Scientific Forecaster Discussion
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Area forecast discussion
National Weather Service New York New York
152 am EDT Wed Mar 29 2017
low pressure will move southeast of Long Island tonight followed
by high pressure Wednesday through the day Thursday. Low
pressure approaching from the central states will impact the
region Thursday night into Saturday. High pressure will build in
on Sunday and Monday. Another disturbance may affect the area
Near term /until 6 am this morning/...
rain ending by 09z for extreme east sections.
Lows tonight in the lower 40s invof NYC, upper 30s most
elsewhere, and isolated mid 30s well inland.
Short term /6 am this morning through 6 PM Thursday/...
dry weather with a northwesterly breeze. Despite a cooler deep
layer air mass in place, sfc temperatures will actually be
warmer than Tuesday because of deep mixing. Mostly sunny skies
are progged, with some fair weather cu especially northwest of NYC.
Took the high side of guidance for temps, with mid/upper 50s
most places, and upper 40s/lower 50s in the higher elevations.
Guidance may be underdone by quite a bit on winds for Wed
evening as low pressure off to the east intensifies. Model
soundings out east show winds 35-40 kt atop the mixed layer.
Trended forecast higher, with gusts up to 25 lasting until about
Lows should be in the mid 30s invof NYC, lower 30s along the
coastlines and in the NYC suburbs, and 25-30 elsewhere.
Long term /Thursday night through Tuesday/...
high pressure builds in for Thursday, then moves offshore Thursday
night. High temperatures on Thursday will be in the low to mid 50s.
Clouds will increase Thursday night as warm advection begins to move
in ahead of an approaching low pressure system. Expect periods of
rain starting Thursday night into Saturday. Some lingering cold air
across the northern portions of our County Warning Area Thursday night may result in
a mix of snow and rain before warm advection increases. So have kept
the mix of snow and rain inland. High temperatures on Friday and
Saturday will be in the mid 40s to around 50.
Canadian high pressure builds in for late Saturday night into
Monday. Another disturbance may approach for Tuesday. Temperatures
during this period will be in the mid to upper 50s which is near
normal for this time of year.
Aviation /06z Wednesday through Sunday/...
low pressure departs this morning. A cold front pushes through
the region this afternoon...with high pressure building towards
the area tonight.
Conditions expected to gradually improve to VFR through
10z...then remain so through the taf period.
Northwest wind gusts of 15 to 20 kt develop between 11 and 13z...with
peak gusts to 20-25 kt this afternoon. Northwest gusts likely last for
Metro terminals into the start of the evening push. Gusts
diminish after 00 to 02z. Winds expected to be right of 310
magnetic through the period.
Outlook for 06z Thursday through Sunday...
late tonight...VFR. North-northwest winds.
Thursday...VFR. Am northwest winds backing west in PM.
Friday...MVFR/IFR conditions in rain developing in the am for
Metro terminals...with IFR in wintry mix possible for northern
terminals. MVFR/IFR conditions in rain likely in the afternoon.
Friday night and Saturday...MVFR/IFR in rain likely...gradual
improvement on Saturday. East/NE winds g20-30kt at coastal
advy level winds are also possible on the ocean this morning.
Given the marginal nature of these winds, have not yet issued
Small Craft Advisory.
Gusts 25-30 kt are likely on all waters Wed night as low
pressure to the east intensifies and high pressure builds from
the west. Some 5-ft seas could linger into early Thu morning.
Potential for Small Craft Advisory conditions increases from
late day Friday through Saturday night with increasing
southeasterly winds ahead of an approaching system.
no additional hydrologic concerns anticipated through tonight.
Additional rainfall of 1/2 inch to 1 inch is possible Thursday
night through Saturday. No hydrologic concerns anticipated.
an approaching low pressure system will likely bring some minor
coastal flood impacts to vulnerable coastal communities during
the Friday night high tide. Tidal departures of 1 to 1 1/2 ft
are needed to reach minor flood levels and 2 to 2 1/2 ft for
moderate flood levels during that time.