Special Marine Warning 140, NWS Philadelphia/Mount Holly

Area Forecast Discussion
National Weather Service Mount Holly NJ
119 AM EDT Fri Aug 25 2017

.SYNOPSIS...
Canadian high pressure will build southward into the region through
this weekend before progressing offshore around the middle of next
week. This high will bring a period of dry and seasonably cool weather
to the Mid-Atlantic through at least the beginning of next week. A
tropical or subtropical low is expected to develop east of the Florida
coast this weekend and lift slowly northeastward off the East Coast
next week. At this time, the system is expected to remain well southeast
of the area.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
On water vapor satellite imagery, The short wave trough axis
appears to still be over Central Pennsylvania. This is
supported by the current radar trends with showers just starting
to move into Berks County. Adjusted PoPs up and extended
through the rest of the night for locations west of the I95
corridor to reflect current radar trends and the slower arrival
of the trough. Also adjusted sky cover across the region as an
extensive mid level cloud shield is already expanding across the
region.

As mentioned by the previous shift, do not expect temperatures
to drop too much from where they are currently given the
increasing mid level clouds.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/...
Partly to mostly sunny. Seasonable. Max temps 1 to 5 degrees
below normal. 850 temps maybe 1C less than today so temps 1 to
2F cooler than what occurred on Thursday. Light northwest winds
except seabreezes developing on the coast.

A couple of models show isolated light shower potential but
now, we are not forecasting any sprinkle activity since we're
unsure where it might occur, if at all.

This forecast was a 50 50 blend of the 12z/24 GFS/NAM MOS.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
An extended period with fair weather will continue in the long term.
High pressure will remain in control of the weather as it slides
across southern Canada and then off into the Atlantic early next
week. The models are in general agreement with the above situation.
The GFS model is showing some light precip near the shore areas
Saturday with the low level flow being onshore at that time. I don't
feel confident enough with this attm to raise pops into the slgt chc
range. Cloud cover across the coastal areas was increased however.
Temperatures will be a couple degrees below normal for late August,
overall pleasant for this time of year.

Next week, the onshore flow with the retreating high and an upper
trough developing across the east U.S. will result in increasing
chcs for clouds and showers. We therefore have continued with the
slight chc or low chc pops for most areas at those times. A sub-
tropical low over the east coast towards the middle of next week,
should remain far enough away to keep any significant showers
activity out of our CWA. This will be something to watch however.
Temperatures are expected to stay near seasonal norms, with more
humidity however.

&&

.AVIATION /05Z FRIDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

VFR conditions are expected today and tonight. Mid level clouds
are already moving into the region and may persist for much of
the TAF period, but expect any ceilings to be above 5000 ft AGL.
A few showers may move over KRDG, KABE, and KILG through 12Z,
but based on upstream observations, even if they do move over a
TAF site, conditions should remain VFR.

Winds will be generally light (less than 10kt) and mostly out of
the north or northwest. The one exception is between 18 and 00Z,
a light sea breeze may develop and move into KACY (and possibly
KMIV). This could shift the winds to southerly or even
southeasterly, but wind speeds should remain light.

Outlook...

Sat thru Tuesday...A prolonged period of VFR conditions
expected with high pressure across the area. A few low clouds
near the shore possible Saturday. Winds mostly under 10 knots.

&&

.MARINE...
Winds and seas are expected to remain below small craft advisory
conditions through Friday.

Outlook...

Friday night through Sunday...Winds and seas below advisory
criteria. Fair weather.

Sunday night through Tuesday...SCA seas developing on the ocean
Sunday night and Monday then persisting into Tuesday. Sub-SCA
seas over Delaware Bay. Mostly fair weather expected.

Rip Currents...

There is a Low risk for the development of dangerous rip
currents at NJ and DE ocean beaches on Friday. However, with
late day sea breezes developing, the shift to a S to SE wind may
result in a localized moderate risk for the development of
dangerous rip currents, mainly at NJ ocean beaches late in the
day. Confidence is low at this time, so will keep the forecast
risk at Low.

