000
FXUS61 KOKX 241149
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
749 AM EDT Sat Jun 24 2023
.SYNOPSIS...
A warm front lifts through the region this morning. A weak
trough will then linger nearby through the rest of the weekend.
Thereafter, a slow moving upper level disturbance and frontal
system will affect the area for much of the next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
Water vapor imagery shows a fairly well defined shortwave
lifting NNE towards the area this morning. The shortwave along
with some upper jet dynamics has been bringing widespread
showers with some embedded moderate to heavy downpours. Have not
seen many lightning strikes out of the stronger activity with
the closest one to our area over eastern PA earlier this
morning. Have continued to mention slight chance of thunder, but
this may end up being a very isolated occurrence. Showers will
otherwise continue into the morning before tapering off from
south to north late this morning as the shortwave lifts north.
This will also help bring the warm front through the region.
Brief height rises are expected this afternoon, especially for
eastern portions of the area. Lingering energy from the upper low
that has been hanging back to our north and west will slowly
approach this afternoon and evening. A lingering surface trough
looks to remain nearby, likely over the Lower Hudson Valley and NE
NJ. These features support a high chance to low likely PoP across
the Lower Hudson Valley and NE NJ. Cannot rule out showers or a
thunderstorm further east, but coverage looks lower with little
upper level support and the surface boundary further west. The
atmosphere will be moist with PWATs near 1.75 inches, so any shower
or storm could produce locally heavy rainfall. Minor flooding would
be the main concern.
Otherwise, temperatures will be near seasonably levels in the upper
70s to low 80s. Humidity levels will continue high with dew points
in the upper 60s.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
Convection likely diminishes this evening with loss of heating.
Main uncertainty for tonight revolves around whether or not fog
develops and becomes widespread, especially near the coast.
Have included patchy fog for now for the eastern half of the
area. One negating factor is the winds look to be SSW-SW in the
low levels over S-SE. 15-20 kt of flow is also indicated on
forecast soundings above the surface, which could help keep
dense fog from developing due to turbulent mixing. Dry
conditions should prevail overnight, but it will be quite humid
with lows in the 60s.
A similar convective environment looks to set up on Sunday.
There will still be a lingering surface trough in the vicinity.
The aforementioned closed low likely opens up as it begins to
move over the area. These features along with potential
convergence of inland moving sea breezes support development of
showers and thunderstorms, mainly in the afternoon and evening.
The airmass is marginally unstable and shear is weak. Lower and
middle level winds look weaker than on Saturday, so convection
could be slow moving leading to a minor flooding and/or
localized flash flooding threat. WPC has continued with a
marginal risk for excessive rainfall, mainly across the western
half of the area. Efficient heating is expected Sunday morning
into the afternoon, with highs getting into the low to mid 80s.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
The pattern remains unsettled through the midweek with gradual
improvement possible for late in week. Another closed upper
low tracks into the Great Lakes/Ohio Valley for early next
week, before opening into a deep trough approaching the coast
for the mid to late week.
For Mon thru Wed, a broad surface low (stacked under the closed
low) will slowly move east into NY/PA, with a series of warm
fronts/surface trough moving through the region. This setup will
remain fairly persistent, as weak shortwaves act as a trigger
for torrential downpours and tstm activity in a high PWAT, deep
warm cloud depth, and marginally unstable airmass. WPC marginal
excessive rainfall threat, particularly for areas from NYC metro
and N&W and during diurnal hours, continues to be reasonable
with potential for localized flash flooding with any training
convection. Will also have to watch mesoscale trends in the
coming days as a localized strong to severe tstm threat is
possible at least for Monday afternoon and evening along and
west of the Hudson River corridor. The threat is a bit more
uncertain heading into Tuesday and Wednesday (mainly NYC and
interior). SPC currently has the region in a general
thunderstorm risk for Day 3 (Monday) with a marginal risk off
to the west. The CSU machine learning severe probabilities are
a bit higher for the same time period, with mainly marginal
risk levels nearing the coast. Convection/flash flood details
will of course be refined as the weekend progresses.
Models in general agreement with the closed upper low opening and
broad surface low/trough moving overhead in the late week period,
but spread in depth and location of trough. Potential that the main
WCB of subtropical moisture flow may have pushed east of the region
mid to late week, which would transition shower/tstm activity to
more of a diurnal pulse strong to marginally severe cold pool
convection threat.
Seasonably warm and humid conditions through the period with sub-
tropical environment. Highs generally in the upper 70s to lower
80s.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
A warm front is lifting through early this morning. After fropa, a
weak low pressure trough will linger over western portions of the
Tri-State area through the weekend.
Widespread IFR/LIFR cond to start over the area as rain and
embedded moderate showers accompany warm fropa. Flight cat will
be slow to improve this AM, but think most sites will eventually
make it to MVFR by afternoon except for maybe KSWF/KGON, which
may take til 18Z-19Z.
Chances for showers/tstms should increase again going into this
afternoon, especially from NYC west from about 18Z-23Z.
Activity east of there should be more isolated to scattered in
coverage.
Will have to watch for return of fog and low stratus with
IFR/LIFR cond mainly after midnight.
Light SE winds become S 5-10 kt after warm fropa.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Unscheduled AMD still likely. Medium confidence on timing of
changing flight cat and on shower/tstm timing/chances.
The afternoon haze potential forecast for KJFK is YELLOW,
implying slant range visibility of 4-6SM outside of cloud.
OUTLOOK FOR 12Z SATURDAY THROUGH WEDNESDAY...
Sunday: Chance of showers/MVFR. Afternoon/evening tstms
possible.
Monday: Showers likely. Tstms possible, especially
afternoon/evening. MVFR cond expected, IFR possible. S-SE winds
G15-20kt.
Tuesday and Wednesday. Showers likely. Slight chance of tstms.
MVFR or lower possible at times. S-SE winds G20-25kt.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
-- Changed Discussion --
Some patchy fog is still possible today, but do not think it
will be widespread or dense.
SCA wind gusts could develop on the ocean waters as early as
late Monday into Monday night, but are more likely on Tuesday
into Wednesday as southerly flow increases ahead of a slow
moving frontal system. Similarly, marginal SCA ocean seas may
develop late Monday into Monday Night, with higher likelihood
Tue into Wed with persistent and increasing southerly flow.-- End Changed Discussion --
&&
.HYDROLOGY...
Locally heavy rainfall is possible in any showers or
thunderstorms through this evening. Minor flooding could occur
especially in poor drainage and low lying areas.
For Sunday through Monday, a scattered low lying/poor drainage
flood threat and localized flash flood threat exists,
particularly for areas from NYC metro and N&W and during
afternoon and evening hours. Hydrologic impacts Tuesday into the
middle of the week may be be determined by the extent of the
rainfall this weekend into Monday.
&&
.TIDES/COASTAL FLOODING...
There is a moderate risk of rip current development for all
ocean beaches through Sunday due to a continuation of 3-ft
southerly swells.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...DS/NV
NEAR TERM...DS
SHORT TERM...DS
LONG TERM...DS/NV
AVIATION...BG
MARINE...DS/NV
HYDROLOGY...DS/NV
TIDES/COASTAL FLOODING...