412
FXUS61 KOKX 252008
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
408 PM EDT Thu Jul 25 2024
.SYNOPSIS...
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A cold front passes through the region into this evening. High
pressure then builds in from the west on Friday, before sliding
offshore late Saturday. The high slowly drifts east through early
next week, while an offshore low may track northeast of the area
Sunday night into Monday. A slow moving frontal system will
approach Tuesday into Wednesday, sliding east to end the week.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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Low pressure over southeastern Canada treks north and east into
the Canadian Maritimes, sending a cold front through the region
locally into this evening. The front is currently moving through
as of 20Z, with a few widely isolated showers out ahead of it.
This activity will attempt to work south and east into late day,
and can`t rule out a locally heavy downpour or thunderstorm as
it does. Highest chance for coastal areas on east, but most will
not see wet weather with the frontal passage.
Perhaps more noticeable, drier air behind the fropa will gradually
begin to filter in, dropping dew points and allowing a much less
humid regime to set up. By early evening, dew points should
range from the upper 50s to middle 60s for much of the area,
except eastern areas, where the front may not have pushed through
there by this time, and humid conditions are expected to linger
for the first few hours of tonight. Clearing skies tonight with
temperatures falling back into the 60s for most.-- End Changed Discussion --
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
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Behind the frontal passage, a drier, more tranquil, regime sets up
into this weekend. Surface high pressure over the Great Lakes Friday
slides over the region Saturday, before shifting offshore Saturday
night. Aloft, a lingering trough exits offshore and heights begin to
quickly climb Saturday as ridging over the Upper Great Lakes
translates eastward.
Abundant sunshine expected both afternoons with perhaps a bit of
diurnal cu development, but even this may be limited with subsidence
from the nearby high. Temperatures will be quite seasonable for late
July, with afternoon highs generally around the mid 80s, and parts
of the urban NE NJ corridor getting into the upper 80s. The real
difference however will be dew pts, largely in the 50s to near 60,
which will allow much more comfortable conditions relative to the
high humidity experienced much of this week. Overnight lows fall
back into the 60s for most, though 50s are likely in parts of Orange
Co and the LI Pine Barrens, with potentially decent radiative
cooling conditions setting up. Dry conditions persist through this
period.-- End Changed Discussion --
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
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Models in fairly good agreement with NE US coast upper troughing
developing into a large but weak cutoff upper low that drifts NW
across the area Sun into Mon, before eventually shearing NE Tuesday
ahead of next approaching trough from the Central US.
At the surface, weak high pressure is expected to preside over the
area to start the weekend, and likely to end the weekend. The one
caveat is that latest model trends are for low pressure to develop
well of the Carolina coast along a stalled offshore front Sat/Sat
night, in response to developing the upper low, and retrograde N/NW
towards the NE US coast Sun into Mon. Low confidence on the model
evolution of this low with inherent NWP convective parameterization
predictability issues with this upper low over the gulf stream. At
this point, ensemble QPF probs of > 1/2" of rain in 24 hr for the
Sun/Mon periods are very low (10% of less). With that said,
deterministic and ensemble trends bear watching through the weekend,
with a non-zero potential for heavy rainfall and strong winds
(particularly southeastern areas) if more intense and landward
migrating scenarios bear out.
Independent of this feature, deepening southerly flow ahead of
approaching Central US shortwave will bring increasingly humid
conditions to the region Mon thru Wed. N/NW shearing closed low will
bring potential for isolated diurnal shra/tsra activity for much of
the region. Less convectively active conditions potentially Tuesday
in wake of shearing low and well ahead of approaching frontal system
front from the west. Increased potential for shra/tsra activity
Wednesday into Wed night with approach and passage of shortwave
trough and associated pre-frontal trough, and then cold front.
Isolated diurnal shra/tsra threat could continue on Thu, with
lingering troughing aloft and weak cold front in the vicinity.
Highs generally near seasonable through midweek (mid to upper 80s
interior, lower to mid 80s coast). Potential for heat to continue to
build late week into weekend, as noted by CPC in 8 to 14 day
outlook, in response to strengthening subtropical ridging across both
the SW/SC US as well as western Atlantic, centered near Bermuda.-- End Changed Discussion --
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
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An approaching cold front will move through early this evening.
High pressure will then build from the west.
VFR with W-NW flow around or just over 10 kt, with some gusts 15-20
kt. KGON the exception with a sea breeze attm, but gust front from
earlier tstms to the north should turn winds WNW there too late this
afternoon. Winds shift NW to NNW (right of 310 mag) after cold fropa
to 10 kt or less and remain there tonight into early Fri afternoon.
Gusts 15-20 kt again possible after 14Z-15Z.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Peak gusts could reach 20 kt late this afternoon.
OUTLOOK FOR 20Z FRIDAY THROUGH MONDAY...
Friday afternoon through Monday: VFR.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
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Ocean seas may occasionally build to as high as 5 ft through
this evening with a cold frontal passage. Otherwise, with a weak
pressure gradient over the area, winds and seas remain below
Small Craft Advisory criteria through the beginning of next
week.-- End Changed Discussion --
&&
.HYDROLOGY...
No hydrologic impacts are expected through the middle of next
week.
&&
.TIDES/COASTAL FLOODING...
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A moderate risk of rip current development at the ocean beaches
remains in place through Friday with a 3 to 4 ft S/SE swell at a
7 to 8 second period.
The most vulnerable shoreline areas along the south shore of
Nassau County and western Long Island Sound may approach and
touch minor flood thresholds with tonight`s high tide.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...DR/NV
NEAR TERM...DR
SHORT TERM...DR
LONG TERM...NV
AVIATION...BG
MARINE...DR/NV
HYDROLOGY...DR/NV
TIDES/COASTAL FLOODING...