645 
FXUS61 KOKX 040046 CCA
AFDOKX

Area Forecast Discussion...CORRECTED
National Weather Service New York NY
846 PM EDT Sat Apr 3 2021

.SYNOPSIS...
High pressure settles across the region through Sunday. A low
pressure area meanders just south of Nova Scotia for Monday 
through early Tuesday before drifting farther southward out into
the open Atlantic Tuesday afternoon through midweek. Meanwhile,
high pressure west of the region builds in for Tuesday and 
remain in control through Thursday night with its center staying
well to the north within Southeast Canada. An area of low 
pressure approaches for Friday and into the start of next 
weekend.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Forecast mainly on track with just some minor adjustments made 
to temperatures, dewpoints and cloud coverage to better match 
observed trends.

A shortwave trough crossing the upper Great Lakes in a northwest 
flow will bring in some mid-level and upper level clouds across
the area tonight. However, with very dry low levels, no 
precipitation is expected.

Lows tonight will be in the mid 30s to around 40 across most of the 
area with lower 30s across inland locations.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
Considerable cloud cover will still be expected to stream into 
the region Sunday morning. Broken cloud cover will likely remain
into the afternoon with cold pool aloft and diurnal 
instability.

High temperatures will push into the mid to upper 50s to near 60 
Sunday. Cloud cover should dissipate for the most part Sunday 
Night, with low temperatures in the upper 30s to lower 40s 
across NYC/NJ metro and low to mid 30s across far outlying 
areas.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Upper level low and surface low meander south of Nova Scotia 
for Monday into Monday night. Local weather is expected to 
remain dry. These both move farther southeastward out into the 
open Atlantic for Tuesday through Tuesday night. The pressure 
gradient will be tight for Monday with a gusty NW flow that will
eventually diminish at night as the gradient relaxes Monday 
night through Tuesday night. 

For high temperatures Monday, downslope flow and accounting for
vertical mixing up to near 850mb using NAM12 raw temperatures 
combined with a relatively warmer national blend of model data 
results in high temperatures upper 50s to lower 60s with some 
mid 60s for parts of Northeast NJ. Looking at entire forecast 
region, coastal locations are relatively slightly warmer than 
the interior. A national blend of model data with some slight 
adjustments for parts of Eastern Long Island was used for lows 
Monday night, which are forecast to range from the mid and upper
30s across the interior, to mostly lower 40s along the coast 
with some mid 40s within NYC.

Relatively warmer across the interior for highs Tuesday and a 
little cooler along the coast. Highs forecast are in the upper 
50s to lower 60s, warmer though across the interior compared to 
the coast.

A narrow upper level ridge and surface high pressure then build
in for Wednesday through Thursday. The ridge flattens out 
Thursday night through next Saturday while surface high pressure
weakens and gives way to a frontal system with low pressure 
approaching from the south and west.

Dry conditions remain until late Thursday night when next rain 
showers come back into the forecast. The rain looks to be more of a 
stratiform long duration rain event Friday into next Saturday as the 
frontal system and low move closer to the region. 

Winds stay pretty light and mainly near 10 mph or less Wednesday 
through Wednesday night. A more consistent SE-E flow getting near 10-
15 mph is forecast Thursday through Thursday night with a slight 
increase for Friday into next Saturday, getting more into a 10 to 20 
mph range, higher end of range along the coast. 

Temperatures for highs are forecast to be between 5 and 10 degrees 
above normal for Wednesday with cooler temperatures Thursday through 
next Saturday. Thursday is expected a little warmer of the days with 
it being dry, more in the upper 50s to lower 60s and then mainly 
upper 50s for Friday and next Saturday with rain back in the 
forecast.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
High pressure will remain south and west of the region into tonight. 
A weak surface trough passes nearby Sunday morning. A strengthening
pressure gradient will then develop between offshore low pressure
and high pressure to the west. 

Mainly VFR through the TAF period. There is a low chance for a brief 
period of MVFR ceilings around 025 early Sunday morning.

Any weak seabreezes early this evening will dissipate and the
remainder of the night will feature a light W/NW flow. On 
Sunday, there could be a significant amount of variablity due to
the proximity of a surface trough, especially into the early 
afternoon with local seabreezes and a westerly flow less than 10
kt. There is some uncertainty with the timing of a stronger 
W/NW flow in the afternoon. It is possible that seabreezes could
persist at the coastal terminals longer than forecast. W-NW 
winds at 10-15kt G20kt are forecast to develop by late 
afternoon.

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

A weak flow Sunday morning into early afternoon is likely to
result in a variable wind direction.  

.OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY...
.Sunday Afternoon-Night...VFR. 
.Monday...VFR. NW wind gusts 20-25 kt possible.
.Tuesday...VFR. W-NW wind gusts 15-20 kt possible.
.Wednesday-Thursday...VFR.

&&

.MARINE...
Below SCA conditions expected through Sunday. SCA conditions 
forecast for Monday due to winds but are forecast to be below 
SCA Monday night through Thursday night.

Steep pressure gradient still in place will keep a gusty NW flow
Monday. Forecast has wind gusts around 25 kt for all waters 
during the day. Seas are below 5 ft for all waters. 

High pressure eventually comes back into control for Tuesday into 
Thursday. Seas stay below 5 feet through Thursday night. Wind gusts 
are forecast to remain below 25 kt Monday night through Thursday 
night.

&&

.FIRE WEATHER...
Elevated fire weather conditions continue on Sunday as dry 
conditions persist with min RH values of 30 to 40 percent. For 
the first half of the day, winds will be less than 10 mph, 
however W/NW winds are forecast to strengthen in the afternoon
to 10-15 mph with gust up to 20 mph. 

&&

.HYDROLOGY...
No hydrologic issues expected through the middle of the week. 
For Thursday night through next Saturday, rain is in the 
forecast but is expected to be spread out over a long period of 
time with intensity of light to moderate. No hydrologic issues 
expected at this time.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.

&&

$$

SYNOPSIS...Fig/JM
NEAR TERM...Fig/JM
SHORT TERM...Fig
LONG TERM...JM
AVIATION...DW
MARINE...Fig/JM
FIRE WEATHER...//
HYDROLOGY...Fig/NV