Area Forecast Discussion
Issued by NWS Upton, NY

Home |  Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
053
FXUS61 KOKX 231818
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
218 PM EDT Mon Sep 23 2024

.SYNOPSIS...
High pressure near Maine will continue to nose southward through
Tuesday. A frontal system then approaches on Wednesday and
moves across on Thursday. High pressure slowly returns Friday
and Saturday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Nudged up PoPs just a bit to chance (25-30%) over the western
half of the region this afternoon. A few sprinkles or showers
associated with a weakening shortwave across Pennsylvania and
Upstate NY may be able to work into NE NJ, the LoHud Valley, and
the NYC metro before ridging and dry air in place helps to
dissipate this activity. Any rain that does make it to the
ground should be rather spotty and light. Otherwise, forecast
remains on track and previous discussion follows.

Upper trough and associated offshore low will continue pushing
further east over the western Atlantic through tonight. Upper
ridge axis overhead to start the day flattens as a weak
shortwave approaches. The shortwave likely washes out this
afternoon and evening with ridging taking over by tonight.

High pressure near Maine will continue to ridge down through the
northeast. The aforementioned shortwave should lead to partly
sunny/mostly cloudy conditions through much of the day. The
latest high resolution models are simulating some weak radar
returns ahead of the weakening shortwave, which reach the
western half of the area late this morning into the
afternoon/early evening. The surface ridging from the high
pressure and dry subcloud layer will likely limit how much
reaches the ground. High temperatures will be slightly below
normal in the upper 60s and lower 70s.

Mostly cloudy conditions likely continue tonight as there will
moisture in the low to mid levels moving around the periphery of
the building ridge aloft. Lows look to fall into the lower 50s
inland and middle to upper 50s closer to the coast.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
Ridging will remain along the eastern seaboard on Tuesday as a
much more organized upper trough amplifies across the central
states. This pattern will continue to bring varying levels of
clouds during the day, but there should be some sunshine at
times. Highs on Tuesday continue slightly below normal in the
upper 60s and low 70s.

The upper ridge axis starts sliding east Tuesday night into
Wednesday. The surface ridging may weaken a bit, but still
remain nearby across the New England coast. The upper trough is
progged to split as the northern stream rushes out ahead of the
southern stream. This should effectively prevent a deeper
moisture feed up into the northeast. The northern stream
shortwave sends a frontal system towards the area on Wednesday,
with chances for showers slowly increasing through the day. Have
capped PoPs at chance with the higher probabilities from the
NYC metro on northwest. The lingering surface ridging prevent
much progress into CT and Long Island, at least into the early
evening. High temperatures continue slightly below normal in the
upper 60s and low 70s.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Key Points:

* showers continue mid week with a passing frontal system.

* Greater likelihood of dry weather from Fri into the weekend.

No significant changes in the long term period and stuck close to
the previous forecast/NBM.

A frontal system will move across the region during the start of the
long term period, mainly Wednesday night through Thursday night.
Expect at least some chance POPs for the entire region during this
period.

By Thu, a complex pattern will have taken shape over North America,
with an omega block developing as upper ridging gets pinched off
over the upper Great Lakes region, one closed low moves across
Eastern Canada into the western Atlantic, and another closed low
remains nearly stationary over the Plains and the Mississippi
Valley. The low moving across Canada should send a back door front
down through on Fri, with sfc ridging once again nosing down from
eastern Canada from that point on into the weekend.

High temperatures in the long term will remain in the 70s each
day.

&&

.AVIATION /15Z MONDAY THROUGH FRIDAY/...
High pressure remains in control today.

Mainly VFR conditions into much of tonight. Cigs are forecast
to lower back to MVFR or close to it Tue morning mainly after
12Z.

E-NE winds around 10 kt, with some brief gusts 15-18 kt, should
veer more to the E and diminish to under 10 kt this evening,
then back NE overnight.

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

Ocnl G15-18kt possible this afternoon.

OUTLOOK FOR 18Z TUESDAY THROUGH FRIDAY...

Tuesday afternoon: VFR. NE-E winds around 10 kt. Ocnl G15-20kt
possible.

Wednesday: Chance of showers with MVFR cond from the NYC
metros north/west, otherwise VFR.

Wednesday night: Chance of showers with MVFR cond throughout,
but mainly after midnight at KISP/KGON. Slight chance of a tstm
in the evening from the NYC metros north/west.

Thursday: Chance of mainly morning showers/MVFR cond, otherwise
VFR.

Friday and Saturday: VFR.

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

&&

.MARINE...
Elevated long period swells from slow departing offshore low
pressure will continue for several days. A Small Craft Advisory
remains in effect on the ocean waters and has been extended through
Tuesday Night. This may need to be extended into Wednesday even
though seas should begin subsiding Tuesday night into Wednesday.
Winds are expected to remain below SCA levels through Wednesday.

An extended period of hazardous 5+ foot seas should continue into
at least Wednesday night. Seas may either subside below 5 ft by
Thursday, or seas may at least be confined closer to 20 nm
offshore and beyond.

&&

.HYDROLOGY...
There are no hydrologic concerns through next weekend.

&&

.TIDES/COASTAL FLOODING...
Minor coastal flooding continue with high tide this afternoon,
but impacts and areal coverage will be less than previous days.
The offshore low responsible for the easterly swell that has
helped pile water into the area will work slowly southeast
through early this week. The combination of these two factors
will bring an end to the widespread coastal flooding after high
tide this afternoon. No changes were made to the ongoing
headlines currently in place through this afternoon

The most vulnerable locations in the south shore back bays,
particularly in southern Nassau, may see brief minor coastal
flooding with high tide Tuesday afternoon. The back bays can be slow
to drain which has occurred in similar past events, so have gone
closer to Steven`s guidance for locations such as East Rockaway,
Reynolds Channel, and Freeport. A coastal flood statement may
eventually be needed for these locations Tuesday afternoon. No
additional issues are anticipated beyond that time.

The high risk of rip currents continues through Tuesday evening
with offshore low pressure still bringing long period E/SE
swells.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Coastal Flood Advisory from 2 PM this afternoon to 6 PM EDT
     this evening for CTZ009.
NY...Coastal Flood Advisory from 2 PM this afternoon to 6 PM EDT
     this evening for NYZ071.
     Coastal Flood Advisory until 3 PM EDT this afternoon for
     NYZ074-075-178-179.
     High Risk for Rip Currents through Tuesday afternoon for NYZ075-080-
     081-178-179.
NJ...Coastal Flood Advisory until 3 PM EDT this afternoon for
     NJZ006-106-108.
MARINE...Small Craft Advisory until 6 AM EDT Wednesday for ANZ350-353-
     355.

&&

$$

SYNOPSIS...BC/DS
NEAR TERM...DR/DS
SHORT TERM...DS
LONG TERM...BC
AVIATION...BC/BG
MARINE...BC/DS
HYDROLOGY...BC/DS
TIDES/COASTAL FLOODING...