Area forecast discussion
National Weather Service Mount Holly New Jersey
625 PM EDT Sat may 25 2013
Synopsis...
low pressure near the New England coast will lift gradually to the
northeast through Sunday. Meanwhile, high pressure located near
northwest Ontario will build to the south and east. A section of the
high is forecast to pass over our region around Monday night before
moving off the coast. A warm front approaching from the southwest is
expected to arrive Tuesday night and Wednesday. High pressure is
then anticipated to build into our region from the south for
Thursday through Saturday.
&&
Near term /until 6 am Sunday morning/...
low pressure will remain near the coast of New England through
tonight. This will continue to circulate a chilly airmass across our
County Warning Area within a cyclonic flow. The flow above the surface will
gradually lessen through the night, however the tightened pressure
gradient will maintain some wind despite the boundary layer cooling.
The depth of the mixing layer will shrink through the night however,
which will lessen the surface winds/gusts.
There continues to be plenty of moisture wrapping around the surface
system and also the closed upper-level low. At the same time, drier
air is getting drawn in from the west and southwest. There will
still be just enough lift across our far northern zones for awhile
this evening to generate a few showers or sprinkles. Therefore, we
continued the idea of lowering probability of precipitation from southwest to northeast
there through about midnight. We did add in a layer of sprinkles
given some light radar returns rotating southeastward.
Based on a continuation of a light to moderate wind overnight, no
threat of frost across the far north is expected. No major changes
were made to the low temperatures at this time. The sky cover was adjusted
which included an increase north of Philadelphia for awhile longer.
The hourly temperature/dew point grids were adjusted starting with
the latest observations, then some of the lamp/lav guidance was
blended in.
&&
Short term /6 am Sunday morning through 6 PM Sunday/...
moderating trend expected as temperatures will run 5 to 10
degrees warmer than today. Northwest flow will continue over the region
but winds will not be as strong. No precipitation expected and
cloud cover generated by daytime heating will not be as widespread
as today, so most areas will see quite a bit more sunshine than
they did today. Previous forecast tracked very well, and high
temperatures were left unchanged.
&&
Long term /Sunday night through Saturday/...
a middle level low is forecast to be located over New Brunswick,
Canada on Sunday evening with a ridge axis extending from Texas to
western Ontario. The low will lift to the northeast. The ridge
will build to the east and it is expected to influence our region
from the middle of the work week into next weekend. As a result,
we are anticipating a warming trend along with increasing
humidity.
High pressure will continue to build into our region from the
northwest for Sunday night and Monday. A mainly clear sky is
anticipated for Sunday night and the wind should fall below 5 miles per hour
at most locations. Temperatures are forecast to drop into the 40s
in much of our region. Minimum readings may be in the lower 50s in
highly urbanized areas. Some spots in the Poconos and in far
northern New Jersey could drop into the middle and upper 30s and
there may be some patchy frost from late Sunday night into early
Monday morning. A light northwest to west flow on Monday will
likely continue to bring dry air into our region. The dry air
should warm efficiently and we are expecting a 30 plus degree
diurnal temperature range at most locations. Afternoon readings
are forecast to rise well into the 70s.
Another cool dry night is expected for Monday night as surface
high pressure passes through our region. The air mass will likely
have modified a bit by that time and minimum temperatures should
be about 5 to 7 degrees warmer than those on Sunday night.
As the high passes off the coast on Tuesday, the surface flow
should switch to the southeast and south and afternoon
temperatures are forecast to get near 80 degrees in much of our
region.
A warm front approaching from the southwest may bring a slight
chance of showers to our region beginning on Tuesday afternoon
with a better chance of showers for Tuesday night into Wednesday.
As conditions destabilize on Wednesday afternoon with increasing
low level moisture and daytime heating we may see a few
thunderstorms, as well.
The warm front is anticipated to lift to our north for Thursday
through Saturday. Warm and humid conditions are expected through
the period. Daytime high temperatures are forecast to approach 90
except right along the coast and in the elevated terrain.
Overnight minimum readings should be mostly in the 60s due to the
increased humidity.
&&
Aviation /00z Sunday through Thursday/...
the following discussion is for kphl, kpne, kttn, kabe, krdg,
kilg, kmiv, kacy and surrounding areas.
Tonight...VFR, with ceilings around 7,000 feet from kabe to kphl to
kacy northward dissipating mainly from southwest to northeast.
Northwest winds 15-20 knots with gusts to around 25 knots,
diminishing to 10 to 15 knots.
Sunday...VFR. Northwest winds increasing to 15 to 20 knots with gusts
to around 25 knots by middle morning.
Outlook...
Sunday night through Tuesday...VFR.
Tuesday night and Wednesday...conditions possibly lowering to
MVFR as a warm front lifts through our region. There is a chance
of showers and afternoon thunderstorms.
Wednesday night and Thursday...mainly VFR with possible MVFR
conditions in haze and fog during the late night and early morning
hours.
&&
Marine...
gale warnings continue. The gale flag will continue though the
evening period with the decent pressure gradient across the region
and the cold northwest flow. Clouds/showers across the northern New Jersey
coastal waters which will end by midnight. Winds will decrease
toward midnight...with gales probably being converted back to Small Craft Advisory
flag overnight. Small Craft Advisory conditions will likely continue for much of
Sunday with dry weather.
Outlook...
high pressure will influence the coastal waters of New Jersey and
Delaware for Sunday night through Tuesday. A warm front is
expected to lift through our region during Tuesday night and
Wednesday followed by another area of high pressure for Thursday.
Wind speeds and wave heights will likely remain below the Small
Craft Advisory criteria through the period.
&&
Phi watches/warnings/advisories...
PA...none.
New Jersey...none.
Delaware...none.
Maryland...none.
Marine...Gale Warning until 2 am EDT Sunday for anz430-431-450>455.
&&
$$
Synopsis...gorse/iovino
near term...gorse
short term...szatkowski
long term...iovino
aviation...gorse/szatkowski/iovino
marine...szatkowski/iovino
