Area Forecast Discussion
Issued by NWS Upton, NY

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KOKX 221733
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
1233 PM EST Wed Feb 22 2017

.SYNOPSIS...
A weak front dissipates as it approaches this morning. High
pressure centered well off the Carolina coast will influence the
weather through Thursday. A spring-like pattern for the end of
this week will transition into a more seasonal pattern for the
second half of the weekend into the beginning of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
There is still some lingering sprinkles across portions of the
Lower Hudson Valley and Long Island. These should diminish over
the next few hours. Mid and high level clouds still persist, but
think there should be enough breaks this afternoon to allow
temperatures to warm into the 50s, possibly touching 60 degrees
in the NYC metro.

Weak front continues to dissipate as it encounters a ridge axis
and high pressure over the western Atlantic. This high will
remain in place tonight. Light southerly flow overnight will
result in increasing low level moisture. Development of low
stratus and fog is likely under strengthening inversion. Some
dense fog is possible, but there is uncertainty in location and
duration at this time. Low temperatures will be in the upper
30s inland and low to mid 40s along the coast.

&&

.SHORT TERM /THURSDAY/...
Main challenge for Thursday is extent and duration of low
clouds and fog, especially near the coast. High pressure remains
offshore with southerly flow continuing around it. Current
expectation is that there will be dissipation of low clouds and
fog for enough warming to push temperatures into the middle and
upper 60s north and west of the city. Closer to the coast,
onshore flow should hold temperatures in the upper 50s to lower
60s. However, if low clouds hold on longer, temperatures could
be held down.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Models in fairly good agreement with east coast ridging to end the
week...ahead of a PAC trough sliding into the central Plains Friday
and then phasing with a polar low to the south of Hudson bay on Sat.
The shearing trough slides through the NE on Sunday...with generally
zonal flow heading into early next week.

Unseasonably mild conditions continue Fri/Sat in deep SW flow ahead
of the Pac trough and associated strong low pressure moving through
the central US and into the Great Lakes. Although temps will be
above normal on FRI...A PAC shortwave and associated low pressure
moving through Southern Quebec Thursday Night will push a cold front
through the region Thu Night/Fri. Latest GFS/NAM and high res
solutions indicating this cold front remaining south of the region
through Fri night...with a Canadian Maritime influence on the
region. This would result in stratus and temps holding in the 50s
for much of the region on Fri. Have trended forecast in that
direction based on climatology and better resolving NAM/high-res
solutions. With weak warm advection over the frontal boundary to the
south...and weak shortwave energy moving through aloft...a few
showers possible on Fri. If front remains to the south of the region
Fri night...an increasing chance for stratus...drizzle and fog could
be expected Friday Night into Sat morning as low-levels moisten and
isentropic lift begins to increases.

Models in decent agreement with PAC upper low shearing into the
northern stream low on Saturday...with associated trough and frontal
system swinging towards the region late in the day and then though
Sat night. Warm front should be able to gradually move north on Sat
with strengthening llj...with temps climbing back into the 60s on
gusty southerly flow by late in the day. Main rain activity appears
to be along and possibly just in wake of the cold front late Sat
into Sat eve as 40-50 kt llj and approaching shortwave energy
interact with +2-3 std of gulf moisture and weak elevated
instability. Potential for a brief period of moderate/heavy rain and
even some embedded thunder with activity along the front. Heaviest
activity though looks to be to the North and West of the region with
stronger shortwave forcing and better .

In the wake of the front...a dry and cooler airmass will build in
for Sat night/Sunday on gusty NW flow. Temps should cool to near
seasonable levels for Sunday.

Lack of model consensus continues for Monday and Tuesday with
generally weak northern stream and Pac energy moving through the
region in a near zonal upper flow. Signals for an associated weak
system with light precip to move through the NE/Mid Atlantic...but
at this point does not look like much of an event. Thermal profile
supporting would support wintry precip if precip was heavy enough.

Otherwise moderating conditions heading towards midweek...with
considerable model spread in timing/intensity of next system.

&&

.AVIATION /17Z WEDNESDAY THROUGH SUNDAY/...
High pressure off the Mid Atlantic coast will produce a weak
onshore flow across the terminals tonight and Thursday.

VFR conditions will give way to MVFR or lower after sunset as
fog and/or low stratus begin to develop. MVFR visibilities
initially develop after 03Z at coastal terminals before
spreading inland around 06Z. There is still quite a bit of
uncertainty related to the specific timing, location, and
duration of any lower ceilings/visibilities Thursday morning.
The best chance for IFR or lower conditions appears to be
between 09-15Z before conditions gradually improve during the
late morning.

Light southerly flow this afternoon will give way to light and
variable winds at all terminals tonight before becoming SW on
Thursday.

     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: No unscheduled amendments expected during the
daylight hours this afternoon. Uncertainty exists in the timing
of developing MVFR or lower conditions tonight.

KLGA TAF Comments: No unscheduled amendments expected during the
daylight hours this afternoon.  Uncertainty exists in the
timing of developing MVFR or lower conditions tonight.

KEWR TAF Comments: No unscheduled amendments expected during the
daylight hours this afternoon.  Uncertainty exists in the
timing of developing MVFR or lower conditions tonight.

KTEB TAF Comments: No unscheduled amendments expected during the
daylight hours this afternoon.  Uncertainty exists in the
timing of developing MVFR or lower conditions tonight.

KHPN TAF Comments: No unscheduled amendments expected during the
daylight hours this afternoon. Uncertainty exists in the timing
of developing MVFR or lower conditions tonight.

KISP TAF Comments: No unscheduled amendments expected during the
daylight hours this afternoon.  Uncertainty exists in the
timing of developing MVFR or lower conditions tonight.

.OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY...
.18z Thursday-Saturday...MVFR or lower in stratus and fog. Chc
of light rain or drizzle.
.Saturday night...MVFR likely with rain and a slight chance of
thunderstorms early. Gusty S winds becoming NW.
.Sunday...VFR...Gusty NW winds.
.Monday...VFR early...becoming MVFR. Chance of rain or snow.
Winds becoming S-SW around 10 kts.

&&

.MARINE...
A relaxed pressure gradient over the waters will limit winds
to 10 kt or less and seas to remain below small craft advisory
levels through Thursday.

Winds and seas are forecast to remain below Small Craft Advisory
levels from Thursday Night through Friday night. Small Craft
Advisory criteria is likely over the weekend associated with the
approach and passage of a cold front.

&&

.HYDROLOGY...
No hydrologic impacts are expected through Thursday. 1/4/ to 3/4
inch of rain...with locally up to an inch is possible late
Saturday into Saturday night. No significant hydrological
impacts are expected.

&&

.CLIMATE...
The following are record maximum minimum temperatures for
Thursday February 23, 2017 along with the forecast minimum
temperature.

Record Max Minimum Temperature   Forecast Minimum Temperature
------------------------------   ----------------------------
Central Park........55 (1985)    46
LaGuardia...........54 (1985)    46
Kennedy.............47 (1990)    43
Islip...............46 (1990)    40
Newark..............51 (1985)    45
Bridgeport..........40 (1985)    40

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...None.

&&

$$
SYNOPSIS...Fig/NV
NEAR TERM...DS
SHORT TERM...Fig/DS
LONG TERM...NV
AVIATION...IRD
MARINE...Fig/NV
HYDROLOGY...Fig/NV
CLIMATE...


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.