Flash Flood Watch 11, NWS Philadelphia/Mount Holly

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WGUS61 KPHI 312346
FFAPHI

Flood Watch
National Weather Service Mount Holly NJ
746 PM EDT Wed Jul 31 2019



DEZ001-MDZ008-NJZ008>010-012-013-015>019-PAZ070-071-101>106-
010100-
/O.EXP.KPHI.FF.A.0011.000000T0000Z-190801T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
New Castle-Cecil-Morris-Hunterdon-Somerset-Middlesex-
Western Monmouth-Mercer-Salem-Gloucester-Camden-
Northwestern Burlington-Delaware-Philadelphia-Western Chester-
Eastern Chester-Western Montgomery-Eastern Montgomery-Upper Bucks-
Lower Bucks-
Including the cities of Wilmington, Elkton, Morristown, 
Flemington, Somerville, New Brunswick, Freehold, Trenton, 
Pennsville, Glassboro, Camden, Cherry Hill, Moorestown, 
Mount Holly, Media, Philadelphia, Honey Brook, Oxford, 
West Chester, Kennett Square, Collegeville, Pottstown, 
Norristown, Lansdale, Chalfont, Perkasie, Morrisville, 
and Doylestown
746 PM EDT Wed Jul 31 2019

...FLASH FLOOD WATCH WILL EXPIRE AT 8 PM EDT THIS EVENING...

The Flash Flood Watch for portions of northern Delaware,
northeast Maryland, New Jersey, and southeast Pennsylvania will
expire at 8 PM EDT this evening. Although additional showers and
thunderstorms are possible overnight, the threat for heavy rain
leading to flash flooding is low with additional rounds of showers
and thunderstorms.

$$

Area Forecast Discussion
National Weather Service Mount Holly NJ
839 PM EDT Tue Jul 30 2019

.SYNOPSIS...
Surface troughing will remain in place across the Mid-Atlantic
through the middle of the week. A weak cold front is forecast to
move across the area late Wednesday through early Thursday as high
pressure builds across New England through the end of the week. The
frontal boundary will linger just south of the area through early
next week.
&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
840 PM Update...Due in part to some scattered showers/storms
that affected portions of eastern PA this evening hourly
temperatures have been running a bit cooler than forecast in
places so some adjustments were made accordingly. Otherwise,
these storms continue to generally diminish due to the loss of
daytime heating and it should be a quiet night with conditions
remaining on the warm and muggy side.

Previous Discussion: The main focus for showers and
thunderstorms will remain to our west and northwest into this
evening. We will continue to mention a chance of showers for
Berks County, the Lehigh valley, the Poconos and northwestern
New Jersey. There is little potential for any additional
convection from the Interstate 95 Corridor southeastward.

Any precipitation that affects our northwestern counties into this
evening should dissipate with the loss of daytime heating. The
overnight hours are expected to be clear to partly cloudy in our
region. Low temperatures will favor the upper 60s and the lower 70s
with a light and variable wind.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
A cold front approaching from the northwest will result in an
increasing potential for showers and thunderstorms in our region for
Wednesday, especially in the afternoon. The boundary is forecast to
extend from New England, across northern Pennsylvania to the Ohio
River Valley late on Wednesday afternoon.

A surface trough to the lee of the Applachians is expected to be
well established in our region on Wednesday. We are anticipating
isolated strong wind gusts and locally heavy rainfall with the
thunderstorms on Wednesday afternoon.

The forecast mid level flow on Wednesday afternoon suggests a
northeasterly storm motion around 20 MPH. However, the orientation
of the approaching front and the location of the surface trough may
contribute to some training.

Conditions will remain humid on Wednesday with dew point readings
around 70. High temperatures will likely favor the 80s. The wind is
expected to be from the southwest and west around 5 to 10 MPH.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
Strong to severe thunderstorms across the area Wednesday evening
should weaken into the overnight hours. Heavy rain will still be
a threat, mainly south and east, through about midnight local
time. Expect this activity to wane overnight. Models are still
trying to figure out what happens to the cold front after it
moves through the area Wednesday night and Thursday morning.
Precipitation chances should lower during this period as the
front sags to the south, but the front will likely stall just to
our south. The GFS is quite aggressive at bringing
precipitation into the southern CWA as a midlevel vort max moves
in from the southwest Thursday night and Friday. The CMC/ECMWF
look much drier, keeping precipitation confined primarily to
Delmarva or to our west through this period. Given the rather
wet bias the GFS has exhibited recently and the tendency for
troughs to be more effective in general at scouring
precipitation to the north of stalling fronts (at least for a
time), sided the forecast on the drier side. That said, I do
have mentionable PoPs south of I-76 Thursday and Friday (and
everywhere Friday), given the uncertainty. Friday (and possibly
Saturday) appears to be the best chance for widespread showers
and thunderstorms beyond Wednesday.

