Area Forecast Discussion
Issued by NWS Upton, NY-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KOKX 131731
Area Forecast Discussion
National Weather Service New York NY
1231 PM EST Fri Jan 13 2017
Polar high pressure over the Great Lakes builds east this
afternoon and then across the Northeast tonight. The high moves
east of the area on Saturday. A weak wave of low pressure passes
along a stationary boundary well south of the area late Saturday
into Saturday night. High pressure builds over the region Sunday
into Monday, and moves offshore Monday night as a warm front
approaches, then moves through Tuesday. A cold front moves through
Wednesday into Wednesday night. Weak high pressure builds in
.NEAR TERM /THROUGH TONIGHT/...
Temperatures have nearly leveled off and may hold steady the next
couple of hours before beginning to fall off. Made some slight
upward adjustments to temperatures based on latest trends.
On the heels of a cold frontal passage earlier this morning,
gusty NW winds will bring in a colder airmass across the region.
By late afternoon, most locations will be in the mid 30s to
Tonight, mid and high level clouds increase from the west as a
wave of low pressure moves out of the Ohio Valley. Overnight lows
fall into the teens and 20s.
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
High pressure remains north of there region Saturday morning,
then starts to slide eastward during the afternoon. Meanwhile, a
wave of low pressure moves out of the Ohio valley Saturday
morning and passes south of the region Saturday evening, as it
travels along a stationary front. Expect a mostly cloudy period
with a chance of snow. Forecast models keep most of the
precipitation south of the region, and with a strong high
pressure system nearby, will limit POPs to chance or slight
chance, with the highest pops across the southern half of the
CWA. Its possible the northern half of the CWA remains dry.
Overall with this being a light QPF event, only expecting a
dusting to a light coating.
Any snow ends Saturday evening, with drier weather expected for
most of Saturday night.
Expect cold temperatures through the short term period. Highs
on Saturday will only reach the upper 20s to lower 30s, with
most locations remaining below freezing. Saturday night, lows
fall into the teens and 20s.
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Near zonal flow will predominate at the beginning of the extended
period with a southern stream shortwave expected to phase with a
northern stream wave during Monday, and then progress to the east
Monday night through Wednesday. The forecast remains fairly
consistent with the previous thinking. At the surface and warm front
will be developing to the west and southwest of the region Monday
night with increasing isentropic lift. Moisture will be rather
limited. Thermal profiles still support a chance of a wintry mix
inland ahead of the warm front, with sleet and freezing rain
possible. Will keep the probabilities at chance, with some
uncertainty to the exact timing of the warm front development and
movement, and with weak ridging ahead of the front. Tuesday morning
the warm front is expected to lift to the north, however, with the
surface low remaining well to the west the timing of the northward
push remains uncertain and there could be a more prolonged period of
wintry weather into Tuesday.
Later Tuesday the upper flow becomes rather diffluent and weak with
little eastward progress of the cold front with the low moving into
southern Canada. Will keep a chance of precipitation Tuesday night
into Wednesday night. Weak ridging builds ahead of the next southern
stream shortwave for Friday. So will keep slight chance probabilities
Thursday into Friday.
.AVIATION /18Z FRIDAY THROUGH THURSDAY/...
-- Changed Discussion --Gusty northwest winds will continue, diminishing after 00z. Winds
will then gradually shift to the north then northeast overnight,
then subside as high pressure builds to the north. Winds tomorrow
will gradually go from northeast to more southerly in the
Light snow will be possible late Saturday afternoon-evening as a
low pressure system passes to the south, but confidence is too low
to mention in the TAFS.
NY Metro Enhanced Aviation Weather Support...
Detailed information, including hourly TAF wind component forecasts,
can be found at: http:/www.weather.gov/zny/n90
KJFK TAF Comments: End time of gusts may be earlier than forecast.
KLGA TAF Comments: End time of gusts may be earlier than forecast.
KEWR TAF Comments: End time of gusts may be earlier than forecast.
KTEB TAF Comments: End time of gusts may be earlier than forecast.
KHPN TAF Comments: End time of gusts may be earlier than forecast.
KISP TAF Comments: End time of gusts may be earlier than forecast.
.OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...
.Friday night...VFR. NW-N winds diminishing to below 10KT late.
.Saturday-Saturday night...Sub VFR is possible in light snow late
Saturday afternoon/Saturday evening. Best chance of Sub VFR will be
across southern terminals.
.Monday night-Tuesday...MVFR or lower possible in rain near the
coast, and wintry mix inland.
.Wednesday...MVFR or lower possible in rain.
-- End Changed Discussion --
SCA conditions are expected on the ocean waters today as gusty NW
winds occur behind an earlier cold frontal passage. Winds and
seas gradually subside tonight.
Sub-SCA conditions are then expected after 06z tonight
through Saturday night as a weak gradient over the waters will
keep conditions tranquil.
A weak pressure gradient force will be across the forecast waters
Sunday into Monday as high pressure builds over the waters, then
moves offshore. A weak warm front will approach west of the waters
Monday night into Tuesday.
Winds and seas will remain below small craft advisory levels Sunday
No significant precipitation is forecast this weekend into the
middle of the week.
MARINE...Small Craft Advisory until 6 PM EST this evening for ANZ355.
Small Craft Advisory until 1 AM EST Saturday for ANZ350-353.