Areal Flood Advisory 201, NWS Philadelphia/Mount Holly

Area Forecast Discussion
National Weather Service Mount Holly NJ
1004 AM EDT Sat Aug 12 2017

.SYNOPSIS...
A cold front will move across the east coast tonight. High
pressure will briefly build across the area Sunday night into
early next week. The front will stall to the south Monday into
Tuesday as an area of low pressure develops along the boundary
and moves eastward along the front. Another frontal boundary may
affect the area Wednesday, before high pressure briefly builds
across the area Wednesday night, then offshore Thursday. A
frontal system could then affect the area late next week or
early next weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Showers will continue to pass across parts of northeastern
Maryland, Delaware and southern New Jersey until early
afternoon. The showers are expected to sink gradually to the
south.

Meanwhile low clouds will remain over eastern Pennsylvania, New
Jersey and the upper Delmarva for the balance of the morning.
The clouds are forecast to lift slowly.

A cold front extended across the eastern Great Lakes and the
Ohio River Valley this morning. The boundary will move eastward
and it is expected to reach central Pennsylvania and western
Virginia toward evening. A line of showers and thunderstorms is
forecast to develop in advance of the front and it should arrive
in Berks County, the Poconos and the Lehigh Valley late this
afternoon. The thunderstorms there may bring strong wind gusts
and hail along with frequent cloud to ground lightning and heavy
rainfall.

Depending upon how much clearing takes place this afternoon,
conditions may be slow to destabilize over parts of southeastern
Pennsylvania and New Jersey. As a result, the showers and
thunderstorms may lose some of their strength as they move
farther to the east late in the day.

High temperatures are expected to favor the lower 80s. Once the
marine layer erodes, the wind should settle into the south and
southwest around 8 to 12 MPH.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
The low pressure system will be crossing thru New england
tonight. A weak cold front attached to the low will cross our
area from NW to Se overnight. Scattered showers and a few tstms
will be ahead of the front this evening into early tonight,
before pops decrease towards dawn. Low will drop into the upper
50s to low 60s across the nrn areas, and remain closer to 70
over Delmarva and metro Philadelphia.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
The cold front is forecast to push south of the area by Sunday
morning, before a secondary front or surface trough may cross
the area later on Sunday into Sunday night. Moisture and lift
will weaken during the day, so it now looks like Sunday will be
a dry day.

The initial cold front is forecast to stall to our south
through Monday and Tuesday. Weak high pressure is forecast to
affect the area Sunday night into early next week. An area of
low pressure is expected to develop along the front to the south
and moves to our east Monday night through Tuesday. Also, a
possible tropical low may lift northward over the Atlantic and
combine with this low and move eastward along the front. Just
like the last couple of days, the GFS remains farther south and
east than the ECMWF with the low. There still remains the
possibility some showers could move across portions of the area
Monday through Tuesday, so we'll keep chance POPS in the
forecast for now. Also on Tuesday, a weak surface trough may
move across the area which may help create a few showers or
thunderstorms as well.

Another frontal boundary may move across the area Wednesday,
Wednesday, before high pressure briefly builds across the area
Wednesday night, then offshore Thursday. This frontal boundary
and subsequent high pressure are forecast to contain dry
weather. However, we move into the end of the week into the
early part of the weekend, a warm front may lift across the area
as high pressure builds offshore, followed by a cold front. The
timing is uncertain as the GFS is slower than the ECMWF, but
they both do indicate this system. So we'll have a chance of
showers and thunderstorms from Thursday night through Friday
night for now.

&&

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

A period of lower CIGS/VSBYS is across the terminals this
morning, before conditions will improve during the late
morning/early afternoon hours. More showers and tstms are
expected this afternoon and into the evening as a cold front
crosses the area. More MVFR/IFR will be possible at those times.
Light variable winds early today will become SW at 5 to 10 kts
this afternoon. VFR conditions expected later tonight behind the
cold front.

OUTLOOK...
Sunday-Wednesday...Generally VFR conditions. Scattered showers
and thunderstorms possible Monday-Tuesday which may temporarily
reduce conditions.

&&

.MARINE...
Winds and seas will increase a bit this afternoon ahead of the
low pressure system and front approaching from the Great Lakes.
it doesn't appear that SCA conditions will be reached, so we
will hold on the flag for now. A few gusts in the low 20s kts
are possible and seas could reach 3-4 ft on the ocean, so near
SCA conditions. Sct showers and tstms will bring some locally
higher winds and seas this afternoon and in to the evening. Fair
weather expected later tonight behind the cold front.

