Area Forecast Discussion
Issued by NWS Upton, NY-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KOKX 280835
Area Forecast Discussion
National Weather Service New York NY
435 AM EDT SAT MAY 28 2016
Bermuda high pressure will remain across the region through
the weekend. A cold front passes through the area late Monday
into Tuesday. High pressure returns for the middle of the week. A
cold front approaches from the west on Friday.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --An unseasonably warm day is in store for Saturday as deep ridging
builds aloft and Bermuda high pressure remains over the area.
Temperatures will approach 90 degrees across NE NJ and the
interior Lower Hudson Valley. Southerly winds will increase this
afternoon which will likely prevent temperatures in the city and
interior southern CT from warming much above the middle to upper
80s. Near the coast, highs will reach the upper 70s and lower 80s.
Convection chances appear lower than on Friday as there is not much
of a trigger with deeper ridging over the area. Instability will be
largest away from the stronger sea breezes north and west of the
city so this is where slight chance to chance pops exist for a
shower or storm. Best chance appears to lie across the NW interior
which ends up closest to surface boundary to the north of the area.
There is a moderate risk for the meteorological enhancement of rip
current formation at Atlantic Beaches today.
-- End Changed Discussion --
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
Any convection that develops should dissipate with loss of daytime
heating this evening. Backdoor cold front to the north will not
make much progress south and will likely stall well to the north
and east. Do not see much of a trigger or support for any
shower/storms overnight so the forecast is dry after midnight.
Low temperatures will be close to ten degrees above normal in the
Ridging begins to break down aloft on Sunday as heights fall
through the day with an approaching shortwave from the west.
Forcing is weak during the day so will once again show best
chances for any convection north and west of the city where better
instability will reside. Moisture will be on the increase however
as southerly flow off the western Atlantic strengthens. Highs
should end up a few degrees cooler than Saturday with the stronger
southerly flow and a few more clouds in the afternoon.
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
The main focus of the long term is Sunday night into Monday as the
ridge continues to break down and shift east. A shortwave
approaches from the west Sunday night in combination with an
increasing southerly flow which will advect tropical moisture from
remnants of tropical system off the Carolinas. Precipitable
waters are progged to be near 2 inches and these values are close
to the maximum observed precipitable water for May 30 per SPC
Sounding Climatology. The region will also lie in the favorable
right entrance region of a 80-100 kt upper level jet and low level
winds will also increase.
Pattern recognition with all of these ingredients shows the
potential for a predecessor rain event during this time frame with
locally heavy rainfall. The biggest uncertainty lies in where
heaviest bands of rain will set up. Even with this uncertainty,
have increased pops to categorical late Sunday night into Monday
as all of the aforementioned ingredients come together. Have also
included mention of thunder, although instability will likely be
on the low side. See hydro section for more details.
The shortwave axis moves across the area late Monday into Monday
night which will push the deep moisture plume to the east ending
the rain. Cold front will likely be slower to move through the
area and may not completely clear the area until Tuesday.
Deep ridging builds over the northeast Wednesday and Thursday.
Surface high pressure should move across New England on Wednesday
and then set up over the Canadian Maritimes on Thursday. A cold
front approaches from the west in conjunction with a shortwave
trough. The trend in temperatures should be closer to seasonal
norms for the middle and end of next week.
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --High pressure will remain off the Mid-Atlantic coast into tonight.
Mainly VFR through the TAF period. There is a chance for mvfr
fog/haze early this morning at KSWF and KHPN. There is also the
chance for isolated-scattered showers/thunderstorms across the
Lower Hudson Valley and interior S CT, with the best chance at
KSWF - so have VCSH there this afternoon.
Winds generally light and variable or SW at under 10 kt this
morning. Should see 10-15kt seabreezes from late morning to mid
afternoon, except at KSWF where wsw flow at under 10 kt should
develop by mid afternoon. Winds become light and variable this
evening at all but KJFK/KLGA/KEWR/KISP, where winds become ssw-sw
at under 10kt.
.OUTLOOK FOR 06Z Sunday through Wednesday...
.Late Saturday night-Sunday...Mainly VFR with afternoon sea
breezes. Chance of MVFR or lower in any isolated to scattered
afternoon and evening showers/thunderstorms mainly at Lower Hudson
Valley/interior S CT terminals.
.Sunday night-Monday...MVFR or lower likely. Showers/thunderstorms
could produce locally heavy rainfall. LLWS possible at southern
terminals Sunday night.
.Monday night-Tuesday night...Becoming VFR Monday Night.
.Wednesday...VFR with afternoon seabreezes.
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A weak to moderate pressure gradient over the region through
Wednesday will keep sustained winds to 15 kt or less over the waters
around Long Island. With no significant swells currently forecast
during this time frame, seas should remain below Small Craft levels
No significant widespread precipitation is expected through Sunday.
Rainfall amounts around one to one and a half inches are possible Sunday
night into Monday with locally higher amounts. Minor urban or
poor drainage flooding is possible from the heaviest rainfall.