502
FXUS61 KOKX 201130
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
730 AM EDT Sun Apr 20 2025

.SYNOPSIS...
A cold front pushes well south of the area this morning. High
pressure builds in tonight and gradually slides east on Monday.
A weak frontal system approaches Monday and moves through
through Monday night into Tuesday. Weak high pressure builds
into the region Wednesday and Thursday. Another frontal system
is expected to affect the area Friday into the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Key Messages:

* Much cooler but still above normal temps today (Highs in the
  lower to upper 60s).

* Elevated threat for wildfire spread across the Tri-State today.
  SPS in effect for southern CT and southeastern NY for today.

* Patchy frosty possible for portions of E LI and coastal
  central and southeastern CT tonight, where growing season has
  started.

Vigorous northern stream closed low slides east from Quebec and
through the Canadian Maritimes today into tonight, while southern
upper ridging builds back towards the region tonight. At the
surface, a cold front pushes well south of the region this AM,
with weak Canadian high pressure building in Sunday Night and
sliding east on Monday.

Overall gusty NW winds 15-20G25-30mph, drier and much cooler conds
expected today. Temps will still run several degrees above normal
with unseasonably mild start to the day, deep mixing and plenty
of sunshine in a gradual caa regime. Continued close to NBM
50th percentile for temps based on the above, which has a better
representation of warmer temps along the coast in NW flow than
the NBM deterministic. Temps in the lower to mid 60s interior
and mid to upper 60s for city/coast. NBM deterministic max T are
generally running in the lowest 25th quartile, which appears
low based on synoptic regime.

Canadian high pressure noses in tonight with potential for good
radiational cooling conds for the first half of the night for
pine barrens of LI and interior Tri- State with temps dropping
into the lower to mid 30s and bringing patchy frost conditions.
Not enough frost coverage across coastal areas where growing
season has started to issue frost headline. Also, signal for
increasing cloud cover late tonight with approach of elevated
warm front, which would limit radiational cooling potential.
Elsewhere, temps dropping into the 40s for the city/coast.

&&

.SHORT TERM /MONDAY/...
Key Messages:

* Below seasonable temperatures on Monday, giving way to well above
  seasonable temps on Tuesday.

* Light rainfall event Monday Night.

A vigorous closed upper low over the SW US lifts through the central
plains today and into the upper Great Lakes on Monday, and then
opens up and slides east through Ontario/Quebec on
Tuesday/Tuesday Night. At the surface, a resultant low pressure
system takes a similar track, sliding NE through the Great
Lakes on Monday and then across southern Ontario/Quebec into
Northern New England Tuesday into Tuesday Night. Locally, its
associated warm front approaches Monday Night, followed by
occluded/cold front crossing late Monday Night into Tue AM.

A strengthening return SE flow develops Monday as high pressure
slides offshore. Maritime flow off mid 40 degree waters, and
developing/ne advecting stratus under a strong low-level
inversion and elevated warm frontal passage, will likely result
in temps running a few degrees below seasonable across the
region on Monday (mid 50s along southern and eastern coasts to
around 60 interior). NBM deterministic, generally in the lowest
25th quartile, looks good based on above.

High-res models are signaling potential for a few showers or
sprinkles Monday AM with elevated warm frontal passage.
Soundings are rather dry with ridging surface and aloft, so not
expecting much out of this activity.

LLJ will strengthen ahead of approaching frontal system, with
surface warm front approaching and entering the region Monday
Night. Modest theta- e advection and lift over this boundary
will bring potential for scattered showers Monday Night. Limited
forcing and moisture, and lack of instability, will keep QPF
light. Warm front likely lifts north of most of the area late
Monday Night, before weak occluded/cold front crosses Tues AM.

Drying conditions Tuesday in wake of cold front. Sct cu
development likely Tuesday aft with shortwave moving through to
the north and secondary cold front approaching. Otherwise deep
mixing and still mild 850mb temps(7-10C), will likely result in
unseasonably warm temps areawide (mid to upper 70s) on gusty
westerly flow. Temps could challenge the daily record high for
KISP. Southern and eastern coastal areas could be well into the
70s (warmer than current forecast) as well if westerly flow
materializes as modeled. Will side towards 50-75th percentile
NBM based on downslope flow regime. Once again, NBM
deterministic max T are generally running in the lowest 25th
quartile, which appears low based on above.

Weak cold front sags south of the region Tuesday Night. With mixed
low-levels and little change in airmass, continued mild
conditions likely with lows in the mid to upper 40s for much of
the area, lower 50s NYC/NJ metro.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
No significant changes in the long term and stuck fairly close to
the previous forecast/NBM.

Dry weather is expected Wednesday through Thursday night with mostly
sunny to partly cloudy skies under weak high pressure.

The high moves east on Friday, with another shortwave/low pressure
system approaching for late Friday into Saturday. Mainly looking at
just chance POPs (30-35 percent) for now. Drier weather returns for
Sunday.

&&

.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
High pressure builds into the area today.

VFR through the TAF period.

WNW-NW continue to increase this morning and will generally be
15-20 kt with gusts 25-30 kt in the morning. Can not rule out an
isolated higher gust, especially this morning. Winds gradually
weaken in the afternoon with gusts likely ending by evening.
Tonight, winds become light and variable.

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

Can not rule out an occasional peak wind gust.

.OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY...

Monday: VFR, then MVFR or lower possible at night with a chance
of showers.

Tuesday: Mainly VFR. Chance of showers early. SW wind gusts 15-20 kt
possible.

Wednesday and Thursday: VFR.

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

&&

.MARINE...
SCA gusts expected mainly on nearshore waters today, while SCA ocean
seas (due to residual southerly swell) slowly subside through early
afternoon.

Sub SCA conditions expected on all water this evening, continuing
thru Monday afternoon as high pressure moves across the waters.

Marginal SCA conditions possible on the ocean waters Monday Night
into Tuesday morning with frontal passage, but latest trend has been
slightly weaker with winds and waves.

Otherwise, conditions will remain below SCA levels Tuesday afternoon
through Friday with a relatively weak pressure gradient over the
waters.

&&

.FIRE WEATHER...
Dry conditions continue, with only spotty wetting rain across
Orange and Putnam counties yesterday, elsewhere little if any
rainfall.

Elevated wildfire spread threat exists today with highs in the 60s,
northwest winds of 15-20G25-30 mph and min RH values in the lower to
mid 20 percent range.

SPS for elevated threat of fire spread has been coordinated for
southeastern NY and CT with state land and fire management
partners and neighboring offices. Coordination on fuel
conditions and possible fire weather headlines will be conducted
with NJ state land and fire management partners later this
morning.

&&

.HYDROLOGY...
There are no hydrologic issues through next week.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 PM EDT this evening for ANZ331-
     332-335-338-340-345-350-353-355.

&&

$$

SYNOPSIS...BC/NV
NEAR TERM...NV
SHORT TERM...NV
LONG TERM...BC/NV
AVIATION...BC
MARINE...BC/NV
FIRE WEATHER...
HYDROLOGY...BC/NV