Scientific Forecaster Discussion
fxus61 kokx 300538
Area forecast discussion
National Weather Service New York New York
138 am EDT Thu Mar 30 2017
high pressure will remain over the region through Thursday. Low
pressure will impact the area Thursday night through Saturday.
High pressure builds in for Sunday through Monday night.
Another area of low pressure affects the region Tuesday. High
pressure builds back on Wednesday.
Near term /until 6 am this morning/...
high pressure continues to build to the north overnight.
Scattered clouds, and continued winds late this evening and
possibly into the overnight will have an impact on overnight
lows. Assuming north winds of at least 5 kt continue, ideal
radiational cooling may not occur. Raised lows slightly in
spots. Overnight lows will range from the upper 30s to the upper
Short term /6 am this morning through 6 PM Friday/...
high pressure drifts across the forecast area on Thursday,
resulting in fair weather and light winds. Expect mid and high
clouds to move in from the west during the afternoon and
evening. A blend of the guidance, which was in good agreement,
was used for temperatures.
Clouds continue to thicken and lower Thursday night as low
pressure approaches the region. Pops gradually increase
overnight. Will cap pops at high chance for now. Precipitation
will generally be plain rain, however a wintry mix may be
possible across the lower Hudson Valley and Connecticut.
Temperatures on Thursday will only reach the upper 40s and
lower 50s. Lows Thursday night will fall into the 30s.
Long term /Friday night through Wednesday/...
low pressure system will track east on Friday. As this storm
approaches, precipitation will spread across the area from west to
east. Rain may come down moderate to heavy at times Friday into
Friday night as a secondary low develops off the mid Atlantic
coast. This storm may produce anywhere between 1 to 1.5 inches
of rainfall from Friday into Saturday morning. While there could
be some urban and poor drainage nuisance flooding, impacts on
rivers and streams is not expected.
After some lingering showers Saturday morning, surface high pressure
builds in thereafter, keeping the area dry through the rest of the
weekend into Monday. High pressure moves offshore Monday night,
allowing for another low to affect the area Tuesday.
Temperatures during the long term will be seasonable, with the
exception of Friday and Saturday.
Aviation /06z Thursday through Monday/...
VFR conditions are expected through much of the taf period as
high pressure builds in through Thursday. MVFR conditions move
in at the 30 hr taf sites at the end of the taf period as low
pressure approaches Thursday night. Light rain is expected after
09z, except a mix of rain and ice pellets for kswf.
Gusts have, for the most part, died off. There may be occasional
gusts to 20 kt, mainly for the city terminals, over the next
hour or two, but they should not be prevailing. Sustained winds
diminish to 10 kt or less overnight into Thursday morning. Sea
breezes develop Thursday afternoon with wind speeds remaining
below 10 kt. Some interior terminals may become light and
variable for Thursday.
Sea breeze timing Thursday could be off by 1-2 hours.
Outlook for 06z Friday through Monday...
Thursday night...mainly VFR, chance of rain/snow mix inland and
rain near coast, highest chances overnight.
Friday...MVFR/IFR conditions developing in rain for Metro
terminals, with IFR in wintry mix possible for northern
terminals in the morning. MVFR/IFR conditions in rain in the
afternoon. Southeast winds g20-25 knots at the coast.
Friday night and Saturday...MVFR/IFR in rain with gradual
improvement by Saturday afternoon/evening. East/NE winds g20-30kt
at coastal terminals.
northerly winds continue overnight as low pressure tracks out
to sea and high pressure builds into the region. Winds
overnight are expected to generally remain below Small Craft Advisory levels,
however a few isolated gusts to 25 kt may be possible,
especially on the eastern waters. Winds and seas will remain
below small craft conditions through Thursday night.
Winds should remain below 25 kt through Friday morning. An
approaching frontal system will increase the pressure gradient
across the waters and bring wind gusts along the ocean waters to 25
kt to 30 kt Friday afternoon into Saturday. Peconic and gardiner's
bays may see gusts 25 kt to 30 kt late Friday night into Saturday,
while the back bays may see 25 kt gusts Friday night. Winds diminish
Saturday night, and remain below Small Craft Advisory criteria for the rest of the
Waves build to 5 to 8 ft on the ocean Friday night into Saturday
morning, then diminish Saturday night, but should remain above 5 ft
through Sunday morning. Thereafter, waves remain below 5 ft through
the rest of the long term.
between 1 and 1.5 inches of quantitative precipitation forecast is possible from Thursday night
through Saturday morning. While there could be some urban and poor
drainage nuisance flooding, impacts on rivers and streams is not
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.
short term...British Columbia