414
FXUS61 KOKX 131951
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
351 PM EDT Sun Oct 13 2024
.SYNOPSIS...
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A low pressure system moves through the area late tonight into early
Monday morning. High pressure slowly builds through mid-week
before settling over the area late week into the weekend.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
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Vigorous northern stream trough over the Great Lakes swings into W
NY/PA by Monday morning. At the surface, a stationary warm front
remains draped w to e across souther portions of NYC/LI this
afternoon. Associated surface low over PA tracks ene across the
region tonight, with trailing cold front moving through by
around daybreak.
Challenging forecast in terms of how far north the warm front
pushes through the region this evening. Trend over the last 24
hour has been for slower approach of shortwave and surface wave
from the west and slower strengthening of llj, combined with CAD
from rain-cooled airmass across Central New England, the warm
front will likely have trouble making much progress north of LI
and NYC/NJ metro this eve.
Increasing clouds this evening, including stratus across LI and
SE CT. Potential for scattered showers tonight as surface low
and cold front move thru the region, particularly NW of NYC
through this evening ahead of approaching pre-frontal trough
and cold front and then across LI/CT overnight with
strengthening LLJ. Potential for thunder with cold frontal
passage tonight (00z to 09z) is very limited (but non-zero)
with weak elevated instability above 650-750mb capping, and
trailing shortwave energy.
Slightly above seasonable temps, particularly coast and east tonight
with cloud cover and before caa kicks in Monday. Lows in the mid 50s
city/coast, mid 40s well N&W.-- End Changed Discussion --
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY/...
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Closed upper low slides up the St Lawrence River valley Monday
into Tuesday, with associated long wave troughing over the
eastern 1/2 of the US digging deep into the southern US. At the
surface, slow pressure strengthens as it lifts through New
England on Monday and stacks under the closed low over SE Canada
Mon Night into Tues.
Cold front crosses Mon AM, with reinforcing cold front crossing Mon
afternoon. CAA W/NW flow ensues through thru Tuesday under a
cyclonic flow regime. Considerable instability cu expected both
Monday and Tuesday aft in this regime, with dry conditions
outside of an isolated sprinkle with shortwave/secondary cold
frontal passage Mon aft. A strong W/NW pressure gradient will
result in frequent gusts of 25 to 30 mph on Monday, and 20 to 25
mph on Tuesday.
Highs will likely occur in the morning Monday (upper 50s interior/
lower 60s to 65 city/coast), remaining steady or slowly dropping in
the afternoon. Highs on Tuesday (coolest of fall season so far)
likely holding in the lower 50s interior / upper 50s coast which
seem reasonable based on 850 hpa temps dropping to -2 to -4C w/ deep
mixing.
Mixed low-level Mon Night will keep temps from fully bottoming out,
but potential for temps to radiate into the lower to mid 30s across
far outlying areas.-- End Changed Discussion --
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
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There have been no major changes to the forecast mid week through
the end of the week.
*Key Points*
*The coolest temperatures of Fall 2024 will continue Tuesday night
into Thursday night.
*A warming trend begins Friday with temperatures returning to
normal, then potentially above normal next weekend.
*No precipitation is expected.
The weather pattern will start out with a highly anomalous,
positively tilted upper trough over the east coast Tuesday night
into Wednesday. 500 mb height anomalies average 2 to 3 standard
deviations below normal for this time of year. The trough axis will
slowly push offshore by Thursday taking with it any surface
cyclogenesis. The trough pushes further out over the Atlantic Friday
into next weekend as a large ridge and positive 500 mb height
anomalies builds over the east. This will allow the surface high
over the central states mid week to build overhead and remain in
control Friday into next weekend.
Wednesday will remain breezy with NW flow, fairly deep mixing, and
building high pressure off to the west. NW winds may gust 20-30 mph.
The flow then weakens through the end of the week and will remain
light next weekend. The coolest day of the period looks to be
Wednesday with highs in the lower 50s inland and middle to upper 50s
near the coast. These readings are 10-15 degrees below normal for
mid October. Highs will begin moderating Thursday and return to
normal Friday in the 60s before approaching 70 degrees next weekend.
Lows Tuesday night, Wednesday night, and Thursday night look to fall
into the low to mid 30s inland and 40s for coastal/metro areas. This
will bring the potential for frost inland, especially where winds
weaken or become light Wednesday night and Thursday night.-- End Changed Discussion --
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
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A front remains nearly stationary just south of Long Island,
possibly moving slightly northward this evening as a wave of
low pressure approaches from the west. The low moves into
eastern Pennsylvania early this evening, and tracks through the
area tonight and to the northeast Monday.
Mainly VFR, with an area of MVFR stratus moving across Long
Island and along the southeastern Connecticut coast, and IFR at
KSWF with light showers. The chance of showers remains at KSWF
into late tonight, with a chance at the NYC metro terminals this
evening into late tonight.
Low confidence in the wind forecast as a front remains nearly
stationary just south of the terminals, and a wave of low
pressure approaches from the west, affecting both the wind
direction and speed. Any gusts along the coast will be
occasional until around sunset. Gusty W/NW winds develop Monday
morning behind the low, with gusts up to 30 kt. LLWS likely at
the metros, and KISP, as SW winds increase to 40-45 kt at FL020.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Amendments possible, mainly KJFK, for ceilings with stratus in
the area. Uncertainty with the wind forecast, with timing of
wind shifting to the south, as this is dependent on a frontal
boundary to the south and approach of low pressure to the west.
OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
Monday afternoon: VFR. NW winds 15-20 kt, gusts 25-30 kt,
occasionally gusting up to 35 kt. Winds and gusts diminish
10-15 kt, gusts 15-20 kt during the evening, with gusts ending
around 06Z Tuesday.
Tuesday and Wednesday: VFR. W-NW winds 10-15G20-25kt.
Thursday through Friday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
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Easterly winds across LIS this afternoon, switching to SE/S
this evening. Otherwise, southerly winds increase to SCA across
ocean and southern and eastern bays/sound this evening, and
continue into tonight. A brief respite in winds likely overnight
as surface low move across, and then SCA gusts expected across
all waters Monday behind the cold front. Winds gradually subside
Monday Night. In response, waves build to 5 to 8 ft on the
ocean late today into tonight, before gradually subsiding Monday
night.
SCA gusts appear likely Tuesday night into Wednesday. Winds will
weaken Wednesday night and should remain below SCA levels Thursday
into Friday with high pressure building over the waters. Ocean seas
are expected to remain below 5 ft.-- End Changed Discussion --
&&
.HYDROLOGY...
There are no hydrologic concerns through the start of next
weekend.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 8 AM to 11 PM EDT Monday for ANZ331-
335-338.
Small Craft Advisory from 8 PM this evening to 11 PM EDT
Monday for ANZ332-340.
Small Craft Advisory until 11 PM EDT Monday for ANZ345.
Small Craft Advisory until 2 AM EDT Tuesday for ANZ350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...DS/NV
NEAR TERM...NV
SHORT TERM...NV
LONG TERM...DS
AVIATION...MET
MARINE...DS/NV
HYDROLOGY...DS/NV