Scientific Forecaster Discussion
Area forecast discussion
National Weather Service New York New York
359 PM EST Thursday Dec 25 2014
high pressure builds over the southeastern U.S. Through Saturday. A
cold front crosses the tri-state on Sunday. This front stalls out
well to the south of Long Island...as cold Canadian high pressure
builds in from the west throughout next week. Multiple lows pass
along the front for the early part of next week.
Near term /until 6 am Friday morning/...
broken-overcast pancake strato-cumulus that filled in this afternoon in the northwest
flow will mix out with loss of surface heating early this evening
with skies become clear.
Narre-tl along model soundings way underestimated this cloud
deck...but regardless...fully expect it to dissipate.
Otherwise...winds drop off quickly. Lows are blended NAM and GFS
MOS which had nearly no spread.
Short term /6 am Friday morning through Saturday/...
ridging aloft with above normal temperatures for the period.
Have forecast above NAM/GFS MOS based on nearly full sun and 552 dm
thickness for Saturday. Also...ensemble MOS from 00z..ekd MOS and
GFS parallel all suggesting 50-55. Looks like a great day to be
outside with light winds.
Long term /Saturday night through Thursday/...
overall...in the middle to upper levels...the ridge flattens going
into early next week. This leaves a zonal flow through midweek and
then a trend towards more of a trough across the northeast towards
the end of the week.
At the surface...a weak parent low moves through southeast Canada
and into the Canadian Maritimes Sunday...dragging a cold front
across. The front then stalls well south of Long Island going into
early next week with multiple areas of low pressure riding along
the front. One big feature to note next week is the very strong
high pressure moving into the northwest U.S. Likewise...a very
cold source of air will be moving into the northwest U.S. This
airmass gradually moves south and east through the week.
In terms of sensible weather...an increasing chance of
precipitation late Saturday night into Sunday associated with the
cold frontal passage. The amounts are light...with less than a
quarter of an inch likely. Much of it is forecast to fall during
the day Sunday into Sunday evening...so this allows most precipitation to
be rain showers especially near the coast. Interior will probably
have more chance of seeing some snow showers. The next precipitation is
only slight chance for Monday into possibly Monday evening. Colder
air in place here but amounts very light...a few hundredths of an
inch or less. The precipitation will be a mix of rain and snow...but
again with aforementioned light amounts...no accumulation of any
snow is forecast.
Temperatures overall a colder trend. Above normal highs
Sunday...near normal Monday...and below normal thereafter.
Aviation /20z Thursday through Tuesday/...
high pressure will continue to build in. Gusty west flow will gradually
diminish and broken VFR ceilings will also scatter after sunset.
..NY 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: high confidence wind forecast.
Klga fcster comments: high confidence wind forecast.
Kewr fcster comments: high confidence wind forecast.
Kteb fcster comments: high confidence wind forecast.
Khpn fcster comments: high confidence wind forecast.
Kisp fcster comments: high confidence wind forecast.
Outlook for 21z Friday through Tuesday...
Sunday...MVFR with chance of light rain.
Tuesday...low confidence VFR.
winds lower though the evening to Small Craft Advisory level by midnight. Waves on
the ocean that are currently as high as 8 feet will lower as well.
Waves on the eastern ocean waters could hold on to 5ft Small Craft Advisory
criteria a few hours after the Small Craft Advisory ends at 08z.
Sub-Small Craft Advisory conditions are anticipated on Friday into next week. The
only exception would be Sunday when 5 feet seas are forecast for the
ocean southeast of Montauk Point. There is uncertainty associated
with this and is dependent on how the cold front and parent low
trend with the response of the pressure gradient.
dry through Saturday night with no significant precipitation expected
from Sunday-Wednesday at this time.
Marine...Small Craft Advisory until midnight EST tonight for anz330-335-
Small Craft Advisory until 3 am EST Friday for anz350-353-355.