939
FXUS61 KOKX 181134
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
734 AM EDT Tue Jun 18 2024
.SYNOPSIS...
High pressure stretching in from the western Atlantic remains in
control through late this week. A frontal boundary approaches from
the north on Friday and likely stalls over or just north of the
area through Saturday. That front lifts north as a warm front
Saturday night and another cold front approaches from the west
Sunday into Monday.
&&
.NEAR TERM /THROUGH TONIGHT/...
Forecast remains on track with only minor adjustments to account
for the latest observations of temperatures and dew points.
The upper level ridge continues to build over the area today
with increasing low level moisture due to a S/SW flow courtesy
of the offshore high pressure system. As heights ride over the
area, subsidence aloft will gradually warm the lower atmosphere.
As the BL mixes with daytime heating, high temperatures are
expected to rise into the upper 80s to low 90s for much of the
inland areas.
These hot temperatures combined with the added moisture will
result in heat index values of 95-100 degrees for NE NJ, the
Lower Hudson Valley, and portions of western interior southern
CT. As a result, a heat advisory remains in effect for these
areas. Coastal areas and NYC will remain relatively cooler with
a flow off the ocean preventing high temperatures from rising
more than the upper 80s to near 90. Low temperatures tonight
will be in the upper 60s to low 70s.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
The strong ridge remains in place Wednesday and Thursday with
continued heat over the entire region. The heat intensifies
slightly and expands a bit to the east for Wednesday and even
moreso for Thursday. The main headline change at during this
timeframe is the addition of northern Middlesex and northern
New London counties in Connecticut for Wednesday through
Thursday for heat index values of 95-100. It is likely that heat
advisories will be expanded closer to the coast on Thursday as
heat continues to expand.
Low temperatures each night will be warm, generally in the
upper 60s to middle 70s with the warmest spots in and around the
NYC metro.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
**Key Points**
* The heat wave is expected to continue in the long term period,
potentially peaking on Friday and continuing through the weekend
for some locations.
* The combination of the heat and humidity will produce heat index
values of 95 to potentially up to around 105 during this time
frame away from the coast. The most impactful effects from the
heat will be felt further away from the cooler effects of the
ocean, particularly across the Lower Hudson Valley, northeast NJ
and interior CT.
* Not much relief at night with warm and humid conditions as
overnight lows will be in the upper 60s to the middle 70s, with
dew points remaining well into the 60s.
By Friday morning, the upper level ridge over the area will have
likely already flattened in response to an upper level trough moving
through northern Canada, resulting in a zonal flow over the area.
High pressure centered offshore will also continue to weaken and
drift east. This pattern still results in hot and humid conditions
across the area with the heat wave potentially peaking Friday and
continuing through Sunday for some locations (mainly northeast NJ
and the Lower Hudson Valley).
On Friday, a frontal boundary will be approaching from the north and
will likely stall over or just north of the area through Saturday
before lifting north Saturday night. Given the frontal boundary and
some weak disturbances moving through aloft, there will be chances
of showers and thunderstorms Friday as well as increased cloud
cover. This has the potential to affect high temperatures and have
trended highs down just slightly for now. Chances of showers and
thunderstorms continue through the weekend. Although there are no
hydrologic concerns at the moment, it is worth noting that there may
be a chance for any shower or thunderstorm to produce heavy
downpours given pwats around 2 inches. A cold front will approach
from the west Sunday into Monday and likely move through sometime
later on Monday, bringing at least a brief change in airmass.
It is important to exercise caution with the intense heat and high
humidity, thus it is important to take precautions to protect one`s
health, particularly those without effective cooling and/or adequate
hydration.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
High pressure remains in place offshore through the TAF period.
VFR with a S-SW flow through the TAF period.
S-SW flow increasing to near 10-15 kt this afternoon into the
early evening with gusts near 20-25 kt. Not every terminal is
expected to have gusts. Winds drop below 10kt tonight.
There could be an isolated shower or thunderstorm near KSWF this
afternoon. Confidence in occurrence is very low at this time.
Any shower/thunderstorm that does develop will likely not make
it to the other terminals.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Start and end timing of gusts could be a few hours off from the TAF.
Potential for occasional gusts a few kt higher than what is in
the TAF.
OUTLOOK FOR 12Z WEDNESDAY THROUGH SATURDAY...
Wednesday and Thursday: VFR. S-SW wind gusts 15-20 kt afternoon
into early evening.
Friday and Saturday: Potential for MVFR or lower conditions in
showers and thunderstorms, mainly in the afternoon/evening
hours.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
With high pressure largely in control, sub Small Craft Advisory
conditions are expected to prevail through the weekend. Winds
and waves may start to increase towards the end of the day on
Sunday as a southerly flow picks up ahead of a cold front.
&&
.HYDROLOGY...
A stalled frontal boundary could bring showers and thunderstorms to
the area Friday through the weekend and then a cold front moving
through the area early next week will bring additional
shower/thunderstorm chances. It remains too soon to determine
whether there will be any hydrologic impacts. Any impacts would
likely be very localized and more of the minor urban type.
&&
.TIDES/COASTAL FLOODING...
There remains a moderate rip current risk at the ocean beaches
today and Wednesday.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory from noon today to 8 PM EDT Thursday for CTZ005-
006.
Heat Advisory from noon Wednesday to 8 PM EDT Thursday for
CTZ007-008.
NY...Heat Advisory from noon today to 8 PM EDT Thursday for
NYZ067>070.
NJ...Heat Advisory from noon today to 8 PM EDT Thursday for NJZ002-
004-006-103>108.
MARINE...None.
&&
$$
SYNOPSIS...MW
NEAR TERM...MW
SHORT TERM...MW
LONG TERM...JT
AVIATION...JT
MARINE...JT/MW
HYDROLOGY...JT/MW
TIDES/COASTAL FLOODING...