727
FXUS61 KOKX 252341
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
641 PM EST Mon Nov 25 2024
.SYNOPSIS...
A storm passing to our north will push a warm front through the area
Tuesday morning, quickly followed by a cold front. High pressure
then follows through Wednesday. Low pressure will then impact the area
on Thanksgiving before exiting to the northeast Thanksgiving night
into Friday. High pressure will then gradually build in this weekend
into early next week.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Low pressure strengthens as it tracks east over the Great Lakes with
the support of a negatively tilted upper trough. This will send a
warm front our way, which is expected to be positioned just off to
our south near daybreak. CAMs continue to depict spotty showers
passing through late this evening out ahead of the main batch of
rainfall - which should enter the western fringe of the forecast
area near daybreak. Low levels may be too dry at first to support
this spotty precip, but keeping in a slight chance of showers for it
seems reasonable. Clouds and rising dewpoints will promote above
normal low temperatures.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
The warm front lifts through at least a portion of the forecast area
Tuesday morning, followed by a cold front closer to noontime. Rain
pushes west to east across the area, ending near noon for NYC metro,
and a couple of hours after that for eastern LI/SE CT. Rain totals
should be in the range of a quarter to a third of an inch. Afternoon
clearing with a W-NW wind will help push high temperatures above
normal, with mid to upper 50s inland and around 60 for coastal
areas.
High pressure builds in from the west Tuesday night through
Wednesday. Westerly winds diminish Tuesday evening and remain at
around 10 mph or less through Wednesday afternoon. Dry weather and
near normal temperatures are expected through the period.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
-- Changed Discussion --
**Key Points**
*Low pressure on Thanksgiving will bring another wetting rainfall
(0.50"-1.00") across the region.
*The rain could briefly mix with wet snow across the higher
elevations of the interior at the onset Thanksgiving morning.
*The rain should begin tapering off Thanksgiving evening followed by
mainly dry conditions Friday through early next week.
*Much colder air begins to arrive on Friday and will ultimately
lead to well below normal temperatures to end Meteorological
Fall and beginning of Meteorological Winter.
The main focus for the beginning of the long term will be with a
shortwave that develops low pressure near the Tennessee and Ohio
Valleys Wednesday night. The upper flow pattern is progressive
allowing the system to quickly impact the area on Thanksgiving.
The model guidance still has some differences, mainly with the track
and intensity of the low. The deterministic ECMWF and much of its
ensemble have been stronger with the low and further north, tracking
the system over or just north of the area. The GFS/GEFS, CMC/GEPS,
NAM12, ICON, and UKMET all have a weaker low and track south of
Long Island. The new 11/25 12z ECMWF and EPS have trended a bit
weaker and further south with a track now along the Long Island
coast, but is still stronger than much of the guidance. It
should be noted that the ECMWF AIFS has been a weaker and
further south solution for its last several cycles, appearing to
agree more with the rest of the guidance compared to the
deterministic ECMWF. The differences arise with the handling of
the shortwave trough and energy with the deterministic ECMWF
containing a more amplified trough compared to the weaker and
further south guidance.
Overall impacts look similar with a mainly rain event despite the
aforementioned model differences. Even with the weaker/south
solutions, there is not enough cold air to support much wintry
precipitation. The only chance would be at the onset across the
higher elevations of the interior. Any wet snow would be brief and
quickly change to rain around or just after daybreak on
Thanksgiving. Rain will be widespread throughout much of the day,
but should begin tapering off from west to east in the mid to late
afternoon as the low begins to pull away to the northeast. Rainfall
looks steady and could be moderate at times with amounts ranging
from one half to one inch. If the stronger ECMWF/EPS members verify,
rainfall amounts could be a bit higher, especially the southern half
of the area. Breezy conditions are also likely with potential for
wind gusts 20-25 mph, especially as the system departs late in the
day and at night.
The GFS and a few of its ensemble members hold back some energy and
try to bring in some light precip. These solutions may be outliers.
