837
FXUS61 KOKX 090003
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
803 PM EDT Tue Oct 8 2024
.SYNOPSIS...
Weak high pressure resides nearby through Wednesday with a
series of weak fronts pushing through. A stronger high
pressure systems builds across the area Thursday. High pressure
will be in place Thursday night through Friday. A cold front
moves through Saturday. High pressure again briefly takes hold
Saturday night before a low pressure system and associated warm
and cold fronts impact the area Sunday into Monday. The low then
lingers to our north on Tuesday.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
-- Changed Discussion --
Hourly dewpoints needed touching up in the early evening to
account for current observations. Otherwise, the forecast
remains on track.
A weak cold front/trough will slide through during the first
half of tonight. No sensible wx concerns with this weak
convergence boundary. With the loss of daytime heating any
shower activity to the NW will have difficulty getting further
southeast across the CWA. There may be enough lift at and just
above 700 mb to produce some showers aloft, but with a dry sub
cloud layer this should at most manifest itself to some widely
scattered sprinkles in a few spots. Don`t have this in the
official forecast, but remains a possibility with any sprinkle
coverage being quite limited.
Dew point readings tonight should be in the upper 30s to lower
half of the 40s. A light W flow initially start to become more
NW later at night. In any case the winds will remain light, and
thus a good radiational cooling set up despite some clouds
around from time to time early and mostly to the north. Don`t
think it gets quite cold enough for frost, as temperatures
bottom out around 40 in the coldest spots across the interior,
otherwise 40s to mostly lower half of the 50s in the more urban
locations. Used a MET / MAV blend for temps to better capture
the locality of radiational cooling.
For Wednesday expect a good deal of sunshine, especially through
the first half of the afternoon. As the afternoon progresses
some cumulus develops at the 5 to 10 kft level. This will be
more prevalent across interior and northern sections at first,
then progress east later in the afternoon. Have chosen to remove
all showers from forecast database as soundings look quite dry.
As another weak cold front off to the west approaches towards
the evening, there could very well be a couple of light showers
or some sprinkles. Once again the sub cloud layer looks dry and
CAMs not showing much with their forecast reflectivity so have
kept PoPs minimal. There will be a dry low level westerly flow
with dew point readings in the upper 30s and lower 40s, so it
will be quite dry near and just above the surface. If there were
to be any light shower or sprinkle activity, NWP hints at some
activity very late in the day and for the first half of the
evening across mainly northern most zones. The moral of the
story, here is remaining pre-dominantly dry despite the approach
of another weak cold front late Wed and Wed evening.-- End Changed Discussion --
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY/...
Clearing takes shape from WSW to ENE towards the second of the
evening. The winds take on more of a northerly component for the
late evening and into the overnight behind the weak boundary.
Thus, the stretch of dry weather continues in the short term
period. Look for partly cloudy to mostly clear skies into early
Thu morning. The wind should stay up enough to preclude strong
radiational cooling in most spots, and thus no frost. Perhaps
some sheltered valley locations could get some degree of
radiational cooling before the NW winds kick up. Most lows will
be in the 40s, and closer to 50 for the metro. A stronger high
pressure system builds into the day Thursday with a stiff NW
breeze. Thursday will one of the coolest days of the fall thus
far despite sunshine. Temperatures will only max out in the low
and middle 60s, with perhaps even a few upper 50s for daytime
maxes across far northern locations.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Temperatures will cool on Thursday. With light winds and clear
skies, conditions will be optimal for radiational cooling to
take place. The NYC city metro will cool into the upper-40s
while the majority of the area will be in the mid/low-40s.
Upper-to-mid-30s are possible in parts of the interior. Have
added patchy frost to some of these areas for Thursday night.
Surface high pressure with a ridge aloft will remain in place on
Friday. Some warm air advection will occur under a westerly
flow. Highs will be in the warmer than the previous day in the
mid-60s to near 70 under sunny skies.
A strengthening surface low with a shortwave trough aloft move
into the Great Lakes Friday night and then into Quebec and the
Canadian Maritimes into Saturday. This low will bring a cold
front through the area on Saturday, but expecting it to be dry
with no precipitation. High pressure will briefly follow this
front into Saturday night with zonal heights aloft. Expecting a
continuation of warm temperatures on Saturday due to continued
westerly flow. Highs will be up into the low/mid-70s.
More models have come into agreement on a solution for our next
system Sunday into Tuesday with the 12Z GFS, 12Z ICON and 12Z
ECMWF all with similar solutions and only the 12Z GDPS
differing.
A trough will be digging into the Great Lakes on Sunday with a
surface low pressure system and an associated warm front and
cold front. This low is expected to gradually strengthen as a
trough deepens aloft over much of the Northeastern US Monday
into Tuesday while the surface low is expected to straddle the
US-Canadian border, eventually moving into NE Quebec by Tuesday.
Warm air advection will take place along with increasing
moisture advection on Sunday as onshore flow increases with a
passing warm front. With us in the warm sector along with a
strong 40-50 kt LLJ jet, positive vorticity advection aloft, and
PWATs around 1 inch, some showers are possible ahead of and
along the cold frontal passage which will occur Sunday night
into Monday morning. The strong LLJ will also help increase
winds at the surface with forecasted wind gusts currently
progged to be 20-25 mph Sunday night.
Following the front, on Monday and Tuesday, a deep trough will
remain over the region. Partly cloudy skies will remain as
rounds of mid-level energy continue to swing around the upper-
level trough. Under continued NW flow, cold air advection will
take place Monday into Tuesday. Highs on Monday will be in the
mid-60s to upper-50s, with highs possibly even colder on Tuesday
in the low-60s to mid- 50s. However, early next week is day 7
and 8 in the forecast, so this is subject to change somewhat.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
A weak frontal boundary will pass through tonight. High pressure
builds in for Wednesday.
VFR through the TAF period. A few brief showers may be possible
this evening or overnight at the inland and CT terminals.
W to SW flow this evening shifts to the NW after the cold
frontal passage which looks to occur between 04Z and 06Z
tonight. However, winds will be less than 10 kt through the
night. WNW flow continues tomorrow for inland terminals, with a
shift to the SW for coastal terminals with potential influence
from sea breezes.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
No unscheduled amendments expected.
OUTLOOK FOR 00Z THURSDAY THROUGH SATURDAY...
Wednesday night and Thursday: VFR. NW winds G15-20kt possible.
Friday: VFR.
Saturday: VFR. WNW winds G15-20kt.
Sunday: S winds G15-20kt in the afternoon. Chance of showers
with possible MVFR cond at night.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Sub-SCA conditions have returned to all ocean waters as waves
have dropped below 5 feet. There will still be a lingering long
period ESE swell through mid week.
Marginal small craft conditions then become more likely into
day Thursday. Any 20 kt gusts on the ocean are expected to
weaken Thursday night with sub-SCA conditions holding through
the day Friday. Friday night into Saturday afternoon gusts may
again near 25 kts on ocean zones followed by sub-SCA conditions
through Sunday morning. Sunday afternoon into Sunday night wind
gusts may exceed 25 kts on ocean waters as well as south shore
bays and the sound entrance. Waves will also increase on ocean
waters with the increasing winds, reaching 6-8 feet Sunday
night.
&&
.HYDROLOGY...
There are no hydrologic concerns through early next week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JE/BR
NEAR TERM...JE/BR
SHORT TERM...JE
LONG TERM...BR
AVIATION...JP
MARINE...JE/BR
HYDROLOGY...JE/BR