FXUS61 KOKX 090206
Area Forecast Discussion
National Weather Service New York NY
1006 PM EDT Wed Jul 8 2020
Weak high pressure remains through Thursday. Low pressure will
slowly move up the Mid-Atlantic coast Friday into Saturday,
followed by a series of weak fronts moving through the region
through early next week. High pressure builds in for the middle
of the week.
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Mid level deck across area from upstream convection will
gradually dissipate while working east. The second half of the
night will be mainly clear with the potential for patchy low
clouds and fog, especially near the coast.
It will be another warm, humid night with lows in the the upper
60s to lower 70s. This is about 3 to 5 degrees above normal.
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
For Thursday, the humid airmass remains with flow becoming more
S-SE in the afternoon. More subsidence is evident in the mid
levels for Thursday. Convective coverage will be much less.
However, with the expected warmer temperatures (expecting
overall a few degrees warmer than the previous day), instability
will increase and a few showers and thunderstorms will be
possible with daytime trough development, mainly north and west
of NYC. Trough again is very weak so any convection will
quickly subside in the evening with loss of daytime heating.
Regarding the heat advisory, this was kept up since heat index
values are again expected to reach the mid to upper 90s and for
NYC and northeast NJ this will be the second day in a row for
heat index values of at least 95 degrees. Wednesday's
occurrences of heat indices in the mid 90s were more isolated
and this coverage is expected to be greater for Thursday
afternoon. So, the heat advisory remains in place until 6pm
For Thursday night, the upper level ridge axis moves east of
the region and the low pressure will begin to approach from the
south and west. Clouds will increase Thursday night and with the
continued onshore flow, min temperatures forecast will be mild
in the upper 60s to lower 70s once again. Chances for rain
showers increase overnight into daybreak Friday.
There is a moderate risk for rip current development at Atlantic
Ocean beaches on Thursday as long period southerly swell
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Low pressure will move up the Mid Atlantic coast on Friday,
passing over the region Friday night into Saturday morning.
Showers and thunderstorms are expected, especially Friday afternoon
and evening likely just north and east of the surface low as it
pulls subtropical Atlantic moisture. Still low confidence on
location of the heavy rain potential.
An upper-level trough and its associated cold front will move
into the area Saturday, resulting in hot and humid conditions
and the increase chance for showers and thunderstorms on
Saturday and Sunday. The cold front will move off to the east
Monday, but the upper-level trough will remain overhead bringing
a potential for diurnal convection as well as a gradual trend
to a more seasonable airmass through early next week. High
pressure builds back across the area for the middle of the week.
Temperatures during the long term period will be in the upper
80s to near 90 with overnight lows in the upper 60s to mid 70s.
High rip current risk is possible for Friday.
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
Weak high pressure will remain in control through Thursday.
A mainly VFR forecast overnight with the potential for MVFR
conditions to redevelop from east to west overnight into early
Thursday morning, with IFR conditions possible at KGON.
S-SW winds less than 10 kt will back to the S-SE Thursday
.OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY...
.Thursday night...Chance MVFR or lower in stratus Thursday
.Friday-Saturday...MVFR or lower conditions likely in showers and
thunderstorms. Chance E-SE gusts 20-25kt for Friday into Friday
.Sunday-Monday...MVFR or lower possible at times with a chance of
showers and thunderstorms.
The pressure gradient will remain relatively weak through
Thursday night. Conditions on the forecast waters will remain
below SCA thresholds.
As a coastal low pressure approaches from the south, SCA conditions
are expected mainly on the ocean waters from Friday and into the
weekend. Seas will subside slightly on Sunday but will remain above
SCA conditions through early in the week.
Urban and poor drainage flood threat exists with any
thunderstorm activity through Thursday. Main reason being a
lack of steering flow so thunderstorms will be slow moving.
Convective coverage will be more isolated Thursday.
There is increasing potential for a moderate to heavy rainfall
event Friday into Saturday as a coastal system moves up the Mid-
Atlantic coast. Exact timing and track are still uncertain, but
this system has the potential to produce at least 1 to 2 inches
of rain with higher amounts possible with heavier bands.
NYC NOAA Weather Radio Station KWO35 (162.55 MHz) is undergoing
its final stages of testing, and is operating at full power.
NY...Heat Advisory until 6 PM EDT Thursday for NYZ072>075-176-178.
NJ...Heat Advisory until 6 PM EDT Thursday for NJZ004-006-103>108.
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