Scientific Forecaster Discussion
Area forecast discussion
National Weather Service New York New York
426 am EDT Monday Mar 10 2014
a couple of areas of low pressure pass to the north this morning
and tonight...followed by weak high pressure on Tuesday. A low
pressure system passes through the region around the middle of
the week...with high pressure building in behind it. A cold front
then passes through the area on Saturday.
Near term /until 6 PM this evening/...
weak low pressure diving southeast across NE England this morning will
continue to weaken as it encounters a zonal to slightly ridging
pattern aloft. There will still be enough lift and available
moisture for low chances of precipitation. Thermal profiles support snow for
the most part...but a mix of rain and snow would be expected for
southern sections. Otherwise...dry for the afternoon. Based on
mixing to 925mb and anticipated afternoon cloud cover...a mav/NAM
MOS blend looked good. Highs around normal levels.
Short term /6 PM this evening through 6 PM Tuesday/...
another area of low pressure will cross New England tonight. This
one will be stronger than the one moving by this morning...however
the best lift will be displaced farther north and east this
time...and moisture won't be as deep either. Will therefore go with
a dry forecast.
Cold advection behind this system looks to be minimal and short
lived. So on Tuesday...925mb temperatures actually warm up a couple of
degrees. This will bring US a warmer day under partial sunshine.
Again...a mav/NAM MOS blend was used...which pushes our highs
Long term /Tuesday night through Sunday/...
the focus of the long term continues to be the middle-week system...as
an amplifying wave aloft approaches the region and induces cyclogenesis
from the Ohio Valley to the New England coastline. As was mentioned
by previous forecast...confidence continues to grow in the track of
the system...but nailing down the specifics about thermal
profiles...and subsequent p-types...will remain a challenge.
The 500 mb wave currently just off the Pacific northwest coastline will be passing
across the plains/Midwest to begin the long term period. At the same
time...a shortwave in the polar jet will be diving southeast out of
Manitoba. The interaction and phasing between the two will set the
stage for deepening surface low pressure that looks to pass
near/just south of our area Wednesday night. Still some differences
in positioning and timing...but 00z European model (ecmwf)/GFS/ggem are showing
better agreement with the general features...as opposed to the last
few days. Based on trends with the 00z suite...did not make dramatic
changes to the previous forecast. Event looks to start out with a
wintry mix across far northwest areas and rain everywhere
else...eventually transitioning to all rain during the day
Wednesday...before changing to snow from northwest to southeast as the low departs
and cold air rapidly filters into the area. Regardless...at present
the most likely track of the system is not overly favorable for
significant snow across most of the area. Still...this system is
predicated off a complex interaction of waves aloft and small
adjustments to the track of the low pressure system could result in
notable changes to the low-level thermal profile...especially on
Wednesday for northwest areas.
High pressure builds in behind the departing low on Thursday. Strong
cold air advection will likely keep temperatures below freezing area wide...around 15-20
degrees below normal for this time of year. Additionally...the
strong pressure gradient will result in blustery conditions
Wednesday night into Thursday.
SW flow will develop on Friday...helping warm temperatures back up through
Saturday. Slight chances for some light precipitation on Saturday with a
passing cold front...but looks to be relatively insignificant at
Aviation /09z Monday through Friday/...
a weakening clipper system will dissipate to the north of the
region this morning...with a stronger clipper tracking to the
Mainly VFR through the taf period. A period of light snow showers
with MVFR conds possible between 09z and 14z...mainly for northern
terminals. This aft/eve...only an isolated rain shower threat with
brief MVFR conds.
SW winds today...becoming west behind a frontal passage after 06z
tonight. Winds generally under 10 knots.
..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)
Kewr fcster comments: no unscheduled amendments expected.
The afternoon kewr haze potential forecast is green...which implies
slant range visibility 7sm or greater outside of cloud.
Kjfk fcster comments: no unscheduled amendments expected.
Klga fcster comments: no unscheduled amendments expected.
Kteb fcster comments: no unscheduled amendments expected.
Khpn fcster comments: MVFR conditions possible in light snow
between 09z and 13z.
Kisp fcster comments: no unscheduled amendments expected.
Outlook for 06z Tuesday through Friday...
Tuesday-Tuesday night...VFR. West winds with gusts to 20kt during the
Wednesday-Wednesday night...sub-VFR likely in snow and/or rain.
Thursday...improving to VFR early. Northwest g25-30kt.
west-southwest flow today of 10-15kt on the waters today with some gusts up to
around 20kt. A weakening cold front will pass through early on
Tuesday and help winds veer west to west-northwest. Winds could be just strong
enough for a brief time in the morning such that seas could build up
to 5 feet along with a gust or two near 25kt over the eastern ocean
waters. Will hold off on issuing an Small Craft Advisory here since if the criteria
is met...it will be for a brief period. Otherwise...sub-sca
conditions are expected to prevail through the day.
Small Craft Advisory winds and seas develop late Wednesday with the developing low
pressure system. Gales are then possible behind the departing low
late Wednesday night into Thursday. Small Craft Advisory conditions will likely
continue through part of Thursday night...before winds and seas fall
below criteria by Friday morning. Strengthening SW winds could bring
Small Craft Advisory conditions back by late Friday on the ocean though.
no significant widespread precipitation expected through Tuesday.
There is potential for significant precipitation during the middle
of this week as a storm system tracks near the region.
Currently...around 1/2 to 1 inch of precipitation is forecast...but
uncertainty in the forecast details continues at this time and this
could change significantly.
the National oceanic and atmospheric administration weather radio transmitter that serves the New York City
metropolitan area remains out of service due to radio frequency
interference with the U.S Coast Guard transmitter.
For more information see the following public information
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