Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 200136

Area Forecast Discussion
National Weather Service Mount Holly NJ
936 PM EDT Mon Jun 19 2017

A cold front will move through the area tonight and offshore by
Tuesday morning. A secondary cold front will gradually approach from
the northwest Wednesday before dissipating over the area Wednesday
night. Bermuda high pressure looks to influence our weather once
again late in the week. Another frontal system may affect the area
sometime during the weekend.


An upper-level trough over the Great Lakes region continues to
shift eastward. This will drive a cold front across our area
later this evening.

The bulk of the organized convection has moved off the coast this
evening, with some showers and thunderstorms lingering in its
wake due to some height falls occurring with the incoming
upper-level trough. The dew points are expected to start
lowering overnight especially in the northern and western

The remaining convection is moving through Delaware and into
southern New Jersey this evening. The storms have shown some
weakening as the move towards the northeast. Heavy rain and
gusty winds can be expected as these storms roll through. A
period of some showery conditions may linger behind the storms
for a few hours.

Adjusted temperatures, dew points, and sky conditions with this
update to better reflect current conditions and trends.


Our area will be under the influence of an upper-level trough and
associated cyclonic flow Tuesday. This will allow a cold front to
push offshore early, however some lingering showers or thunder are
possible near the southeast zones to portions of Delmarva in the
morning. Otherwise, drying is forecast to work south and east during
the day, with this most noticeable especially to the north and west
of I-95. Despite a cold front clearing the area, it will be a warm
day although much of the area will get a break from the humid
conditions as the day progresses.

High temperatures are an even blend of MOS and continuity.


Slightly cooler, but near normal temperatures, and somewhat
drier air moves into the region during the midweek. A mostly dry
period is expected Tuesday night through Thursday with a few
exceptions. The frontal boundary that moves thru our region
tonight will stall to our south tomorrow, then the northern edge
of precip along the front may expand northward toward southern
DE late Tuesday night and Wednesday as a disturbance tracks
along it. Additionally, diurnally-driven showers may develop
during peak heating Wednesday afternoon across the higher
terrain of northeastern PA and northwestern NJ as a shortwave
trough tracks nearby to the north.

It appears that another cold front an associated upper trof will
approach from the northwest Friday or Saturday, but timing is
uncertain at this point. The front may also be preceded by a
surge of tropical moisture from the Gulf of Mex. Given the
uncertainty for forcing and the overall summer-like pattern, the
forecast includes a chance of t-storms for Friday and through
the weekend for the entire area.


The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Through tonight...As of 00z, an area of rain/showers is behind a
departing line of thunderstorms. Some lingering showers and
local MVFR/IFR conditions may occur for awhile in the wake of
the line of thunderstorms. Otherwise, improving to VFR overnight
although some local light fog is possible. Southwest to west-
southwest winds diminishing to less than 10 knots.

Tuesday...VFR overall. A few morning showers possible near and south
and east of KACY and KMIV. West-southwest to southwest winds
increasing to around 10 knots.

Tuesday night through Thursday...Mainly VFR conditions
expected. Low possibilities for sub-VFR restrictions from
stratus/fog late night/early morning each day. Southwest winds
10 kt or less.

Friday and Saturday...Chance for MVFR or tempo IFR conditions
in showers and thunderstorms. SW winds gust to 20 kt during the
afternoon on Friday.


The Small Craft Advisory has been cancelled on the Upper
Delaware Bay as winds have fallen below 25 knots.

The Small Craft Advisory remains in effect through Tuesday on our
ocean waters. The Small Craft Advisory is in effect for the
Lower Delaware Bay until 11:00 PM.

A gusty south to southwest wind continues into tonight as a low-
level jet moves across the region. These winds will diminish
overnight. The wave heights on our ocean waters should remain in the
5 to 8 foot range through tonight. A line of gusty thunderstorms is
expected to move through this evening. While the winds should be
below advisory criteria Tuesday, seas on the ocean should be about 5

Tuesday night through Saturday...Winds and seas expected to
remain below SCA headline criteria.

There is a moderate risk for the development of dangerous rip
currents for Tuesday along the coast of Delaware and New
Jersey. There is around a 7 second southerly wind wave on top
of a very long period (around 14 seconds) southeasterly ground
swell. This combination results in an elevated risk for the
development of dangerous rip currents.

The primary wave period is forecast to be around 7 seconds
through Wednesday. However, the underlying 13 to 16 second
southeasterly swell is expected to linger into the mid week
period. As a result, the risk for the development of dangerous
rip currents is anticipated to be at least moderate through the
period along the coasts of Delaware and New Jersey.


NWS NWR and phone broadcast of the marine and surf zone
forecast problems continue here at NWS PHI. Hope to resolve
later today or Tuesday.


MARINE...Small Craft Advisory until 6 PM EDT Tuesday for ANZ450>455.
     Small Craft Advisory until 11 PM EDT this evening for ANZ431.


Near Term...Gorse/Meola
Short Term...Gorse
Long Term...AMC/Klein
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