Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Mount Holly New Jersey
842 am EDT Sat Aug 29 2015
high pressure will continue to become centered offshore today.
Meanwhile, a weak disturbance is expected to move across the
northeast on Sunday. High pressure overall though will tend to
dominate our weather through much of next week, then a weak cold
front may slide into our region on Thursday.
Near term /until 6 PM this evening/...
high pressure at the surface across the area will continue to ease
offshore where it becomes more centered. This will start a more
pronounced southerly flow, although still on the lighter side. The
airmass is forecast to warm a bit today, which will translate into a
warmer afternoon although the humidity levels are anticipated to
remain on the low side. There should be a sea breeze this afternoon,
which will keep the coastal areas a bit cooler.
A short wave trough over the Midwest this morning will gradually
shift eastward. This will also assist in the low-level flow across
our area turning more southerly. There is a little cirrus around,
and with heating we should get some cumulus development. It appears
that any convective development remains near the Great Lakes and
Ohio Valley which is much closer to the aforementioned short wave
trough and also a weak cold front.
An update was issued to adjust the hourly temperatures and dew
points based on the latest observations. It is a cool start across
much of the County Warning Area with several locations down into the 50s. These will
rebound nicely with ample heating along with some warming aloft. The
lamp/lav guidance was blended in through the morning hours.
Short term /6 PM this evening through 6 am Sunday/...
more of the same tonight. High pressure moves a bit more
eastward and there could be an increase in mainly high clouds, but not much
else to talk about. Dew points will begin a slow increase as well.
Long term /Sunday through Friday/...
the long term isn't much more exciting than the short or near
term, with high pressure mostly the dominant feature through the
Sunday and Sunday night...a weak upper level short wave trough
will cross the region through this period, but it should be
filling and weakening as it does so. Thus, chances for any
precipitation in our area are slim, so have kept the period dry.
Monday through Tuesday...high builds further east through this
time, with the ridge axis over the region by Tuesday evening. The
short wave trough that earlier model runs had shown digging
through the region on Tuesday evening has all but disappeared,
meaning rain chances have also decreased. So have changed the
forecast to have no mention of showers through this time. With the
high building in, 1000-500 mb thicknesses will also increase
through this period, leading to a modest warming trend despite the
lack of any low level warm air advection.
Wednesday through Friday...weak cold front looks to slide in from
the north through this time. However, the front should be slowing
as frontolysis begins through this period, so do not anticipate
and significant cooling trend. However, the front could serve as a
focus for low level confluence leading to some rain chances
through this period.
Aviation /13z Saturday through Wednesday/...
the following discussion is for kphl, kpne, kttn, kabe, krdg,
kilg, kmiv, kacy and surrounding areas.
Today...VFR with some cumulus developing around 5000 feet. Light and
variable to calm winds, becoming southwesterly and increasing up to
10 knots. A sea breeze this afternoon should turn the winds more
south or south-southeast at kacy.
Tonight...VFR overall with remaining cumulus dissipating in the
evening. There is a chance for localized MVFR fog toward Sunday
morning. Winds becoming light and variable at most terminals, to
Sunday through Tuesday...mostly VFR conditions expected,
localized MVFR possible with br each morning.
Wednesday...mostly VFR conditions expected, isolated thunderstorms
possible late in the day.
no marine flags are anticipated through the near and short term
periods. Seas will generally be in the 2 to 3 feet range. Wind will generally be
S to SW in the 5 to 10 knots range with gust in the 15 to possibly as high
as 20 knots especially Erly tonight.
Sunday...a few gusts near or above 20 knots possible Sunday evening,
otherwise winds and seas should stay below Small Craft Advisory
Monday through Wednesday...winds and seas should stay well below
small craft criteria.
several factors come into play today. There will
be southeasterly swell, though it should be light. However, we will
have a full moon and S to SW wind that could gust in the 15 to 20 knots
range, especially during the late afternoon. Also seas will be 2 to 3 feet
and wave periods of 10 to 11 seconds.
The combination of all of these factors will give a moderate risk of
rip currents in New Jersey today. In Delaware, we will continue to
carry a low risk.