936
FXUS61 KOKX 200521
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
121 AM EDT Sun Oct 20 2019
.SYNOPSIS...
High pressure will drift out to sea tonight. Low pressure will
track off the Carolina coast by Sunday, and pass well to the
south from Sunday into Sunday night. Weak high pressure will
follow for Monday before a frontal system moves across Tuesday
into Tuesday night. High pressure will follow for Wednesday and
Thursday, before another frontal system approaches Friday into
Saturday.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
High pressure over the area will present a tricky temperature
forecast for tonight, as good initial radiational cooling may be
offset by increasing clouds through the early morning hours.
Because of the increase in clouds, a blend of the guidance was
used as opposed to the coldest numbers. If the clouds do not
slow the radiational cooling, lows could be several degrees
lower than forecast, particularly across the outlying areas.
Patchy frost has been included in the forecast for these areas.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
Low pressure will reach Cape Hatteras around 18Z, then continue
east northeast through Sunday night. The NAM is a northerly
outlier in the 12Z model suite. For this reason, precipitation
amounts and probabilities have been held back from the wettest
NAM solution. The forecast area may be in the gradient from rain
to dry with this event, as it looks likely that southern and
western areas will at least see some rain, with some of the
modeling keeping parts of CT dry. The forecast leaves room for
adjustment should a solid trend/consensus develop with the 00Z
model runs. Otherwise, increasing clouds can be expected, with
temperatures around 60 during the day and nighttime readings
mainly in the 40s. The NBM was followed closely for temperatures
with the clouds and easterly component low level wind.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Long range guidance in closer agreement on timing on the next
frontal system to pass through Tue into Tue night. Showers
appear most likely from late day Tue night into Tue evening,
with no more than a lingering shower out east by daybreak Wed.
Could be some bands of heavier showers, mainly NW of the CWA
where better mid level forcing should be headed, but with ECMWF
forecasting a wave of low pressure to develop along the front
farther south, could see heavier showers with any associated LLJ
that develops, with the higher chances for that across Long
Island and CT.
High pressure and dry conds follow for Wed through Thu night,
then another frontal system may follow for Fri into Sat. Latest
op ECMWF has completely backed off its prior idea of phasing of
northern/southern streams leading to a meridional trough tapping
into Gulf moisture, so forecast then somewhat uncertain.
Temps should remain at least a few deg above normal through the
period.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
High pressure moves offshore overnight. Low pressure then
tracks well south of the area late today into tonight.
VFR this morning with conditions lowering to MVFR at most
terminals this afternoon in -RA. The chance of rain is less
across the interior and Connecticut terminals with more
coverage anticipated across NYC and Long Island terminals. -RA
ends from west to east 00z-04z with conditions improving to VFR
late tonight.
Light and variable winds early this morning will become SE-E
after 12z. The flow should become NE this afternoon and increase
a bit with coastal terminals around 10 kt late this afternoon
into the evening. Winds continue to back to the N late tonight
around 10 kt or less.
.OUTLOOK FOR 06Z MONDAY THROUGH THURSDAY...
.Sunday night...MVFR improves to VFR late.
.Monday...VFR.
.Tuesday...Showers likely with MVFR or lower conditions,
especially late day and at night.
.Wednesday-Thursday...VFR.
&&
.MARINE...
Winds and seas will remain below SCA levels through the day on
Sunday with high pressure generally over the area. NE winds will
increase Sunday night, with gusts aoa 25 kt possible after
midnight, especially on the ocean. An advisory may be needed.
Longer term, ocean seas of 5 ft or more likely into mid week,
first as post-tropical cyclone Nestor passes well to the SE,
then as a frontal system passes through Tue night.
&&
.HYDROLOGY...
No hydrologic impacts are anticipated through Sunday night.
Rainfall of up to 1/2 inch may be possible well NW of NYC late
day Tue into Tue night.
&&
.EQUIPMENT...
NYC NOAA Weather Radio Station KWO35 (162.55 MHz) remains off the
air.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.
&&
$$
AVIATION...DS
NWS OKX Office Area Forecast Discussion
