593
FXUS61 KOKX 041133
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
733 AM EDT Sat May 4 2024
.SYNOPSIS...
High pressure remains in place along the New England coast into
tonight. A cold front then slowly approaches from the west on
Sunday, eventually tracking through the region Monday. The
boundary likely stalls to our south Monday afternoon through
Wednesday before returning as a warm front late in the week.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
The forecast remains on track. Amplified ridging aloft remains
over the Eastern US today, with surface high pressure in place
along the New England coast. This will maintain a persistent
onshore flow through the weekend, and lead to cooler than
typical temperatures for early May.
Meanwhile, a weak area of low pressure associated with a shortwave
riding over the ridge passes well to the northwest through the
Upper Great Lakes late in the day, sending a slow approaching
frontal boundary toward the region. While a spotty shower can`t
be ruled out this afternoon, mainly in far western portions of
the region, the day will be predominantly dry. Expect a fair
amount of cloud cover, thickening into this evening as the ridge
axis shifts offshore, allowing deeper moisture to advect into
the area in the SW flow. This should lead to eastward expansion
of shower coverage off to the west that very gradually begins to
work in tonight, likely after midnight even for the farthest
west locales.
With the return flow and cloud cover, temperatures this weekend run
up to 10 degrees below normal, with afternoon highs in the low to
mid 60s today, falling into the 40s overnight into Sunday AM.-- End Changed Discussion --
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
By Sunday, the shortwave associated with an upper low over
Central Canada attempts to break down the ridging over the East
Coast, with the surface front draped along the Midwest starting
to make progress eastward. Guidance continues to advance this
boundary quite slowly, with the fropa perhaps not occurring
locally until Monday. Ahead of it, plenty of deep moisture in
the column and weak lift should instigate shower activity by the
mid morning, at least for the western half of the region,
before spreading east by the afternoon. Showers may continue
intermittently into Sunday night before tapering west to east.
QPF appears light with this activity, generally ranging from a
quarter to a half inch.
The shortwave energy pushes offshore Monday with the surface
boundary stalling to our south and west. Ridging builds once
again across the Great Lakes in response to a large upper low
over the Northern Plains and Northern Rockies. Latest guidance
is less enthused about energy riding under this and interacting
with the stalled boundary, which would allow a return of
steadier rain chances depending on placement. Trimmed back PoPs
Monday night as a result, though still not out of the question a
few showers make it into Long Island from the south. After the
chilly Sunday in the low to mid 50s for most, temperatures
rebound on Monday in SW flow back into the 70s across the
interior and areas away from maritime influence.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
Tuesday begins with high pressure to our north and a stationary
front across the Mid-Atlantic. This front is expected to slowly push
north towards us as a warm front through the day. Looks like most of
the day will be dry, but still a low threat of showers over roughly
the western half of the forecast area - closer to the deeper
moisture and lift.
A ridge aloft flattens Tuesday night into Wednesday with a surface
low tracking east across the northern Great Lakes. The warm front
will continue to try to push into the forecast area during this
time, however a synoptic onshore flow off of cold waters along with
influence from low pressure over the Canadian Maritimes with both
serve to hold this front to our south. Chance of showers for this
period, and maybe even a rumble of thunder Weds afternoon with
elevated instability pushing in from the west.
The surface low to our north then weakens with the flattening ridge
aloft Weds night into Thursday with another wave of low pressure
heading east - this time tracking through the southern Great
Lakes/Ohio Valley. The boundary to our south doesn`t make much
progress as the surface low is weak along with no significant llj to
help push the front northward. PoPs however increase in the
afternoon into nighttime with the approach of the surface low and
associated moisture and lift.
Best guess right now is that this system shifts through at some
point Thursday night into Friday, but there`s uncertainty with this
timing. There`s also the potential of yet another wave of pressure
forming to our west and maintaining rain chances through all of
Friday.
NBM was used for temperatures through the long term.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
High pressure remains in place through tonight.
VFR today into early evening. MVFR develops later in the evening,
with cigs lowering to IFR overnight. A shower possible starting late
this afternoon, however rainfall doesn`t become likely until Sunday
afternoon.
ESE-SE winds around 10kt through the TAF period.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of IFR onset may be forecast to be a couple of hours too
soon, and even possible that cigs do not lower to IFR at all
tonight.
OUTLOOK FOR 12Z SUNDAY THROUGH WEDNESDAY...
Sunday...MVFR/IFR. Showers likely mainly in the afternoon. SE winds
G15-20kt.
Monday...MVFR/IFR in the morning, then MVFR/VFR in the afternoon.
Tuesday...VFR.
Wednesday...MVFR or lower with a chance of showers.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Sub-SCA conditions can be expected through the weekend with high
pressure along the New England coast maintaining an easterly or
southeasterly flow across the waters and speeds generally at or
under 10 kt.
Winds and seas should then remain below SCA criteria through
the middle of next week with a weak pressure gradient in place.
&&
.HYDROLOGY...
There are currently no hydrologic concerns through next week.
&&
.TIDES/COASTAL FLOODING...
-- Changed Discussion --
Astronomical tides will increase with the approach of a new moon
Tuesday night along with the threat of minor coastal flooding each
night through this period and possibly including Wednesday night as
well.
A coastal flood statement has been issued for this evening`s high
tide cycle across Southern Fairfield County with benchmarks expected
to be just reached in a few spots. Statements may be expanded to
include Southern Westchester and Southern Nassau Counties for Sunday
night. Advisories may eventually be needed for these zones and
Southern Queens Monday night, and even more so for Tuesday night.
Statements may be needed during this period for other parts along
western LI Sound as well as lower NY Harbor.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JC/DR
NEAR TERM...DR
SHORT TERM...DR
LONG TERM...JC
AVIATION...JC
MARINE...JC/DR
HYDROLOGY...JC/DR
TIDES/COASTAL FLOODING...JC