discussion on 2023-06-22

000
FXUS61 KOKX 230014
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
814 PM EDT Thu Jun 22 2023

.SYNOPSIS...
High pressure over the Gulf of Maine slides into the open Atlantic
tonight ahead of an approaching warm front. The front lifts through
the region Friday. Weak low pressure meanders over the Northeast
this weekend as frontal boundaries remain nearby. Another
series of frontal boundaries will affect the area from the
beginning to the middle of next week.

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
-- Changed Discussion --Updated temperatures and POPs for this evening as temperatures
are warmer than previous forecast and given lack of returns on
the radar, POPs were too high. Otherwise, forecast is on track.

A warm front remains to our south associated with a low over the
Carolinas. The low is expected to track to the north and west,
bringing the warm front closer tonight. A small wave of light
showers/drizzle is expected to trek across our eastern areas this
evening, but is looking a lot less than in previous model runs.

Cloud cover remains persistent into tonight due to the warm
front providing ample lift to our south. Moisture will increase
overnight from south to north with the warm front`s approach,
leading to areas of fog early Friday morning and increasing
precip chances, especially further west. Overnight should steer
clear of any widespread precip before Friday.-- End Changed Discussion --

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
A closed upper low tracks into the Ohio Valley on Friday, while at
the surface, a warm front lifts through the region. The day likely
begins on the showery side as the warm front moves through. Dew
points rise into the upper 60 to near 70 with southerly flow
developing post fropa in the morning. Most showers and thunderstorms
look to occur west of our area, with interior locations having a
better chance of precip than coastal locations. The warm front
should still provide enough lift to produce intermittent light to
moderate showers. The risk for excessive rainfall has been shifted
inland away from our area as most of the forecasted heavier precip
has trended in that direction. PWATs from multiple CAMs still bump
up into the 1.8-2" threshold, which would be near the max moving
average of 2" for this time of year. Due to this, rain chances still
reach likely thresholds for tomorrow. NBM continues to overdo precip
for Friday, just like it did today, so I stuck closer to our CONSALL
guidance for rain chances Friday, with some hand edits.

Temperatures will be warmer than Thursday with the region lying in
the warm sector, though still below normal values for late June.
Highs top out in the mid 70s for most, and remain mild overnight
into Saturday morning. Stuck close to NBM guidance for
temperatures.

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Weak low pressure at the surface and frontal boundaries near the
forecast area this weekend will provide enough lift needed for
showers and thunderstorms to develop over the weekend. A weak upper
trough weakens as it moves toward the area from the west. However,
models have backed off on any widespread precipitation, and given
the poor performance of the models over the past couple of cycles in
regards to the recent rain, or lack thereof, any confidence in heavy
rainfall is low. Any heavy rain this weekend looks to be isolated,
with higher chances of occurring mainly north and west of New York
City. The NBM shows just under a 20% chance of 1.00" of rainfall in
24 hours for KJFK. Additionally, slightly lower PWAT values are
noted in the deterministic models, though peak values are still
around 2.00" across the area. So, while the overall average
precipitation for the weekend is lower, any heavy shower or
thunderstorm could still produce close to 2.00" of rainfall. But
again, the more likely place for this would be areas north and west.

Another cutoff develops over the central Great Lakes region Sunday
night into Monday. This cutoff low, along with its associated
frontal boundaries and upper trough will continue the chances for
precipitation for the beginning through the middle of next week as
it slowly moves east. This time frame appears to be a better chance
for heavier rain, but again, with the poor performance with the
models, it is low confidence at this point.

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --A warm front slowly approaches the region tonight and slowly moves
across on Friday before pushing north Friday night.

Showers are not expected for the most part through tonight, although
TAFs do reflect some scattered light showers and drizzle
occasionally, with a better chance late at night for western
terminals. After some brief VFR ceilings initially early this
evening, conditions should quickly go to MVFR late this evening,
with ceilings lowering to IFR tonight with low stratus. Some fog and
drizzle develops late, especially further east. There will be the
potential for some terminals to lower to LIFR overnight into early
Friday morning, otherwise IFR through the Friday morning push.
Conditions are forecast to improve to MVFR mid to late morning and
into Friday afternoon. Rain showers should increase Friday morning
for western terminals and be more scattered for eastern terminals
through the day. Some heavier showers with thunder then become a
possibility from 18z and into the evening, with the best chance of
occurrence for western most terminals. This is being handled via
PROB30 groups for the time being.

The winds settle in at 5-10 kt tonight with any gusts subsiding. The
winds become E-ESE later into early Friday morning without much
change in speed. Winds become more SE near 10 kt Friday afternoon.

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

Amendments may be needed for changing flight categories through the
period, along with timing adjustments with shower activity. A period
of VFR is possible for Friday afternoon, but confidence is too low
to include in TAF at this time.

OUTLOOK FOR 0Z SATURDAY THROUGH TUESDAY...

Friday Night: Showers and MVFR likely, along with pockets of
likely IFR. Chance of thunderstorms, mainly in the evening. SE
to S winds.

Saturday: Showers and MVFR likely. IFR possible. Possible
thunderstorms.

Sunday-Monday: Showers likely. Slight chance of thunderstorms. MVFR
or lower possible at times. S-SE wind gusts 15-20 kt Monday
afternoon into Monday night.

Tuesday. Showers likely. Slight chance of thunderstorms. MVFR or
lower possible at times. S-SE wind gusts near 20-25 kt.

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

.MARINE...
Winds have diminished to less than 25 kt across the waters, and
the SCA on the non-ocean water and the SCA has been cancelled
for these areas. A SCA remains in effect for the ocean waters
through 8 am Friday for seas of around 5 ft. Waves on the ocean
are expected to slowly diminish through the night.

Waves approach 5 ft on the ocean waters Sunday
afternoon into Sunday night. Waves may diminish Sunday night
into Monday, but then increase to SCA level Monday through
middle of next week with a prolonged period of southerly flow
ahead of an approaching frontal system.

Winds of 25 to 30 kt are now possible over most waters Tuesday
afternoon into Tuesday night as the southerly flow increases with
the approach of the next frontal system. The harbor and Western sound
may remain below 25 kt however. Thereafter, winds remain below 25
kt.

.HYDROLOGY...
With the lack of precipitation Wednesday through today (Thursday)
and recent poor model performance, the threat for flash flooding is
lower than previous forecasts. The Weather Prediction Center now
has a marginal risk mainly for areas north and west of New York City
for the weekend. Average forecast rainfall amounts through Saturday
afternoon are between 0.5-1.00". However, peak PWAT values are still
around 2.00", and any heavy shower or thunderstorm could produce 1
to 2 inches of rainfall. Better chances for excessive rainfall now
appears to be for the beginning into the middle of next week as
another frontal system slowly approaches the area. However, there is
still a good deal of uncertainty at this time.

.TIDES/COASTAL FLOODING...
There is a moderate risk of rip current development for all
ocean beaches for Friday and Saturday.

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 8 AM EDT Friday for ANZ350-353-355.

$$
SYNOPSIS...JP/BR
NEAR TERM...JP/BR
SHORT TERM...BR
LONG TERM...JP
AVIATION...JE
MARINE...JP/BR
HYDROLOGY...JP/BR
TIDES/COASTAL FLOODING...