Scientific Forecaster Discussion
Area forecast discussion
National Weather Service New York New York
1257 PM EST Sat Feb 28 2015
high pressure builds into the area through tonight...before
moving off the coast Sunday. A cold front will pass through the
area Sunday night. High pressure briefly builds Monday night into
Tuesday. Then another frontal system impacts the area for the
middle of next week. High pressure builds back in for the end of
Near term /through tonight/...
12z kaly and kokx soundings as well as 12z BUFKIT data suggest
mixing to around 950 hpa this afternoon. Based on this lowered
highs a couple of degrees. Remainder of forecast remains on track.
Quiet weather conditions on tap through tonight...with 850-700 hpa
ridge building over the area. Lows tonight should be in the single
digits across the interior valleys and The Pine Barrens of Long
Island and middle to upper teens across the city and immediate
Short term /Sunday through Monday/...
high pressure begins to move off the coast on Sunday. Clouds will
quickly increase Sunday afternoon with snow developing from west
to east. Latest model guidance continues to speed up the
progression of this system...with the precipitation forecast to
begin Sunday afternoon and Sunday evening and wrapping up by late
Sunday night into early Monday morning.
Precipitation should start out as snow...with a brief period of
freezing rain...mainly across Li and New York metropolitan after midnight. Right
now...looking for 2 to 5 inches of snowfall across the lower
Hudson Valley and CT...with 1 to 3 inches and a light ice
accretion to the south. Conditions dry out Monday morning with a
gusty northwest flow and another shot of unseasonably cold air.
Long term /Monday night through Friday/...
strong high pressure briefly builds in Monday night into Tuesday
with another frontal system to bring overrunning precipitation to
the area Tuesday night into Wednesday. This time around warmer
heights aloft and SW flow will result in a quick transition over
to rain from south to north. Will continue with chances of
precipitation in the forecast through Wednesday night due to the
uncertainty with the progression of the system. There is the
possibility of a transition back to wintry precipitation Wednesday
night...with precipitation lingering into Thursday morning.
High pressure builds across the area Friday...with colder and dry
conditions and temperatures dropping well below normal...
especially Thursday night and Friday.
Aviation /18z Saturday through Thursday/...
strong high pressure just to the west will move overhead
tonight...then weaken Sunday morning as a warm front approaches.
Expect VFR conds with light/calm winds through early Sunday
morning...then visibility rapidly lowering to IFR during middle to late
morning as light snow develops.
S-SW winds 5-10 knots at kgon and north-northwest winds 5-8 knots at kbdr/kisp
should become light to calm this evening as the high passes
overhead. Light winds in NYC metropolitan this afternoon likely to be
north-northwest then backing west-northwest before also going light/variable tonight.
Outlook for 18z Sunday through Wednesday...
*** forecast precipitation types/snow amounts for Sunday afternoon/night will
be updated between 20z-21z ***
Sunday...snow with IFR conditions developing.
Runway accumulations of less than an inch expected.
Sunday night...MVFR/IFR conditions expected. Snow...changing to
a wintry mix at the NYC metropolitan and Long Island terminals late.
Total most likely total runway accumulations of 3-5 inches at
kswf...2-3 inches at khpn/kbdr/kgon...and 1-2 inches at the NYC
metropolitan and Long Island terminals.
Monday-Monday night...becoming VFR early. Northwest winds g15-25kt in the
afternoon and evening.
Tuesday night...IFR conditions possible. Snow...changing to a wintry
mix after midnight. Low level wind shear possible after midnight.
Wednesday...IFR conditions possible in rain. Low level wind shear possible.
Wednesday night...MVFR conditions likely...IFR conditions possible.
Rain...mixing with or changing to snow after midnight.
minor changes were made this update to reflect the latest trends
in observations and guidance. The forecast appears on track.
High pressure will keep conditions below Small Craft Advisory levels until
Monday...when a frontal system will bring increasing winds and waves
across all of the waters. The winds and seas will subside on
Tuesday...then ramp up again Tuesday night and Wednesday to Small Craft Advisory levels as
another frontal complex approaches. The front may stall in the
vicinity of the waters Thursday...keeping Small Craft Advisory conditions locked in.
there is the potential for a light to moderate snow event late
Sunday into Monday morning. This event will have no immediate
impact on the hydrologic service area.
Ice will continue to develop on local area rivers and streams as
temperatures remain well below average.