Scientific Forecaster Discussion
fxus61 kokx 230432
Area forecast discussion
National Weather Service New York New York
1232 am EDT Sat Jun 23 2018
high pressure retreats to the northeast as warm front
approaches from the southwest through Saturday. The front lifts
to the north Sunday, followed by a cold front in the afternoon
to evening hours. High pressure then builds through mid week,
giving way to a warm front Wednesday night into Thursday.
Near term /until 6 am this morning/...
a surface ridge axis lifts to the north and east as the warm
front approaches. A few showers have developed across portions
of the area. Guidance continues to differ with the timing of
the onset of the measurable rain, but the emphasis continues to
be towards daybreak. The best chance of showers is across the
southwestern portion of the region, gradually spreading
northward. Much of eastern Long Island and southeast Connecticut
should remain dry through the night due to the proximity of the
ridging and drier low level air. Instability is weak and will
therefore leave out the mention of any thunder overnight.
Lows will be near seasonable levels in the lower 60s with
Short term /6 am this morning through 6 PM Sunday/...
showers and isolated thunderstorms are likely in the morning
with the best thermal forcing ahead of the filling upper low
moving into the eastern Great Lakes. Warm front continues to
approach with an easterly flow through the day, veering around
to the southeast toward evening. The activity will likely
dissipate in coverage late morning and into the afternoon with
the potential for a long break. However, the associated upper
trough will move across the area in conjunction with the warm
front toward the late afternoon/early evening. This combined
with increasing elevated instability will result in another
period of widespread showers and scattered thunderstorms.
Locally heavy downpours will also be possible with precipitable
water values approaching 2 inches.
The warm front may get up as far as Long Island Saturday night
with the showers exiting late in the evening.
Highs on Saturday will only be in the lower 70s due to cloud
cover, rain, and easterly flow.
Lows Saturday will be mild with the warm front in close
There is a moderate risk of rip currents at Atlantic Ocean
beaches on Saturday.
Long term /Sunday night through Friday/...
a weak low pressure system shifts through the northeast on
Sunday with a cold front moving through during the afternoon to
evening hours. Expecting at least scattered showers and
thunderstorms during this period with the highest overall
chances occurring north of the city. High temperatures will be
High pressure builds in during Monday, but with a cyclonic flow
aloft there could be a shower or two across southeast CT. Partly
cloudy with near normal temperatures. The high pressure center
moves through on Tuesday with sunny conditions and highs close
The high will be to our east on Wednesday, and a return SW flow
will bring warmer and more humid conditions. It appears the
daytime hours for most areas will be dry as showers ahead of an
approaching warm front remain to the west. The warm front moves
through, then a cold front slowly approaches Thursday into
Friday. Timing of the cold front is not certain, so will go with
slight chance to chance pops Wednesday night through Friday.
Rising temperatures aloft will allow for highs in the 90s for
the city and some inland areas Thursday and Friday. If the cloud
cover is lower then currently anticipated, then highs could be
a even a few degrees higher than what's in the forecast.
Aviation /06z Saturday through Wednesday/...
high pressure centered near Nova Scotia and extending into New
England will drift east through Saturday as a warm front and low
pressure approach. The warm front will likely remain to the
south of the terminals through 00z Sunday. There is a low chance
the front moves through late in the forecast period.
VFR with periods of MVFR ceilings as stratus moves through the
terminals. A few light showers will be possible. Late tonight
light showers will become widespread along with MVFR
conditions, lowering to IFR and possibly LIFR toward Saturday
morning. A brief improvement to MVFR is possible during Saturday
A rumble of thunder will be possible with the showers Saturday,
with the best chance of thunder late in the afternoon into the
East wind backs to east to NE overnight, winds then remain NE to east
through Saturday until the warm front approaches late in the
day. Winds will be 10 to 15 knots along the coast and 5 to 10 knots
Outlook for 00z Sunday through Wednesday...
Saturday night...MVFR to IFR, possibly lower conds. Showers
likely, possibly a tstm.
Sunday...chance of MVFR or lower conds in mainly late
Wednesday...mostly VFR. Chance of showers/tstms with MVFR or
lower conds mainly at kswf.
a Small Craft Advisory has been issued for the ocean waters due to an easterly
flow building seas to around 5 ft. Occasional gusts up to 25 kt
will also be possible. The gradient slacken in the afternoon
with the approach of a warm front. Seas may return to 5 ft or a
bit higher Saturday night with a building southerly swell.
Sustained winds from Sunday through Tuesday are expected to
remain below 15 kt with any gusts below 25 kt on all waters. A
lingering swell will however maintain Small Craft Advisory conds on the ocean
waters Sunday through Monday morning. For Wednesday, a
strengthening SW wind brings Small Craft Advisory conds back to the ocean waters
and perhaps some of the other area waters as well.
there could be a few locally heavy downpours late tonight
through Sunday, but no hydrologic impacts are anticipated.
Rainfall totals late tonight through Saturday night will average
around half an inch.
NYC National oceanic and atmospheric administration weather radio station kwo-35 (162.55 mhz) remains off
the air for an extended period of time.
Marine...Small Craft Advisory from 6 am this morning to 2 PM EDT this
afternoon for anz350-353-355.