Area Forecast Discussion
Issued by NWS Upton, NY-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KOKX 210821
Area Forecast Discussion
National Weather Service New York NY
421 AM EDT Fri Oct 21 2016
Showers today as a cold front gradually approaches from the west
and then moves through late tonight. Deepening low pressure will
track across New England into Quebec this weekend bringing windy
conditions to the Tri-State. A cold front will pass through on
Monday, followed by building high pressure through the middle of
.NEAR TERM /THROUGH TONIGHT/...
Dense Fog remains spotty, so we will continue with a statement
for Suffolk County on Long Island and in the elevated areas of SE
CT, the Hudson Valley and into NE NJ. Also along the CT River.
Would say that the warm front extends from the CT Coast to near
Newburgh as of 08Z.
While latest RADAR shows very little PCPN in the local area, NWP
has been persistent in showers, some heavy developing this morning
from the Jersey Coast north across the City and into New England.
The PCPN Shifts to the East this afternoon. Thus, would expect a
period of dry WX for the Mid Day into mid to late AFTN (lowered
POPs to 30%) for all but eastern sections (Likely POPs there).
Have removed thunder from the forecast as instability is very
marginal - but would not be surprised is there were a flash or two
with the shower activity this morning that pushes east this
By evening....PCPN comes back from the west as the cold front
finally gets here.
With this in mind, have followed the GFS MOS for temps into the
lower to mid 70s - that may even be a bit low. Also, with the
Cold Advection not starting until very late tonight, have gone
with the warmer GFS MOS again tonight.
.SHORT TERM /SATURDAY/...
Winds, cool temps, clouds and light showers make for a real fall
like day on Saturday. CAA keeps temps steady of falling slightly
thought the day.
Showers are scattered and light...mainly in the morning. Skies
become partly sunny as we downslope of the Appalachians in the
AFTN. POPs go from 50 down to 30 through the day.
Main story is the wind which will gust to 40 mph in the afternoon (just
below advisory level of 45+. Some airports like JFK is have
sustain wind speeds into the lower 30s - which is technically
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Global models remain very similar with the evolution of the system
this weekend as a cutoff low embedded in a negatively tilted upper
trough lifts northward across New England and into eastern Canada.
Showers tapper off from south to north Saturday night as moisture
and forcing lift northward with the low. Gusty west winds up to
35 mph will continue through much of Sunday with around a 980 mb
low across eastern Canada.
A clipper type system will be racing towards the forecast area
Sunday night into Monday morning. This will allow winds to back
briefly to the west-southwest. The cold frontal passage looks to
be early enough in the day to not allow much of a warmup, so high
temperatures are similar to Sunday, which is close to or slightly
The airmass that builds in for the Tuesday and Wednesday time period
looks to be around 10 degrees below average, and will have the
potential to produce a freeze across much if not all of the
interior, possibly getting into some of the coastal zones.
A frontal system of Pacific origin approaches from the Great Lakes
on Thursday. There are magnitude issues with how deep the low is
between the 00Z GFS and ECMWF, but overall the timing with this
system is remarkably close for this far out in time.
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
A warm front lifts to the north early this morning, followed by a
cold front approaching from the west and a wave of low pressure
approaching from the south today. SE/ESE winds of 5 to 10 kt
through the day...becoming light and variable this evening.
Early Morning: Conditions improving to mvfr...except local ifr
interior terminals...in wake of warm frontal passage between 06z
and 08z. Then indications that conditions come back down to
widespread ifr/lifr towards daybreak...but some uncertainty on
Late Morning/Afternoon: Improvement to mvfr vsby with ifr cigs as
the morning progresses...continuing thru the afternoon. SHRA
likely. Low prob of an isolated tsra.
Evening: Potential deterioration to widespread LIFR or lower
conditions this evening. SHRA likely.
.Outlook for 06Z Saturday through Tuesday...
.Late Tonight...Improvement to MVFR conditions in wake of cold
frontal passage...with continued shower activity likely. NW winds
.Saturday...Becoming VFR. WNW-NW winds G25-30KT likely.
.Saturday Night...Most likely VFR with very low chance of MVFR.
WNW-W winds G30-35KT likely.
.Sunday...VFR. W winds G25-30KT likely.
.Sunday Night-Monday Night...VFR with isolated to scattered
showers possible. WNW-NW winds g20-25 kt possible at eastern
terminals Sunday night. NW winds g20-25KT possible Monday/Monday
.Tuesday...VFR with NW winds g20-25KT possible.
Fairly tranquil today. Seas increase on the Ocean tonight.
Main even is prolonged Gales this weekend as low pressure deepens
to our north.
Gales are likely to continue across the waters on Sunday, especially
across the ocean waters. Wind gusts may briefly drop below 25 kt
Sunday night before a cold frontal passage on Monday brings a
return to SCA levels through Tuesday.
Showers today and tonight. Totals should average 1/4 - 1/2". No
hydrologic problems are expected.
Light PCPN is expect on Saturday.
Mainly dry weather is expected thereafter.
More isolated minor coastal flooding with this afternoon`s high
tide cycles. Generally 1-2 ft departures are needed for minor
A statement will be issued.
MARINE...Gale Warning from 6 AM Saturday to 6 PM EDT Sunday for ANZ330-
Small Craft Advisory for hazardous seas from 6 PM this evening
to 6 AM EDT Saturday for ANZ350-353-355.