805
FXUS61 KOKX 051453
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1053 AM EDT Sun May 5 2024

.SYNOPSIS...
High pressure along the New England coast weakens locally as it
shifts farther offshore today ahead of an approaching cold front
from the west. The front eventually tracks through the region late
Monday, stalling to our south. High pressure then briefly returns
before the stalled boundary lifts back north as a warm front
Tuesday night. A series of low pressure centers then impact the
weather from Wednesday through Saturday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Made minor adjustments to the probabilities through this
afternoon to better reflect the current conditions, and then
trends as an upper shortwave moves slowly eastward into the
ridge over the region. Also made minor adjustments to the
temperatures which will have little diurnal change with cloud
cover and rain.

A rather unsettled close to the weekend with rain, clouds, and
cooler than typical conditions for early May. Stubborn amplified
ridging aloft over the Eastern US begins to break down today as
a shortwave swings east through the Great Lakes and into
southeast Canada. A weak area of low pressure associated with a
shortwave running into and over the ridge passes well to the
northwest through the Upper Great Lakes. This will help push a
frontal boundary toward the region, though will take plenty of
time getting here. Ahead of it, surface high pressure centered
near the Canadian Maritimes will maintain onshore flow as it
begins to shift farther out into the western Atlantic.

More organized shower activity moves through the region this
afternoon as the shortwave axis translates east over the shunted
ridge. Timing for this rain looks to begin for western areas by
midday, spreading slowly eastward into CT and Long Island by
mid afternoon, then continuing intermittently into the evening
before tapering from west to east overnight. Rates will be
light, as will QPF.

Look for areas of fog development tonight in the weak onshore flow
and saturated low levels from the residual moisture. May be locally
dense in spots, and will need to monitor this evening should any
potential headlines be needed into the AM commute.

With the rain, clouds, and return flow temperatures run 10 to 15
degrees below normal today, with afternoon highs in the 50s. These
temperatures likely remain steady overnight, or even rise a few
degrees toward Monday AM.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
Lingering showers should largely come to an end for eastern
areas in the morning hours on Monday, with fog likely hanging
around elsewhere before burning off by mid to late morning.
Temperatures jump 20 degrees for some compared to Sunday as SW
flow helps to advect in some milder air, rebounding into the 70s
across the interior and areas away from maritime influence.

Can`t rule out a few pop up showers in the afternoon ahead of the
trailing cold front, but coverage appears limited on CAMs at this
point with decreased moisture. The front finally moves through
Monday night and stalls over the Mid-Atlantic on Tuesday. The
boundary eventually lifts back north as a warm front, but before
this, ridging returns, along with weak surface high pressure.
This should set up the driest day of the week so far on Tuesday,
with drier air working in. Another mild afternoon with downsloping
helping the interior and areas away from the coast to warm into
the mid to upper 70s. Night will remain mild, generally in the
50s, with lower 60s in the urban metro.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Models over the past 24 hours have trended farther south and
slightly stronger regarding an area of low pressure tracking through
the Great Lakes Region and heading towards us Tuesday night into
Wednesday. There is therefore more confidence that an associated
warm front advances through a good portion of the forecast area
during Wednesday before a trailing cold front sinks south through
here Wednesday night. Shower chances increase Tuesday night with the
best chances occurring through the day Wednesday and generally higher
across the northern zones, which will be closer to the low center.
More instability is now anticipated - being in the warm sector.
Thunderstorms will therefore be possible during Wednesday, and given
potential shear profiles, steepening mid-level lapse rates with a
bit of a cold pool aloft, and CAPE aloft, will need to monitor
trends for the potential of strong wind gusts and small hail. NBM
was used for high temps, which are now expected to reach the lower
80s for NE NJ and parts of the Lower Hudson Valley and city. Mainly
70s for most of the rest of the forecast area.

The cold front stalls not too far to our south Wednesday night and
remains to our south while another wave of low pressure from the
Great Lakes Region approaches. Looks like an occlusion may occur as
a weak secondary low forms along the stalled boundary to our south,
resulting in a broad area of low pressure shifting through during
late Thursday night into Friday. Potential remains for yet another
wave of low pressure to pass nearby the area Friday night into
Saturday. There will be at least some chance of showers for each
period from Wednesday night through Saturday night. The highest
chances appear to be Thursday afternoon into night, but might linger
into Friday morning as well. NBM looked good for temperatures
through the period.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
High pressure weakens today as a frontal system slowly approaches
from the west.

Cigs lowering to IFR in the next hour or two, likely remaining IFR
through the TAF period. Showers continue this morning without
VSBY restrictions, but showers become more likely this
afternoon, then remaining likely well into tonight.

ESE-SE winds around 10kt or less through this evening with some
occasional gusts up to 20 kt through this afternoon, shifting
more southerly late tonight.

 NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

Timing of IFR onset may delayed by an hour or two. Chance that MVFR
cigs develop for a few hours this afternoon.

OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY...

Sunday night: IFR with showers ending.

Monday: IFR to MVFR in the morning, then MVFR, becoming VFR in
the afternoon. A slight chance of showers, an isolated
thunderstorm possible.

Tuesday: VFR, becoming MVFR to IFR late at night.

Wednesday: MVFR or lower with a chance of showers. Thunderstorms
possible mainly in the afternoon.

Thursday: Mainly MVFR. Showers likely, mainly in the afternoon.

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

&&

.MARINE...
Made minor adjustments to increase the southeasterly winds
across the western waters where a little stronger pressure
gradient force exits with the approach to a frontal system to
the west and the high remaining anchored off the northeast
coast. Also, with the increased flow the seas near the NY Harbor
Entrance are a little higher than forecast and increased seas
to near 4 feet.

Otherwise winds and seas are expected to remain below SCA
conditions through Thursday, but ocean seas may rise to 5 ft
Thursday night.

&&

.HYDROLOGY...
There are currently no hydrologic concerns through this week.

&&

.TIDES/COASTAL FLOODING...
Tide levels fell short of Stevens Institute NYHOPS guidance last
night. Given its forecast for tonight`s high tide, expecting at most
isolated spots over Southern Fairfield County to touch minor
flooding thresholds, but it`s more likely that levels will fall just
short of benchmarks. Will therefore hold off on issuing a statement
for this area for the time being. Statements will be more likely
here for Monday night, as well as statements possibly needed for the
south shore back bays of Nassau County.

The potential of a more widespread minor flooding event that would
necessitate advisories will probably hold off until Tuesday and
Wednesday nights for these same areas as well as southern Queens.
Statements for these 2 high tide cycles may be needed for other
parts along western LI Sound as well as lower NY Harbor and
Brooklyn.

&&

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

&&

$$

SYNOPSIS...JC/DR
NEAR TERM...DR/MET
SHORT TERM...DR
LONG TERM...JC
AVIATION...JC/20
MARINE...JC/DR/MET
HYDROLOGY...JC/DR
TIDES/COASTAL FLOODING...