066
FXUS61 KOKX 051211
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
811 AM EDT Mon May 5 2025
.SYNOPSIS...
A stalled frontal boundary remains within the area through Tuesday.
The front regains movement to the north Tuesday night. The
system will then pass through on Wednesday. A cold front will
approach from the northwest on Thursday and stall nearby
Thursday night as low pressure develops along it over the Mid
Atlantic region. The low will then pass slowly south of Long
Island on Friday and east of New England next weekend. Another
cold front may approach from the northwest on Sunday.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
Forecast adjusted with POPs, still mostly across Eastern Long
Island and SE Connecticut with the rain. Expecting this rain to
expand back west late this morning into the afternoon.
Mid and upper level cutoff low continue to slowly approach from the
west. At the surface, a frontal boundary settles within the area,
stalling out.
Through today, rain is expected to increase in coverage and
intensity. CAMs depict increases in reflectivity in various sized
areas over different parts of the region.
Low level forcing increases today, allowing for greater convergence
and lift. Some easterly wind gusts near 20 to 25 mph are forecast.
Instability lowers today with some cooling in lower levels. However,
PWATs still near 1.5 inches.
Minor flooding will become more probable with the training of cells
as parallel low is present from lower to upper levels. Flash
flooding still just a slight chance or isolated in coverage.
Max temperatures a blend of CONSraw and NBM but limited to no
more than 63 degrees Fahrenheit.-- End Changed Discussion --
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
-- Changed Discussion --
Mid and upper level cutoff low continue to approach from the west
tonight through Tuesday night.
Low level winds eventually become more southeast tonight into
Tuesday. East to southeast winds relatively higher across Long
Island and Southern CT tonight. Low level winds maxima shift
farther east of the region Tuesday into Tuesday night.
Upper level southerly winds increase tonight into Tuesday. For
this time period, the upper level jet streak right rear quadrant
approaches, eventually moving into western parts of the region.
Vertical synoptic lift increases as a result of increasing upper
level divergence.
Elevated instability as shown by model near zero values of Showalter
Indices develops across the region late tonight into Tuesday.
Rain continues tonight across the region and with a higher chance of
heavy rain as well which some CAMs are indicating with their max
reflectivity values. Slight chance of thunderstorms tonight as well.
Tuesday, expecting more shower like nature to the rainfall. For
western areas, some increase in surface CAPE forecast so a
chance of thunderstorms with otherwise slight chance of
thunderstorms. Rain showers widespread during the day with
decreasing coverage at night. Still minor flooding possible with
a marginal risk for flash flooding.
Temperatures forecast a little warmer Tuesday using NBM and CONSraw
blend, getting more into the mid 60s for western areas, lower 60s
for eastern areas. Not much diurnal cooling of temperatures Tuesday
night with lows just in the 50s.-- End Changed Discussion --
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
An upper low and its weak sfc reflection will pass across on Wed.
Cold pool aloft plus daytime heating should generate enough
instability for afternoon showers/tstms especially north/west of NYC
(likely PoP there). Winds aloft will be weak due to the ULL passing
across so severe potential looks nil attm.
After this system passes through, a nrn stream trough digging S
through the Great Lakes will close off over or near the OH Valley
Thu night into Friday. This will send a sfc cold front toward the
area on Thu, then as the low closes off sfc cyclogenesis should take
place over the Mid Atlantic region, with the low passing slowly
south and east Fri into Sat. Have only slight chance PoP for showers
with the cold front, then higher chance PoP with the low development
throughout Thu night-Fri, and for Long Island/S CT Fri night. As the
low pulls away this weekend, have only slight chance PoP for Sat,
and mainly dry for Sunday, though it is possible another cold front
may approach from the NW as another northern stream upper trough
moves across S Canada.
Temps should be a little above normal through most of the period,
except cooler on Fri due to clouds/higher PoP with the low passing
to the south.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
Frontal boundary remains stalled within the region through the
TAF period.
Low clouds and occasional fog expected. Periods of rain through
the TAF period. Mainly IFR to LIFR forecast.
Some coastal terminals could get to upper end of IFR with
increasing winds and gusts this afternoon into early evening.
Visibilities could get to MVFR at times but otherwise mainly IFR
expected.
Winds are easterly near 10 kt much of the TAF period. Some sites
will increase to near 15 kt with gusts near 20 kt this afternoon
into this evening.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Categories could fluctuate between LIFR and IFR through the TAF
period.
.OUTLOOK FOR 09Z TUESDAY THROUGH FRIDAY...
Tuesday: Rain/showers and IFR. Possible thunderstorms, mainly
afternoon/evening. SE gusts 15-20kt mainly during the day.
Wednesday: Chance of MVFR or lower with showers likely and a chance
of thunderstorms.
Thursday: MVFR possible with a chance of showers, mainly at
night.
Friday: MVFR possible with a chance of showers. A slight chance
of thunderstorms.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Conditions start out below SCA. Winds are expected to pick up this
afternoon into tonight with southeasterly wind gusts near 20 kt. An
occasional 25 kt gust will be possible. Non-ocean waters remain
below SCA thresholds through Tuesday night. However, ocean seas are
expected to build to 5 ft starting after 2PM this afternoon and
continuing through the day Tuesday. Hoisted a SCA for the ocean
zones to cover this, which will be mainly due to seas. Fire Island
Inlet to Montauk start at 2PM this afternoon and west of Fire Island
Inlet starts at 6PM this evening. Both SCA segments end at 6PM
Tuesday. The higher ocean SCA seas could very well linger through
Tuesday night.
Residual 5-ft seas should linger on the outer ocean waters E of Fire
Island Inlet into Wed and E of Moriches Inlet Wed night. Otherwise
sub advisory criteria expected longer term from Wed through Fri
night, but with long period 4-ft swells persisting on the ocean and
corresponding rougher conditions at the ocean inlets.
&&
.HYDROLOGY...
A little less than 48 hour storm total QPF going until 2AM Wednesday
has mostly near 2 to 3.5 inches of rain across the region.
Locally higher amounts will be possible.
Hourly rainfall rates at times could reach near 1 inch per hour.
HREF indicates max 3 hr QPF that for small areas within the region
reach near 2 inches.
With overall rainfall amounts increased from prior forecast and a
relatively shorter time window for this storm total, the probability
for flooding has increased through early Tuesday morning. Still
think this will be primarily minor flooding. Still think minor
flooding would be most common type of flooding especially for
low lying, poor drainage and urban areas. However, there will
be a slight chance of flash flooding, near 15 to 20 percent. In
terms of areal coverage of flash flooding, this still equates to
isolated.
Marginal risk for flash flooding with otherwise minor flooding
possible Tuesday latter half of morning through Tuesday evening.
No hydrological impacts expected mid to late week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 2 PM this afternoon to 6 PM EDT
Tuesday for ANZ350-353.
Small Craft Advisory from 6 PM this evening to 6 PM EDT
Tuesday for ANZ355.
&&
$$
SYNOPSIS...BG/JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...BG
AVIATION...JM
MARINE...BG/JM
HYDROLOGY...BG/JM