000
FXUS61 KOKX 231849
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
249 PM EDT Fri Jun 23 2023
.SYNOPSIS...
-- Changed Discussion --
A warm front will approach today and lift through tonight.
Meanwhile, weak low pressure will meander over the Northeast
this weekend as frontal boundaries remain nearby. Another slow
moving frontal system will impact the area early next week. The
front may push through next Wednesday or Thursday.-- End Changed Discussion --
&&
.NEAR TERM /THROUGH TONIGHT/...
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Aloft, there will be some mid level height falls throughout
today as a ridge moves offshore and a trough approaches from the
west. At the surface, a warm front will continue to slowly
approach from the south. Ahead of the front, there will continue
to be ESE-SE flow that will keep a cooler more stable maritime
environment in place.
Without much synoptic forcing today, the shower coverage will
grow in areas that are forecast to get more unstable. Highest
model surface instability is shown to occur across the more
interior parts of the region across parts of interior NE NJ and
parts of the Lower Hudson Valley.
Showers are traversing parts of the region this afternoon,
mainly across parts of Lower Hudson Valley, Southern CT and
Central to Eastern Long Island where showers will be more
numerous. Otherwise, shower coverage will be isolated to
scattered.
Max temperatures have been lowered, only expected to reach
lower 70s for most locations with some mid 70s across parts of
the interior.
For tonight, continued height falls in the mid levels with some
added synoptic forcing with an incoming upper level jet streak
overnight. The left front quad of this jet streak moves near the
area. This will enhance synoptic lift. At the surface, the warm
front continues to approach and the boundary itself starts to
move in late this evening into overnight. Overnight, the warm
front will slowly makes its way northward across the area. There
is uncertainty on how far north the warm front gets as model
have recently over estimated the speed of the warm front.
In terms of weather, outside of Northeast NJ and Lower Hudson
Valley, where more numerous shower coverage is forecast this
evening, shower coverage this evening will be mainly scattered.
Any instability during the day will decrease this evening so
not expecting much for thunderstorms. Patchy fog expected to
develop especially with any lulls in shower activity.
Expecting an increase in elevated instability late tonight as
the warm front gets more into the region. In combination with
the aforementioned increase in synoptic lift, expecting an
increase in shower coverage overnight and an increase for
thunderstorm chances as well. With higher precipitable waters,
some showers and thunderstorms will result in heavy downpours.
Patchy forecast going into overnight especially across eastern
sections of the region but is expected to break up from west to
east with the more vertical mixing as showers increase and
traverse the area for the latter half of the overnight period.
The lows tonight were taken from MOS consensus which were
relatively warmer compared to NBM and the raw consensus data,
with mainly upper 60s expected.-- End Changed Discussion --
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
-- Changed Discussion --
For Saturday morning, expecting widespread showers and scattered
embedded thunderstorms. Aloft, still some height lowering and
jet streak still south of the region with its left front quad
enhancing lift. The warm front boundary may become nearly
stationary within the area. An area of low pressure approaches
the area from the west.
The synoptic enhancement decreases Saturday afternoon into
Saturday evening with the exit of the upper jet streak and
height tendency becoming more steady. With warm air advection on
a continued southerly flow and much of the area in the warm
sector, there is forecast to be more surfaced based instability
especially across western sections of the region. This will
allow for an increasing likelihood of showers and an increasing
chance of thunderstorms for the afternoon into early evening
Saturday. Again, with high precipitable waters in place (near
1.8 inches), could have heavy downpours with some showers and
thunderstorms. Forecast high temperatures Saturday range from
mid 70s to near 80.
Models are conveying a decrease in convection Saturday night
with the loss of diurnal instability and without much synoptic
forcing aloft. Trough will be weakening aloft along with low
pressure and frontal boundary at the surface. Forecast lows from
consensus of MOS, mainly upper 60s still without much change in
airmass.
Warm and muggy conditions expected as we remain in the warm
sector with mainly diurnal showers/tstms likely Sunday
afternoon/evening and especially NW of NYC. PW will approach 2
inches at times, with high precip efficiency, so once again
heavy downpours are possible.
