000
FXUS61 KOKX 280444
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1244 AM EDT Sun Apr 28 2024

.SYNOPSIS...
A warm front approaches early this morning and moves north
through the day. A weak trough moves through tonight, with high
pressure briefly building in Monday morning. A back door cold
front moves through Monday afternoon into Monday evening. A
frontal system approaches from the west and moves through the
area Tuesday afternoon and night. High pressure then builds in
for the middle of the week before another frontal system
potentially affects the area to close out the week.

&&

.NEAR TERM /UNTIL 7 AM THIS MORNING/...
Made some minor adjustments to PoPs as the majority of the
precip is in the form of showers and coverage does not warrant
likely PoPs except for the east end. Some weak elevated
instability is noted just to our NW, so a shower that spills
south towards the Lower Hudson Valley could have a rumble of
thunder. These showers should dissipate towards day break.

Otherwise, the upper ridge axis continues to nudge into the
region. At the same time, good agreement in shortwave energy
shearing through Ontario and into western Quebec. At the
surface, the high pressure, centered just S/SE of the area, will
slide farther SE tonight. Meanwhile, weak low pressure tracks
NE through Ontario into Quebec tonight with associated weakening
warm front approaching early this morning and lifting NE of the
area thereafter.

WAA and cloud cover will have temps noticeably milder then the last
few nights, with lows generally in the 40s.

&&

.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM MONDAY/...
Upper ridge axis remains fairly stationary just to the west of
the region Sunday thru Monday, while a northern stream shortwave
digs into SE Canada. Weak shortwave forcing rounding the upper
ridge slides east Sunday morning, with another train of
vorts/weak shortwave approaching late Sun and tracking across
northern and eastern portions of the region Sunday night.

At the surface, warm front dissipates overhead or lifts north
Sun AM, ending shower threat. Weak surface troughing appears to
linger over the area, with more distinct pre-frontal approaching
late in the day and crossing Sunday Night. Ahead of this, the
region becomes warm sectored Sunday with temps moderating to
above seasonable levels with strong waa aloft, but still model
spread on max temps dependent on cloud cover, seabreeze timing,
and depth of mixing. Interestingly, deterministic NBM temps
(bias corrected and MAE weighted model blend) are generally
running close to the 10th-25th percentile of the NBM ensemble
spread (raw model and MOS inputs). Will lean towards a blend of
deterministic and 50th percentile of NBM, with potential for
temps to be several degrees warmer than forecast across NYC/NJ
metro and interior with breaks in cloud cover and remaining
north and west of the synoptically enhanced seabreeze along the
coast. There appears to be an opportunity for a period of partly
to mostly sunny skies between the Sun AM strato-cu dissipating
and ahead of increasing high/mid deck in mid-late aft.

Pre-frontal trough approaches late Sunday and passes thru Sunday
night. Not a tremendous amount of forcing, but combo of vorts moving
through aloft and surface trough moving through in a 2 to 2 1/2 std
PWAT airmass (weakly unstable across far western areas) support
potential for scattered showers. Low prob for a thunderstorm
Sun eve across far NW areas of the region

The passage of the surface trough Sunday night leaves behind a deep
W/NW flow Monday morning, which should allow for rapid drying and
deep mixing to at least 850mb (temps of 13-14C). Still quite a bit
of spread on how high max temperatures could reach based on
timing of a backdoor cold front in the afternoon. Once again,
deterministic NBM temps are generally running close to the
10th-25th percentile of the NBM ensemble spread. Based on
favorable heating conditions for at least the first half of the
day will ride closer to 50th percentile. This supports potential
for summerlike conditions (warmest day so far this Spring) with
widespread temps in the lower to mid 80s. Potential for temps
to be a few degrees warmer than forecast if cold frontal timing
is slower, with a few spots making a run at record highs for the
day (mid to upper 80s).

Backdoor cold front could spark an isolated shra or trsa late
Mon/Mon eve across western portions of the Tri-State with some
weak instability and moisture pooling.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
*Key Points*

*Cooler conditions Tuesday and Wednesday, but still above  normal. A
slight warmup then for week`s end.

*Mainly dry conditions expected with a few chances of showers and
thunderstorms as multiple frontal systems impact the area   during
the period.

Upper ridging along the eastern seaboard weakens while moving out
into the Atlantic on Tuesday. At the same time, a weakening frontal
system on the backside of the ridge moves into the area with a
chance of showers, possibly a thunderstorms Tuesday afternoon/night.
Not expecting strong and/or severe convection with weak instability
and an easterly flow. Ridge then is forecast to amplify over the
eastern third of the country Wednesday into Thursday, more so than
what we saw 24 hours ago.
Mainly dry conditions during this time once any lingering rain exits
the area Wednesday morning. Another upper trough then lifts north
out of the intermountain west Wednesday into Thursday, then up into
the Great Lakes Friday into Saturday. This will send another
weakening frontal into the area to close out the week.

As for temperatures, an easterly flow on Tuesday following a
backdoor cold front will return highs closer to normal. The trend in
the NBM and much of the 12Z guidance has been cooler for that day. A
gradual warmup can then be expected for the rest of the week with
temperatures 3 to 5 degrees above normal along the coast, but to 5
to 10 degrees inland. Chance of rain and cloud cover Saturday knocks
temps down a bit.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
A warm front approaches tonight and remains in the vicinity
through this evening.

Low end VFR this becoming MVFR tonight, generally after
05Z from west to east, mainly because of lowering cigs. There
is a low chance of seeing vsbys come down below 6 SM, except
perhaps for KGON, and that is only for a brief time. Showers
will continue falling intermittently thru about 14Z before
drying out with slow improvement to VFR into the early
afternoon. High end IFR cigs possible at times in the early
morning hours, especially at KSWF, KHPN, KBDR, and KGON, but
can`t be ruled out elsewhere.

Another round of showers after 00Z Monday, with low probability
of thunder for KSWF and KHPN. Not enough confidence to put in
TAFs attm but bears watching.

S winds remain rather light through the TAF period. A shift
more to the SSW or SW is expected at most terminals Sunday
morning.


NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

Timing of MVFR conditions tonight may be off by a couple of
hours.

IFR cigs possible Sunday AM.

Improvement to VFR on Sunday may be off by a few hours.

OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY...

Sunday night: VFR with a light SW flow.

Monday: VFR. Winds under 10 kt.

Tuesday: MVFR or lower possible with afternoon showers and isolated
thunderstorms.

Wednesday: VFR. Winds under 10 kt.For the first half of the
night,

Thursday: VFR. Light winds.

Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90

&&

.MARINE...
Winds and seas will remain below advisory levels through the
weekend under a weak pressure gradient regime. Coastal jet thru
this will bring marginal SCA wind gusts (20- 25kt) near the
entrance to the NY Harbor.

Much of next week looks to be below sub-SCA with a weak flow across
the waters. Potential fog development due to warmer air moving
over the colder waters (SSTs near 50F) early next week, but
still too early for any specific details on timing and extent.

&&

.HYDROLOGY...
No hydrologic concerns through the end of next week.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.

&&

$$

SYNOPSIS...NV/DW
NEAR TERM...DS/NV
SHORT TERM...NV
LONG TERM...DW
AVIATION...JP/DBR
MARINE...NV/DW
HYDROLOGY...NV/DW