Area forecast discussion
National Weather Service Mount Holly New Jersey
933 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 at least 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. This
has happened fairly quickly already this evening.
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 grazing our far northern zones for
awhile this evening to generate at least some sprinkles. Since
this looks rather light and spotty, and radar returns are now weak
we opted to carry sprinkles up north for the remainder of the
evening. However, a more organized area of showers is rotating
southward across eastern New York state. This appears to be with a
short wave and deformation type feature. The latest hrrr shows
this fairly well with it weakening as it rotates southeast and
then east. This may get some showers into our far northern zones,
therefore added some 20-30 probability of precipitation late this evening before lowering
overnight.
Based on a continuation of at last some wind overnight, the threat
for any frost is rather low at this time. No major changes were made to
the low temperatures at this time. The sky cover was adjusted which
included a tighter gradient, with nearly a clear sky across the
southern areas. There are some middle to high level clouds well to
our southwest, however with the upper-level flow from the
northwest these should generally dive to our south. 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 /02z 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 near kabe to
kpne to kacy northward gradually thinning out. Northwest winds
around 10 knots with some local gusts to near 20 knots this
evening, then most terminals losing the gusts.
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...
the Gale Warning was cancelled from Little Egg Inlet, New Jersey
on southward including Delaware Bay. A Small Craft Advisory was
issued for these areas through the day Sunday. The winds have
dropped off quite a bit this evening so far, and now it is a
matter of how much mixing occurs. We believe the mixing will not
be enough to allow gale force gusts to occur, and model guidance
holds 35-40 knots of wind at 925 mb farther north. Therefore we
held onto the Gale Warning across the northern two ocean zones
through 06z tonight for now. Once this gets dropped, a Small Craft
Advisory will need to be raised. On Sunday, the main gusts to
around 25 knots may be more nearshore as the boundary layer warms
more compared to today /Saturday/.
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...Small Craft Advisory until 6 PM EDT Sunday for anz430-431-
452>455.
Gale Warning until 2 am EDT Sunday for anz450-451.
&&
$$
Synopsis...gorse/iovino
near term...gorse
short term...szatkowski
long term...iovino
aviation...gorse/szatkowski/iovino
marine...gorse/szatkowski/iovino
