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000
FXUS61 KOKX 212235
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
535 PM EST Fri Feb 21 2020

.SYNOPSIS...
High pressure slowly builds to the south through the weekend.
The high will slide offshore over the Atlantic on Sunday and
Monday. Weak low pressure approaches from the south and west
Monday night and moves near the region on Tuesday. A stronger
low pressure approaches on Wednesday and moves across the area
Wednesday night and Thursday.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Mainly updated dew points as they have been running lower than
forecast this evening. Many locations have seen dew points range
between 0 and 5 below. This is indicative of how dry the
airmass is over the region. The dew points should slowly rise
this evening into the single digits.

Clear skies are forecast as high pressure builds from the
southwest, and ridging builds aloft.

The forecast challenge for tonight will be minimum temperature
for areas prone to radiational cooling. Weak shortwave passes
well to the north late tonight, and a sfc trough passes. Winds
will back to the west, and a slight increase in the pressure
gradient is expected along with an increase in winds aloft. This
will hinder good radiational cooling later tonight (after
midnight). However, if winds decouple sufficiently this evening,
temps could fall quickly outside of the urban areas. In
general, went slightly above MOS for those locations prone to
radiational cooling based on the above thinking, but much colder
than blended databases. Lows will range from the mid 20s in and
around NYC metro, to the lower teens in the normally colder
locations. A few single digits cannot be ruled out, if winds
lighten more than forecast, and for a longer duration than
forecast.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
Clear skies are expected this weekend as a ridge of high
pressure builds. Temperatures during the day may very well over
perform (especially Sunday) in westerly downslope flow and
gradual WAA. Temps will rise through the 40s Saturday, and into
the 50s Sunday under abundant sunshine. Leaned warmer than MOS.

Temperatures at night show fall into the 20s, except lower 30s
around NYC metro.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
The quiet pattern the Tri-State area will observe for this weekend
will end next week as a more active weather pattern takes shape.

Monday will continue tranquil with increasing clouds late in the
day. A split jet stream flow pattern will be in place with a
northern stream shortwave passing across SE Canada and a southern
stream shortwave moving across the central States. Above normal
temperatures in the upper 40s and lower 50s are anticipated for
highs on Monday.

A noticeable trend in the models over the last 24 hours is to dampen
the southern stream wave out faster as it approaches the northeast.
The surface low associated with the shortwave looks to weaken as it
approaches Monday night. Lingering surface ridging over the New
England on Tuesday also creates a challenge for precipitation
development. The combination of the surface ridging and weakening
shortwave leads to lower probabilities for precipitation.
Temperature profiles are supportive of plain rain where precip does
occur and any rain will be on the light side. The highest chance for
light rain appears to be Tuesday with lower chances Tuesday night as
heights rise aloft and shortwave energy weakens. Cannot completely
remove the mention of light rain Tuesday night into Wednesday
morning as lingering overrunning may remain in place.

A ridge amplifies along the Western North America on Wednesday leading
to a deepening downstream trough over the Central States. The models
have continued to come into agreement that this next trough will
deepen another surface low over the Middle Atlantic on Wednesday and
then lift the low across the northeast Wednesday night into
Thursday. The persistent pattern this winter of inland tracking lows
will continue with this system as the consensus of guidance
indicates the parent low moves towards the eastern Great Lakes with
a potential secondary developing over New England. Plain rain is the
most likely precipitation type in this scenario late Wednesday
through Wednesday night with mild air in place. Will have to watch
if any wrap around precip can make it across the region as colder
arrives when the low departs Thursday morning, but this looks like a
very low probability at this time.

The upper trough becomes a closed low late Thursday into Friday as
it tracks across New England. Conditions should dry out with
temperatures falling below normal for the end of February.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
High pressure remains across the terminals through the forecast
period with VFR conditions.  No cloud expected with unrestricted
visibility through the TAF period.

Winds becoming W this evening diminishing to 5-10 kt. Winds then
back farther WSW-SW later this evening continuing overnight and
Saturday. A few gusts 15-20 kt are possible Saturday afternoon.

.OUTLOOK FOR 20Z SATURDAY THROUGH WEDNESDAY...
.Saturday through Sunday night...VFR.
.Monday...VFR. a slight chance of MVFR late in the day in
ceilings and light rain.
.Monday night and Tuesday...Rain likely with MVFR or lower.
.Wednesday...Chance of Rain with MVFR or Lower.

&&

.MARINE...
Winds will be rather tranquil to start the night, but should
increase as the night progresses. Westerly flow increases
further by Saturday morning, and will issue a SCA for the ocean
waters east of Fire Island Inlet. Do expect seas to build to 5
ft for those eastern waters. Sub SCA conditions are expected
elsewhere.

SCA winds and seas may extend into the evening Saturday night,
but will not extend the hazard attm.

As high pressure passes south Sunday, winds back to the SW, and
will remain sub SCA.

Sub-SCA conditions are expected on the waters Monday into Tuesday
with a weak pressure gradient in place. An approaching low pressure
system Tuesday night and Wednesday should help build seas to SCA
levels on the ocean. Winds may also gust to around 20 kt on the
waters on Wednesday.

&&

.HYDROLOGY...
No hydrologic issues are expected.

&&

.EQUIPMENT...
NYC NOAA Weather Radio Station KWO35 (162.55 MHz) is still
operating at reduced power.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 6 AM to 6 PM EST Saturday for ANZ350-
     353.

&&

$$
SYNOPSIS...DS/PW
NEAR TERM...DS/PW
SHORT TERM...PW
LONG TERM...DS
AVIATION...IRD
MARINE...DS/PW
HYDROLOGY...DS/PW
EQUIPMENT...