703
FXUS61 KOKX 012009
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
409 PM EDT Wed May 1 2024

.SYNOPSIS...
A frontal boundary remains in the vicinity tonight, pushing east
on Thursday, followed by high pressure Friday into Friday night.
The high moves off the coast Saturday as a cold front
approaches. This front moves through Sunday night into Monday
morning, then stalls south of the region. The front moves back
north as a warm front Tuesday into Wednesday.


&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Frontal boundary remains in the vicinity tonight, though dry
conditions should prevail. There may be some weak lift towards
morning to account for some drizzle, but right now, think that
this will more likely take the form of fog and low clouds. Went
with patchy fog, but it could be more widespread for eastern
areas as we head toward daybreak.

With clouds in the area tonight and a light southeasterly flow,
low temperatures will be just a degree or two above normal for
this time of year, in the upper 40s to lower 50s

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY/...
Low pressure passes well north of the area Thursday, helping to
push the frontal boundary through the forecast area during the
day. The low, and associated developing shortwave dive
southeast, passing east of the area overnight tonight.
Thereafter, high pressure builds in from southeastern Canada at
the surface while a high amplitude ridge over the eastern Great
Lakes moves slowly east, but its ridge axis remains just west or
begins to enter the forecast area by the daybreak Saturday. Have
gone with a dry forecast based on weak dynamics and track of the
low and upper shortwave.

The main forecast challenge will be the high temperatures for
Thursday. The area may be warm sectored for a brief time during
the day Thursday, and the southwesterly to westerly flow that
develops may help to bring in warm temperatures for this time of
year. Given previous discussion on how cool NBM has been
lately, and looking at NBM probabilities of greater than 75 and
then 80 degrees, thinking is that much of New York City and
points north and west will see highs in the low 80s, while
southern portions of the city much of Long Island, and
southeastern Connecticut remain in the upper 60s to lower 70s.
However, there is a great amount of spread in the NBM, with 15
to as much as 18 degree difference noted between the 25th and
75th percentiles. Therefore, there is a rather large amount of
uncertainty with the temperature forecast.

Seasonably warm conditions expected Thursday night with lows
generally in the 50s region-wide. Temperatures drop back to near
normal on Friday.


&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
An upper level ridge over the area Friday night into Saturday, as
the flow becomes near zonal into early next week. A longwave upper
trough across eastern Canada amplifies into the northeast Tuesday and
moves off shore Wednesday as another upper ridge builds to the west
of the area and moves into the region Wednesday. At the surface high
pressure along the northeast and mid Atlantic shifts slowly east
into Saturday as a cold front approaches. This front tracks across
Sunday night into Monday, and becomes nearly stationary as the flow
becomes parallel to the boundary. A period of some heavier showers
will be possible Sunday as precipitable water values increase to 1.3
inches. Then Tuesday into Wednesday high pressure builds south from
the Hudson Bay region of Canada into the eastern Great Lakes. With a
deep low tracking northward from the northern plains into southern
Canada Tuesday into Wednesday the stalled cold front will move
slowly northward as a warm front. There is uncertainty as to the
movement of the front as high pressure, and an upper ridge will be
in place. Temperatures Friday night through Sunday will be around 5
degrees above normal, and then Sunday night into Wednesday 5 to 10
degrees above normal. For highs and lows Monday through Wednesday
used a blend of NBM and NBM 75th percentile to raise temperatures a
few degrees above the NBM.
Depending on the movement of the warm front next week, there is a
chance that a few locations will have a record high low Monday night
into Tuesday morning.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
Weak high pressure remains just east of the area through this
evening, then gives way to a weak frontal system approaching
from the west. There is some uncertainty as to how quickly
the associated warm front/cold front get through the area on
Thursday, which could lead to wind timing and intensity issues.
The front may struggle to get east of the coastal terminals.

Mainly VFR for the remainder of this afternoon. Widespread
IFR/LIFR conditions are the forecast to develop this evening
into the early morning hours Thursday. Improvement to VFR is
forecast to occur quickly after 12Z Thursday.

SE winds generally 10kt or less through the overnight, then
gradually veering from west to east on Thursday as a frontal
system attempts to work across the area. The westerly wind shift
may remain west of the KLGA and KJFK for much of the day,
before going around in the early evening. There is fair amount
of uncertainty as to how far east the west winds get on
Thursday. W/NW winds 10-15kt G20kt are possible for those
locations that do come around.

 ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

There is only low to medium confidence on the timing of IFR
ceilings tonight.

The timing of the wind shift to the W/NW on Thursday could be
delayed significantly, especially at KLGA and KJFK. Warm front
could get hung up across the area during the daytime hours.

OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...

Thursday Afternoon: VFR everywhere. Some W/NW gusts around
15-20KT in the afternoon.

Friday: VFR.

Saturday: Mainly VFR. Chance of showers and MVFR cond in the
afternoon, becoming likely overnight.

Sunday...Chance of MVFR or lower in showers. ESE winds G15-20kt.

Monday...VFR.

Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90

&&

.MARINE...
A weak pressure gradient remains in place, with an extended
period of conditions below SCA levels tonight through Monday
night.

&&

.HYDROLOGY...
There are currently no hydrologic concerns through early next
week.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.

&&

$$

SYNOPSIS...JP/MET
NEAR TERM...JP
SHORT TERM...JP
LONG TERM...MET
AVIATION...DW
MARINE...JP/MET
HYDROLOGY...JP/MET