Scientific Forecaster Discussion

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Area forecast discussion 
National Weather Service New York New York
334 PM EDT Thursday Apr 17 2014

Synopsis...
high pressure slowly retreats to the northeast through Friday
night. Another area of high pressure system move slowly southeast
across the region Saturday through Monday. Low pressure will move
toward the area Tuesday then east of the area Wednesday followed
by another high pressure system.

&&

Near term /until 6 am Friday morning/...
main concern/question for tonight is how much cloud cover currently
over the ocean overspreads the region. Thinking is that cloud cover
will overspread at least coastal sections of the County Warning Area. Unsure just
how much further inland the clouds will travel.

As a result...thinking that temperatures will remain above
freezing...at least where the frost/freeze program has started. So
will convert the freeze watches to frost advisories...and keep the
frost advisories that are already in effect up.

There is a chance that frost may not even develop with the cloud
cover...however if clouds do not move in...or we get breaks in the
clouds frost will be possible.

Otherwise...expect a dry night with lows falling into the middle and
upper 30s. Of course temperatures may have to be nudged down a bit
of clouds take longer to move in. Went slightly above a mav/met
blend for temperatures tonight.

&&

Short term /6 am Friday morning through Friday night/...
weak high pressure will remain over the region Friday and Friday
night.

A northern stream shortwave will pass north of the region on Friday
and given lack of low level moisture...only expect to see increase
in middle-high clouds on Friday ahead of the shortwave.

Friday night will remain dry...however skies will remain mostly
cloudy with the shortwave passing nearby.

Mav/met guidance in good agreement and used. Temperatures on Friday
will reach the upper 40s and 50s...while Friday night falls into the
30s and lower 40s.

&&

Long term /Saturday through Thursday/...
dry weather is forecast Saturday through early Tuesday as a slow
moving Canadian high pressure system moves slowly across the region.

For Saturday...with the approach of high pressure and the advection
of strong subsidence...there will be an enhanced risk of fire spread
under full sun as humidities decrease to less than 30 percent and northwest
winds increase to 10-15 miles per hour during the afternoon. Temperatures are
forecast near normal values in the 60s.

For Sunday...a light onshore wind flow will develop as high pressure
moves off the coast causing afternoon high temperatures mainly in the 50s
across Long Island and southern CT...with low 60s north and west of
NYC.

Forecast models show a digging amplifying upper level short wave
approaching Wednesday causing cyclogenesis near the local area with
our next chance of rain...Tuesday afternoon through Wednesday. At
this time...this appears to mainly be a light to possibly moderate
rainfall of 1/4-1/2 inch.

&&

Aviation /20z Thursday through Tuesday/...
high pressure over northern New England moves towards the Canadian
Maritimes during the day today.

A sea breeze has developed and moved inland over NYC terminals.
After 02z winds should become east again and then diminish to 8-12
knots after 02z Friday.

Mainly VFR. Cloud remnants from sea breeze producing overcast conditions
across city terminals at or below 4thsd feet. Also watching areas of stratus
off Long Island and east of Nantucket for any signs of moving
inland. Will introduce MVFR ceilings in the tafs because of increasing
low level moisture after 02z-05z Friday but may be earlier depending
on trends. Ceilings should scour out late Friday morning.

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: low confidence on gusts..potential up to
20kt. Direction backing to 090-110 mag after 02z. Watching stratus
offshore and may amend for MVFR ceilings depending on trends.

Klga fcster comments: moderate confidence in wind speed/direction.
Winds 15-20 knots.

Kewr fcster comments: moderate confidence in wind speed/direction.
Wind direction backing to 090-110 mag after 02z.

Kteb fcster comments: moderate confidence in wind speed/direction.

Khpn fcster comments: moderate confidence in wind speed/direction.

Kisp fcster comments: moderate confidence in wind speed/direction.
Wind direction backing to 090-110 mag after 02z. Watching stratus
offshore and may amend for MVFR ceilings this afternoon.

Outlook for 12z Friday through Monday...
Friday-Friday night...MVFR ceilings scour out late Friday morning.
Saturday...MVFR conditions possible with low chance of -shra.
Saturday night-Sunday...VFR.
Monday...VFR.

&&

Marine...
a Small Craft Advisory remains in effect for the ocean waters where
gusts are reaching 25 knots and seas are around 6-7 feet. This small
craft remains in effect through Friday. Sub-Small Craft Advisory conditions are
expected on the remainder of the waters.

Winds and seas are forecast to fall below Small Craft Advisory levels Friday
night...however some lingering 5 feet seas may remain for the first
part of the night...especially across the eastern waters.

Winds and seas are forecast to remain below Small Craft Advisory
levels Saturday through Monday as high pressure moves slowly across
the coastal water.

South winds and seas will increase with the approach of low pressure
on Tuesday and possibly meet Small Craft Advisory levels Tuesday
afternoon. After a brief lull Tuesday night..northwest winds may
increase to Small Craft Advisory levels on Wednesday.



&&

Hydrology...
dry weather is forecast through Tuesday morning. There is a
chance for 1/4 - 1/2 inch rainfall associated with a low pressure
system Tuesday afternoon through the day Wednesday.



Note...minor flooding continues along the Connecticut River. For
additional information...please refer to the latest flood warnings
from National Weather Service Taunton Massachusetts.

&&

Okx watches/warnings/advisories...
CT...frost advisory from 1 am to 9 am EDT Friday for ctz009>012.
New York...frost advisory from 1 am to 9 am EDT Friday for nyz069>071-
078>081-177-179.
New Jersey...frost advisory from 1 am to 9 am EDT Friday for njz004-103>108.
Marine...Small Craft Advisory until 6 PM EDT Friday for anz350-353-355.

&&

$$
Synopsis...BC/gc
near term...British Columbia
short term...British Columbia
long term...gc
aviation...ird
marine...BC/gc
hydrology...BC/gc