Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 301422
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
1022 AM EDT Fri Sep 30 2016

.SYNOPSIS...
A frontal boundary will remain stationary to our south today
through Saturday with high pressure to our north, and an area of
low pressure to our west. The high pressure will begin to break
down Saturday night into Sunday. The low to our west will then
lift through the Great Lakes region and into the northeast over
the weekend, before weakening on Monday. This will pull the
frontal boundary across our area Sunday. High pressure builds to
our north for Tuesday into Thursday with a northeast flow across
the area.

&&

.NEAR TERM /THROUGH TONIGHT/...
Heaviest rains have basically occurred in the watch area and the
remaining rains will decrease in intensity to drizzle from south
to north later today.

Two day totals since roughly 12z/28.

Harbeson        13.89"
Stockley        11.05
Ellendale        9.68
Selbyville       8.62
Georgetown ASOS  8.65


In the process of trimming watches and warnings in a general
clean up after the event.

Will post around noon, a two 48 hour storm total rainfall summary
and a few max wind gusts that occurred between 1 PM yesterday and
5 am this morning...mostly in the 40-44 kt range from Dover DE
then northeastward along the coasts.

Rivers still rising... appears southern DE...highest stream stage
since 1999 will occur...the 10-14" rains were real. DOX STA has a
good handle on the amounts. Legacy STP that most everyone sees is
too low and I`m using for now, an 80 20 blend weighted to the DOX
STA.

Tonight...The mid level flow shifts a bit more southwesterly
overnight, this will decrease the moisture advection somewhat.
Additionally, the pressure gradient will continue to relax,
meaning low level flow will drop off sharply through the overnight
hours. With very limited instability, expect all precip overnight
to be stratiform and light.

&&

.SHORT TERM /SATURDAY/...
Cloudy and not quite as cool... a bit of drizzle or a few low top
showers possible.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Unsettled weather continues to be forecast for much of the
extended period, especially into the weekend.

By Sunday, the high to our north begins to move eastward, and the
low to our west will begin lifting back toward the Great Lakes
region. This will eventually pull the frontal boundary to our
south across our area on Sunday. There will continue to be a
chance of showers through Sunday as several short wave/vorticity
impulses move across the area as the closed low aloft begins to
break down and lift to the northeast.

On Monday, the mid-level low will be moving across the area, and
the surface low to our north will weaken as it moves into New
England. As the mid-level low crosses the area, there could be
some scattered showers affecting the area Monday into Monday
night.

For Tuesday into Thursday, high pressure builds to our north and
noses its way across our area. With the high to our north, an
onshore flow will develop again, which may end up leading to more
cloud cover and cooler conditions. The mid-level trough continues
to slowly move across the area Tuesday, which could keep a chance
of showers across the area. By Wednesday and Thursday, the trough
moves eastward, but with the northeasterly flow and continued
moisture, there could be some light rain or drizzle across the
area.

The focus beyond the extended turns to Hurricane Matthew. The
current tracks from the long term guidance is for the system to
make the turn to the right and away from the coast before reaching
our area. We will need to continue monitoring the forecast over
the next several days for adjustments to the forecast track.

&&

.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.

Today...MVFR cigs variable IFR conditions in periods of rain and
drizzle. Gusty northeast winds 20 to 30 kt slowly diminishing
later on.

Tonight...Probably mostly IFR cigs with a chance of showers late.
North-northeast wind.

Saturday...IFR cigs should improve MVFR CIGS. mainly north=east
wind.


OUTLOOK...
Saturday night...A prolonged period of MVFR or IFR conditions
with periods of rain is expected to affect the TAF sites through
the period. East to northeast winds are expected to gust 15-20
knots on Saturday.

Sunday-Monday...Some improvement, possibly to VFR. Showers remain
possible.

Monday night-Tuesday...MVFR or IFR conditions likely to return.
Showers remain possible again. East to northeast winds are expected to
gust 15-20 knots on Tuesday.

&&

.MARINE...
Gale conditions continue on the NJ coastal waters, but winds are
expected to decrease this afternoon. Once winds drop below gale
conditions, a small craft advisory will replace the GLW through
tonight due to both wind gusts near 25 kt and lingering high seas.

Otherwise, SCA today DE Bay and SCA DE Atlc waters into Saturday
though mainly for hazardous seas tonight and Saturday. gusts still
near 35 kt near the entrance to De Bay should diminish shortly.

OUTLOOK...

Saturday night-Sunday...Winds and seas expected to drop below Small
Craft Advisory levels.

Sunday night-Monday night...Conditions expected to remain below
Small Craft Advisory levels.

Tuesday...Small Craft Advisory conditions may return to the waters.

RIP CURRENTS... This mornings forecast was the last of this season.
Thank you for your support, especially spreading the safety
messages. We think lack of awareness of the silent danger of rip
currents is why so many lives are lost. For best chance of safety,
swim in the presence of lifeguards.

