861
FXUS61 KOKX 012105
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
405 PM EST Sun Dec 1 2024
.SYNOPSIS...
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Low pressure slowly lifts northeast out of eastern Canada, while
high pressure builds in from the southwest to start the week. High
pressure then weakens and slides farther south on Wednesday. A
low pressure system will pass to our north and impact the area
Wednesday night into Friday, with the associated cold front moving
through on Thursday. High pressure builds back in at least briefly
early next weekend. Another low pressure system could pass to the
north late in the weekend.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
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Upper trough across the Northeast gradually translates east
during this time, while low pressure over the Canadian Maritimes
lifts out into the North Atlantic. Strong polar high pressure
over the Northern Plains builds south and east into the Tennessee
and Ohio Valleys during this time. This will allow for dry,
cold conditions to continue, with a diminishing westerly flow
tonight. Lows will range from the upper teens to the mid and
upper 20s at the coast (upper teens Pine Barrens Region of LI).-- End Changed Discussion --
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY/...
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High pressure builds in gradually from the south and west during
this time with a NW flow. Winds will be weaker than recent days,
but gusts of 15 to 20 mph are a possibility each afternoon,
especially on Tuesday. The airmass will change little, with
highs in the upper 30s to around 40 each day. Tuesday may be a
touch warmer. Lows will be in the lower 20s to around 30 at the
coast. This is still about 7 to 10 degrees below normal.-- End Changed Discussion --
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
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Key Points
*Temperatures will run below normal through the long term period,
with highs likely not making it out of the mid 30s on Friday and
Saturday for most.
*A clipper low will bring light rain and snow and gusty winds to the
area Wednesday night through Friday.
Potent shortwave energy diving down from near the North Pole will
aid in deepening a clipper low as it passes over the Great Lakes and
to our north. This low will drag a cold front through the area
sometime on Thursday and impact the area Wednesday night through
Friday. The system lacks significant moisture and all the global
guidance shows only light QPF amounts. However, it is worth noting
that the QPF has trended up slightly over the past 24-48 hours. The
latest NBM deterministic QPF has 0.10 to 0.40 inches from west to
east. It will likely be cold enough across the interior to remain as
snow for the whole event, which could mean some light snow
accumulation. Down at the coast, this would likely start off as rain
or rain/snow, then transition to rain and then potentially end as
snow. Timing of the PoPs has shifted a bit earlier from the previous
forecast. It is a progressive system, with PoPs likely starting
Wednesday night and ending by Thursday afternoon.
The more impactful weather from this system may end up being the
winds and cold air that will be filtering in behind it. Used NBM
90th percentile and global guidance consensus to bump winds above
what the NBM deterministic was showing. This was due to good
agreement across the global guidance and what model soundings were
showing. We will likely be in between a 1030-1035mb high to the west
and 975-985mb low to the northeast. Current forecast has sustained
winds peaking at 20 to 25 mph, with gusts peaking at 35 to near 40
mph. These peak values will likely be Thursday into Thursday night.
The first push of cold air comes behind the cold front, but there
looks to be a secondary push on Friday. 850mb temps look to bottom
out Friday evening around -12 to -15C. These values are below the
10% moving average for the OKX sounding per SPC`s Sounding
Climatology Page. Low temps Thursday night look to be in the 20s,
with highs on Friday likely not making it out of the mid 30s.
Model spread increases for next weekend. It looks like high pressure
should at least briefly build in for early Saturday. The question is
how long the high sticks around and how fast a system upstream
approaches and how far south it tracks. Latest Canadian and ECMWF
hold off this system until early next week while the GFS brings it
through late next weekend. High temps will be affected on Saturday
depending on which solution happens. Current forecast has highs on
Saturday similar to Friday, but if GFS is correct, winds will become
southerly early Saturday and likely result in much warmer
temperatures. It is worth nothing the GEFS is starting to show more
members that line up with the deterministic GFS with this system.-- End Changed Discussion --
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
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VFR through the TAF period.
W wind gusts should end 22-23z with wind speeds settling under 10 kt
overnight. The flow veers to the NW by Monday morning and increases
to around 10 kt late morning into the afternoon.
...NY Metro (KEWR/KLGA/KJFK/KTEB)TAF Uncertainty...
End time of gusts may be off by 1-2 hours.
An occasional gust 15-18 kt possible Monday afternoon.
OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
Monday PM-Tuesday: VFR. NW winds G15-20 kt possible Monday and
Tuesday afternoon.
Wednesday: VFR during the day. Chance of MVFR in snow and/or rain
showers at night. SW winds G15-20 kt.
Thursday: Mainly VFR. Chance of a rain and/or snow shower. W winds
10-20G30-35 kt.
Friday: VFR. NW winds 15-20G25-35 kt.
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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SCA conditions with marginal winds and seas will persist on the
ocean waters through the first half of this evening. Thereafter,
expect sub-SCA conditions with a diminishing westerly flow
overnight. High pressure gradually builds in from the southwest
Monday into Tuesday.
Sub-SCA conditions expected through at least the first half of
Wednesday. Winds and waves pick up late Wednesday ahead of a cold
frontal passage and potentially reach gale force by midnight
Wednesday night. The cold front likely passes through Thursday
afternoon and gale force winds could continue through early Friday
out of the northwest. Ocean seas during this time could peak around
10 to 12 feet. Conditions fall to SCA level late Friday and then
below SCA by late Friday night.-- End Changed Discussion --
&&
.HYDROLOGY...
There are no hydrologic concerns through next week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 10 PM EST this evening for ANZ350-
353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...JT/DW
NEAR TERM...DW
SHORT TERM...DW
LONG TERM...JT
AVIATION...DS
MARINE...JT/DW
HYDROLOGY...JT/DW