Low does not mean NO risk! Please be smart selecting where you
swim. Safety requires a flotation device available nearby and
preferably swimming within sight of a lifeguard.

Also...not only are we hearing stories of bacteria here and
there along the NJ coast, but we were informed of a few Man O
War stings. So even in this outstanding weather pattern, follow
the advice of local officials regarding your swim zones.

IF anyone is seeking advice for choosing swim days along the NJ
and DE coasts...the next couple of days should be potentially
nicer versus next week (bacteria and Man o Wars issues excluded)
Next week, the swimming safety and comfort is expected to
diminish as noted below.

Early next week...the risk for the formation of dangerous rip
currents should increase to at least moderate. Atlantic waters
will become rough and more difficult to manage for swimmers
because of increasing easterly swells and persistent onshore
flow in association with the high re-centering to our north and
some sort of low pressure system moving northeast, off of the
southeast coast of the United States. The result, the building
of an 8 second easterly swell...possibly to 7 feet or so by
Monday or Tuesday, at least along the southern NJ and DE coasts.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.

&&

Synopsis...CMS
Near Term...Johnson
Short Term...Drag
Long Term...O'Hara
Aviation...Johnson/O'Hara
Marine...Drag/MPS/O'Hara

Hazardous Weather Outlook
National Weather Service Mount Holly NJ
242 PM EDT Thu Aug 24 2017

DEZ001-002-MDZ008-012-015-019-020-NJZ001-007>010-012-015>019-021-
PAZ054-055-060>062-070-071-101>106-252000-
New Castle-Kent-Cecil-Kent MD-Queen Annes-Talbot-Caroline-Sussex-
Warren-Morris-Hunterdon-Somerset-Middlesex-Mercer-Salem-Gloucester-
Camden-Northwestern Burlington-Cumberland-Carbon-Monroe-Berks-Lehigh-
Northampton-Delaware-Philadelphia-Western Chester-Eastern Chester-
Western Montgomery-Eastern Montgomery-Upper Bucks-Lower Bucks-
242 PM EDT Thu Aug 24 2017

This Hazardous Weather Outlook is for central Delaware, northern
Delaware, northeast Maryland, central New Jersey, northern New
Jersey, northwest New Jersey, southern New Jersey, east central
Pennsylvania, northeast Pennsylvania and southeast Pennsylvania.

.DAY ONE...This Afternoon and Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

DEZ003-004-NJZ013-014-020-022>027-252000-
Inland Sussex-Delaware Beaches-Western Monmouth-Eastern Monmouth-
Ocean-Atlantic-Cape May-Atlantic Coastal Cape May-Coastal Atlantic-
Coastal Ocean-Southeastern Burlington-
242 PM EDT Thu Aug 24 2017

This Hazardous Weather Outlook is for southern Delaware, central
New Jersey and southern New Jersey.

.DAY ONE...This Afternoon and Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

The risk of rip currents is expected to increase early next week for
the New Jersey and Delaware beaches. Coastal flooding may also become
a concern next week.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

ANZ430-431-450>455-252000-
Delaware Bay waters north of East Point NJ to Slaughter Beach DE-
Delaware Bay waters south of East Point NJ to Slaughter Beach DE-
Coastal waters from Sandy Hook to Manasquan Inlet NJ out 20 nm-
Coastal waters from Manasquan Inlet to Little Egg Inlet NJ out 20 nm-
Coastal waters from Little Egg Inlet to Great Egg Inlet NJ out 20 nm-
Coastal waters from Great Egg Inlet to Cape May NJ out 20 nm-
Coastal waters from Cape May NJ to Cape Henlopen DE out 20 nm-
Coastal waters from Cape Henlopen to Fenwick Island DE out 20 nm-
242 PM EDT Thu Aug 24 2017

This Hazardous Weather Outlook is for Atlantic coastal waters and
Delaware Bay Waters.

.DAY ONE...This Afternoon and Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.