Scientific Forecaster Discussion
Area forecast discussion
National Weather Service New York New York
747 PM EDT Wednesday Jun 3 2015
high pressure over New England moves off the New England coast
tonight and Thursday. High pressure moves off the New England
coast tonight and Thursday. Weak low pressure passes off to the
south and east Friday into Friday night...while a weakening cold
front passes through by daybreak Saturday. High pressure will then
build across the area over the weekend. A frontal system will
affect the area for the start of the next week.
Near term /until 6 am Thursday morning/...
overall...main adjustment was to increase clouds across the
forecast region for tonight. BUFKIT model soundings show increase
in strato cumulus for tonight and this is being observed from surface
and satellite data moving northward across central New Jersey and
into some portions of the local region. Temperatures were a few
degrees less than in the forecast database this evening. Made
some slight adjustments for these but kept min temperatures the same as
before. The increase in clouds will slow down the temperature
cooling later tonight.
High pressure remains north of the region tonight...while a frontal
boundary remains south of the area. As a result...expect an easterly
flow across the region. Low pressure will develop off the southeast
coast and slowly move northward. As it does...the frontal boundary
south of the region will lift northward...allowing clouds to move
back into the region. Despite the increasing cloud cover...conditions
will remain dry. Overnight lows will drop into the upper 40s and
50s. Followed a mav/met blend.
Short term /6 am Thursday morning through Thursday night/...
high pressure north of the region gradually moves off the New
England coast through the short term. Meanwhile...low pressure south
of the region slowly lifts to the north. The County Warning Area will remain in
between these two systems...resulting in a continued easterly flow.
It will remain mostly cloudy to overcast through the period. Dry
conditions are expected to continue into Thursday...however will
continue to mention low chance probability of precipitation Thursday night.
Temperatures could be tricky Thursday depending on how far north the
front lifts and how much cloud cover we have. For now...highs on
Thursday are expected to climb into the middle and upper 60s.
Thursday night...lows fall into the lower and middle 50s.
There is a moderate risk of rip currents at the Atlantic Ocean
Long term /Friday through Wednesday/...
westerlies for the most part have retreated north to along the
U.S./Canadian border with a weak southern branch closed low moving
off the middle Atlantic coast at the start of the period. Pattern
amplifies early next week with a trough digging across eastern
Canada...the Great Lakes...and northeast. There are some significant
timing issues...in particular...with the frontal system Monday into
Wednesday. The 12z GFS is on the slow end...while the European model (ecmwf) is at the
faster end of the envelope. The ggem supports the European model (ecmwf)...while the
gfes supports the operational run. Preference at this time is to
split the difference until better run to run continuity develops.
At the surface...weak low pressure will pass south and east on Friday into
Friday night...with a dissipating cold front washing out across the
area by daybreak Sat. There is a low chance of showers during this
time due to weak forcing and a fairly stable airmass. High pressure
follows for the remainder of the weekend. A frontal system then
approaches Monday into Tuesday night...with a chance of showers and
thunderstorms. Once again...there is some uncertainty amongst the
global models with the timing of this system. The best chance for
organized convection looks to be Tuesday ahead of the cold front...with
increasing instability and deep-layer shear.
Temperatures during the period will be at or just above climatology...with the
warmest days looking to be Sat and Tuesday.
Aviation /00z Thursday through Monday/...
as high pressure moves slowly east off the New England coast...low
pressure will move northeast passing southeast of Long Island.
Winds...southeast winds 5-10 knots will gradually become east-NE after 06z then
east-southeast 8-12 knots after 13z Thursday.
Ceilings...around 3500 feet across central New Jersey will mv north as MVFR ceilings
around 1200 feet across eastern Long Island mv west. There is a low
chance of MVFR ceilings 1000-1500 feet after 05z across the NYC metropolitan.
Chance of rain...will increase from S to north during the day Thursday with no
restrictions to visibility anticipated.
New York metropolitan enhanced aviation weather support...
Detailed information...including hourly taf wind component forecasts can
be found at: http:/www.Erh.NOAA.Gov/zny/n90 (lower case)
Kjfk fcster comments: potential for MVFR ceilings developing after midnight.
Klga fcster comments: potential for MVFR ceilings developing after midnight.
Kewr fcster comments: potential for MVFR ceilings developing after midnight.
Kteb fcster comments: potential for MVFR ceilings developing after midnight.
Khpn fcster comments: potential for MVFR ceilings developing after midnight.
Kisp fcster comments: potential for MVFR ceilings developing by 03z.
Outlook for 12z Thursday through Sunday...
Thursday afternoon...mainly VFR.
Thursday night-Friday morning...MVFR possible with areas of rain
developing mainly at southern terminals.
Friday afternoon-Saturday morning...spotty MVFR possible with a
slight chance of showers/tstms. North winds g 15-20 knots possible Saturday
Saturday afternoon-Sunday night...VFR. North winds g 15-20 knots possible
Monday...MVFR or lower possible in any showers/thunderstorms.
high pressure remains north of the forecast waters tonight...then
moves off the New England coast Thursday and Thursday night.
Meanwhile...a weak low off the southeast coast slowly tracks
northward. Winds will remain from the east-northeast through
Thursday night and strengthen a bit on Thursday with the low moving
closer to the high. Winds and seas for the most part will remain
below small craft levels...however there could be a brief period of
5 feet seas Thursday afternoon. Also...a few occasional gusts to 25 knots
will be possible. Because the conditions look marginal...will hold
off on any small craft advisories for now.
Sub-Small Craft Advisory conditions expected through Sunday night. Waves build on a
southerly flow on Monday to above 5 feet as a cold front approaches
from the west.
no significant precipitation is expected through the weekend.
Widespread significant precipitation is possible starting Monday
with an approaching frontal system.
short term...British Columbia