Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 310152

Area Forecast Discussion
National Weather Service Mount Holly NJ
952 PM EDT MON MAY 30 2016

Tropical moisture remained over eastern New Jersey and the Delmarva
Monday afternoon. This moisture will shift off the coast this
evening as a cold front approaches from the west. The cold front
will track through the region late Monday night into early Tuesday.
High pressure will follow for the middle of the week. A cold front,
attached to low pressure moving across eastern Canada, will slide
across the Mid Atlantic region on Friday or Saturday. The remainder
of the forecast period looks to be unsettled due to another
approaching low pressure system.


Not many changes with the 930 PM update. The band of showers that
has been over the shore all day is finally starting to full shift
off shore. A few showers have developed behind the main band
across south NJ, but those should be mostly light and likely won`t
last much past midnight. An additional line of showers and
thunderstorms was over the western half of the region, just ahead
of the cold front. This line is starting to fall apart as the
cooler outflow takes over. Thus, we should see decreasing chances
for rain through the overnight hours. PoPs were adjusted to match
current radar trends. Otherwise no major changes with this

The cold front is still on track to slowly slide east over the
region through the overnight hours.

Despite lower dew points behind the front, fog should develop
across most areas tonight given the very wet ground. However,
given the drier air moving in, do not expect widespread dense fog
on land. Low tonight...mild with mid/upper 60s in most areas.


Weak high pressure will arrive across the area Tuesday. Skies will
be mostly sunny across most of the region with some cloudiness
across the Delmarva and extreme srn NJ. We will continue with slgt
chance or low chance pops across these areas...since some of the
low level moisture from Mondays system will not yet have exited
these areas. It will be a warm day with highs in the low/mid 80s
across the region.


Overview...The period starts with a cold front exiting stage right
in the atlantic, with another weak cold front well to our north
situated west to east from the Great Lakes east to Maine. This front
will eventually lift north away from the region as surface high
pressure and mid-level ridging builds in. High pressure will be the
main story Wednesday through at least Thursday, maybe into Friday. A
cold front is forecast to cross the area on Friday or Saturday. For
the remainder of the weekend and into early next week, a deep trough
is forecast to settle over the east as strong ridging develops over
the Rockies.

Temperatures...For reference, normals for PHL are in the upper 70s
and upper 50s. For the period, temperatures will be near or above
normal. Depending on how deep and fast the east coast trof becomes
established, the end of the period could transition into the below
normal range.

Precipitation...Small POP showers have been been painted in the
grids for Tuesday night across the southern zones. Currently, dry
conditions are expected Wednesday into Thursday, but keep an eye
open over the ocean to see if any stratus and/or fog develops and
gets pushed onshore. Scattered thunderstorms are expected late in
the week with the cold front. Then the mid-level trof is forecast to
take over and provide the region with unsettled weather.

Winds...Winds will become northeast Tuesday night and go east on
Wednesday and then southeast before the frontal passage. Winds will
go northwest behind the late week cold front, then southwest as the
trof settles in. It could be a bit gusty on Wednesday and Thursday,
especially near the coast.

Impacts...The probability for widespread hazardous weather is low.


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

Many TAF sites will start this evening VFR, but expect areas of
fog to develop across much of the region, reducing visibilities to
at least MVFR and possibly IFR (especially for locations that have
seen heavy rain over the last 24 hours such as KILG, KPHL, and
KPNE). The fog should continue through much of the night.
Visibilities should begin to improve between 10 and 15Z.

Winds will be southerly or southwesterly to begin the TAF period,
shifting to northwesterly by 12Z as a cold front moves through the
region. However, wind speeds through out the TAF period should be
near or below 10KT. There is a chance that a sea breeze could
develop tomorrow afternoon, shifting the winds at KACY and
possibly KMIV to southeasterly.

Tuesday night through Thursday...Mainly VFR. Few showers psbl far
South Tuesday night.

Thursday through Saturday...Mainly VFR, except MVFR conditions in
scattered showers and thunderstorms.


The only significant hazard for the waters continues to the the
areas of dense fog. The dense fog advisory continues over night
for the coastal waters and the lower Delaware Bay. The moisture
enriched atmosphere and the chilly sea temps will provide the
favorable conditions for this sea fog. Conditions will improve
Tuesday once a cold front crosses the waters and drier air
arrives. Winds and seas should remain sub-sca thru the period.
Showers are expected tonight decreasing in coverage late.

Tue night through Saturday...Sub-small craft advisory conditions
expected through the period, although a persistent and solid 3 to 4
sea on the ocean seems likely through much of the period. East winds
could get gusty on Wednesday and Thursday. Isolated showers are
possible across the southern waters on Tuesday night. No precip
expected Wednesday into Thursday. Scattered showers and
thunderstorms are possible Friday and Saturday.


Most of the heaviest rain has ended, however we continue to
monitor for hydro concerns as even moderate rain over the areas
that had the heaviest rain earlier today could cause flooding
primarily in poor drainage areas. However, with the cold front
entering the western portions of our region, the flooding threat
will be decreasing through the overnight hours.


MARINE...Dense Fog Advisory until 6 AM EDT Tuesday for ANZ431-450>455.


Near Term...Johnson/O`Hara
Short Term...O`Hara
Long Term...Drag/Kruzdlo/O`Hara
Hydrology...Johnson is the U.S. government's official web portal to all federal, state and local government web resources and services.