Scientific Forecaster Discussion

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Area forecast discussion 
National Weather Service New York New York
518 am EDT Sat Apr 19 2014

Synopsis...
high pressure builds east today...and then settles over the Gulf
of Maine for the start of the new week. A complex storm system
will impact the tri-state from Tuesday into Wednesday. High
pressure then builds towards...then over the region into Friday.

&&

Near term /until 6 PM this evening/...
a weak cold front continues to move across the region early this
morning. Behind the front...high pressure centered over the Great
Lakes will build east today. With nearly zonal flow aloft and
ridging at the surface...will expect northerly winds to increase to
around 15 miles per hour with 20-25 miles per hour gusts. Skies clear out later this
morning...giving to abundant sunshine this afternoon.

Maximum temperatures will top off in the low to middle 60s. A blend of met/mav
MOS guidance was used.

&&

Short term /6 PM this evening through Monday night/...
quiet conditions on tap for the start of the new week as high pressure
moves into eastern Canada on Sunday...and then settles over the
Gulf of Maine Monday before moving offshore Monday night.

Clear skies and light winds tonight and Sunday night will result
in excellent radiational cooling conditions...allowing lows to drop
into the upper 20s to around 30 across outlying areas of the lower
Hudson Valley and interior portions of southern CT...as well as
The Pine Barrens of Long Island. Elsewhere...lows drop into the
low to middle 40s in/around NYC...and in the middle to upper 30s
elsewhere.

As the high tracks east...winds shift to a cooler easterly flow on
Sunday...with highs almost 10 degrees cooler than today in most
spots. Highs top off in the middle to upper 50s near the coast...and
in the low 60s inland. Southerly flow keeps temperatures in the 50s for
coastal areas on Monday...but the interior will be able to warm
into the middle/upper 60s.

Clouds increase from west to east late Monday night as a cold
front approaches from the west. Lows drop into the 40s.

&&

Long term /Tuesday through Friday/...
a full latitude trough develops in response to phasing between the
northern and southern streams. This developing trough moves into
the eastern Great Lakes and central Appalachians Tuesday...to the
East Coast Tuesday night...and then slowly exits to the east
Wednesday...as it begins to take on a negative tilt.

There appears to be a solid consensus amongst the models that
Tuesday morning will be dry...then showers will slowly build in
from northwest to southeast Tuesday afternoon and evening. The showers then will
taper of from northwest to southeast later Tuesday night. Given consensus...have
increased probability of precipitation to likely throughout Tuesday night. Do have a
slight chance (chance far NE zones) of showers Wednesday morning
in response to core of the middle-upper trough passing over the area.

Deep layered ridging then builds in from Wednesday night through
Thursday night then slides to the east on Friday. For now have
gone with a dry forecast in this time frame due to the influence
of the ridge. It should be noted that the 00z European model (ecmwf) has sped up a
northern stream trough compared to the 12z European model (ecmwf) and remainder of
the 00z guidance...and would no bring some rain in on
Friday...while all the latter guidance has Friday dry. If the
trends in the European model (ecmwf) continue...then probability of precipitation would have to be added to
the forecast for Friday.

For temperatures in the extended used a blend of
mex/men/ekd/ece/ecm/wpc guidance. Temperatures Tuesday should be
above normal ahead of the slow moving cold front...with the
possibility that areas from NYC on west could reach or just go past
the 70 degree mark. Below normal temperatures return for
Wednesday...raise to near normal levels on Thursday...then should
be above normal on Friday. Note...depending on the exact extent of
cloud cover and precipitation on Wednesday...there is some
potential that it could be a bit cooler than forecast. For
Friday...if the 00z European model (ecmwf) is correct...then highs could be at
least 5-10 degrees cooler than currently forecast.

&&

Aviation /09z Saturday through Wednesday/...
a weakening cold front crosses the area into this
afternoon...followed by high pressure building down from south
central Canada into tonight.

VFR through the taf period.

Winds have been slower to veer to the northwest from the SW than
expected...so have delayed winds getting to the left of 300
true/310 magnetic until 12-13z. Appears winds should gust to
around 15-20kt from late morning into middle afternoon. Gusts abate
by early evening as winds veer to the north then north-northeast-NE and speeds
fall below 10 knots.

Outlook for 06z Sunday through Wednesday...
late Saturday night-Tuesday morning...VFR.
Tuesday afternoon-Wednesday morning...rain showers likely...with MVFR or
lower possible. Northwest-north winds g202-5kt possible late Tuesday
night/Wednesday morning.
Wednesday afternoon...most likely VFR...with low chance MVFR.
Northwest-north wind g 20-25kt possible.

&&

Marine...
Small Craft Advisory for hazardous seas remains in effect for ocean waters until 6
am this morning as seas continue to average right around 5
feet...but are slowly subsiding.

Otherwise...conditions should remain just below Small Craft Advisory criteria this
weekend. Occasional wind gusts to 25 knots are possible this afternoon...
especially on the sound and eastern ocean waters.

Tranquil conditions then expected into Monday night.

Sub-small craft conditions are forecast Tuesday with a relatively
relaxed gradient over the waters. There is a chance for gusts to
Small Craft Advisory levels on all waters from Tuesday night into Wednesday.

&&

Fire weather...
a dry day today with gusty north-northwest flow will result in min relative humidity values
between 20-30 percent along with wind gusts of 20-25 miles per hour at times.
This will enhance fire spread potential. A Special Weather
Statement will be issued to highlight this concern.

&&

Hydrology...
no significant precipitation is expected through the start of the
new week.

There is a chance for significant rainfall from late Tuesday into
Wednesday morning. However...the probability of this appears lower
than it did yesterday. At this time...there is too much
uncertainty to specify exact amounts or any potential impacts - if
any.

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...none.
New York...none.
New Jersey...none.
Marine...Small Craft Advisory for hazardous seas until 6 am EDT early
this morning for anz350-353-355.

&&

$$
Synopsis...maloit/mps
near term...mps
short term...mps
long term...maloit
aviation...maloit
marine...maloit/mps
fire weather...
hydrology...maloit/mps