417
FXUS61 KOKX 131755
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
155 PM EDT Sun Oct 13 2024
.SYNOPSIS...
A warm front stalls over the forecast area today. A cold front
moves through late tonight into early Monday morning. High
pressure slowly builds through mid-week. High pressure settles
over the area Friday and Saturday.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Challenging forecast in terms of how far north a warm front pushes
into the region this afternoon. 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
late this aft/eve. Meanwhile, fairly good model agreement in the
stratiform rain shield only skirting northern portions of the
region through this afternoon, with most of the region dry.
Increasing clouds later this afternoon/evening. Better potential
for a few showers tonight as surface low and cold front move
thru the region. Potential for thunder with cold frontal passage
tonight is very limited with weak elevated instability above
650-750mb capping, but trailing shortwave energy.
A significant temperature gradient is expected across the forecast
area today, with areas well north and northeast of NYC seeing
highs around 60, while LI see highs in the upper 60s to lower
70s, and middle 70s for NYC/NJ metro. However, there is a
large spread in temperatures seen in the NBM for today (as much
as 11 degrees in some cases) as there is uncertainty in where
the frontal boundary will be. If it ends up farther north than
is currently forecast, then temperatures will likely be warmer
than what is currently in the forecast. If it remains to the
south, then cooler temperatures can be expected.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
A slight chance for showers Monday morning with a cutoff low over
the Northeast providing some weak lift and some steep lapse rates
noted in the forecast soundings in the lowest levels of the
atmosphere, but much of any showers will occur north of the area,
closer to the cutoff low. As the low treks farther northeast,
chances for showers fall, so dry conditions expected everywhere by
Monday afternoon.
Highs on Monday will be seasonable, ranging from the upper 50s
inland, to the upper 60s along the coast. With the strengthening low
pressure to the north and the high building in, a strong pressure
gradient will set up over the area, and breezy conditions are
expected, with gusts of 20 to 30 mph.
Continued cold advection through Tuesday as the upper low spins over
northern New England and southeastern Canada will mean even cooler
temperatures for Tuesday. Highs are not expected to climb above the
50s, with overnight lows Monday night into Tuesday in the middle to
upper 30s away from the coast, and in the lower to middle 40s along
the coast. Winds remain above 5 kt at night, so this will preclude
the formation of frost.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
A slow moving, positively tilted upper trough will linger over the
region on Wednesday, then start to pull away on Thursday. This will
induce sfc cyclogenesis well offshore, and also prevent high
pressure to the west from building in too quickly. Once the trough
pulls away and heights rise aloft, the high to the west should build
in more strongly and settle over the area later this week.
This pattern will usher in the coolest air mass of the season, with
well below normal temperatures on Wednesday (highs only in the 50s)
and then gradually moderating daytime temps after that under mostly
clear skies. With that plus fairly light winds, most nights will
radiate well, with lows in the 30s inland and 40s coastal/metro
areas, and frost inland especially Wed night and Thu night.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
-- Changed Discussion --
A warm front was moving slowly through KEWR and KJFK and along
the south shore of Long Island at 17Z, and will move slowly
north through the afternoon. Meanwhile, low pressure approaches
from the west, moving into eastern Pennsylvania early this
evening. The low tracks through the area tonight and to the
northeast Monday.
VFR. A chance of light showers at KSWF, into late tonight, with
a chance at the NYC metro terminals this evening into late
tonight. Only a chance of brief MVFR ceilings at KSWF and KGON.
Low confidence in the wind forecast as the direction and speeds
are dependent on where the warm front moves and possibly
stalls, and the timing of the wave of low pressure moving into
the terminals. A few gusts 15 to around 20 kt along the coast
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...
No unscheduled AMD expected. Uncertainty with the wind forecast,
with timing of wind shifting to the south, as this is dependent on
the movement of a warm front. There is a chance of gusts 15-20
kt at KEWR and KJFK.
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...
Southerly winds increase to SCA across ocean and southern and
eastern bays/sound this afternoon, 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.
Marginal SCA gusts possible Tuesday, otherwise sub SCA thru Thu
as high pressure slowly builds eastward toward the waters and
the pressure gradient gradually relaxes.
&&
.HYDROLOGY...
There are no hydrologic concerns through the start of next
weekend.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 11 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...BG/JP
NEAR TERM...JP/NV
SHORT TERM...JP
LONG TERM...BG/JP
AVIATION...MET
MARINE...BG/JP
HYDROLOGY...BG/JP