000
FXUS61 KOKX 111010
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
610 AM EDT Mon Sep 11 2023
.SYNOPSIS...
Weak low pressure and a cold front slowly shift through the area
today into this evening, moving farther offshore overnight. The next
frontal system approaches on Tuesday and passes through on
Wednesday. High pressure will then be in control Thursday and
Friday.
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
The forecast is mostly on track. Adjusted PoPs for the next few
hours slightly for eastern zones based on the latest radar
trends.
Weak low pressure and cold front will be slowly shifting through the
region today. Lift from both features, in addition to a mid level
shortwave shifting through near the NW zones late morning into
the afternoon, will help trigger showers with a chance of
thunderstorms.
Models seem to favor eastern zones, closer to the low center, for
higher chances of rain this morning. Then with the passage of the
shortwave and cold front, chance are more evenly distributed across
the entire forecast area. Severe weather is not expected due to weak
winds aloft and relatively unfavorable low and mid level lapse
rates.
Flooding is however is more of a concern. Cell training along with
slow forward motion presents a threat of at least minor flooding.
PWATs will be higher over eastern zones this morning, then an
eastward advection of lower PWATs occurs this afternoon. The
convective potential will be hampered by the rainfall/cloud cover
that happens this morning, so rainfall may not be as efficient as it
could be. In general, CAMs have not performed too well over the past
24 hours with rain distribution, but some hi-res guidance such as
HREF did a decent job predicting at least where rain would develop
and shift (and timing) with Friday`s and Saturday`s rainfall - not
so much for Sunday. Do not have the confidence to go with a Flash
Flood Watch at this time with the uncertainty regarding where heavy
rainfall could fall. FFG values have lowered in some areas due to
Sunday`s rainfall, particularly in parts of CT where rain over
the past 24 hours has been relatively higher. With that said,
still wouldn`t have enough confidence that current FFG
thresholds would be met with enough coverage to issue a Watch
for any given area. WPC has much of the area in a slight risk
for flash flooding. Isolated to scattered instances of flash
flooding will be possible, but a more widespread flash flooding
event does not appear likely.
Still muggy today with dewpoints averaging around 70 before falling
tonight. High temperatures in the upper 70s to lower 80s. Rain
threat shifts east tonight, lowering while doing so as the weak cold
front moves through. Lows tonight mostly 65-70.-- End Changed Discussion --
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
The weak low and cold front will slowly shift farther out to sea on
Tuesday, but any surface ridging over the forecast area will be
short-lived as the next system approaches from the west. Can`t
completely rule out a shower or thunderstorm during the day as a
shortwave passes through. Most, if not all of the day will be dry
however. Still muggy as dewpoints will still be in the range of
65- 70. High temps generally around 80 - slightly higher than
normal.
The 500mb longwave pattern then becomes more amplified Tuesday night
into Wednesday as a trough axis, and possibly a closed 500mb low,
shifts in the vicinity if the eastern Great Lakes Region. This
will help send a cold front our way Tuesday night, with the
front progged to pass through during Wednesday. Some
disagreement regarding the timing of the frontal passage, which
will have some implications on the severe weather potential.
Should a later passage occur, a better chance of strong gusts as
0-6km bulk shear could be 25-35 kt. PWATs increase ahead of the
cold front, so will need to monitor trends for flooding
potential. In any case, it appears that rain will be likely on
Wednesday with some thunderstorm potential.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
The airmass dries out significantly on Thu and thru the
remainder of the extended. In the absence of any impacts from
Lee, fair wx can be expected.
The NBM with local adjustments was used for temps thru the period.
Monitor https:/www.weather.gov/okx/tropical or
https:/www.nhc.noaa.gov for the latest NHC forecasts on Hurricane
Lee and others.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
A front draped over southern New England and through eastern
Pennsylvania will meander nearby today. A wave of low pressure
tracks near the area this afternoon and evening, dragging the
front east and through the region.
Generally MVFR or IFR conds through the early morning hours
with occasional showers and mist. Conditions slowly improve to
VFR by late morning for most. Spotty showers linger through the
morning in some areas, with another round of showers and
thunderstorms developing in the afternoon.
Winds will be light and variable through the morning. Sea
breeze development is expected by the afternoon for coastal
terminals, particularly KJFK, KBDR, and KGON. Elsewhere, light
and variable much of the day, with a light northerly flow
developing tonight into Tuesday.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
There is low confidence with specific timing of lowering
conditions overnight and timing and coverage of showers and
thunderstorms later today. Locally IFR possible at times
through the morning.
Possible lowering of conditions once again early Tue AM.
OUTLOOK FOR 06Z TUESDAY THROUGH FRIDAY...
Monday night: Mainly VFR. Possible low stratus toward daybreak.
Tuesday: Mainly VFR. Isolated showers possible.
Wednesday: Showers likely with MVFR to IFR possible. Chance of a
thunderstorm.
Thursday and Friday: VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
With a weak pressure gradient in place, winds and seas will remain
below SCA thresholds today through Tuesday. While winds remain
below advisory levels on Wednesday, swell from tropical system Lee
may push seas above 5 ft, with elevated seas then lasting through
the end of the week. Seas around 15 ft possible Fri-Sat.
Monitor https:/www.weather.gov/okx/tropical or
https:/www.nhc.noaa.gov for the latest NHC forecasts on Hurricane
Lee and others.
&&
.HYDROLOGY...
Primarily minor small stream and poor drainage flooding is
possible today, but flash flooding is possible as explained in
the near term section of this forecast discussion. Flooding is
not anticipated for Tuesday, then on Wednesday there is a risk
for primarily minor flooding with a low chance of flash
flooding. Locally up to 2 inches of rainfall is possible both
today and again on Wednesday, but for both events amount of a
half inch to an inch and a half are more likely.
No hydrologic impacts are expected in the long term.
&&
.TIDES/COASTAL FLOODING...
There is a moderate rip current risk at the Atlantic beaches
today and Tuesday. This risk increases on Wednesday, with both high
surf and dangerous rips possible on the oceanfront as early as
Thursday. This would then continue into Friday and and Saturday.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JC
NEAR TERM...JC
SHORT TERM...JC
LONG TERM...JMC
AVIATION...DR
MARINE...JMC/JC
HYDROLOGY...JC
TIDES/COASTAL FLOODING...