OUTLOOK...
Sunday-Wednesday...Sub Small Craft Advisory conditions expected
through the entire period.

RIP CURRENTS...
The risk for the development of dangerous rip currents remains
low for today. However, it may approach moderate along the New
Jersey Shore late in the day as wind speeds increase from the
south.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.

&&

Synopsis...Robertson
Near Term...Iovino
Short Term...O'Hara
Long Term...Robertson
Aviation...Robertson/O'Hara
Marine...Robertson/O'Hara

Hazardous Weather Outlook
National Weather Service Mount Holly NJ
914 AM EDT Sat Aug 12 2017

DEZ001>003-MDZ008-012-015-019-020-NJZ008>010-012-013-015>023-027-
PAZ070-071-104-106-131315-
New Castle-Kent-Inland Sussex-Cecil-Kent MD-Queen Annes-Talbot-
Caroline-Morris-Hunterdon-Somerset-Middlesex-Western Monmouth-Mercer-
Salem-Gloucester-Camden-Northwestern Burlington-Ocean-Cumberland-
Atlantic-Cape May-Southeastern Burlington-Delaware-Philadelphia-
Eastern Montgomery-Lower Bucks-
914 AM EDT Sat Aug 12 2017

This Hazardous Weather Outlook is for central Delaware, northern
Delaware, southern Delaware, northeast Maryland, central New
Jersey, northern New Jersey, northwest New Jersey, southern New
Jersey and southeast Pennsylvania.

.DAY ONE...Today and Tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

DEZ004-NJZ014-024>026-131315-
Delaware Beaches-Eastern Monmouth-Atlantic Coastal Cape May-
Coastal Atlantic-Coastal Ocean-
914 AM EDT Sat Aug 12 2017

This Hazardous Weather Outlook is for southern Delaware, central
New Jersey and southern New Jersey.

.DAY ONE...Today and Tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

ANZ430-431-450>455-131315-
Delaware Bay waters north of East Point NJ to Slaughter Beach DE-
Delaware Bay waters south of East Point NJ to Slaughter Beach DE-
Coastal waters from Sandy Hook to Manasquan Inlet NJ out 20 nm-
Coastal waters from Manasquan Inlet to Little Egg Inlet NJ out 20 nm-
Coastal waters from Little Egg Inlet to Great Egg Inlet NJ out 20 nm-
Coastal waters from Great Egg Inlet to Cape May NJ out 20 nm-
Coastal waters from Cape May NJ to Cape Henlopen DE out 20 nm-
Coastal waters from Cape Henlopen to Fenwick Island DE out 20 nm-
914 AM EDT Sat Aug 12 2017

This Hazardous Weather Outlook is for Atlantic coastal waters and
Delaware Bay Waters.

.DAY ONE...Today and Tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

NJZ001-007-PAZ054-055-060>062-101>103-105-131315-
Sussex-Warren-Carbon-Monroe-Berks-Lehigh-Northampton-Western Chester-
Eastern Chester-Western Montgomery-Upper Bucks-
914 AM EDT Sat Aug 12 2017

This Hazardous Weather Outlook is for northern New Jersey, east
central Pennsylvania, northeast Pennsylvania and southeast
Pennsylvania.

.DAY ONE...Today and Tonight.

Scattered thunderstorms are expected to move in from the west late
this afternoon and this evening. A few of these storms could become
severe and produce locally damaging winds.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is possible late this afternoon and evening.

JRK

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1006 AM EDT SAT AUG 12 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1159 PM     TSTM WND DMG     1 W TRAPPE              38.66N  76.08W
08/11/2017                   TALBOT             MD   911 CALL CENTER

            A TREE WAS TAKEN DOWN BY THUNDERSTORM WINDS ONTO WIRES.

&&

EVENT NUMBER PHI1701465

GAINES

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1124 AM EDT SAT AUG 12 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1159 PM     TSTM WND DMG     1 W TRAPPE              38.66N  76.08W
08/11/2017                   TALBOT             MD   911 CALL CENTER

            A TREE WAS TAKEN DOWN BY THUNDERSTORM WINDS ONTO WIRES.

1100 AM     FLOOD            6 E SELBYVILLE          38.46N  75.11W
08/12/2017                   SUSSEX             DE   TRAINED SPOTTER

            A POND AND STREAM OVERFLOWED WHICH FLOODED A LARGE
            PORTION OF A YARD.

&&

EVENT NUMBER PHI1701465 PHI1701466

GAINES