262
FXUS61 KOKX 131150
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
650 AM EST Fri Dec 13 2024
.SYNOPSIS...
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Strong high pressure will build over the Northeast through
tonight and dominate through Sunday. A weakening frontal system
will approach Sunday night and move across on Monday. A
stronger frontal system will move across Monday night into
Tuesday, followed by high pressure Tuesday night into Wednesday.
A developing low pressure system to the southwest could begin
to impact the area on Thursday.-- End Changed Discussion --
&&
.NEAR TERM /THROUGH TONIGHT/...
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Forecast on track early this morning. Mid level clouds
associated with an upper jet streak will diminish by mid
morning leading to a sunny, cold and dry day across the Tri-
State. An upper trough will remain over the Northeast today
before shifting east tonight, which will allow strengthening
high pressure to build over the region.
Temperatures will struggle to rise above the lower 30s for
highs. Several interior locations may struggle to rise to
freezing. Some of the usual warmer spots could briefly reach
the mid 30s. The air mass is quite dry and have lowered dew
points well into the single digits across the entire area.
Winds will not be as strong as Thursday, generally 5-10 mph with
possibly a few gusts to 15 mph in the morning. Winds should
drop off more in the afternoon. However, the wind will make it
feel like it is in the upper teens and low 20s in the morning
and mid to upper 20s in the afternoon.
The surface high will be nearly overhead tonight as it continues
to strengthen due to strong confluence behind the departing
upper trough. Radiational cooling conditions look ideal allowing
temperatures to bottom out in the teens across much of the area
with the NYC metro in the lower 20s.-- End Changed Discussion --
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
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Shortwave ridging builds over the Northeast Saturday into
Saturday. The combination of the ridging and confluent flow
behind the departing upper trough will allow the central
pressures to increase to between 1046-1049 mb in the core of the
high. These levels are just below the highest observed in
December and all-time in the Northeast. See Climate section
below for information.
Subsidence underneath the ridging will bring another clear and
cold day. Highs should be a few degrees higher than Friday,
but still nearly ten degrees below normal in the middle 30s.
Another cold night with nearly ideal radiational cooling
conditions on tap for Saturday night. Lows will be in the teens
across the interior and Long Island Pine Barrens with lower 20s
most elsewhere.
The ridge axis begins to shift east on Sunday. The surface high
will also start to weaken as it shifts off the New England coast
in the afternoon and evening. Dry conditions continue, but
there will be increasing clouds late ahead of the next
shortwave. Highs will likely be in the middle to upper 30s
inland and lower 40s near the coast. The shortwave quickly
approaches from the Great Lakes and Ohio Valley Sunday night.
Much of the energy with this system passes to the north. A weak
front or surface trough will accompany the shortwave. Thermally
forced precip is progged to move into the western half of the
region late Sunday night. There are concerns that the modeling
may be overdoing the precip in this scenario due lingering
surface dry air and ridging. The shortwave energy passing to the
north would also limit the amount of forcing to overcome the
aforementioned negating factors. Will continue to follow the
model consensus blend for now to support chance PoPs for the
western half of the area. The precip may start as a wintry mix
as thermal profiles suggest some freezing rain and sleet may mix
with any brief light snow across the interior of NE NJ and
Lower Hudson Valley. These details will need to be fine tuned in
subsequent forecasts. There is also a chance that any precip
would hold off till later Monday morning which could then
introduce warm enough air for mostly plain rain.-- End Changed Discussion --
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
The aforementioned shortwave weakens further on Monday as it
passes nearby or across upstate New York and New England,
bringing mainly light rain. Inland sections should continue
seeing a wintry mix just after day break before changing to all
rain. There may not be much of a break in precip before the
next frontal system begins to arrive Mon night, and even if
there is, with the area sitting north of a stationary front and
lingering low level moisture, expect clouds to linger and some
fog to develop Mon evening before rain develops ocean again.
The front to the south should lift thru as a warm front on Tue as
the second sys approaches, bringing a light to moderate rainfall.
Fcst carries chance PoP into Tue night, but with incoming 00Z
guidance showing cold fropa late day Tue or early Tue evening, conds
may improve more quickly than fcst.
Wed at any rate looks dry as high pressure slides across. Then PoP
chances increase for late Wed night into Thu with a lead impulse
ahead of an intensifying low fcst to move up the coastal plain by
some guidance on Fri. Temps may initially be cold enough for some
light snow or a wintry mix inland late Wed night into Thu morning,
then precip should quickly transition to rain throughout.
Temps will be above normal thru the period especially on Tue, when
then area gets into the warm sector and temps rise well into the
50s, to near 60 in spots.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
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VFR as high pressure builds eastward from the Plains states.
W-WNW winds either side of 10 kt early will increase by
14Z-15Z, with gusts 15-20 kt, before diminishing again by late
afternoon. Winds then shift to the NW 10 kt or less toward
sunset, then become N less than 10 kt tonight.
...NY Metro (KEWR/KLGA/KJFK/KTEB)TAF Uncertainty...
Gusts in the late morning and afternoon may only be occasional,
and could abate after 18Z.
OUTLOOK FOR 12Z SATURDAY THROUGH TUESDAY...
Saturday: VFR.
Sunday: MVFR cigs likely at the NYC metro/coastal terminals in
the afternoon, spreading inland during the evening. Chance of
a wintry mix at KSWF and rain elsewhere, mainly after midnight.
Monday: Wintry mix still possible at KSWF early, otherwise light
rain likely with MVFR or lower cond expected. Fog may develop
at night with IFR cond possible.
Tuesday: Light rain likely with IFR or lower cond possible.
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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Ocean seas around 5 ft should linger E of Fire Island Inlet this
morning, with SCA remaining in effect til 12 PM. Otherwise, a
weak pressure gradient will lead to winds and seas below SCA
levels through Sunday. Seas may build to 4 ft Sunday night as
high pressure departs off the New England coast, but conditions
remain below SCA levels.
SE flow increasing to 15-20 kt Mon night and then veering to the
SW after a warm fropa on Tue should push ocean seas up to 5-6
ft from late Mon night into Tue night. A few gusts up to 25 kt
may also be possible on the ocean daytime Tue.-- End Changed Discussion --
&&
.HYDROLOGY...
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No hydrologic impacts are expected attm.-- End Changed Discussion --
&&
.CLIMATE...
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Very strong high pressure is forecast to settle over the
Northeast by Saturday. The potential high sea level pressure
(SLP) is close to the highest observed across the Northeast not
only in December but in any calendar month based on data from
WPC. The highest observed SLP in the Northeast ranges from
1052-1054 mb, which occurred on February 13, 1981. The highest
observed SLP at Central Park was 1052.5 mb, which also occurred
on February 13, 1981. The highest observed SLP in the Northeast
for December ranges from around 1049-1053 mb (1051.8 mb at
Central Park), which occurred on December 25, 1949.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until noon EST today for ANZ350-353.
&&
$$
SYNOPSIS...BG/DS
NEAR TERM...DS
SHORT TERM...DS
LONG TERM...BG
AVIATION...BG
MARINE...BG/DS
HYDROLOGY...BG/DS
CLIMATE...