast Canada will result in a quasi
zonal mid level flow across the region Tuesday through Thursday.
Then, more of a ridging pattern is conveyed by the forecast models
Friday into Saturday in the mid levels but there is still potential
for the ridge to breakdown with trough development to the south and
west. A deeper much more amplified trough approaches from the west
next Sunday.
At the surface, the area will be in between high and low pressure
Tuesday but the pressure gradient will be weak. The high pressure
gradually builds more into the area Tuesday night into Wednesday
morning. The high pressure then shifts offshore for the rest of
Wednesday and continuing into Wednesday night.
A trough of low pressure approaches Wednesday night and moves across
early Thursday. A larger area of low pressure will be moving well
south of the region and out into the Atlantic. Another low may
impact the region Friday into next weekend but the model uncertainty
increases in this timeframe of the forecast. The forecast models
generally agree with high pressure northeast of the region and low
pressure south of the region. Models vary in their depiction of the
location of the low pressure center and its magnitude. Models have a
general better agreement with the high location, Southeast Canada
into the Canadian Maritimes.
In terms of weather, rain showers chances are forecast Wednesday
into Thursday with the low pressure trough. Another prolonged chance
of rain showers is forecast Friday into next weekend but confidence
is lower in this part of the forecast so do no expect rain to last
all day and all night.
Overall, temperatures are not expected to deviate significantly from
normal. There could be some frost for interior areas north and west
of NYC for late Tuesday night into early Wednesday morning.
Noting increased pressure gradient and increased easterly flow
Friday through next Sunday, removed Pine Barrens radiational cooling
effect for lows Friday night and Saturday night, because of winds
staying up and mitigating the radiational cooling. Thus, expecting a
less vast range of low temperatures in general across the region for
these nights.-- End Changed Discussion --
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
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Shower activity has gradually ended from southwest to northeast
across the region this afternoon as a wave of low pressure and
cold front advance northeast.
Cigs/vsbys have improved to VFR behind the showers, with the
exception at KGON where IFR/MVFR conds linger. VFR forecast for
all after 22z this evening.
Winds have shifted to the WNW or NW behind the low, with the
exception of KGON, where SE flow continues for several more hours
until the frontal wave moves through. The NW flow then continues
through tonight, backing a bit to the W or SW Monday afternoon.
Speeds 10-15 kt, with gusts up to 20 kt this afternoon, and around
10 kt on Monday. A few widely scattered showers are possible Monday
afternoon, with highest chances across the interior, particularly
KSWF, though cannot be ruled out elsewhere.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Gusts may be more occasional this afternoon and early evening.
A rain shower or two is possible Monday afternoon, confidence in
coverage is low.
OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
Monday Aft/Eve: VFR. W wind around 10 kt.
Tuesday and Wednesday: VFR.
Thursday and Friday: MVFR or lower in rain showers.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
SCA has been extended for the eastern Sound though 00Z with sfc low
still to the southwest and southeast gusts near 25kts still
occurring just downstream. Expecting that the gusts weaken rapidly
once the low passes by and winds shift back to the W/NW. SCA conds
continue into tonight on all ocean waters with seas still 4-6ft to
the west and near 7ft east of Moriches Inlet. Hazardous ocean seas
may linger into daytime Monday east of Moriches Inlet.
Tuesday through Thursday night, pressure gradient overall will be
relatively weak, allowing for forecast conditions on all waters to
remain below SCA thresholds. SCA conditions forecast on most waters
Friday into Friday night with an increasing pressure gradient from
high pressure northeast of the waters and low pressure to the south.
This will help drive an increasing easterly flow.
&&
.MARINE...
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SCA has been extended for the eastern Sound though 00Z with
southeast gusts near 25kts still occurring just downstream.
Expecting that the gusts weaken rapidly once the low passes by
and winds shift back to the W/NW. SCA conds continue into
tonight on all ocean waters with seas still 4-6ft to the west
and near 7ft east of Moriches Inlet. Hazardous ocean seas may
linger into daytime Monday east of Moriches Inlet.-- End Changed Discussion --
&&
.HYDROLOGY...
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There are no anticipated hydrologic concerns from Monday
through Sunday.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 9 PM EDT this evening for ANZ332.
Small Craft Advisory until 6 AM EDT Monday for ANZ350-353.
Small Craft Advisory until 2 AM EDT Monday for ANZ355.-- End Changed Discussion --
&&
$$
SYNOPSIS...JM/DBR
NEAR TERM...DBR
SHORT TERM...DBR
LONG TERM...JM
AVIATION...DR
MARINE...JM/DBR
HYDROLOGY...JM/DBR