472
FXUS61 KOKX 201721
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
121 PM EDT Fri Jun 20 2025
.SYNOPSIS...
Low pressure will move across northern New England and eastern
Canada today as high pressure builds to the south, while a
weakening disturbance approaches from the northwest late today.
A warm front will pass to the north this weekend as the high
becomes established off the Mid Atlantic and Southeast coasts.
The high will remain in place early to mid next week. A frontal
system may impact the area late next week.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Mostly sunny via downslope W flow gusting to 25-30 mph for much
of the day, with temps reaching the lower/mid 80s in most
places. A trailing shortwave trough may generate isolated to
widely sct showers/tstms from NYC north/west late this
afternoon.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
Any ongoing isolated to widely scattered convection in the late
day hours should wane after sunset. Expect partly to mostly
cloudy skies tonight especially inland as cloud debris from an
upstream MCS overspreads the area.
Fcst for daytime Sat is dry, with expectation that another
upstream MCS should pass to the north along a warm front late
day Sat into Sat night, but this will have to be watched as it
could skirt areas from NYC north/west per SPC Day 2 Outlook
which carries a marginal svr risk. Temps should be a little
warmer, near 90 in NYC and NE NJ and in the mid/upper 80s
elsewhere.
Another MCS should traverse ern CT on Sunday. As mentioned in
the SPC Day 3 outlook, guidance varies substantially regarding
the strength/timing of the shortwave trough moving across New
England Sunday morning, and there is some potential for isolated
strong tstms. A slower system could result in a more robust
diurnal threat, while a faster system may confine the primary
threat to the morning. Attm have confined this threat to SE CT
mainly for the morning hours.
Meanwhile, high heat and increasing humidity should commence on
Sunday. H8 temps reaching 21-22C (at least in urban NE NJ) with
a downslope W flow supports GFS MOS idea of high temps reaching
100 in urban NE NJ, the upper 90s in surrounding areas
including NYC, and the lower/mid 90s elsewhere to the
north/east. A blend of the NBM and its 90th percentile is also
close to these values; NBM 90th percentile has more widespread
100+ temps inland as well as higher temps into eastern CT, but
did not go with these higher numbers as any convection could
limit temps especially across SE CT. Heat index values as
dewpoints increase should be a few degrees higher, with 105
possible in urban NE NJ, 100-104 for the NYC metro area and
parts of the Hudson Valley/SW CT, and mid/upper 90s most
elsewhere except for coastal SE SE and the south shore/forks of
Long Island.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Key Messages:
* Increasing confidence in hot and humid conditions early next
week.
Global guidance continues to show a shift in the pattern as a
large sprawling high pressure system develops to the south
early next week. This will result in dry and mostly clear
conditions under a light SW flow. This will advect moisture into
the area so that dewpoints rise into the upper 60s to low 70s
through early to mid next week. As a vertically stacked ridge
develops, height rises allow the middle and lower atmosphere to
warm such that 500 mb heights of 597 dm are positioned over the
area by Monday and Tuesday.
Ample surface heating will provide for the lower BL to mix down
these warmer temperatures with surface temperatures expected to
climb into the middle 90s to possible near 100 for some
locations Monday and Tuesday. The immediate coast may rise into
the low to mid 90s as well, with a generally W-SW flow
preventing the ocean from cooling the air mass much. Given the
high dew points coinciding with the heat, heat index values for
interior portions of the area may exceed 100 degrees for
several days. Closer to the coast, heat index values in excess
of 95 degrees remain possible. The peak of the heat will be on
Monday and Tuesday.
By Wednesday, heights begin to fall a bit as the ridge slowly
weakens, giving way to more mid-level energy approaching from
the north. This may also result in the development of afternoon
showers and thunderstorms Wednesday and Thursday as the heat
gradually falls off. Highs on Wednesday will still be above
average, generally in the upper 80s to mid 90s. By Thursday,
highs return to near normal with temperatures in the low to
mid 80s. A frontal system may develop and impact the area late
in the week as well.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
Western Atlantic high pressure builds in today and remains in
control through the weekend.
VFR conditions through the TAF period. An isolated
shower is possible this evening and then again on Saturday,
mainly NW of the NYC metro.
WNW-NW winds 10-15 kt with gusts around 25 kt. Winds may back
towards the SW this evening, especially near the coast. Gusts
will end 23-00z with winds continuing to diminish this evening.
The flow may start out WNW-WSW Saturday morning before becoming
SW into the afternoon. Afternoon S sea breezes are likely at
coastal terminals.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
End time of gusts this evening may be off by 1-2 hours.
Timing of S sea breezes at JFK and LGA on Saturday afternoon may
be off by 1-3 hours.
Winds at EWR and TEB could become S or SSE with sea breeze
passage late Saturday afternoon.
.OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...
Saturday Afternoon-Sunday. Mainly VFR. Slight chance of
showers/thunderstorms, Saturday night into early Sunday.
SW wind gusts 15-20 kt on Sunday.
Monday-Tuesday: VFR.
Wednesday: VFR. Slight chance of showers and thunderstorms in
the afternoon and evening.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
-- Changed Discussion --
SCA continues for all the non ocean waters until 19Z, with the
expectation that gusts up to 25 kt on land will affect the near
shore waters. SCA continues for the ocean waters for these gusts
and also for seas 4-6 ft through the morning, and E of Fire
Island Inlet this afternoon/evening.-- End Changed Discussion --
&&
.HYDROLOGY...
There are no hydrologic concerns through the middle of next week.
&&
.TIDES/COASTAL FLOODING...
There is a high rip current risk for the ocean beaches of
Suffolk and a moderate risk elsewhere, with lingering 4-5 ft
seas on a 7s wave period.
Saturday looks moderate for Suffolk and low elsewhere, with
diminishing swell.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...High Risk for Rip Currents until 9 PM EDT this evening for NYZ080-
081.
NJ...None.
MARINE...Small Craft Advisory until 3 PM EDT this afternoon for ANZ331-
332-335-338-340-345-355.
Small Craft Advisory until 11 PM EDT this evening for ANZ350.
Small Craft Advisory until 6 PM EDT this evening for ANZ353.
&&
$$
SYNOPSIS...BG/MW
NEAR TERM...BG
SHORT TERM...BG
LONG TERM...MW
AVIATION...DS
MARINE...BG/MW
HYDROLOGY...BG/MW
TIDES/COASTAL FLOODING...