NYC Office Forecast Discussion

000
FXUS61 KOKX 281827
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
127 PM EST Tue Jan 28 2020

.SYNOPSIS...
A series of upper level disturbances will move across into
tonight. A cold front will also pass through this evening. High
pressure will then gradually build in through Thursday night
before moving offshore on Friday. There is then much uncertainty
with a potential coastal low this weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Again some slight adjustments with temperatures, dewpoints, and
cloud coverage were made to better reflect current observed
trends.

Downsloping NW flow proving to warm up temperatures a little
more than previously forecast. Highs more in the low to mid 40s
as a result accounting for this and a little more sun. Generally
partly sunny conditions expected towards the coast and mostly
cloudy inland.

Mid level shortwave moving farther southeast of the region with
some brief ridging locally through mid afternoon will allow for
scattering and thinning of clouds. However, expecting the
clouds to increase and thicken again late this afternoon in
advance of another shortwave from the northwest with a cold
front approaching at the surface.

Mid level disturbances rotating around an upper low in the
Canadian Maritimes, and mainly low level cyclonic flow with
moisture trapped beneath an H8 inversion, will maintain a
decent amount of cloud cover today.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
Sfc high pressure will build southward into the region tonight,
with gradual clearing mainly after midnight, then a mostly
sunny day on Wed. Low temps tonight should be in the 20s,
perhaps some upper teens in some of the interior valleys, then
high temps on Wed should be fairly close to those of today, with
upper 30s/lower 40s expected.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
At the onset of the period, an upper trough will be pulling away
from the Canadian maritimes, while ridging builds across the
east as a trough begin to take shape over the mid section of the
country. The latter of which poses a good deal of uncertainty
for the upcoming weekend.

Before then though, high pressure builds across the northeast
through Thursday night, before retreating offshore on Friday.
Temperatures will be a shade below normal Thursday and then
moderate into the upcoming weekend with highs around 40 and lows
in the 20s inland to the lower 30s at the coast.

For days now, the global guidance has been bouncing around with
the intensity and track of a coastal low that develops off the
eastern seaboard Friday night into Saturday. Multiple streams
within the southern branch itself and complex interaction
between embedded shortwaves are producing a variety of
solutions. Further compacting this interaction, is additional
Pac shortwave energy moving into western Canada today. Overall
though, the placement of the upper trough over the east this
weekend is not too dissimilar amongst the guidance. The
operational GFS is the deepest of the operational members and
tracks the low just inside the 40N/70W benchmark on Saturday.
The GEFS mean is farther offshore like GGEM and ECMWF, both of
which also have a weaker wave passing to the south and east
Friday night before the main low. For the time, have a low
chance for rain or snow along the coast Friday night and again
with the main low Saturday into Saturday night.

Another important fact here is the airmass is only marginally
cold and the exact track will be critical in precipitation
type. Even the GFS track, which is often favorable for snow at
the coast, is supporting mainly rain at the onset with a
transition to snow at the end.

Bottom line, it is much too early to be specific with any
details at this time. Perhaps, as some of the Pac energy moves
onshore today, we will begin to get more consensus in the
guidance.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
Low pressure over the Canadian Maritimes slowly moves east as a
large area of high pressure gradually builds in from the west.

VFR. BKN-OVC clouds 4-6 kft through this evening should
gradually scatter and clear overnight.

NW winds prevail 10-15 kt with gusts to around 20 kt. The gusts
should end this around 21-23z. NW winds 5-10 kt continue tonight
and then should average around 10 kt on Wednesday.

     NY Metro Enhanced Aviation Weather Support...

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

KJFK TAF Comments: Gusts may be occasional at times this
afternoon.

KLGA TAF Comments: Gusts may be occasional at times this
afternoon.

KEWR TAF Comments: Gusts may be occasional at times this
afternoon.

KTEB TAF Comments: Gusts may be occasional at times this
afternoon.

KHPN TAF Comments: Gusts may be occasional at times this
afternoon.

KISP TAF Comments: Gusts may be occasional at times this
afternoon.

.OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY...
.Wednesday through Friday night...VFR.
.Saturday...MVFR or lower possible in rain or snow.
.Sunday...Mainly VFR. Slight chance rain or snow. NW gusts 15-20
kt possible.

&&

.MARINE...
Conditions remain below SCA levels into this evening, with
winds gusting just over 20 kt and seas 4 ft on the ocean.
Expect more tranquil conditions late tonight into Friday as high
pressure builds in.

The next chance of SCA conditions should be over the weekend,
with the potential of a coastal low impacting the waters.
Uncertainty in track and intensity remains high.

&&

.HYDROLOGY...
No hydrologic impacts are anticipated through Friday.

&&

.EQUIPMENT...
NYC NOAA Weather Radio Station KWO35 (162.55 MHz) is still
operating at reduced power.

&&

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

&&

$$
SYNOPSIS...Goodman/DW
NEAR TERM...Goodman/JM
SHORT TERM...Goodman
LONG TERM...DW
AVIATION...DS
MARINE...Goodman/DW
HYDROLOGY...Fig/DS
EQUIPMENT...

NWS OKX Office Area Forecast Discussion