Area Forecast Discussion
Issued by NWS Upton, NY

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FXUS61 KOKX 220805
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
405 AM EDT Sun Oct 22 2017

.SYNOPSIS...
Dry and mild today as high pressure pulls away from the region.
The weather then becomes rather unsettled for Tuesday and
Wednesday with potentially heavy rain. Relatively strong gust
winds are likely on Tuesday. Dry weather returns for late week
into the weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Some patchy/localized radiation fog is likely in the valleys
and Pine Barrens, but believe is will not be extensive enough to
included in the forecast grids - at least at this time.

Other than some gradual increase in cirrus - looks like a fine
day with temps still about 15 degrees above normal in the mid to
upper 70s. Forecasting 1 degree short of the Record at KBDR -
elsewhere we`ll fall 5 to 10 degrees short. GFS/ECMWF MOS Blend
used which seems to work very well on Saturday.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
Low level moisture increases tonight with a light SE flow.
Models suggest stratus moving in with better chances of at least
a broken deck occurring west of eastern LI and CT. This leads
to a partly to mostly cloudy Monday. There appears to be enough
isentropic and low level lift for a chance of a sprinkle in the
afternoon as there`s significant subsidence above 800 hPa
causing stratocu to spread.

Highs will still range mostly 70-75.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
NWP remains on track with a deep upper level trough with strong
meridional flow approaching the region Monday night as the jet
dives into the Southeast. The question that remains is the
timing of the very slow moving frontal passage. The GEFS has
about 10 members that support the slower deterministic ECMWF
timing. Thus, a good chance for rain to continue through
Wednesday especially on Long Island and CT.

Then, mainly dry weather is expected by Thursday night through
next weekend.

Winds are a potential issue Tuesday through Tuesday evening.
There is a low level jet ahead of the cold front and the models
have pretty good agreement with the 50-60 KT magnitude. Thinking
of gusts of 35 to perhaps 45 KT.

Have kept the TSTMs for Tue AFTN and Evening with potential for
long narrow CAPE.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
VFR expected through at least 03z Mon with high pres OHD gradually
moving east through tonight.

There is a low chance of MVFR-IFR fog through 12z at
KSWF/KHPN/KGON/KISP.

Light and variable winds through the remainder of the night.
S/SE winds 8-12 kt develop later this morning and afternoon with
seabreeze enhancement at coastal terminals.

Aft 03z tonight, the second night of onshore flow, may start
seeing indications of fog and/or stratus development, however
timing and extent of MVFR/IFR conds is uncertain attm.

.OUTLOOK FOR 06Z MONDAY THROUGH THURSDAY...
.Late Sun night-Mon...MVFR/IFR possible in stratus and fog into
Mon morning, then VFR. S/SE G20 kt Mon aftn.

.Mon night-Tue...Potential a period of S/SE G30-40 KT with LLWS
SSW 45-55kt@2kft for coastal terminals. Could occur during
morning push. MVFR/IFR developing in -RADZ Monday night,
continuing with SHRA and low prob/sparse TSRA Tuesday.

.Tue night-Wed...IFR possibly continues in showers Tue
night...improving to MVFR Wed.

.Wed night-Thu...VFR, with iso-sct MVFR in SHRA. W/NW wind.

&&

.MARINE...
Quiet conds on all waters through Mon as high pressure over the
area slowly shifts east. The pressure gradient will begin to
tighten on Mon as low pressure strengthens over the Great Lakes.
SCA conds are expected to develop Mon night with the potential
for gale force gusts Tue into Tue night, all waters. The gale
potential will depend on mixing over the waters, but should be
able to mix down 35-40kt forecast at 1000mb, especially over the
ocean. Winds just off the deck may be slightly weaker on the
non- ocean waters and gales may only occur with any heavier
showers/tstms.

Winds will slowly diminish from W to E Tue night, and the
progression of the front/LLJ will determine the end time for the
SCA/gale hazards. May need to keep headlines up into Wed for the
eastern waters. Seas on the ocean are forecast to remain above
5 ft through Thu, due to a SE swell from a good fetch around
the departing high. This could be overdone however.

&&

.HYDROLOGY...
Expect nuisance urban ponding late Tuesday into Wednesday,
especially across the NY Metro, Long Island and Southern CT.
Storm total of 1.5 to 3" now expected, but flash and river
flooding are not anticipated.

&&

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

&&

$$
SYNOPSIS...Tongue
NEAR TERM...Tongue
SHORT TERM...Tongue
LONG TERM...Tongue
AVIATION...24
MARINE...24
HYDROLOGY...Tongue



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