Scientific Forecaster Discussion

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Area forecast discussion 
National Weather Service New York New York
424 am EDT Wednesday Apr 16 2014

Synopsis...
high pressure builds over the region today and drifts northeast
tonight and Thursday. High pressure remains over the northeast
Friday into the weekend as multiple low pressure areas ride a
stalled front to the east. The high finally pushes off to the
east beginning of next week with low pressure returning for middle
week.

&&

Near term /until 6 PM this evening/...
a freeze warning remains in effect early this morning as cold air
moves in behind a strong cold front and temperatures fall below
freezing. Record lows are possible this morning. See climate
section below. The last of the wintry mix of precipitation was
moving out of New London County and the Twin Forks at 08z.

Ridge builds into the region through today. Gusty northwest flow
will be diminishing through this morning and into early afternoon
as cold advection weakens and winds aloft diminish...with mixing
to around 900 mb. Temperatures will be well below normal with
highs in the 40s. Normal highs are around 60.

&&

Short term /6 PM this evening through 6 PM Thursday/...
ridge remains across the region tonight into Thursday as surface
high remains to the northeast and ridges down along the eastern
slopes of the Appalachians. The cold air mass will remain in place
tonight into Thursday. Temperatures will again approach of fall
below freezing across the area. No records are expected to be
broken tonight unless temperatures fall lower than forecast as
skies will be clear and winds will initially be light in the
evening. Then with the high building to the northeast winds will
increase from the northeast bringing in cooler northern Atlantic
air later tonight into Thursday. Thursdays highs will only be a
couple of degrees higher than todays highs.

&&

Long term /Thursday night through Tuesday/...
initially dry weather Thursday night as the center of the surface
high pushes north and east while the area remains under broad
ridging. Global models suggest weak low pressure development along a
stalled front offshore that could bring light precipitation into the area by
Friday morning...then slowly spreading to the north Friday night into
Sat. 00z GFS a bit more pronounced in the development of the low and
the resulting precipitation with the suggestion of interaction between a
southern stream shortwave with the northern stream trough/closed
low. All other models keep a distinct separation between the two so
went ahead and maintained the slight chance/chance probability of precipitation for now with
uncertainty on just how widespread the precipitation occurs. An approaching
front Sat could trigger scattered rain showers as the upper level trough
swings through. Things then dry out for Sat night-Sunday with zonal flow
setting up aloft and high pressure building south into the
northeast.

Some model discrepancies in the handling of the next low pressure
system next week. 00z GFS lingers the high over the northeast then
brings a weak front in from the west while European model (ecmwf) and CMC both
develop a decent area of low pressure off coastal Florida and track
to the north along a stalled front. Flow aloft suggests more of a
GFS solution in this case...so sided more to a GFS/wpc
blend...bringing probability of precipitation in Monday night and keeping them in place
through Tuesday with the front remaining in the vicinity and
multiple shortwaves riding the flow aloft.

Cooler weather in store for the tri state area Thursday night/Friday as
the positioning of the high keeps a cooler easterly/northeasterly
flow despite warm air advection aloft. However...as winds shift for the
weekend...expect temperatures to warm back to near normal. Overall...temperatures
expected to remain warm enough with timing of precipitation to keep precipitation in
the form of rain. Thursday night will be the coldest night in the
extended...though currently not expecting frost/freeze issues in
areas currently in the growing season.

&&

Aviation /08z Wednesday through Sunday/...
cold front continues to work its way across the terminals...and
then high pressure builds over the area into this evening.

Conds will improve from west to east from MVFR/IFR to VFR as the
back edge of the precipitation works its way across the region. By
08z...conds should be VFR throughout.

Main issue will be the winds. Northwest winds...320-350 true...will range
from 15-20 knots with 25-30 knots gusts through this morning. Winds
gradually diminish during the day as winds veer to the north. Wind
gusts should abate by late afternoon as the winds continue to veer
to the north.

Outlook for 06z Thursday through Sunday...
Wednesday night-Thursday...VFR. East wind g around 20kt possible.
Thursday night-Friday night...VFR.
Saturday...possible MVFR conditions with low chance of -shra. West-northwest
wind g25-30kt possible.
Saturday night-Sunday...VFR

&&

Marine...
wind gusts have diminished below gale force on all the waters and
will remain below gale as winds aloft slowly diminish through the
morning hours. Small craft gusts will continue into the afternoon.
Then seas on the ocean remain at small craft levels tonight into
at least Thursday with an easterly flow developing and increasing.

Brief period of 25 knots gusts on the ocean waters Thursday night...with
winds diminishing heading into Friday as high pressure builds over the
waters. Winds remain sub-Small Craft Advisory conditions through the beginning of
next week. Seas remain elevated on the ocean during the
period...finally subsiding by late Sat. Seas then expected to remain
below 5 feet into next week.

&&

Hydrology...
dry today through Thursday. Then no significant precipitation
that would have hydrologic impacts is currently forecasted
Thursday night through the middle of the next week.

Note...minor flooding continues along the Connecticut River.
Additional heavy rainfall will likely cause water levels to continue
to rise through the week...with potential for moderate flood levels
to be reached. Monitor the latest flood warnings from National Weather Service Taunton Massachusetts.

No significant precipitation is expected from Thursday into early
next week.

&&

Climate...
record lows for this morning April 16:

Ewr - 26 in 1943 forecast low - 29
bdr - 29 in 1981 forecast low - 29
NYC - 29 in 1928 forecast low - 29
LGA - 31 in 1943 forecast low - 29
JFK - 33 in 1962 forecast low - 30
isp - 32 in 2008 forecast low - 30

&&

Okx watches/warnings/advisories...
CT...freeze warning until 10 am EDT this morning for ctz009>012.
New York...freeze warning until 10 am EDT this morning for nyz069>075-
078>081-176>179.
New Jersey...freeze warning until 10 am EDT this morning for njz004-006-
103>108.
Marine...Small Craft Advisory until 2 PM EDT this afternoon for anz330-
335-338-340-345.
Small Craft Advisory until 6 PM EDT Thursday for anz350-353-
355.

&&

$$
Synopsis...Sears/met
near term...met
short term...met
long term...mas
aviation...mps
marine...Sears/met
hydrology...Sears/met
climate...