497
FXUS61 KOKX 222028
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
328 PM EST Wed Jan 22 2025

.SYNOPSIS...
High pressure builds over the region into tonight, shifting offshore
on Thursday. Weak low pressure passes offshore into Thursday night.
High pressure builds across from the southwest Friday into Saturday.
A cold front sweeps across Sunday, followed by another cold front
Tuesday.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
High pressure builds over the region into this evening, shifting
offshore overnight.

Weak shortwave energy passing north in the flow brings in some high
clouds this evening and tonight, but no precipitation expected with
such a dry air mass in place, 12Z OKX sounding progged PWATs at just
0.06 inches. Winds calm this evening as the center of the high moves
overhead. While temperatures tonight not expected to be quite as
extreme with the cloud cover, the calm wind and relatively fresh
snowpack should once again allow locales to fall a bit below blended
guidance, and went with bias corrected MAV/MET instead. With this,
should still fall down into single digits and teens regionwide,
and the coldest could slip just below zero or close to it, mainly
interior LoHud Valley, SW CT, and perhaps the LI Pine Barrens.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
Core of the cold eases Thursday as offshore high pressure allows a
light SW flow to develop, helping to moderate the air mass.
Temperatures remain below normal though, and 925 mb temperatures -8C
to -10C should translate into the 20s for most in the afternoon, or
lower 30s along the coast.

A weak mid level shortwave continues to swing east on Thursday,
though limited moisture and forcing will keep conditions dry
locally. Rather, some mid and high clouds likely persist into the
afternoon. Weak surface low develops offshore and passes east,
enhancing the cloud cover over Long Island and southern CT into
the early evening before skies clear out everywhere. Temperatures
Thursday night should fall back into the single digits inland,
teens along the coast, and around 20 for the NYC metro.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
The northern branch of the jet stream will continue to be the main
driver in the weather regime across the region. Overall, a series of
northern branch shortwaves will race nearby and move quickly
through. The main function of this will be to reinforce cold and dry
air into the region. Temperatures overall will continue to average
below normal despite being at the coldest point of the season / year
climatologically. There will be a few days where temperatures
average near the climatological norms, with other days averaging
noticeably below.

The main story, or lack thereof is that there appears to be no
significant storms in sight throughout the long term period. A look
at Ensemble sensitivity at 500 mb does indicate some uncertainty in
the positioning / speed of perhaps subtle amounts of energy
attempting to emerge out of the SW US. However, there doesn`t appear
to be enough uncertainty around meaningful energy getting east in
the southern branch of the jet stream. This has downstream
implications for our area in that any northern branch feature will
not be able to interact or phase with southern stream energy, and
thus any northern branch shortwaves should remain moisture starved.
Overall the ensemble sensitivity add confidence for the cold and dry
cP regime to continue.

Towards the tail end of the period the ensemble sensitivity appears
to shift the uncertainty more towards the behavior of the northern
branch of the jet stream. At this time there are varying solutions
with respect to the deterministic and ensemble suite guidance with
respect to 500 mb heights and thus thickness values along with
subsequent sfc temperatures. Temperatures late in the period could
range anywhere from near seasonable values to well below normal.
Thus uncertainty around temperatures increase substantially towards
Wednesday. This larger spread is easily seen in the NBM temperature
distribution.

&&

.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
VFR with high pressure over the terminals tonight. The high weakens
on Thursday as it moves to the south.

The flow continues to weaken this evening and will become light and
variable tonight. SW winds under 10 kt then develop Thursday morning.

 ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

No unscheduled amendments expected.

.OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...

Thursday Afternoon-Friday: VFR.

Saturday: VFR. W gusts 15-20 kt NYC metro/coastal terminals.

Sunday-Monday: VFR. W-WSW gusts 20-25 kt.

Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90

&&

.MARINE...
Sub Small Craft Advisory conditions on all waters through Thursday.
Increasing NW flow may allow 25 kt gusts to develop on the ocean
Thursday night, otherwise, with a relatively light pressure
gradient in place Friday into a good portion of Saturday sub
advisory conditions are expected.

Small craft conditions may develop on the ocean waters Saturday
night, with the potential for more widespread small craft
conditions into Sunday and Monday.

&&

.HYDROLOGY...
No hydrologic issues are anticipated through this weekend.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.

&&

$$

SYNOPSIS...JE/DR
NEAR TERM...DR
SHORT TERM...DR
LONG TERM...JE
AVIATION...DS
MARINE...JE/DR
HYDROLOGY...JE/DR