The NBM does keep a very low PoP (around 20 percent) and have left
this in the forecast for now until more the trough evolution is
better resolved. Otherwise, conditions will be dry to end the week
and continue into the weekend. The low pressure that impacts us on
Thanksgiving will move into southeast Canada/Maritimes and meander
this weekend into early next week. Sprawling high pressure with
arctic origins will build into the east of the Rockies this weekend.
The region will lie between the high to the west and low to our
northeast, which will lead to breezy and cold conditions this
weekend and early next week.
The NW flow between the systems will usher in the coldest
temperatures of fall 2024. Followed the NBM deterministic for now,
but given the source region of the airmass it would not be
surprising to see temperatures trend colder in future forecasts. The
NBM 25th percentile for example only has highs in the low to mid 30s
Sunday and next Monday. Forecast highs for now will be in the upper
30s to low 40s this weekend and early next week. Lows will mainly be
in the 20s at night although some interior locations could fall into
the teens. The breezy conditions during this time period could make
it feel like it is in the teens during the day.-- End Changed Discussion --
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
High pressure moves offshore to the south tonight with a quick
moving frontal system approach late tonight and passing through
on Tuesday.
VFR with light W/SW winds, possibly becoming light and variable
overnight. Expect lowering VFR cigs tonight, with winds
backing to the SE overnight.
Showers with MVFR conditions and cigs should arrive by 11Z-12Z
at the NYC metros and points north/west, by 13Z KBDR/KISP, and
15Z KGON, as winds veer back to the S-SW around 10 kt. Can`t
completely rule out a brief period of IFR cond before fropa
which should occur by 17Z NYC metros/KHPN/KSWF, 18Z KBDR/KISP,
and 19Z-20Z KGON. Winds then shift to the WNW and become gusty
20-25kt into the evening with clearing skies.
...NY Metro (KEWR/KLGA/KJFK/KTEB)TAF Uncertainty...
No unscheduled amendments expected tonight. Timing of MVFR and
SHRA may be off by an hour or two.
OUTLOOK FOR 00Z WEDNESDAY THROUGH SATURDAY...
Tuesday night: VFR. WNW winds 10-15 with G20-25kt early,
diminishing at night.
Wednesday: VFR.
Wednesday night: Chance of rain with MVFR cond late, except
chance rain/snow at KSWF.
Thursday: Rain with IFR cond likely, possibly a rain/snow mix
early at KSWF. E-NE winds G20kt in the afternoon, becoming NW
at night.
Friday: VFR. NW winds G20kt.
Saturday: VFR. W 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...
Light winds this evening will pick up out of the southeast to south
tonight. This will be in response to a frontal system that will push
a warm front through at least some of the area waters late tonight
into Tuesday morning, followed by a cold front during the first half
of the afternoon. SCA conditions develop on the ocean during the
morning, then across the rest of the waters in the afternoon. Have
issued a SCA accordingly, with the advisory ending Tuesday night.
The advisory might need to be extended into Weds morning east of
Fire Island Inlet, otherwise, sub-advisory conditions prevail across
all waters through the day.
Conditions will begin below SCA levels Wednesday night, but should
become more unsettled with increasing winds and building seas on
Thanksgiving. These rough conditions should then persist into the
upcoming weekend behind the departing storm system and slowly
building high pressure to our west.
&&
.HYDROLOGY...
No hydrologic impacts are expected with the rainfall during
Tuesday, and while 0.5"-1.0" of rain is forecast on Thanksgiving,
there are no hydrologic impacts expected through early next week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from noon Tuesday to 6 AM EST Wednesday
for ANZ331-332-335-338-340-345.
Small Craft Advisory from 6 AM Tuesday to 6 AM EST Wednesday
for ANZ350-353-355.
&&
$$
SYNOPSIS...JC/DS
NEAR TERM...JC
SHORT TERM...JC
LONG TERM...DS
AVIATION...MW
MARINE...JC/DS
HYDROLOGY...JC/DS