Scientific Forecaster Discussion
Area forecast discussion
National Weather Service New York New York
213 PM EDT sun Mar 29 2015
high pressure west of the region builds south and moves off the
southeast coast this afternoon and this evening. A low pressure
system approaches from the northwest tonight with a cold front
crossing the region Monday. A series of low pressure systems will
impact the area through the upcoming week.
Near term /until 6 PM this evening/...
minor tweaks to hourly grids based on latest surface observation and
satellite images. Otherwise...no changes to the forecast as surface
high pressure over the middle-Atlantic slowly drifts to the southeast
this afternoon. With subsidence over the area...can expect sunny
skies with highs in the low to middle 40s...which is close to 15
degrees below the seasonal normal.
Weak northwest flow will gradually back to the SW late as the high moves
into the southeast U.S.
Short term /6 PM this evening through 6 PM Monday/...
weak warm advection strengthens tonight as the surface high
remains off the southeast coast. Northern stream upper flow is
active and the upper ridge quickly breaks down as the next
shortwave approaches. A warm front develops late tonight west of
the area and light precipitation may break out before sunrise.
Colder air will be in place and a wintry mix will be likely at the
start. Some freezing rain is possible in the valleys of
northeastern New Jersey with the colder air trapped at the surface
as warmer air moves in aloft. As warmer air moves in the
precipitation transitions to all liquid.
The upper trough moves through quickly Monday with a surface cold
front passing through by Monday evening. With limited moisture and
most of the lift north of the area will keep chance probability of precipitation early
morning into the afternoon.
Long term /Monday night through Saturday/...
by Monday evening a cold front will be east of the area with
precipitation having ended as an upper trough moves into New
Another shortwave and vorticity maximum will pass through the region
Tuesday night. Rain is expected to spread across the area Tuesday
night into early Wednesday morning...across inland locations there
could be a brief wintry mix overnight on Tuesday. Highs and lows
will be near seasonable levels Monday through Wednesday.
High pressure builds across the area on Wednesday then moves
offshore Thursday...with return flow and warm moist air quickly
spreading north across the area. Next low pressure is expected to
impact the local area either Thursday or Friday...with rain chances
Thursday night into Saturday.
Highs on Thursday and Friday will be in the upper 50s to low
60s...with lows in the low to middle 40s.
Aviation /18z Sunday through Friday/...
high pressure passes to the east this evening...while a frontal
system approaches from the Great Lakes.
VFR. Middle level deck increases late tonight with potential MVFR
ceilings in scattered showers Monday morning. Prefer to keep tafs VFR at this
time due to low confidence in MVFR conditions.
Northwest winds early this afternoon shift quickly to the
west...then become southerly this evening. Gusty west/SW flow develops
toward 18z Monday.
Outlook for 18z Monday through Friday...
Monday after...VFR. West winds 10-15 knots with gusts up to 25 knots.
Tuesday night...possible MVFR or lower conds in -ra.
Thursday...mainly VFR...with MVFR or lower conds in -ra late in
in the day. Possible low level wind shear.
northwest flow 10 to 15 knots with gusts up to 20 knots will diminish to 5 to
10 knots and back to the SW later this afternoon.
For the ocean waters east of Fire Island Inlet...seas will average
5-6 feet...so will keep Small Craft Advisory up through the afternoon.
High pressure over the middle-Atlantic will drift to the southeast U.S.
By late afternoon.
As a low approaches from the west tonight a southerly flow will
develop. This flow increases early Monday morning and small craft
conditions will be likely on the ocean waters by early Monday
morning. Gusts across the remainder of the forecast waters may
approach small craft levels Monday. Lingering small craft seas are
possible on the ocean waters into early Tuesday.
Otherwise below small craft level conditions expected Tuesday
through Thursday...as winds and waves diminish and weak high
pressure builds across the area waters.
no significant widespread precipitation is forecast through the
Rivers and streams are expected to remain below bank full...but
increased river/stream flow across the lower Hudson Valley and
southern Connecticut will continue ice breakup and movement into
this weekend. Isolated ice jams are possible...which if they
occur...could result in localized flooding. Since ice jam flooding
is unpredictable and sudden...interests along ice covered rivers
should monitor National Weather Service forecasts for the latest information.
For details on specific area rivers and lakes...including
observed and forecast river stages and lake elevations...please
visit the advanced hydrologic prediction service /ahps/ graphs on
our web site.
Marine...Small Craft Advisory until 6 PM EDT this evening for anz350-