Area Forecast Discussion
Issued by NWS Upton, NY
FXUS61 KOKX 221113
Area Forecast Discussion
National Weather Service New York NY
713 AM EDT Sat Oct 22 2016
Deepening low pressure will track north across coastal New
England today and then into eastern Canada tonight into Sunday.
Another cold front will move southeast across the area early
Monday morning followed by Canadian high pressure through
Wednesday. Low pressure will move slowly east toward the area
Thursday through Friday.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Cold front has worked as far east as far eastern LI and southeast
CT and will clear the area in the next hour.
Latest radar imagery indicates widespread showers from NYC and
points north and west. with widely scattered to the east. The
intensity has weakened over the last couple of hours with
rainfall rates less than a tenth of an inch an hour. This area
will continue to work north this morning and gradually pivot NE as
a negatively tilted upper trough approaches from the west. This
combined with a steeply sloped frontal surface will produce deep-
layered post-frontal lift that translates slowly east with time.
Showers will work east across LI and CT this morning.
Conditions will begin to gradually dry out this afternoon as the
upper low passes to the north.
More importantly though, will be strong west winds on the
backside of deepening low pressure across coastal New England
today. Pressure rises this afternoon and tightening of the
pressure gradient will result in the potential for gusts up to 50
mph across LI/NYC/SE CT, and 35 to 40 mph elsewhere. The top of
the mixed layer approaches 50 kt near the coast late this
afternoon. It always a tough question as to how much of this mixes
down to the surface, but strong cold advection and decent
pressure rises support a high percentage of these winds
transferring down to the surface. Some of the higher elevations
across the Lower Hudson Valley and NE NJ may even experience
occasional gusts up to 50 mph as well. A wind advisory remains in
effect for NYC/Long Island/SE CT, where the highest pressure rises
occur this afternoon into early this evening. In addition, the
highest sustained winds are expected across the coastal sections,
maximizing offshore of Long Island.
High temperatures will occur around daybreak and then gradually
fall today into the upper 40s and lower 50s. Most locations by
afternoon will be 10 degrees below normal.
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
Any leftover showers tapper off from south to north tonight as
moisture and forcing lift northward with the low. Gusty west winds
up to 50 mph, strongest at the coast, will continue as the low
slowly lifts to the north. Wind advisory remains up overnight for
LI/NYC/SE CT. Winds during the day on Sunday will gusts up to 40
mph for most locations.
Upper trough lifts across eastern Canada on Sunday with a gradually
weakening surface low. High pressure builds east across the
Lows tonight will be near seasonable levels as gusty winds
inhibit strong radiational cooling.
Highs on Sunday rebound to near normal with highs in the mid 50s
to lower 60s.
Clipper low approaches Sunday night and sends a cold front
through the area by daybreak Monday. There is decent lift in the
85h-500h layer with a good chance of showers.
.LONG TERM /MONDAY THROUGH FRIDAY/...
Monday through Wed will be quite cool as a building canadian high
pressure system moves east across New England, bringing overnight
low temps into the 30s across most of the local area, even across
parts of NYC on Tuesday night. Grab those jackets.
Thu-Fri will bring our next chance of rain as low lvl warm air
advection increases between the departing Canadian high and a low
approaching across the Great Lakes.
.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
Behind a cold front, there are rain showers which are moving
across city terminals as well as terminals to the north and west.
These decrease late today into tonight.
The winds have switched to a gusty NW flow for most terminals,
except for KGON. The winds will peak generally in the 20-25 kt
sustained range with gusts near 35kt at times, mainly late this
afternoon into early this evening. The NW flow will lead to an
improvement of category, eventually to VFR by the middle of this
Currently, conditions range from VFR to IFR. The improvement time
to MVFR and VFR could be off by 2-4 hours. In terms of winds,
they could occasionally be off by a few kts.
.Outlook for 09Z Sunday through Wednesday...
.Sunday...VFR. WNW-NW winds G25-35KT likely.
.Sunday night-Tuesday night...VFR, NW winds G20-25KT possible.
An isolated shower possible Sunday Night into Mon Morning.
Westerly gales develop across all waters today as deepening low
pressure lifts north along the New England coast.
Gales are forecast to continue through the day Sunday. Wind gusts
may briefly drop below 25 kt Sunday night before a cold front passes
early Monday morning. Wind gusts of 25-30kt are likely Monday
through Tuesday. Winds and seas are forecast to decrease on
Wednesday as high pressure moves across the area.
Additional rainfall today is expected to be in the range of a
quarter to half an inch with isolated higher amounts. The highest
amounts will be generally over the Husdon Valley.
Sunday night...scattered showers with rainfall of less than one
tenth of an inch is forecast with the passage of a cold front.
Thursday through Friday...A widespread rainfall of 1/2 to 1 inch
is possible with the approach of low pressure from the Great
CT...Wind Advisory from 2 PM this afternoon to 6 AM EDT Sunday for
NY...Wind Advisory from 2 PM this afternoon to 6 AM EDT Sunday for
MARINE...Gale Warning until 6 PM EDT Sunday for ANZ330-335-338-340-345-