814
FXUS61 KOKX 111200
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
700 AM EST Mon Nov 11 2024
.SYNOPSIS...
A cold front will move across the area this morning. A secondary
cold front approaches this afternoon into tonight. Strong high
pressure from the Great Lakes builds in Tuesday through Wednesday
before departing away from the region Wednesday night. A
weakening frontal system will approach from the west on Thursday
while an ocean storm develops near the Canadian Maritimes. This
storm will remain well to the northeast from Friday into
Saturday with high pressure remaining to the west. The high
should build in on Sunday.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
Adjustments with temperatures, POPs for rain showers and cloud
coverage. Otherwise, forecast is mainly on track.
A cold front will move across the area this morning. Main band
of light rain has already shifted southeast of Long Island.
Along the cold front itself, there may be a few rain showers but
with dry and cold air advection, may be quite difficult for
rain to reach the ground. Only have a slight chance of rain
showers for most NW portions of the forecast region to indicate
this for the first half of this morning. Otherwise, mainly dry
conditions are expected for the region.
Winds will veer from SW to W for latter half of the morning
with westerly flow continuing this afternoon.
Clouds not expected to clear out completely as another cold front
approaches the region from the north and west. This will also lead
to a continuation of gusty winds.
850mb temperatures decrease a few degrees from the morning to end of
the afternoon. Forecast high temperatures at the surface from NBM
50th percentile, which were within a degree to the operational
NBM.-- End Changed Discussion --
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
-- Changed Discussion --
For tonight, the secondary cold front continues to approach,
eventually moving across late tonight from NW to SE. This will be a
dry frontal passage with no rainfall expected. Clouds will be
decreasing after this frontal passage and this will also commence
more substantial cold air advection with increasing NW flow.
At 500mb, strong positive vorticity advection evident in the
forecast models behind the frontal passage with a trough moving
through.
850mb temperature forecast to lower more rapidly closer to 4-6
degrees from early evening to daybreak Tuesday. Model 850mb
temperatures by daybreak Tuesday are near to slightly below the
0 degree C mark. Used MAV/MET blend for lows which range mainly
from near 40s for parts of the interior and Pine Barrens of Long
Island to upper 40s within NYC.
For the rest of the short term, strong ridging is conveyed in
the forecast models Tuesday through Wednesday night in the mid
levels. Ridge axis moves in Wednesday night.
For Tuesday, high pressure begins to build in from the Great Lakes.
Steep pressure gradient from strong high center NW of the local area
and low pressure center maintaining its strength in Canadian
Maritimes will set up a NW gusty flow. Gusts up to 35 to
potentially 40 mph are expected.
Boundary layer winds will be higher Tuesday, setting up a
greater difference between sustained winds and the higher gusts.
High temperatures Tuesday from NBM 50th percentile which are a
few degrees less than operational NBM. These highs will be
significantly cooler than the previous day, with highs mainly
from the upper 40s to lower 50s.
For Tuesday night, strong high pressure will continue to build
in from the NW. With subsidence inversion expected to set up
Tuesday night, winds are expected to decouple, leading to wind
speeds diminishing, especially across the interior. The
clearing sky and light winds will allow for efficient
radiational cooling. Winds stay up enough along the coast to
prevent efficient radiational cooling. Lows used MAV/MET blend.
Winds MOS blend today through Tue night, then Superblend/NBM blend
Wed and Wed night.
For Wednesday, high pressure center closest to local area for the
morning and the center of the high actually increases in pressure
during the day as it slowly moves farther away. The high will be
getting more within interior SE Canada. Surface pressure tendency
will be nearly steady Wednesday followed by more of a decrease
Wednesday night. Winds expected to decouple, become very light
Wednesday night and along with mostly clear sky conditions, an even
more efficient radiational cooling night will set up.
Highs Wednesday from NBM, lows Wed night, an even blend of NBM
and MEX guidance.
Possible frost for parts of the forecast region where growing
season still active for late Tuesday night into early Wednesday
morning.-- End Changed Discussion --
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
Ridging aloft continues to weaken as an upper level
shortwave/low pressure approach from the Great Lakes. Forecast
trends continue to keep the bulk of the forcing with this next
system south of the area. This would result in a more dry
forecast. Will keep POPs at just slight chance, however, its
likely POPs will be removed completely in subsequent forecasts.
This weak wave quickly exits to the southeast Thursday night as
surface high pressure and upper level ridging build west of the
region through the first half of the weekend and over the area
on Sunday. Another frontal system may approach the region early
next week.
Temperatures on Thursday will be slightly below normal, with highs
in the 40s to near 50s. By Friday, temperatures are forecast to warm
up to above normal and remain that way though the weekend, with
highs in the mid 50s inland to the lower 60s in the NYC metro area
and across Long Island.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
A cold front moves across the area this morning, followed by high
pressure.
MVFR at the NYC terminals and MVFR/IFR at the outlying terminals
through the morning push. Conditions improve from west to east
with VFR conditions returning around 14-15z for the city
terminals and an hour or two later for eastern most terminals.
Gusty conditions expected for much of the day with westerly
winds 10-15 kt and gusts up to 25 kt. The gusts subside late in
the afternoon and early evening. Gusts increase once again
after 06z Tuesday. Winds on Tuesday become a bit more
northwesterly with gusts 25-30kt.
NY Metro (KEWR/KLGA/KJFK/KTEB)TAF Uncertainty...
Some fluctuation between flight categories are possible early this
morning.
An occasional gust may be higher than forecast.
OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY...
Tuesday: VFR. NW winds near 15-20 kt with gusts 25-30 kt,
becoming more northerly at night. Gusts decrease closer to 25 kt
in the evening before diminishing late at night.
Wednesday: VFR.
Thursday: Potentially MVFR in slight chances of rain.
Friday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
-- Changed Discussion --
SCA extended on ocean zones through Tuesday. SCA potential
lingers on ocean thereafter through Wednesday morning.
Conditions forecast to go below SCA on ocean Wednesday afternoon
through Wednesday night. SCA on non-ocean waters continues until
1PM this afternoon. Then, sub-SCA on non-ocean waters until late
tonight, when SCA wind gusts redevelop and continue likely
through the day Tuesday and potentially Tuesday night as well.
Also potential for SCA wind gusts early Wednesday on parts of
non-ocean waters, with otherwise sub-SCA conditions Wednesday
through Wednesday night on non-ocean zones.
Possible gales on the ocean Tuesday into Tuesday night but
probabilities less than 50 percent. Mentioned possible gales in
the HWO.
Conditions are expected to remain below SCA levels Thursday and
Friday.-- End Changed Discussion --
&&
.FIRE WEATHER...
Recent rainfall will lead to more moist low levels today but
winds picking up after rain has ended will eventually dry out
these low levels this afternoon into tonight. Would think
Tuesday into Tuesday night with higher winds and lower RH would
make potentially another concerning day regarding fire weather
and the increased possibility of brush fire spread.
&&
.HYDROLOGY...
-- Changed Discussion --
Moderate drought conditions have developed per US Drought
Monitor. Stream flows are generally below the 25th percentile of
normal for this time of year. There are no hydrologic concerns
through next week.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 1 PM EST this afternoon for ANZ331-
332-335-338-340-345.
Small Craft Advisory until 6 PM EST Tuesday for ANZ350-353-355.
&&
$$
SYNOPSIS...BC/JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...BC
AVIATION...BC
MARINE...BC/JM
FIRE WEATHER...JM
HYDROLOGY...BC/JM