Area Forecast Discussion
Issued by NWS Upton, NY

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FXUS61 KOKX 202323
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
623 PM EST Sat Jan 20 2018

.SYNOPSIS...
High pressure remains south of the region through the weekend. A
weak cold front will pass through the area tonight. A warm
front, associated with low pressure moving into the upper
midwest Monday, approaches Sunday night and moves through the
area late Monday into Monday night. The low tracks across the
Great Lakes region and through eastern Canada Monday night
through Tuesday night, bringing as cold front across the region
Tuesday. High pressure builds over the area Wednesday through
Friday and moves offshore Saturday.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Only minor changes to the temperatures and dew points for
current conditions. Forecast remains on target.

A weak cold front, associated with low pressure system moving
across SE Canada, will push across the region this evening. High
pressure will remain south of the area. This front comes
through dry, however temperatures do return to more seasonable
levels. Lows tonight fall into the 20s and lower 30s. The NYC
metro area may remain in the middle 30s all night.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
The cold front which will move across the region tonight, will
provide a glancing shot of Canadian air for Sunday. High
temperatures on Sunday will be a good 8-10 degrees cooler than
today. Forecast high temperatures will be in the lower to middle
40s.

12Z NAM continues to show the potential for some stratus to
develop under a strengthening subsidence inversion Sunday
afternoon. There is a higher probability for this to occur
across PA and points west. If stratus does develop this far
east, temperatures may be a few degrees cooler than forecast.

Clouds increase Sunday night along with the possibility of some
light precipitation development Sunday Night into early Monday
morning as a warm front moves towards the region. Will keep
chances a slight chance for now, and most of the precipitation
will be plain rain, however there is the potential for an icy
mix across Lower Hudson Valley and Southern CT in this pattern.
Any icy mix would result in a hazardous Monday Morning commute
for these areas.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Rather strong continuity with model guidance remains with a
frontal system that will be impacting the region late Sunday
night through Tuesday night. As is typical of the ECMWF the low
is a bit slower and not as deep as both the NAM and GFS,
especially Monday night into Tuesday. A blend of the model
guidance and current forecast will keep forecast close to
continuity.

There is uncertainty with the passage of a warm front Monday.
Typical cold air damming is not in place Monday as high pressure
will be moving across southern central Canada with more of a
west to east configuration. In addition mid and upper flow is
initially more zonal and progressive, then as the upper trough
deepens and moves east flow becomes more southerly by late in
the day. Without the cold air in place to the north, the warm
front is expected to move through later Monday afternoon,
especially along the coast, and inland early Monday night. Also,
without the colder air in place the chances for freezing rain
across the interior have diminished, with areas possible at this
time across the northern zones. Otherwise rain is expected and
with strong lift and a low level jet, along with influx of Gulf
of Mexico moisture, periods of moderate to heavy rain will be
Tuesday. A rumble of thunderstorm will also be possible.

After the passage of the cold front and upper trough heights
will be rising and surface Canadian high pressure will be
building in with an extended period of colder and dry weather
into next weekend.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
High pressure remains centered to our south through the TAF
period.

Winds and gusts will continue to subside this evening. WNW
winds under 10 kt at city terminals with light and variable
winds elsewhere. Light NW winds will continue on Sunday before
gradually backing to the W-SW late.

VFR through much of the TAF period. Potential for MVFR ceilings
increases Sunday evening.

.OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY...
.Sunday NIGHT...MVFR possible.
.Monday...MVFR or IFR in chance of -RA. A light wintry mix possible
across interior early Monday.
.Tuesday...IFR or LIFR in rain. LLWS. S winds G25KT morning, WSW
winds G30-35KT possible near the coast in the afternoon.
.Wednesday...VFR. WNW G25-30KT.
.Thursday...VFR. NW winds G20KT.

&&

.MARINE...
Seas may still be at or above 5 ft across the outer waters east
of the Moriches Inlet, as buoy 44097 remains around 7 ft. So
will keep the SCA.

Conditions fall below small craft levels on the eastern ocean
waters by midnight. Then conditions remain below SCA through
Sunday night.

As a warm front moves into the forecast waters Monday and early
Monday night winds and seas are expected to remain below SCA levels.
Once the warm front moves through and winds shift to southerly, and
increase as a cold front approaches, wind gusts will increase late
Monday night through Tuesday. Gusts will likely reach SCA levels
late Monday night into Tuesday across all the waters. With a low
level inversion in place Tuesday higher winds aloft will be
difficult to mix down to the water.
However, there will be the potential for ocean gusts to be near gale
force for several hours during the day Tuesday. Otherwise, with the
increased southerly flow, ocean seas will be building to small craft
levels Tuesday.

There may be a brief period of sub small craft winds late Tuesday
into Tuesday night. Then, once colder air filters into the waters
behind a cold front small craft level wind gusts will be likely
across all the waters late Tuesday night into Thursday morning.
Ocean seas will be slowly subsiding into the northwest flow
Thursday.

&&

.HYDROLOGY...
A frontal system passing through late Sunday night through Tuesday
has the potential to produce 1 to 1 1/2 inches 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 until midnight EST tonight for ANZ350.

&&

$$
SYNOPSIS...BC/19
NEAR TERM...BC/19
SHORT TERM...BC
LONG TERM...19
AVIATION...JC
MARINE...BC/19
HYDROLOGY...BC/19
EQUIPMENT...



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