692
FXUS61 KOKX 190006 CCA
AFDOKX
Area Forecast Discussion...CORRECTED
National Weather Service New York NY
706 PM EST Mon Nov 18 2019
.SYNOPSIS...
Low pressure passes east of New England through tonight. Several
upper level disturbances also move across the region tonight and
Tuesday. Another area of low pressure is expected to develop well
offshore Tuesday night and move away during Wednesday. High
pressure builds into the region Wednesday into Thursday. A cold
front will then cross the area on Friday, followed by a period
of high pressure for the first half of the weekend. An area of
low pressure may impact the area Saturday night into Sunday,
before high pressure builds back into the area on Monday.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Only minor adjustments made with this update to better capture
the latest temperature trends. Otherwise the forecast remains on
track.
Closed low moving east of the Ohio/Tennessee Valleys will
approach the region late this evening and swing through late
tonight into Tuesday morning.
At the surface broad offshore low pressure continues to track
NNE, well east of New England, and towards the Canadian
Maritimes.
Main convergence zone, and band of light rain and drizzle, is
currently focused over the NYC metro area northward into the
Lower Hudson Valley. Into this evening, increasing lift ahead
of the upper low and left front of strengthening ulj, combined
with modest mid-level deformation, and developing surface trough
should have rain become more widespread and increase to
moderate intensity through the evening and overnight. Can
already see this precip enhancement moving northeastward through
central NJ, which should translate and expand into the local
area through the evening. Northern and western portions of the
Tri-State appear to be in favored location for heavier precip,
with potential for 1/3 to 2/3 inch of precip, with lesser
amounts for E LI and SE CT.
Thermal profiles are supportive of plain rain across the entire
area through around 2 am. After 2-3am, potential exists for
mixing with or changeover to wet snow across NW hills of Lower
Hudson Valley and SW CT in response to heavier precip rates
dynamically cooling boundary layer thermal profiles to near
freezing. Potential for a slushy accumulation of less than an
inch in this area, particularly highest terrain, with a
reasonable worse case scenario of 1 to 2 inches. Elsewhere, not
out of the questions to see a few wet snow flakes mix in with
the rain overnight during peak intensity, but no accumulation
expected. Steady precip expected to come to an end from sw to ne
before daybreak, with just some lingering showers coming to an
end Tue morning.
Low generally in the lowers 30s interior, to mid to upper 30s
coast.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
Mean troughing will be the rule, with vigorous shortwave/closed
low pivoting northeast of the region in the morning, followed
by weak shortwave ridging in the afternoon, and then mean
trough axis approaching for Tuesday Night. At the surface, one
low pressure tracks into the Canadian Maritimes on Tuesday, with
a low developing off the SE US coast tonight into Tuesday,
tracking northeast farther offshore for Tuesday Night.
In terms of sensible weather, generally dry conditions with low
level westerly flow and drying. Perhaps a break of sun Tuesday
morning, but high and mid clouds increase ahead of the
approaching trough axis for Tuesday afternoon/Night. Can`t rule
our an isolated shower/sprinkle for city/coast and possibly
flurry interior late Tuesday Night as upper trough/low moves
into the region.
Otherwise, temps a few degrees below seasonable on
Tuesday/Tuesday Night with highs in the mid to upper 40s
Interior, and upper 40s to around 50 city/coast. Lows generally
in the lower to mid 30s Interior, upper 30s to around 40 coast.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
An upper trough over the area to start the long term period
will shift east through the day on Wednesday, allowing upper
ridging and surface high pressure to build across the area
Wednesday night into Thursday. This will usher in a period of
tranquil weather with temperatures closer to normal, albeit with
a good deal of cloud cover on Wednesday under the upper trough.
By the end of the work week, an area of low pressure tracking
through the Great Lakes will send a cold front through the
region on Friday. Fairly significant discrepancies continue
between the available guidance, with a 6 to 12 hour difference
in the timing of the frontal passage. The GFS continues to be
noticeably more amplified with this system with more phasing
between the northern and southern streams, resulting in a slower
frontal passage. Will continue to lean towards the faster, less
amplified, solutions, which would bring scattered showers to
the region during the day on Friday. The best chance for showers
will be north and west of NYC.
