249
FXUS61 KOKX 250821
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
421 AM EDT Thu Jul 25 2024
.SYNOPSIS...
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A cold front approaches today and moves through this evening. High
pressure then builds in from the west for Friday and the first half
of the weekend. High pressure moves offshore Saturday night
into Sunday, and remains offshore into the beginning of next
week. The high moves farther offshore Tuesday into Wednesday as
a pre frontal trough and cold front approach.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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Low pressure over southeastern Canada, will slowly trek northeast
into the Canadian Maritimes by this evening. This will allow a cold
front to slowly approach today, moving through late in the
afternoon into the evening.
Synoptic models and CAMs continue to keep much of the precipitation
offshore. This likely has to do with a strengthening deep layered
westerly flow and gradual mid-low level drying through peak heating
hours. The best shot at any showers or thunderstorms will probably
end up being for eastern zones, as they may be able to destabilize a
bit ahead of the cold front. Additionally, some CAMs are hinting at
some heavier showers that appear to develop along the sea breeze
boundary across easter Long Island that is expected to develop this
afternoon. Perhaps the sea breeze will provide enough lift trigger
some convection. Still, any shower look to be limited in coverage.
Again, any stronger showers or thunderstorm could produce locally
heavy rainfall, but potential for flash flooding remains low.
More clouds than sun today will keep temperatures near normal
despite being warm sectored, with highs in the lower to middle 80s
expected. It will continue to be humid, at least through much of the
morning for most of the forecast area. Dew points int eh upper 60s
to lower 70s will start to slowly decrease from northwest to
southeast from morning onward. By late this afternoon, 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.
Any patchy fog is expected to burn off by mid morning.-- End Changed Discussion --
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
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High pressure continues to build in from the west tonight into
Saturday. An upper level shortwave trough moves through late in the
day Friday into Friday night, but subsidence from the high should
keep conditions dry through this timeframe. Highs will continue to
run at or slightly above normal for this time of year, generally in
the middle 80s. Dew points should fall into the 50s for the entire
area. Went a couple of degrees below the NBM as it typically does
not go low enough in regards to dew points and how dry the air
typically is behind cold fronts. Saturday will see dew points come
up slightly, but should still be less humid than recent days.-- End Changed Discussion --
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
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A relatively quiet pattern will be in place from Saturday night into
the beginning of next week as a strong upper ridge builds toward the
east coast, and then shifts offshore. Meanwhile, a weak cutoff low
remains along the New England coast into Monday, and then is
expected to drift east and become absorbed into a shortwave in the
northern stream Monday night into Tuesday. The shortwave then
remains into Wednesday as energy rotates through the region.
Dry weather will continue Saturday night into Tuesday morning with
temperatures near or slightly above seasonal normals. And with a
relatively dry airmass heat indices will remain near the air
temperatures. Then with the shortwave moving into the region there
will be chances for precipitation later Tuesday into Wednesday.
Humidity levels begin to increase again toward the middle of next
week as the high slides offshore and a return flow sets up.-- End Changed Discussion --
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
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A warm front just to the south of Long Island will lift slowly north
and through the area early this morning, followed by a cold frontal
this evening.
IFR to LIFR/VLIFR conditions remain in place for KHPN, KGON, and
KBDR due to a light and variable to light east wind bringing lower
clouds across LI Sound. At KISP conditions are expected to lower to
IFR and possibly LIFR before morning. There is more uncertainty as
to how far west, and the timing, lower ceilings will move into the
NYC metro terminals, and have low confidence in the forecast for
these terminals.
VFR develops fairly quickly for all terminals early this morning as
winds shift to the southwest and west as the warm front lifts
through the region. Late afternoon into early this evening winds
then shift to the NW behind a cold front. Occasional gusts 15 to 20
kt are possible this afternoon into this evening.
Any showers and/or thunderstorms overnight are expected to be
isolated and have not included in the forecast. Showers and isolated
thunderstorms will be a little more widespread this morning into the
early afternoon ahead of the cold front and have included a VCSH.
And with low confidence in the forecast have not included
thunderstorms.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
There is uncertainty how low and how far west MVFR to IFR ceilings
will be through 10Z, and have low confidence in the forecast.
Afterwards, with winds shifting to the southwest and then west
ceilings are expected to become VFR.
Amendments likely for flight categories overnight and for wind shift
timing into this morning with multiple frontal passages.
OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY...
Late Thursday night 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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With a weak pressure gradient over the area, winds and seas/waves
remain below Small Craft Advisory criteria through the through the
beginning of next week. However, ocean waters may briefly touch
5 ft tonight behind the passage of a cold front.-- End Changed Discussion --
&&
.HYDROLOGY...
No hydrologic impacts are expected through the middle of next
week.
&&
.TIDES/COASTAL FLOODING...
A moderate risk of rip current development at the ocean beaches will
remain through Thursday as a 3 to 4 ft S/SE swell at 7 to 8 seconds
continues. Rip activity could be locally high due to the Spring
tides.
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 high tide.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None.
NY...None.
NJ...None.
MARINE...Dense Fog Advisory until 11 AM EDT this morning for ANZ331-332-
340-350.-- End Changed Discussion --
&&
$$
SYNOPSIS...JP/MET
NEAR TERM...JP
SHORT TERM...JP
LONG TERM...MET
AVIATION...MET
MARINE...JP/MET
HYDROLOGY...JP/MET
TIDES/COASTAL FLOODING...