There is a high risk for the formation of dangerous rip currents
along the NJ shore and the DE beaches today. Wave heights should
slowly diminish this afternoon.

Water temps have cooled into the upper 60s to around 70. So for
those who still enjoy swimming in those somewhat cooler waters...
be alert for the potential strong and dangerous rips toward the
end of next week as a by product of the probable distant seaward
passage of Matthew, provided Matthew makes it north of Bermuda.

&&

.HYDROLOGY...
The heaviest rains have already occurred. The watch is maintained
for several still rising streams.

Appears southern DE...highest stream stage since 1999 will occur...the
10-14" rains were real. DOX STA has a good handle on the amounts.
Legacy STP that most everyone sees is too low and I`m using for
now, an 80 20 blend, weighted to the DOX STA.

Two day totals since roughly 12z/28.

Harbeson        13.89"
Stockley        11.05
Ellendale        9.68
Selbyville       8.62
Georgetown ASOS  8.65

&&

.TIDES/COASTAL FLOODING...
Minor tidal flooding is occuring with this mornings high tide
cycle for all but the tidal Delaware River. Going to be very
close to moderate for upper DE Bay.

As for the high tide cycle this evening, tidal flooding concerns
will depend, to a large part on how quickly the winds drop off
through the day today. For now, am forecasting that winds will
drop off quickly by mid day (except along the far northern shore)
which should lessen the threat for this evening`s high tide. This
will need to be revisited through the day.

&&

.CLIMATE...
Georgetown broke its daily rainfall record with 6.52 inches. Here
are today`s rainfall records.

Sept 30

ACY 1.76 1964
PHL 2.41 2010
ILG 4.32 2010
TTN 1.50 1924
GED 3.15 1964

Updated this morning at 830 AM:

September will be/is a top 10 warmest month through most of our
forecast area, for the 3rd consecutive month!

Also September will be/is enjoying a second consecutive top 5
warmest month in the period of record for PHL and ABE.

We`ve run the actual numbers through the 29th, then added the
forecast high/low for today.

Philadelphia: The 73.5 degree average is 4.4 degrees above the
monthly normal of 69.1. This will be the #5 warmest September on
record for Philadelphia.

Philadelphia September average temperature rankings

75.4 -1881
74.5 -2015
74.1 -1931 74.1 -1930
73.8 -2005
73.5 -2016
72.9 -2010 72.9 - 1921

Philly ranked #7 warmest July followed by a warmest ever August in
the POR dating back to 1874.

Atlantic City: 71.1 degree monthly average temperature, or nearly 4
degrees above the monthly normal of 67.2. This equates to an 8th
warmest September in the period of record dating back to 1874.
Atlantic City recorded a #7 warmest July and then a warmest ever
August.

73.3 - 1961
72.8 - 1881
72.3 - 1931 and 1930
71.7 - 1921
71.6 - 2015
71.5 - 1933
71.3 - 2005

71.1 - 2016 #8
71.0 - 2010
70.6 - 2011 and 1906


Allentown: 69.1 degrees, or 5.2 degrees above the monthly normal
of 63.9 and a 5th warmest September on record. Allentown ranked
8th warmest July and #2 warmest August in the period of record.

70.8 - 1961
70.3 - 1980
69.7 - 2015
69.4 - 1931
69.1 - 2016
68.7 - 2005

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Flash Flood Watch until 4 PM EDT this afternoon for PAZ070.
NJ...High Rip Current Risk until 6 PM EDT this evening for NJZ014-
     024>026.
     Wind Advisory until noon EDT today for NJZ014-025-026.
     Coastal Flood Advisory until noon EDT today for NJZ012>014-
     020>027.
     Flash Flood Watch until 4 PM EDT this afternoon for NJZ016-021-
     023-024.
     Coastal Flood Advisory until 2 PM EDT this afternoon for
     NJZ016.
DE...High Rip Current Risk until 6 PM EDT this evening for DEZ004.
     Coastal Flood Advisory until noon EDT today for DEZ002>004.
     Flash Flood Watch until 4 PM EDT this afternoon for DEZ001>004.
     Coastal Flood Advisory until 2 PM EDT this afternoon for
     DEZ001.
MD...Flash Flood Watch until 4 PM EDT this afternoon for MDZ008-012-
     015-019-020.
MARINE...Gale Warning until 4 PM EDT this afternoon for ANZ452-453.
     Gale Warning until 2 AM EDT Saturday for ANZ450-451.
     Small Craft Advisory until 11 PM EDT this evening for ANZ454-
     455.
     Small Craft Advisory until 5 PM EDT this afternoon for ANZ430-
     431.

&&

$$
Synopsis...Robertson
Near Term...Drag/Johnson 1023
Short Term...Johnson
Long Term...Robertson
Aviation...Drag/Johnson/Robertson
Marine...Drag/Johnson/Robertson
Hydrology...
Tides/Coastal Flooding...1023
Climate...


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