Area Forecast Discussion
Issued by NWS Upton, NY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KOKX 191116
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
616 AM EST Fri Jan 19 2018

.SYNOPSIS...
High pressure will builds to the south through Saturday, while
low pressure passes well to the north on Saturday. A back door
cold front will pass through Sunday night, then return north as
a warm front on Monday ahead of a strong frontal system for
Monday night into Tuesday. High pressure will return for mid
week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Skies should be mostly sunny today, with only some high/mid
level clouds associated with a weak mid level shortwave trough
passing to the north. Temps will be 5-10 degrees warmer than
those of yesterday, with highs mostly in the upper 30s and lower
40s.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
Zonal flow will prevail aloft between a flat trough passing to
the north and ridging along the SE coast. After one more cold
night inland with lows in the teens/20s, and lower 30s for NYC
metro and most of Long Island, downslope flow/WAA will result in
a mild day, with high temps in the upper 40s and lower 50s. It
will however be brisk, as a tightening pressure gradient between
low pressure passing E across Quebec and high pressure along
the SE coast generates W to WSW winds gusting up to 35 mph in
NYC and across Long Island, and 25-30 mph most elsewhere to the
north/west.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Zonal upper flow through the weekend, with confluence of Pacific
and polar jet to the north of the region, and southern stream
energy tracking through the deep south. Continued return flow
around southern high pressure Sat Night into Sunday will allow
for dry and unseasonably mild conditions under a Pacific air
mass, with high temps in the lower and mid 40s on Sunday.

A vigorous polar shortwave moving through southeastern Canada
Sunday night will likely have a back door cold front pushing
through the region, bringing in a more seasonable Canadian
maritime air mass for Monday.

Meanwhile, models in good agreement with the relatively tranquil
pattern being interrupted early next week by the Pacific
energy coming into the Western states today. This Pacific
shortwave will amplify through the SW states, and eventually
phase with subtropical jet energy. The resultant deep closed
low is then expected to gradually track NE across the Central
Plains and Mid Mississippi valley Sunday into Mon, before
approaching the Northeast by Tuesday as it begins phasing with
northern stream energy. There are still some timing/amplitude
differences with this energy, which is manifesting in
timing/track differences of a resultant frontal system as it
tracks toward the region Monday Night into Tuesday. This model
spread should decrease over the next 24 hrs as Pacific energy
comes onshore, but subtle model differences may continue
through Sunday until the subtropical and Pacific energy phase.

Regardless, there has a been consistent model-to-model and run-
to-run signal for a quick moving moderate to heavy rain event
for Monday night into Tuesday, in response to strong deep
layer lift (region under of nose of 65-70 kt LLJ and left front
quad of a 100+ kt jet streak in difluent upper flow) of a
subtropical moisture plume with PW +2 to + 3 standard deviations
above normal over the region, focused ahead of the cold front
and a surface wave. Before that, still appears there is
potential for a light wintry mix N/NW of NYC metro Monday
morning as a warm front moves north with increasing theta-e
advection.

The frontal system pushes through on Tuesday, with breezy
conditions and CAA in its wake, returning dry and more
seasonable temps for Wed/Thu.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
High pressure remains centered to the southwest of the region
through tonight.

VFR through the TAF period.

Winds may briefly strengthen to 10-14 kt this afternoon with an
occasional gust to 18 kt. Otherwise, W flow gradually backs to SW by
this evening.

  ...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: Winds may be stronger than forecast this
afternoon.

The afternoon KJFK haze potential forecast is GREEN, which
implies slant range visibility 7SM or greater outside of cloud.

KLGA TAF Comments: Occasional gusts to 18 kt possible this afternoon.

The afternoon KLGA haze potential forecast is GREEN, which
implies slant range visibility 7SM or greater outside of cloud.

KEWR TAF Comments: Occasional gusts to 18 kt possible this afternoon.

The afternoon KEWR haze potential forecast is GREEN, which
implies slant range visibility 7SM or greater outside of cloud.

KTEB TAF Comments: Occasional gusts to 18 kt possible this afternoon.

KHPN TAF Comments: Occasional gusts to 18 kt possible this afternoon.

KISP TAF Comments: Occasional gusts to 18 kt possible this afternoon.

.OUTLOOK FOR 12Z SATURDAY THROUGH TUESDAY...
.Saturday...VFR. WSW winds G20-25KT.
.Sunday...VFR.
.Monday...Chance of MVFR or lower in -SHRA. S winds G20KT late day.
.Tuesday...IFR in rain. LLWS. S winds G25KT morning, W winds G30-
35KT aftn.

&&

.MARINE...
Could see a stray gust or two up to 25 kt on the outer ocean
waters today, but overall conditions should remain quiet today.

Winds should ramp up tonight into Sat as the pressure gradient
tightens between low pressure passing across Quebec, and high
pressure along the SE coast, with lack of a sfc-based
temperature inversion allowing for wind gusts to increase to
SCA levels tonight, and to minimal gale force daytime Sat on the
ocean waters E of Fire Island Inlet. These conditions should
quickly abate Sat evening, with just some elevated seas
lasting til midnight on the ern ocean waters.

Sub SCA conditions expected Sunday and Monday. Winds and ocean
seas expected to increase to SCA levels late Monday Night into
Tuesday ahead of approaching cold front. SCA conditions likely
continue on W/NW flow and caa flow Tuesday Night through
Wednesday, with potential for a period of Gale conds.

&&

.HYDROLOGY...
A frontal system passing through late Monday night into Tuesday has
the potential to bring around inch of rain. No significant
hydrologic issues are anticipated at this time.

&&

.EQUIPMENT...
NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) is off the
air for an extended period of time.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 6 PM this evening to 6 PM EST
     Saturday for ANZ355.
     Gale Watch from Saturday morning through Saturday afternoon
     for ANZ350-353.
     Small Craft Advisory from 6 PM this evening to 6 AM EST
     Saturday for ANZ350-353.

&&

$$
SYNOPSIS...Goodman/NV
NEAR TERM...Goodman
SHORT TERM...Goodman
LONG TERM...NV
AVIATION...JMC/MD
MARINE...Goodman/NV
HYDROLOGY...Goodman/NV
EQUIPMENT...



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.