526 
FXUS61 KPHI 152145
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
545 PM EDT Sat Sep 15 2018

.SYNOPSIS...
High pressure centered in New England this afternoon will 
continue to influence our weather into Sunday. The remnants of 
Tropical Cyclone Florence are forecast to lift across the 
northeastern states on Monday and Tuesday. High pressure is 
expected to build down from the northwest and north on Wednesday
and Thursday. A cold front is anticipated to approach from the 
northwest on Friday and it should pass through on region on 
Friday night.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
High pressure remains centered to our north and east while 
Florence continues to sit and spin over the Carolinas. This has 
resulted in an E/NE flow persisting. While the overall trend has
been for drier air to work into the CWA, a persistent deck of
stratocumulus has lingered over portions of SE PA, but should
continue to diminish with the loss of diurnal heating. High 
clouds associated with the far northern periphery of Florence 
are expected to persist over Delmarva through at least the
evening. Otherwise, the trend will be for mostly clear skies
through the evening.

As we have seen the last few nights, patchy fog or a low 
stratus deck may try to form late tonight, primarily across E
Central PA and NW NJ, especially in the river valleys. Limiting
factors though will be continuing advection of slightly drier 
air from the E/NE and winds likely remaining a bit too strong in
the boundary layer for widespread fog. 

It will be cooler with lows generally in the 60s.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
Relatively benign weather looks to continue for Sunday as high 
pressure to the NE remains dominant. Most of Eastern PA and NJ 
should see a mainly sunny to partly cloudy day while clouds will
continue to hold tougher over the Delmarva. In fact by late day
deep layer moisture will be increasing over this area as the 
the flow begins to shift to the E/SE advecting in more moisture 
from Florence. This will lead to continuing chances for some 
showers in the Delmarva and perhaps a few thunderstorms as there
will be a bit more instability. Expect highs generally in the 
upper 70s to low 80s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
Surface high pressure is expected to be centered well off Cape 
Cod on Sunday night. As the air mass loses its influence over 
our weather, we are anticipating an increase in cloud cover. 
Also, there may be isolated showers in Delaware and northeastern
Maryland.

Low pressure, the remnants of Tropical Cyclone Florence, is 
forecast to move from the middle Ohio River Valley on Monday 
morning to northeastern Pennsylvania on Tuesday morning. The 
feature is then expected to move off the New England coast on 
Tuesday night. The widespread heavy rain potential during the 
period from Monday into Tuesday should be mainly from the upper 
Ohio River Valley across New York State and into New England. 
However, we continue to anticipate locally heavy rain in our 
region from late Monday into Tuesday. Conditions remain rather 
saturated, so there is the possibility of localized flooding of 
roads and areas of poor drainage. Also, we could experience some
minor flooding along small streams and creeks.

As the system begins to pass off the New England coast, it 
should pull a cold front through our region on Tuesday evening. 
The showers are forecast to come to an end at that time. High 
pressure is expected to build down from the northwest and north 
for Wednesday and Thursday, bringing a period of dry weather. 
Humidity levels should be noticeably lower than those we have 
been experiencing. Dew point readings are forecast to drop into 
the 50s in much of our region.

A cold front is expected to approach from the northwest on 
Friday and it should pass through our region on Friday night. We
may see an increase in cloud cover on Friday, especially in the
afternoon, with a chance of showers from late Friday into 
Friday night. Dry weather should return for Saturday in the wake
of the front.

Daytime temperatures are forecast to be fairly typical for mid 
to late September during the period from Monday through 
Saturday. However, nighttime readings should remain above 
normal.

&&

.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, 
KILG, KMIV, KACY and surrounding areas.

This afternoon...A broken deck of strato cu is affecting most 
sites and will continue to bring MVFR cigs to most sites through
at least mid afternoon. The exceptions are KMIV/KACY where VFR 
looks to prevail. E/NE winds will generally remain around 5-10 
knots or less. 

Tonight...Strato cu diminishes this evening with mainly VFR. 
Overnight, there could be some low stratus or mist that tries to
form but low confidence on this so we kept this out of the TAFs
for this issuance. E/NE winds generally around 5 knots or less.

Sunday...Mainly VFR with winds remaining light...generally E/NE
at 5- 10 knots or less. 

Outlook... 
Sunday night...VFR with some locations lowering to MVFR 
ceilings and visibility values. East wind 4 to 8 knots.

Monday...Varying from VFR to MVFR with an increasing chance of 
showers. East to southeast wind 5 to 10 knots.

Monday night...MVFR and IFR conditions with showers and 
isolated thunder. The rain may be heavy at times. Southeast to 
south wind 5 to 10 knots.

Tuesday...MVFR and IFR conditions with showers and isolated 
thunder. The rain may be heavy at times. Southwest to west wind 
5 to 10 knots.

Tuesday night...Conditions improving to VFR with showers 
ending. Northwest wind 5 to 10 knots.

Wednesday...Mainly VFR. Northwest wind 5 to 10 knots.

Wednesday night...Mainly VFR. North to northeast wind 6 knots 
or less.

Thursday...Mainly VFR. East to southeast wind 5 to 10 knots.

&&

.MARINE...
Buoy observations for the coastal waters of central and northern
NJ show seas below 5 feet and continuing to diminish. Therefore,
have cancelled the small craft advisory for these locations.

For the Delaware and southern New Jersey waters, seas around 5
feet continue, so will keep the SCA going for now, though seas
should gradually diminish overnight. 

For Delaware Bay, the conditions are expected to be below Small
Craft Advisory criteria through tonight and Sunday. 

OUTLOOK...
Sunday night and Monday...No marine headlines are anticipated.

Monday night through Tuesday evening...Waves on our ocean 
waters may build around 5 feet due to a southerly wind 
increasing around 15 to 20 knots. 

Late Tuesday night through Thursday...No marine headlines are 
anticipated.

Rip Currents... 
A High Risk of dangerous rip currents continues into this 
evening, due to persistent onshore flow, swell energy and waves 
mostly in the 4-6 foot range.

At least a moderate risk of rip currents is expected on Sunday,
as medium-to-long period easterly swell persists.

&&

.TIDES/COASTAL FLOODING...
Spotty minor tidal flooding remains possible around the times 
of high tide tonight and again on Sunday night along the upper 
eastern shore of Chesapeake Bay. The most susceptible area is 
from Kent Island down to the Choptank River. The minor flooding 
should not be widespread or impactful enough to warrant an 
advisory.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...High Rip Current Risk until 9 PM EDT this evening for NJZ014-
     024>026.
DE...High Rip Current Risk until 9 PM EDT this evening for DEZ004.
MD...None.
MARINE...Small Craft Advisory until 6 AM EDT Sunday for ANZ452>455.

&&

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