000
FXUS61 KOKX 021148
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
748 AM EDT Sun Jul 2 2023
.SYNOPSIS...
A warm frontal passage today will result in unsettled weather. A
cool front will pass or dissipate over the area on Monday. Weak
high pressure will then build in for the middle of the week.
Another frontal system may impact the area late in the week into
next weekend.
&&
.NEAR TERM /THROUGH TONIGHT/...
Updated the fcst to tweak pops based on radar trends. Otherwise,
the fcst is on track.
Shwrs continue to develop over the area this mrng and spread
newd. No lightning in the region, so kept tstm chances to slight
chance thru the mrng hours. Instability is weak and elevated.
As the warm front passes, there should be a lull in the pcpn and
approximately the wrn third of the cwa should destabilize. The
NAM has been suggesting this and with the front passing during
the day it should allow for at least 1000 J/kg of SBCAPE to
develop in these wrn areas. Although shear is not particularly
strong, there may be enough balance to allow for some
organization. Main threat as far as svr goes would be strong
winds. Therefore, tstms are expected to develop this aftn and
eve as a h7 wave comes thru, and gusty winds have been
maintained in the fcst.
Locally hvy rain also possible with pwats up to 2.5 inches. A
limiting factor may be wly storm motion around 10kt.
After the aftn/eve activity, another round of development is
possible overnight as dpva with the approaching upr trof
provides a trigger. This is perhaps the lowest confidence pcpn
fcst in the near term as previous convection will have an
impact on the environment and the airmass may be too worked
over. On the other hand, activity could be stronger if aftn/eve
tstms don`t materialize.
Humid today, especially ern areas with flow off the water.
The NBM with local adjustments was used for temps today and
tngt.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
H5 low approaches Montreal Mon mrng, with the associated upr
trof on the doorstep of the cwa. Llvl flow veers swly, allowing
the area to heat up. Went abv the NBM based on the flow and the
mid lvl heat ridge over the area. Although the models may be
having a difficult time with initiation, it seems the pattern
should be conducive to the development of aftn and eve tstms.
The limiting factor in the models right now is some weak
shrtwv ridging at peak heating. Have continued with the blended
approach and gone with NBM pops. 0-6km bulk shear increases to
20-30, not huge but enough to yield a BRN blw the multicellular
lvl at times.
The weak sfc front/trof comes thru Mon ngt. Still some chances
for shwrs and tstms Mon ngt, but lesser intensity likely attm.
The front does not have much of an airmass change, and it should
be hot again on the 4th. With relatively low heights and an
unstable airmass, tstms possible in the aftn and eve. Went with
isold coverage in the fcst for now, although coverage may be
closer to sct, especially across the interior, if the scenario
holds.
Went with the MEX for temps on the 4th.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
For the mid week period, mid level ridging and 85h temps around
18C, will result in surface temps 5-8 degrees above normal.
This places much of the area, with the exception of the
immediate south shore of LI and the twin forks well into the 80s
and likely around 90 for NYC metro and points north and west.
Airmass looks to dry out enough with a W/SW flow to keep heat
indices close to the ambient temperature. So at this time, the
threat for heat advisory criteria is low. However, the NBM box
ands whisker plots shows the median temps several degrees warmer
than the deterministic. In some cases, the deterministic is
below the 25th percentile. Thus, the potential is there for
higher temperatures.
For the end of the week, heights fall with the approach of
another upper trough. Temperatures will be cooler in the 80s,
largely due to an increase in cloud cover and chances for
convection and onshore flow.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
A warm front approaches the terminals this morning, and lifts
north of the area during the day today.
The first round of showers has pushed east of the NYC terminals,
and now impacting the terminals east of NYC. These showers
should exit the eastern terminals between 13-14z. Then, there
should be a break in the precipitation with another round of
showers and thunderstorms after 20z. The greatest threat for
convection looks to occur between 20z-00z for NYC, an hour
earlier to the west and slightly later to the east.
MVFR conditions at most terminals right now. A few spots remain
VFR and others are IFR or lower. Widespread IFR or lower will
become very possibly at all terminals this morning with the
passage of a warm front. As the front lifts north of the
terminals late this morning, some improvement is expected,
however how much clearing/improvement remains a bit uncertain.
A lot will be determined how far north the front actually lifts.
Can not rule out some terminals remaining IFR for much of the
day.
Winds are pretty consistent during the TAF period, with a S-SE
flow near 5-10 kt for much of the TAF period. There could be a
few gusts 15-20 kt this afternoon.
The afternoon KJFK, KLGA, and KEWR haze potential forecast is
YELLOW...which implies slant range visibility 4-6SM outside of
cloud.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
There remains some uncertainty with improving conditions late
this morning and early this afternoon. Amendments can be
expected for this.
Timing of thunderstorms this afternoon may be off by an hour or
two, best timing right now looks to be 20z-00z.
OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY...
Monday: MVFR or lower at times day into early evening with
chances of showers and thunderstorms, showers and thunderstorms
likely north and west of NYC terminals afternoon into early
evening. Showers and thunderstorms taper off later in evening
with VFR returning. Some SW wind gusts 15-20 kt afternoon into
early evening.
Tuesday: Mainly VFR. Slight chance of showers and thunderstorms with
MVFR or lower possible day into early evening north and west of NYC
terminals.
Wednesday: Mainly VFR.
Thursday: Mainly VFR. Slight chance of showers and thunderstorms
with MVFR or lower possible afternoon into evening near NYC
terminals and to the north and west of NYC terminals.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
Winds and seas are expected to generally be below SCA levels
through the upcoming week. Waves on the eastern ocean zone may
approach 5 ft tonight into early Tue with a southerly flow
building seas.
&&
.HYDROLOGY...
There is a chance for areas of minor flooding this aftn and eve
with tstms developing across the area. There is a low flash
flood risk, with areas from nern NJ to the Hudson Valley most
prone.
Some localized minor flooding will be possible on Mon if tstms
develop across the area.
No hydrologic issues are expected thereafter attm.
&&
.TIDES/COASTAL FLOODING...
A moderate risk of rip currents is expected through Mon,
although there is the potential rips could reach high on Mon,
particularly ern beaches.
Astronomical tides continue to increase with the approach of a full
moon on Monday. Minor coastal flooding looks likely for tonight`s
high tide cycle, resulting in a coastal flood advisory for southern
Queens and Southern Nassau counties. Meanwhile, a statement has been
issued for southern Fairfield in CT as a few locations may just
touch minor thresholds.
Another round of minor coastal flooding is expected for the Monday
night high tide.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...Coastal Flood Advisory from 7 PM to 10 PM EDT this evening for
NYZ178-179.
NJ...None.
MARINE...None.
&&
$$
SYNOPSIS...JMC/DW
NEAR TERM...JMC
SHORT TERM...JMC
LONG TERM...DW
AVIATION...BC
MARINE...JMC/DW
HYDROLOGY...JMC/DW
TIDES/COASTAL FLOODING...