Area Forecast Discussion
Issued by NWS Upton, NY

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FXUS61 KOKX 081013

Area Forecast Discussion
National Weather Service New York NY
513 AM EST Mon Mar 8 2021

High pressure will build over the area today will sink to the
south late today. A warm front will approach tonight and lift
through Tuesday morning, followed by a cold front Tuesday
evening. High pressure will again build in later Tuesday night
into Wednesday morning, then pass east later Wednesday into
Thursday. A cold front will slowly approach on Friday and
become stationary to the south by Saturday night. Unsettled
weather should continue into the weekend as low pressure
approaches from the Ohio valley.


Subsidence beneath the high will yield sunny skies, with high
temps a couple of degrees above MOS, with mid 40s in NE NJ,
lower 40s most elsewhere, and upper 30s across ern Long Island,
SE CT, and the higher elevations elsewhere.


Clouds should slowly increase with the approach of the warm
front tonight, becoming mostly cloudy after midnight. Low level
WAA may be sufficient to produce a few sprinkles across eastern
Long Island and SE CT late. The cloud cover should moderate low
temps as compared to last night, low temps reached at or before
midnight, then rising overnight tonight

After warm fropa, sunny skies expected, and with downslope flow
and mixing up to 875 mb, temps should be on the mild side, with
lower 60s in NE NJ and NYC, mid/upper 50s most elsewhere, and
lower 50s near the south shore of eastern Long Island and SE CT.
A back door cold front will be entering the area late in the day
as a lobe of high pressure moves from the Great Lakes into
northern PA and upstate NY, but with downslope NW flow (as
opposed to shallow NE flow often seen with marine back door
fronts) do not think temps will see much impact Tue night except
NW of NYC, with lows there in the mid/upper 20s, 30s most
elsewhere, and lower 40s in NYC.

Have forecast lower temps for Tue with a stronger subsidence
inversion in place as the high moves across, followed by onshore
flow as the high shifts east by afternoon. Highs on Wed should
be a fairly uniform lower 50s near the coast and mid 50s inland.


A SW return flow should develop by Thu, with a warming trend
through Friday.

CPC ensemble mean forecasts continue to show convergence on a
return to a positive NAO into the week. Guidance had held steady
with H8 temps of of 8-10 deg C Thu/Fri, with the high slower to
move east on Friday, thus maintaining SW flow for much of the
day. As a result, and if increased cloud cover doesn`t mitigate
temps too much, Friday looks to be another mild day before a
cool-down this weekend.

With SSTs in the lower 40s across the ocean waters, coupled with
the SW wind component, coastal areas will not get as warm as
the interior, and should remain in the mid 50s Thu/Fri. Record
high temps do not appear in jeopardy.

By Fri afternoon, the ridge shifts to the east of the area with
an upper trough passing over New England, and a sfc cold front
passing through Fri night, with precip chances Fri
afternoon/evening, albeit light. The front should then stall to
the south as zonal flow aloft commences, and a deeper closed low
takes shape across the Central Plains and moves east by
Sunday. Cold advection behind the front will drop temperatures
to more seasonable into Sunday.

The stalled boundary remains just south of the area on Sunday
as a surface low develops over the OH Valley, keeping the area
in clouds and light precipitation chances Sunday, especially
Sunday morning. Temperatures may be marginally cold enough
Sunday morning for a rain/snow mix across the interior, with
plenty of time, still, to work out those details.


VFR as high pressure builds to the south through this evening.
A weak cold front approaches Tonight.

NW-NNW winds around 10 kt through the morning push at NYC metro
terminals. Light NW and/or variable winds for outlying
terminals early this morning, then NW winds around 10 kt or less
then prevail after day break. Winds back to the W/SW by late
afternoon, then SW in the evening.

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

Timing of winds backing left of 310 magnetic in the afternoon
could be off by 1 to 2 hours.

.Monday Night through Tuesday...VFR. SW winds Mon Night veering
to W/Ne on Tue.
.Wednesday...VFR. Light winds NE/E winds AM, becoming SE PM.
.Wednesday Night...MVFR or lower in stratus possible for coastal
.Thursday...MVFR or lower AM coastal terminals, then VFR. S-SW
gusts 15-20 kt.
.Friday...Mainly VFR. Chance of showers. S-SW gusts 20-25 kt.

Detailed information, including hourly TAF wind component forecasts,
can be found at: http:/


SW flow as a warm front passes late tonight into Tue AM could
bring minimal SCA conds (both seas and wind gusts) to the ern
ocean waters during that time frame.

By Thu afternoon, strengthening SW flow ahead of an approaching
cold front will result in SCA conds on the ocean, with seas
building to 5 ft and gusts 25-30 kt. Ocean seas will remain
elevated into Saturday afternoon, with seas 5-7 ft and
occasional gusts to 30 kt before diminishing late Saturday.

Ocean seas could begin to build again on Sunday evening, with
occasional gusts to 25 kt.


No hydrologic concerns are expected.




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