Area Forecast Discussion
Issued by NWS Upton, NY

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117
FXUS61 KOKX 251957
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
357 PM EDT Wed Apr 25 2018

.SYNOPSIS...
Low pressure over the Delmarva region will ride up across the
area tonight, with a trailing cold front also passing through
late. The low will move into New England on Thursday. Another
low will move through on Friday, followed by a cold frontal
passage late Saturday. High pressure will then be in control
early to mid next week.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Steady rain now about to pull out of SE CT. With dry slot moving
up into the area expect a break in the precip going into this
evening, with no more than an isolated shower or two, then
return of scattered to numerous showers later tonight as the
weak sfc low moves across and takes a cold front with it, aided
by lift from an accompanying negatively-tilted mid level
shortwave trough.

Meanwhile, with the pressure gradient relaxing tonight and
abundant low level moisture remaining, expect areas of fog to
continue, with potential for dense fog before cold fropa,
particularly across Long Island and southern CT, where both
NARRE/HRRR time-lagged ensembles are flagging highest
probabilities of vsby less than 1/4SM and 1SM, respectively.

Fcst low temps tonight are on the warmer side of the MOS
envelope, in the upper 40s and lower 50s.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
Gusty WNW flow expected along with mostly sunny skies for the
most part after the mid level shortwave passes through. A closed
mid level low passing just to the north may help provide enough
lift for sct-bkn Cu development in the afternoon, more so
inland.

With downslope flow and mixing to between 875-850 mb expect
high temps to approach 70 in NE NJ and rise well into the 60s
most elsewhere.

Thu night should start mostly clear, then become mostly cloudy
overnight as another low begins to approach from the SW. Low
temps should be in the 40s and lower 50s per MOS blend.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Models in good agreement with the closed low over the central
Plains tracking eastward through the deep South on Thursday.
This then lifts north toward the region Friday ahead of the next
northern stream trough digging into the Mississippi River
Valley on Thursday. At the surface, associated low pressure
lifts northeast towards the region on Friday. This is a
progressive system, with what looks like a quick hit of moderate
rain (1/4 to 3/4 inch, locally 1 inch). Still uncertainty on
where the axis of the heaviest rain will be, due to differences
in track of low pressure and consequently placement of best
lift/instability axis.

Models then in general agreement with partial phasing of the
southern energy and digging northern stream trough to develop
a deep trough over the Great lakes into the NE US this weekend.
Some spread in intensity/amplitude of this trough, but general
consensus on its axis moving through Sunday. At the surface, an
associated cold front moves through late Sat/Sat evening, with a
couple of weak troughs moving through Sunday. Seasonable temps
on Saturday in waa ahead of the front, dropping back down to a
few degrees below seasonable on Sunday with cold pool and
instability cloud cover.

In its wake, deep layered ridging builds in for early next week,
with potential for unseasonable warmth by midweek as ridging
takes a Bermuda position. Temps moderate to seasonable on Monday
and then above seasonable on Tuesday. Potential for the first
real warm spell of the season mid to late week, with high temps
in the 80s for NYC/NJ metro and Interior, and well into the 70s
along the coast.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
Low pressure approaches this evening, moves overhead tonight, then
lifts north of the region on Thursday.

IFR or less through midnight. Light rain and drizzle continues
today. Can not rule out some pockets of moderate rain through
midnight.

Fog has started to develop and will continue to overspread the
terminals. Expect the fog to remain over the area until the winds
become westerly (mainly around 08-10Z).

Conditions improve to VFR after 08Z-12Z.

Easterly winds subside late this afternoon, becoming light and
variable for evening push. Winds become westerly late tonight/early
Thursday morning (08-10Z).

 ...NY Metro Enhanced Aviation Weather Support...

Detailed information, including hourly TAF wind component forecasts,
can be found at: http:/www.weather.gov/zny/n90

KJFK TAF Comments: High confidence IFR or less through midnight.

KLGA TAF Comments: High confidence IFR or less through midnight.

KEWR TAF Comments: High confidence IFR or less through midnight.

KTEB TAF Comments: High confidence IFR or less through midnight.

KHPN TAF Comments: High confidence IFR or less through midnight.

KISP TAF Comments: High confidence IFR or less through midnight.

.OUTLOOK FOR 18Z THURSDAY THROUGH Monday...
.Thursday...VFR.
.Friday...VFR. A chance of showers with areas of MVFR
conditions.
.Saturday/Sunday...VFR. W wind 10-15KT, G20-25KT.
.Monday...VFR

&&

.MARINE...
SCA remains in effect for the ocean for elevated seas. SE winds
were still gusting to 25 kt out by Montauk/Orient/Fisher`s
Island, and should diminish there going into this evening.

Marine dense fog advy issued for all waters for tonight as low
pressure moves across and vsby lowers to less than 1 nm in most
places. Cold fropa will shift winds to the W-NW and quickly
scour out the fog late tonight into early thu morning.

SCA seas likely continue on the ocean waters into Saturday
night, possibly lingering into Sunday, due to lingering SE
swells from the mid week system, and then added contribution of
wind waves and southerly swells from a quick moving low on
Friday and winds ahead and behind cold frontal passage Sat eve.

Marginal SCA winds possible, mainly eastern waters Friday
aft/eve on the eastern flank of low pressure.

&&

.HYDROLOGY...
Today`s rainfall has not been causing any hydrologic impact.

QPF 1/4 to 3/4 inch possible Friday with a quick moving low. No
hydrologic issues anticipated.

&&

.EQUIPMENT...
NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) remains off
the air.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Dense Fog Advisory until 6 AM EDT Thursday for ANZ338-345-350-
     353-355.
     Dense Fog Advisory until 6 AM EDT Thursday for ANZ330-335-340.
     Small Craft Advisory until 6 AM EDT Friday for ANZ350-353-355.

&&

$$

SYNOPSIS...Goodman/NV
NEAR TERM...Goodman
SHORT TERM...Goodman
LONG TERM...NV
AVIATION...BC
MARINE...Goodman/NV
HYDROLOGY...Goodman/NV
EQUIPMENT...



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