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-- Discussion containing changed information from previous version are highlighted. --
464
FXUS61 KPHI 220607
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
207 AM EDT Fri Mar 22 2019

.SYNOPSIS...
Low pressure will strengthen as it moves northeast through the
mid- Atlantic region tonight and into New England on Friday.
Behind the low, a cold front will cross our region on Friday.
Over the weekend, the low will move farther away into the
Canadian Maritimes, while high pressure will build in from the
Great Lakes on Saturday and then shift to our south on Sunday. A
cold front is forecast to cross the area on Monday, followed by
high pressure for much of the remainder of next week.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
The center of low pressure is currently over Delaware
Bay/extreme southern NJ and will continue to lift to the
northeast through daybreak Friday. The heaviest of the rain
seems to be winding down, but with all the rain that fell across
the region, it will not take much additional rainfall to result
in street and small stream flooding. Will keep Flood Watch up
through the late night hours. Some snow is possible across the
highest elevations of the southern Poconos late.

There may be some locally dense fog across southern NJ as the
low passes overhead.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/...
The low will continue to deepen through Friday as it moves NE
through New England. Main concern for Friday and beyond will be
strong winds on the backside of the system due to the strong
pressure gradient, deep mixing, and cold advection pattern.
Friday morning may end up mainly dry before a strong shortwave
associated with the main upper level low drops S/E into the
area. This will result in scattered showers redeveloping that
could continue to be mixed with some snow across higher
elevations in the southern Poconos. Otherwise main focus will be
on the winds. Winds will ramp up through the day and expect by
mid to late afternoon W/NW winds will be 15 to 25 with gusts of
at least 30 to 40 mph. Winds will likely be even stronger for a
time Friday night. Highs Friday will range from the upper 30s to
mid 40s over the southern Poconos and NW NJ to the upper 40s to
low 50s elsewhere.

Friday night...secondary cold front crosses the area early in the
evening potentially resulting in a surge of stronger wind gusts.
Profiles indicate 40 to 50 knot winds in the boundary layer but
limiting factor for full mixing will be loss of heating with the
diurnal cycle. Nevertheless, still think there will be a good
potential for wind gusts at least 35 to 45 mph to be realized across
much of the area so Wind Advisory may end up be needed. Otherwise,
except for some scattered snow showers continuing in the southern
Poconos conditions should become mainly dry. Lows by Saturday
morning will range from the 20s across the southern Poconos and NW
NJ to the low to mid 30s elsewhere.

For Saturday, the low pulls away into the Canadian Maritimes with
strong NW winds continuing in its wake as high pressure moves into
the Ohio Valley keeping a tight gradient over the area. Otherwise it
will be dry but seasonably cool under mainly sunny skies.

High pressure moves in for Saturday night and Sunday resulting in
winds finally diminishing with temperatures returning to
seasonable by Sunday afternoon under continuing mainly clear
skies.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
This extended forecast period will start out with a fairly strong
cold front passage on Monday, followed by Canadian high pressure for
Tuesday through Thursday. On Monday a shortwv trof is forecast to
move east into the Ohio valley with moisture spreading ahead of it
across the mid-Atlantic region. Both the latest GFS and ECMWF
are showing precip spreading across the area on Monday and
continuing into Monday night in association with this feature
and with the frontal passage.

Temperatures ahead of the front on Monday should be warm enough for
rain everywhere, but fairly strong cold advection behind the front
may result in precip changing to snow from north to south Monday
night. No significant snow accumulation is expected at this time.
Temperatures on Tuesday and Wednesday look to be a bit below normal,
but may moderate to near normal again by Thursday.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Through tonight...Low pressure will intensify as it moves
northeast through coastal DE and NJ tonight. Cigs will
generally range between low MVFR and IFR. Vsbys will lower in
areas of heavier rainfall. Precip should end from south to north
during the early overnight, but cigs will remain mostly IFR
overnight. Winds will veer from ENE to NW with the passage of
the low

Friday...Conditions should improve to VFR by mid-morning but NW
winds will likely gust 25 to 30 kt during day. Brief local MVFR
conditions are possible in scattered showers.

OUTLOOK...

Friday night and Saturday...VFR conditions expected but NW winds
will continue to gust 30 to 35 kt.

Saturday night through Sunday night...VFR conditions with winds
generally 10 kt or less.

Monday and Monday night...MVFR countdowns possible in areas of
rain or snow showers. Winds around 10 kt shifting from SW to N
on Monday.

Tuesday...VFR conditions with NE winds around 10 kt.

&&

.MARINE...
A Gale Warning remains in effect for all waters, though there is
a lull in the gales that should last into daybreak, then
northwest winds will crank up once again to above gale force
through Friday.

Outlook...

Friday night and Saturday...Northwesterly gales continue for
much of this period, but wind speeds should gradually drop off
late Saturday into Saturday night.

Sunday into Monday...winds and seas are expected to be below
Small Craft Advisory conditions.

Monday night and Tuesday...Northeasterly winds are likely to
increase starting Monday night and continuing into Tuesday. Seas
should subsequently increase as well.

&&

.TIDES/COASTAL FLOODING...
-- Changed Discussion --
High tide along the Atlantic Ocean, Delaware Bay, and tidal
Delaware River below the Commodore Barry Bridge area has passed
and waters will continue to recede. Therefore we cancelled the
Coastal Flood Warning and Advisory along the New Jersey and
Delaware ocean front, as well as the lower Delaware Bay coasts.

The Coastal Flood Advisory remains in effect for the tidal
Delaware River above the Commodore Barry Bridge area into the
early morning hours.

Guidance continues to indicate minor tidal flooding for the
morning high tide later this morning between 9 and 10 AM for
Middlesex, Monmouth, and Ocean counties. The low will continue
to slowly move away from the area through the morning hours, but
before it moves completely out of the area, easterly winds will
likely continue to push water into the northern New Jersey
coastal line. Therefore we have issued a Coastal Flood Advisory
for the next high tide for these counties.

Strong offshore flow will develop through the day Friday, which
will end the coastal flooding threat for subsequent high tides.

No flooding is expected on the upper eastern shore of
Chesapeake Bay.
-- End Changed Discussion --

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
PA...Flood Watch until 6 AM EDT early this morning for PAZ060>062-
     070-071-101>106.
     Coastal Flood Advisory until 6 AM EDT early this morning for
     PAZ070-071-106.
NJ...Flood Watch until 6 AM EDT early this morning for NJZ007>010-
     012-015>019.
     Coastal Flood Advisory from 8 AM this morning to 2 PM EDT this
     afternoon for NJZ012>014-020-026.
     Coastal Flood Advisory until 6 AM EDT early this morning for
     NJZ015-017>019.
DE...Flood Watch until 6 AM EDT early this morning for DEZ001.
MD...Flood Watch until 6 AM EDT early this morning for MDZ008-012.
MARINE...Gale Warning until 6 PM EDT Saturday for ANZ430-431-450>455.
-- End Changed Discussion --

&&

$$
Synopsis...AMC
Near Term...Fitzsimmons/Johnson/MPS
Short Term...Fitzsimmons
Long Term...AMC
Aviation...AMC/MPS
Marine...AMC/Johnson/MPS
Tides/Coastal Flooding...