Scientific Forecaster Discussion
fxus61 kokx 120536
Area forecast discussion
National Weather Service New York New York
1236 am EST Tue Nov 12 2019
low pressure will move across north and west of New York City
overnight into early Tuesday, bringing a strong cold front
through the area in the morning. High pressure builds in from
the west Tuesday night. The high will build across the area
Wednesday and then offshore on Thursday as a weak warm front
passes through. This will be followed up by another cold frontal
passage Friday night and high pressure next weekend. Low
pressure may impact the area late Sunday into Monday.
Near term /through today/...
overcast sky conditions, thickening cloud coverage as clouds
continue to move in from the west tonight. Some more low level
clouds have made their way onto some parts of the coastline.
Vast differences are exhibited in temperatures from upper 30s
across northern portions of Orange County to mid 50s across NYC
Metro and Long Island.
Temperatures are pretty much for the rest of the night expected
to remain nearly constant with a little more southerly flow and
the overcast cloud coverage.
Otherwise, low pressure will track northeast along the stalled
front from western PA to north of the lower Hudson Valley by
morning, sending a cold front into the far western sections of
the area toward daybreak. The front will then clear far eastern
Li and southeast CT by noon. Precipitation remains confined to
the cold frontal boundary, mainly behind the front. With that,
much of tonight will be dry, with precipitation moving into the
western zones after midnight. With boundary temperatures
remaining relatively warm precipitation will begin as rain. The
low and cold front will remain progressive and the period of
precipitation will be confined to Tuesday. The challenge is how
quickly the colder air moves into the area before the
precipitation shuts off. The trend has been for a slower and
more brief period of changeover. Will basically have chance and
slight chance probabilities with the mix and changeover to snow.
Temperatures during Tuesday will also be a challenge and timing
of the colder air will have an impact on the changeover. The
front clears far eastern areas by noon. High temperatures will
occur first thing in the morning. Temperatures will sharply fall
following the cold frontal passage and much of the area will be at
or below freezing by early evening.
Short term /tonight through 6 PM Wednesday/...
temperatures continue to sharply fall Tuesday evening, and
record lows could actually be met for Tuesday just before
midnight. Precipitation may linger across the Twin Forks in the
very early evening hours. However, the trend is for a quicker
ending. The upper trough will be across the east with the trough
axis passing through late Tuesday night as heights begin to
rise. At the surface high pressure will be building to the west
and a strong pressure gradient force will exit between the high
and the departing low. Gusty northwest winds will result in
winds chills in the single digits above zero to around 10 above
across the region. Record lows are likely Wednesday morning.
See the climate section for details on the records.
Long term /Wednesday night through Monday/...
the long term period starts off with an early season Arctic
airmass bringing record cold to the area through Wednesday
night. Both highs and lows will be around 20 degrees below
normal with the possibility that temperatures do not get above
freezing Wednesday afternoon. This is due to a high amplified
upper flow with ridging across the West Coast extending
northward into Alaska with deep-layered northwest flow feeding
into the mean trough across eastern North America. The upper
level low associated with the pool of Arctic air will lift into
eastern Canada Wednesday, so this will be a quick shot of cold
High pressure will then build across the area Wednesday night
and offshore on Thursday. A weak warm front will move across the
region late Thursday. This still looks to be a dry frontal
passage but a sprinkle or flurry can't completely be ruled out.
Another cold frontal passage is on track for the end of the
week, but the airmass this time around will not be as cold as
the previous midweek shot. Low pressure may impact the region
late Sunday into early next week as an upper low along the
southeast coast gets drawn northward ahead of an upper trough
moving across the Mississippi Valley. Temperatures moderate
Sunday into Monday.
Aviation /06z Tuesday through Saturday/...
low pressure moves across mainly northwest of NYC terminals tonight, and
will allow for a strong cold front to move across early Tuesday.
Conditions becoming more MVFR and some IFR outside of NYC terminals.
Precipitation ahead of the cold front will move across mainly
Tuesday morning, mostly rain for most terminals with some brief mix
with snow before all precipitation tapers off in the afternoon. The
exception would be kswf and to some extent khpn where more snow is
forecast (up to a half inch accumulation). No snow accumulation is
anticipated at NYC, Long Island and southern Connecticut terminals.
Kswf and khpn will have the highest chances of getting IFR Tuesday
morning with otherwise mainly MVFR conditions forecast. VFR returns
from west to east mid to late Tuesday afternoon.
Winds will be light through much of tonight, around 10 kt or less
from the S-SW. Winds become gusty with the approach of the cold
front and behind the cold front on Tuesday. Winds are forecast to
become more west-northwest and increase to near 15-20 kt with gusts 25-30 kt.
Outlook for 00z Wednesday through Saturday...
Tuesday night-Wednesday...VFR. Northwest winds g25-30 kt Tuesday night and
northwest winds g20-25 kt Wednesday. Winds diminish Wednesday night.
Thursday-Saturday...VFR. Northwest gusts 15-20 kt Friday night. North-NE gusts
15-20 kt Saturday.
southerly winds will be increasing ahead of a low that will
track west and north of the forecast waters through Tuesday,
with an associated cold front passing through Tuesday. Small
Craft Advisory conditions are expected to develop on the ocean
waters this evening, and then across the remainder of the waters
by daybreak. With the passage of the cold front winds shift to
the west and northwest with winds and gusts increasing across
all the waters. Gale gusts may be possible by late afternoon
across portions of the ocean waters, however, confidence was not
high enough to begin the warning. Gale gusts will be likely
Tuesday night, and a Gale Warning was posted for the ocean
waters, and the eastern sound and eastern Long Island bays. Then
the Small Craft Advisory was extended through Tuesday night across the remainder
of the waters. Winds and gusts will begin diminishing late
Winds will gradually subside on Wednesday as high pressure
builds in from the west. Sub-Small Craft Advisory conditions are forecast
Wednesday night into Friday. Following a cold frontal passage
Friday night, northerly winds will likely bring Small Craft Advisory conditions
back to the waters.
no hydrologic impacts expected through the period.
record lows for Tuesday November 12th
temperature | year
nyc| 26 | 1926
jfk| 29 | 2017
lga| 32 | 2013
ewr| 28 | 2017
isp| 25 | 2001
bdr| 28 | 1957, 2013
Record minimum high temperatures for Wednesday November 13th
temperature | year
nyc| 33 | 1911
jfk| 41 | 2013
lga| 39 | 1977
ewr| 41 | 2013
isp| 39 | 2013
bdr| 38 | 1995
Record lows for Wednesday November 13th
temperature | year
nyc| 24 | 1986
jfk| 25 | 1986
lga| 26 | 1986
ewr| 24 | 1986
isp| 24 | 2001
bdr| 23 | 1986
NYC National oceanic and atmospheric administration weather radio station kwo35 (162.55 mhz) is operating
at reduced power until further notice.
Marine...Small Craft Advisory from 6 am this morning to 6 am EST
Wednesday for anz335-338-345.
Small Craft Advisory from 6 am this morning to 6 PM EST this
evening for anz330-340.
Gale Warning from 6 PM this evening to 6 am EST Wednesday for
Small Craft Advisory until 6 PM EST this evening for anz350-