000
FXUS61 KOKX 151337
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
937 AM EDT Sat Apr 15 2023
.SYNOPSIS...
Weak low pressure approaches from the south today and passes
across the area tonight and then east on Sunday. A cold front
will approach Sunday night and move across the area on Monday.
A secondary cold front will then pass through late day Tuesday.
High pressure builds in for the middle of the next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Fog has become dense across eastern Long Island, and Southern
Nassau and have issued a dense fog advisory until 1 pm. This may
need to be expanded in areal coverage or duration if the fog
expands or remains dense this afternoon.
Otherwise, an upper low over the Mid Atlantic states will lift
slowly NE through tonight, ahead of an amplifying longwave
trough over the mid section of the country. This will result in
increasing rain chances today, with the best chance being north
and west of NYC. Marginal instability and a weakly sheared
environment could result in a few thunderstorms across this
area. Elsewhere, expecting only a chance of showers through
tonight. Airmass will also stabilize by early this evening
across the interior with only a chance of showers as well.
Areas of low clouds/fog will likely hang around the south shore
of LI and coastal SE CT into the afternoon as warm, moist air
moves across the cooler near shore waters. The fog will likely
expand later this evening and into tonight with a light E/SE
flow. Dense fog is possible, especially near the coast.
Highs today will range from near 60 far eastern LI/SE CT, to
around 70 across inland areas and the NYC metro. This will fall
well below the record highs we have been experiencing in recent
days. However, another round of record high minimums are
possible before midnight (see climate section below). Lows
Sunday morning will be in the 50s, about 10-15 degrees above
normal.-- End Changed Discussion --
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
For Sunday, the area will be between systems as the upper low
lifts out of the area in the morning, and heights build aloft
ahead of the negatively tilting upper low/trough lifting into
the Great Lakes. The day should be mainly dry with low
clouds/fog lingering along the immediate coast with some
partial clearing across the interior. The associated cold front
approaches Sunday night and the moves across the area on Monday.
Marginal instability will once again result in a slight chance
of thunderstorms, but showers are likely to be widespread late
Sunday night into the Monday. Rainfall amounts will generally be
a quarter inch or less.
Areas of fog will continue to impact coastal locations until
the cold frontal passage Monday afternoon. The fog is expected
to be more patchy in nature farther inland.
Temperatures will gradually trend downward during this time, but
still remain above normal.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
Following a cold frontal passage Monday, a more seasonable air
mass will move into the region through mid week on a gusty W-NW
flow. A low chance of showers will remain in the forecast for
Tuesday as the upper low moves across the region with a
secondary cold front late in the day. High pressure then builds
in for the middle of the week.
Temperatures will return to seasonable levels or slightly below
by Tuesday and then begin to gradually warm back up Wednesday
into Friday as heights build aloft.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
An area of weak low pressure tracks northward across the region
early this morning and continuing through the afternoon as a frontal
boundary remains over or just north of the region through the TAF
period.
A very tricky forecast with a number of concerns. The first will be
ceilings/visibility forecast through today. There is increasing
confidence that ceilings will gradually fall from east to west and
along coastal locations first, then gradually spread westward across
the interior. We have already seen a few eastern terminals (KGON)
and observations along the forks of long Island fall to under 1000
ft. There has been some slight improvement, however observations just
east of our local area, cigs have remain down all night. For
the NYC terminals, JFK should fall to MVFR around 12z. This
timing may be off by by an hour or two, however once conditions
fall, they should generally remain down. KLGA/KEWR could take a
better part of the day for their cigs to fall. Their ceilings
may not drop to MVFR til mid to late afternoon (20z or so).
Again, confidence not very high with respect to the timing.
Once cigs fall, forecast guidance shows very little improvement,
especially in areas along the coast, (KJFK, KISP, KBDR, KGON). If
conditions fall to MVFR or lower across the interior, there is a
better chance for them to the improve back to VFR than those spots
closer to the coast.
The other concern today will be the potential for convection
this afternoon. SE to E winds at EWR and TEB should help keep
convection west of the terminals, making any convection more of
an enroute issue and less of a terminal issue. Will continue to
monitor trends increase any mention of thunder needs to be
added to KEWR/KTEB. Confidence of any convection at KSWF still
remains low enough to include in the TAF.
Tonight, ceilings fall to MVFR/IFR or less with a continued
chance of showers and fog for all terminals.
Winds remain light out of the south tonight, shifting to the
ESE toward 12Z Saturday. E to ESE winds less than 10 kt prevail
through the day Saturday.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Low confidence TAF forecast with respect to ceilings/vsbys.
Low chance of thunder impacting western terminals today and have
not included at thunder in the TAFs.
...OUTLOOK FOR 12Z SUNDAY THROUGH WEDNESDAY...
Sunday and Monday: MVFR or lower possible in showers. E to SE
winds less than 10 kt on Sunday, increasing to 10 to 15 kt on
Monday.
Tuesday and Wednesday...Mainly VFR. WSW G20-25 kt shifting the
NW Wednesday.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90.
&&
.MARINE...
-- Changed Discussion --
A dense fog advisory has been issued on the ocean, Long Island
Bays, and eastern Long Island Sound until 1 pm. The advisory may
need to be extended in time and areal coverage. Warm, moist air
moving over the colder waters will likely keep areas of fog,
likely dense at times, through Sunday.
Otherwise, an weak easterly flow across the waters through
Monday morning will result in sub-SCA conditions.
SCA cond are possible Monday night through Tuesday mainly on the
ocean waters following a cold frontal passage. Near shore gusts
may be possible on the non ocean waters Tue afternoon,
especially on the wrn Sound and harbor.-- End Changed Discussion --
&&
.HYDROLOGY...
No hydrologic concerns exist through the forecast period.
&&
.CLIMATE...
Daily record high minimum temperatures are possible at a few
sites today.
Apr 15
Central Park...67 (1941)
LaGuardia......64 (1941)
JFK............58 (1960)
Islip..........54 (2012)
Newark.........60 (1960)
Bridgeport.....53 (2012)
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None.
NY...Dense Fog Advisory until 1 PM EDT this afternoon for
NYZ078>081-179.
NJ...None.
MARINE...Dense Fog Advisory until 1 PM EDT this afternoon for ANZ332-
340-345-350-353-355.-- End Changed Discussion --
&&
$$
SYNOPSIS...DW
NEAR TERM...DS/DW
SHORT TERM...DW
LONG TERM...
AVIATION...BC
MARINE...BC/DS/DW
HYDROLOGY...DW
CLIMATE...