Temperatures will be warmer each day, with highs in the upper
70s/lower 80s for Sat, and in the 80s throughout on Sun. Low
should remain a mostly uniform mid/upper 60s.-- End Changed Discussion --
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
No significant changes to the long term forecast Sunday night
through the middle of next week. The weather pattern will remain
unsettled with temperatures near seasonable levels.
Lingering energy from the first slow moving trough will likely
continue lifting across New England Sunday night. Another larger
trough that approaches from the Great Lakes Monday will amplify as
it slowly swings towards the region through Wednesday. This renewed
troughing will bring another frontal system and a continued
unsettled conditions into at least the middle of the week. The trend
on the models over the last several cycles is for the trough to
linger over the northeast into at least next Thursday.
Showers and thunderstorms are possible on Monday afternoon and
evening, but coverage looks greatest to our west closer to the lift
from the upper trough. Higher probabilities are continued to be
indicated on Tuesday into Tuesday night given the focus from the
associated frontal boundary and upper trough. These chances
continues into Wednesday and potentially Thursday, especially if the
trough axis and frontal system are slower to move through the
region. The pattern supports potential of minor urban and poor
drainage flooding. There is also potential for localized flash
flooding, especially if areas see multiple days of showers and
thunderstorms. However, recent poor model performance with
convection here has brought a lower forecast confidence with regards
to where any heavier rainfall totals could occur.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
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A warm front will approach this evening into tonight. Weak low
pressure then meanders nearby this weekend.
Mainly MVFR to IFR conditions this evening. Any MVFR conditions
will deteriorate this evening to IFR, potentially LIFR
overnight into early Saturday morning as the warm front passes
through.
Scattered showers possible into early evening. There may be a
brief lull in showers after 00-02z followed by increasing
showers and possible thunderstorms again early Saturday morning.
Included a prob30 -TSRA to reflect the increased chance. Isolated
thunder is possible again Saturday afternoon across the
interior west of NYC and Lower Hudson Valley.
Light E-ESE winds will become SE this evening and the S 10 kt
or less tonight. The wind direction should remain S tonight
into Saturday.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments likely for changing flight categories. Overall...a
low confidence forecast with regard to timing of flight
categories at any particular terminal.
OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...
18Z Saturday: MVFR or lower. Showers likely with possible
thunderstorms.
Sunday: Chance of MVFR and showers. Thunderstorms possible in
the afternoon and evening.
Monday: Showers likely with thunderstorms possible, especially
in the afternoon and evening. MVFR or lower possible at times.
S-SE wind gusts 15-20 kt.
Tuesday and Wednesday. Showers likely. Slight chance of
thunderstorms. MVFR or lower possible at times. S-SE wind gusts
near 20-25 kt.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Winds and seas look to remain below SCA levels into Sunday
night and then could begin to approach 25 kt on the ocean waters
late Monday into Monday night, but more likely on Tuesday as
southerly flow increases with the approach of the next frontal
system. Seas may also build close to 5 ft, especially late
Monday through Tuesday.
&&
.HYDROLOGY...
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Locally heavy rainfall is possible each day into early next
week, and minor flooding could occur especially in poor drainage
and low lying areas. Particularly through early Saturday,
precipitable waters will be increasing from near 1.75 inches to
near 2 inches, allowing for heavy downpours with showers and
thunderstorms.
Any hydrologic impacts early next week could be determined by
the extent of the rainfall today into this weekend. WPC
currently has mainly the western half of the area in a marginal
risk for excessive rainfall each day through Tuesday.-- End Changed Discussion --
&&
.TIDES/COASTAL FLOODING...
There is a moderate risk of rip current development for all
ocean beaches for today through Saturday.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...BG/JM/DS
NEAR TERM...JM
SHORT TERM...BG/JM
LONG TERM...DS
AVIATION...IRD
MARINE...BG/DS
HYDROLOGY...BG/DS/JM
TIDES/COASTAL FLOODING...