The model differences that develop on Friday will continue to have
ramifications on the forecast into the weekend. Once the front
pushes east of the area, models are in reasonable agreement that
high pressure builds back into the region on Saturday, but diverge
again thereafter. In the operational European, which does not phase
the northern and southern streams with the Friday system, the high
is a more transient feature, quickly moving off to the northeast as
a southern stream surface low approaches Saturday night. On the
other hand, high pressure dominates through the weekend in the GFS,
with any lingering southern stream energy sliding south of the
region and off the Mid Atlantic coast Saturday night. The Canadian
lies somewhere in the middle, with high pressure forcing the
developing southern stream low off the coast well south of the
region, keeping the area dry. Given the uncertainty at this time
frame, will keep at least slight chance PoPs across the area
Saturday night into Sunday. High pressure then builds back into the
region for the start of the new work week.
After remaining a few degrees below normal on Wednesday and
Thursday, temperatures on Friday will rise well into the 50s ahead
of the front, several degrees above normal for this time of year.
Temperatures then fall back into the upper 40s to around 50 for the
remainder of the period. With the exception of Thursday night ahead
of the approaching front, overnight lows will generally range from
the upper 20s to around 30 across the interior to the mid to upper
30s in the New York City metro, near normal for the latter half of
November.
&&
.AVIATION /00Z TUESDAY THROUGH SUNDAY/...
IFR into this evening.-RA and DZ mostly in the vicinity of the
city terminals and points west early on, then becoming more
widespread by late this evening and into the overnight. A pocket
of steadier rain is likely towards 2 to 3z for the city
terminals. At KSWF the rain may mix with snow and possibly
change to all snow before ending towards 12z. Little to no
accumulate is expected at KSWF terminal.
N-NNW winds generally around 10kt this evening, to around 5 kt
late tonight. The winds then go more westerly during the day on
Tuesday at 5 to 10 kt. VFR conditions should return towards 13-15z
across the terminals.
.OUTLOOK FOR 0Z WEDNESDAY THROUGH SUNDAY...
.Tuesday Night...Mainly VFR.
.Wednesday-Thursday...VFR. NW winds gust around 20 kt Weds
aftn/eve.
.Friday...Chance MVFR in rain showers. SW gusts 20-25 kt PM.
.Saturday...Chance MVFR/IFR in rain PM hours.
.Sunday...Chance MVFR/IFR in rain in the morning.
&&
.MARINE...
A Small Craft Advisory continues on the ocean waters through the
day on Tuesday as rough ocean seas in long period easterly
swells will only slowly subside. Otherwise, wind gusts have
fallen below 25 kt on most of the waters as the pressure
gradient continues to relax this evening, and the SCA for the
eastern Long Island Sound and Peconic and Gardiners Bays was
allowed to expire.
Winds and seas will begin to increase Wednesday afternoon as high
pressure builds towards the region from the west and an area of low
pressure well offshore deepens. Winds and seas then decrease below
SCA levels by Thursday morning as the high builds across the waters.
SCA conditions return ahead of an approaching frontal system on
Friday. By Friday night, ocean seas will increase to 5-8 ft with
wind gusts around 30 kt on the ocean. Conditions then subside below
SCA levels by late in the day on Saturday.
&&
.HYDROLOGY...
1/3rd to 2/3rd of an inch of rain is likely tonight.
No hydrologic impacts are anticipated through the forecast
period.
&&
.TIDES/COASTAL FLOODING...
There is only a low prob of approaching/touching minor flood
thresholds across the south shore bays of LI and Queens with Tue
aft high tides, otherwise water levels are expected to stay
below minor flood thresholds for the remainder of the week.
&&
.EQUIPMENT...
NYC NOAA Weather Radio Station KWO35 (162.55 MHz) is operating
at reduced power until further notice.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 PM EST Tuesday for ANZ350-353-355.
&&
$$
SYNOPSIS...FEB/NV
NEAR TERM...FEB/NV
SHORT TERM...NV
LONG TERM...FEB
AVIATION...JE
MARINE...FEB/NV
HYDROLOGY...FEB/NV
TIDES/COASTAL FLOODING...
EQUIPMENT...
NWS OKX Office Area Forecast Discussion
