NYC Office Forecast Discussion

000
FXUS61 KOKX 180229
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
929 PM EST Sat Nov 17 2018

.SYNOPSIS...
High pressure builds across the waters through Sunday with a
weak warm front approaching Sunday night. A slow moving cold
front will drift south of the region on Monday, followed by the
passage of a weak offshore low on Tuesday. An arctic airmass
will likely build in for the end of the week.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Clouds have been slow to clear this evening with abundant
stratocu across the region. Still think these clouds will
eventually scatter and thin out after midnight, but will begin
to see an increase in mid and high level clouds early Sunday
morning.

A cold front over upstate New York will work south and east,
dissipating as it passes through overnight. It will be a dry
cold frontal passage followed by high pressure building east
from the Ohio Valley.

Cloud cover has been holding temps warmer than previously
forecast so have adjusted hourly temperatures up a few degrees.
Lows may end up a degree or two warmer than forecast as well,
but should see lows in the upper 20s and lower 30s inland and
low to mid 30s elsewhere.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
A progressive flow at the base of an upper trough over eastern
Canada will send a series of weak frontal waves from the Mid
Mississippi Valley northeast Sunday through Sunday night. Warm
advection coinciding with upper jet dynamics may allow for some
light precipitation to break out across portions of the Lower
Hudson Valley in the afternoon, which gradually works southeast
Sunday night.

Should the precipitation arrive early enough, there is enough
dry air for some light snow across portions of the Lower Hudson
Valley and interior southwest CT. However, weak warm advection
as the high moves offshore Sunday is forecast to warm the
boundary layer enough for a transition over to light rain
during the night. Any accumulation of snow should be light.
Advisory level snows are not expected.

Highs on Sunday will top out in the upper 30s to lower 40s.
There will be some fall off Sunday evening with temperatures
leveling off or slowly rising for the second half of the night.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
A slow moving cold front will move sewd thru the area on Mon. The
models suggest lgt pcpn, mainly in the form of rain. There could be
pockets of moderate pcpn n of the cold front along the mid lvl
front, so this will need to be watched for a quick dusting of snow
interior late in the day.

As the h5 trof reaches the area and shortwave energy reaches the
front, a weak low is progged to spin up then track newd. All of the
modeling indicates a band of pcpn sweeping thru the cwa. Pops have
been increased to 50 percent. The cold air looks sufficient to be
mainly snow, especially away from the coast.

Fair wx Wed with the cwa between systems. The arctic front however
arrives Wed ngt. The GFS and ECMWF both agree on this timing.
Although the models are dry, some snow shwrs cannot be ruled out.
Pops may need to be included in later forecasts.

Dry wx fcst for Thanksgiving thru Sat with a 1040 or so high
building in. Temps well blw average on Thanksgiving, then moderating
a bit each day thereafter. Rain possible Sat ngt as a Pacific sys
approaches.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
High pressure will slowly build from the NW into Sunday morning.
The high moves offshore Sunday afternoon with a warm front
approaching Sunday night.

VFR through Sunday afternoon. There is potential for ceilings
2500-3000 feet Sunday evening.

W-WNW winds diminish through midnight, veering to NW-N
overnight and N-NE daytime Sunday. Winds continue to veer to the
SE Sunday afternoon. Speeds will be under 10 kt.

.OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY...
.Sunday night...MVFR or lower conds possible in wintry mix
inland with chance rain elsewhere.
.Monday...MVFR or lower conds possible with chance of rain.
.Monday Night-Tuesday...MVFR or lower conds possible in rain or
wintry mix Monday night into Tuesday morning, then chance of
rain Tuesday afternoon. NW winds G15-20kt in the afternoon.
.Tuesday Night-Wednesday...VFR. W winds G15-20kt.
.Wednesday Night-Thursday...VFR. NW winds 15G25kt.

&&

.MARINE...
Sub-SCA conditions on all waters through Sunday night.

Winds and seas blw sca lvls Mon thru Wed, then an arctic front
will bring sca and possible gales Wed ngt into Thu. Winds and
seas then fall blw sca lvls on Fri.

&&

.HYDROLOGY...
Light QPF amounts of 1/4" or less are possible Sunday night
into Tuesday. No hydrologic issues are expected through
Saturday.

&&

.EQUIPMENT...
NYC NOAA Weather Radio Station KWO35 (162.55 MHz) will remain off
the air for an extended period of time.

&&

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

&&

$$
SYNOPSIS...JMC/DW
NEAR TERM...JMC/DS/DW
SHORT TERM...DW
LONG TERM...JMC
AVIATION...DS
MARINE...JMC/DW
HYDROLOGY...JMC/DW
EQUIPMENT...

NWS OKX Office Area Forecast Discussion