428
FXUS61 KOKX 292010
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
410 PM EDT Thu May 29 2025
.SYNOPSIS...
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Weak high pressure moves across the area the first half of the
night and then gives way to another area of low pressure over
the Mid Atlantic states. The latter of which passes to the south
and east on Friday. A much stronger low will approach from the
southwest Friday night and then head north into New England on
Saturday. A trailing cold front will move through Saturday
night. High pressure will then gradually build in through the
middle of next week.-- End Changed Discussion --
&&
.NEAR TERM /THROUGH FRIDAY/...
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The upper low over the Great Lakes begins to get kicked eastward
tonight as jet energy rounds the base of the low. At the same
time, a digging northern trough branch descends across eastern
Canada. Both will interact with one another on Friday, allowing
a full latitude trough to dig southward into the Mid Atlantic
states late Friday into Friday night.
Before then though, weak high pressure quickly moves through the
area this evening, giving way to a weak frontal wave over the
Mid Atlantic states. Latest HRRR soundings show some drying this
evening with the potential for breaks in the cloud cover. There
is some uncertainty whether not there is enough low-level
moisture and cooling to see the development of low stratus and
fog for the second half of the night. For the time, will have
the mention of some patchy fog across the area.
The aforementioned frontal wave passes to the south Friday
morning with a slight chance of showers, then to the east by
afternoon. A weak surface trough or stationary front over the
Lower Hudson valley will then be the focus for some scattered
showers/isolated thunderstorms in the afternoon. Both instability
and shear will be weak, so nothing strong or long lasting. Rainfall
amounts are expected to be light.
Lows tonight are forecast to be in the upper 50s to lowers 60s,
a few degrees above normal. High on Friday will top out in the
70s with a few break in the cloud cover.-- End Changed Discussion --
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY/...
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A stronger frontal wave over the central Appalachians approaches
from the southwest Friday night with a period of moderate rainfall
and possibly some heavier rain in any embedded thunderstorms.
There is some uncertainty with the low track, with a consenus
forecast approach taking it just east of the NYC metro and
Lower Hudson Valley. This should keep the heavier rainfall
to the north and west of the track where there will be better
frontogenetic forcing. System is progressive, instability is
weak, and PW values are near normal. Thus, not looking for high
hourly rainfall rates, nor storm total rainfall values to produce
much more than minor nuisance poor, drainage flooding. Any flash
flood flooding with this system would be isolated. WPC has a
marginal risk of excessive rainfall across the Lower Hudson
Valley and NE NJ at this time. NBM (13Z) probabilities are
around 50-60% across the area for seeing more than an inch of
rainfall. Forecast storm total rainfall across the area is
1.00-1.25" with lesser amounts across eastern LI and SE CT.
These amounts are also over period of more than 6 hours.
Conditions dry out Saturday morning into early afternoon with
a second wave of low pressure moving in during the afternoon/early
evening, but this is also progressive. Expect a round of moderate
showers and possibly embedded thunderstorms. Once again, neither
severe weather or flooding is forecast with this event. Lows
Friday night will remain mild in the upper 50s to lower 60s,
but a bit cooler in the upper 60s to lower 70s on Saturday with
cloud cover and rain chances.-- End Changed Discussion --
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
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Upper trough axis and shortwave lift will maintain shower chances
during Saturday night with a higher likelihood being east of the
city and before midnight.
Upper troughing will remain over the Northeast into eastern Canada
Sunday through early next week. High pressure off to our west will
be slow to build eastward with low pressure meandering over eastern
Canada during this time period. The forecast remains dry Sunday and
Monday despite cyclonic flow aloft. However, multiple shortwaves
spinning around the larger trough could introduce scattered to
broken clouds at times both afternoons. The axis of the trough
should shift to our east Tuesday allowing ridging to build towards
the area into Wednesday with the continuation of dry conditions.
Models differ somewhat regarding the position of a cutoff h5 low
over the western Atlantic and how it weakens the upper ridging over
the forecast area. Potential showers and thunderstorms from a cold
front to the west may push in by the end of the day, but could be
mitigated by the residual ridging aloft.
Temperatures for Sunday will be below normal in the upper 60s, but
should slowly start trending milder early next week. Highs look to
reach the lower 70s on Monday and then should be close to normal by
Tuesday in the middle to upper 70s. Given progged h8 temperatures,
have blended deterministic NBM with the warmer 50th percentile for
both Wednesday and Thursday. Areas unaffected by a sea breeze likely
reach the 80s both days.-- End Changed Discussion --
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
Low pressure passes just south and east of the terminals
through this evening.
Conditions have improved to MVFR at many of the terminals,
however some pockets of IFR remain. Conditions are expected to
slowly improve to VFR for a period late this afternoon/evening
and prevail first half of tonight across the NYC terminals
before lower to IFR or MVFR late tonight/early Friday morning.
The other terminals, should see a shorter period of VFR
conditions before falling back to MVFR/IFR. Some of the eastern
terminals, KGON, may not reach VFR at all.
Winds will back towards the N-NW this afternoon, then become
SW-S by late afternoon. The wind speeds will remain 10kt or
less. The winds turn, expect a period between 18-22z where the
winds become more variable. A light SW-S flow should prevail
tonight.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of improving conditions may be off by 1-3 hours this
morning and afternoon.
Wind direction may become variable for a time this afternoon,
but should settle to the SSW by this evening.
Timing of lowering conditions tonight may be off by several
hours.
.OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY...
Friday: MVFR/IFR ceilings possible with showers possible.
Friday night and Saturday: Showers and possibly a thunderstorm.
MVFR or lower likely. SW-W winds G15-20kt Saturday afternoon.
Sunday through Tuesday...VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
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SCA for seas on the ocean will come down from west to east
tonight. Thereafter, a weak gradient will reside across the
waters with sub-SCA conditions through Friday night. A building
southerly swell is forecast to bring SCA conditions to the
ocean waters on Saturday.
SCA conditions will continue on the ocean Sat night into Sunday,
mainly for hazardous seas. Seas should subside below 5 ft late
Sunday and remain below advisory thresholds through early next
week.-- End Changed Discussion --
&&
.HYDROLOGY...
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Rainfall of 1 to 1.25 inches with locally higher amounts is
possible from NYC north/west Fri night into Sat morning as low
pressure passes through. Hydrologic impacts so far appear to be
limited to minor urban/poor drainage flooding. Also can`t rule
out downpours Saturday afternoon and early evening since
thunderstorms will still be possible.-- End Changed Discussion --
&&
.TIDES/COASTAL FLOODING...
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Any additional widespread minor coastal flooding following the
recent new moon is seeming less likely as tide values gradually
lower and weaker southerly winds being forecast ahead of low
pressure Friday night. However, water levels just barely
touching minor flood benchmarks are possible in spots with the
next two nighttime high tide cycles tonight and Fri night.
A high rip current risk continues into early this evening with SE
swells at around 6 ft. There is a moderate risk for rip current
development during Friday with SE swells lowering to 4 to 5 ft.-- End Changed Discussion --
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...High Risk for Rip Currents until 9 PM EDT this evening for NYZ075-
080-081-178-179.
NJ...None.
MARINE...Small Craft Advisory until 6 AM EDT Friday for ANZ350.
Small Craft Advisory until 2 AM EDT Friday for ANZ353.
Small Craft Advisory until 10 PM EDT this evening for ANZ355.
&&
$$
SYNOPSIS...JC/DW
NEAR TERM...DW
SHORT TERM...DW
LONG TERM...JC
AVIATION...BC
MARINE...JC/DW
HYDROLOGY...JC/DW
TIDES/COASTAL FLOODING...DW