Perhaps the biggest change to the forecast from 36 hours ago is
for Saturday. The 00z GFS and ECMWF both hint at a weak front
moving in from the northwest. This is attendant to a digging
vort max from the established eastern-Canada longwave trough.
The QPF signal has noticeably increased with the ECMWF during
this period, especially to our west, for Saturday afternoon.
Have added/increased PoPs across the board Saturday and Saturday
night, with the highest PoPs west (near the front's expected
position during peak heating) and south (near the languishing
front to our south). The GFS and ECMWF hint at another system on
Sunday as well, but the effects of this second one may be too
far north of our area. For now, have slight- chance PoPs for
Sunday (which is basically climatology).

High pressure may build into the area early next week, but
confidence is rather low given the complicated regime preceding
this.

Forecast temperatures through the period are close to
climatology, varying little day to day.

&&

.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.

Tonight...Mainly VFR. Local MVFR visibility restrictions are
possible...mainly at KRDG, KABE. Variable wind 6 knots or less.

Wednesday...Mainly VFR. Showers and thunderstorms in the afternoon
will reduce conditions to MVFR or IFR at times. Southwest to west
wind 5 to 10 knots.

OUTLOOK...

Wednesday night...A chance of storms during the evening and
early overnight. Gusty/erratic winds and torrential downpours
will be possible with the storms, with brief restrictions to be
expected if/when they impact the terminals. Outside of
convection, mainly VFR with southwest winds 5 to 15 kts becoming
northwest as a front slowly moves through the area.

Thursday through Friday night...Mainly VFR, though there is
some chance of storms both days, especially south and west of
PHL. North winds on Thursday becoming more east or southeast
Thursday night and Friday, with speeds generally 10 kts or less.

Saturday through Saturday night...Mainly VFR, though a chance
of storms exists across the area. Brief restrictions possible.
Winds generally south or southeast up to 10 kts.

&&

.MARINE...
Southwest wind generally 10 to 15 knots tonight and Wednesday. Wave
heights on our ocean waters will be 2 to 4 feet with a long period
southeast swell underlying any wind waves. On Delaware Bay, wave
should be 2 feet or less.

OUTLOOK...

Wednesday night...A good chance of storms lingering into the
evening and early overnight hours, with gusty/erratic winds and
locally higher waves in their proximity. Outside of storms,
sub-advisory winds/seas expected.

Thursday through Saturday...Sub-advisory winds/seas expected. A
chance of storms through the period, primarily off the Delaware
coast.

RIP CURRENTS...

A 13 to 15 second southeasterly swell will continue along the coasts
of Delaware and New Jersey into Wednesday. As a result, there will
be a moderate risk for the development of dangerous rip currents
through that time.

&&

.EQUIPMENT...
The NOAA Weather Radio transmitter located in Howell, New
Jersey (Station WXM-60) was damaged during the storms on July
22. As a result, the radio signal is not transmitting properly.
It will take a while for the repairs to be made. We do not have
an estimate as to when the broadcast will be fully restored.

&&

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

&&

Synopsis...Staarmann
Near Term...Fitzsimmons/Iovino
Short Term...Iovino
Long Term...CMS/Staarmann
Aviation...CMS/Iovino/Staarmann
Marine...CMS/Iovino/Staarmann
Equipment...

Hazardous Weather Outlook
National Weather Service Mount Holly NJ
310 PM EDT Tue Jul 30 2019

DEZ001>003-MDZ008-012-015-019-020-NJZ001-007>010-012-013-015>023-027-
PAZ054-055-060>062-070-071-101>106-311915-
New Castle-Kent-Inland Sussex-Cecil-Kent MD-Queen Annes-Talbot-
Caroline-Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-
Western Monmouth-Mercer-Salem-Gloucester-Camden-
Northwestern Burlington-Ocean-Cumberland-Atlantic-Cape May-
Southeastern Burlington-Carbon-Monroe-Berks-Lehigh-Northampton-
Delaware-Philadelphia-Western Chester-Eastern Chester-
Western Montgomery-Eastern Montgomery-Upper Bucks-Lower Bucks-
310 PM EDT Tue Jul 30 2019

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, east central Pennsylvania, northeast Pennsylvania and
southeast Pennsylvania.

.DAY ONE...This afternoon and tonight.

There is a low probability for widespread hazardous weather.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

There is the potential for locally heavy rain and isolated damaging
wind gusts on Wednesday afternoon and Wednesday evening. The heavy
rain could result in flooding of roadways and areas of poor drainage.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

DEZ004-NJZ014-024>026-311915-
Delaware Beaches-Eastern Monmouth-Atlantic Coastal Cape May-
Coastal Atlantic-Coastal Ocean-
310 PM EDT Tue Jul 30 2019

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

.DAY ONE...This afternoon and tonight.

There is a moderate risk for the development of dangerous rip
currents.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

A moderate risk for the development of dangerous rip currents is
expected for Wednesday.

There is the potential for locally heavy rain and isolated damaging
wind gusts on Wednesday afternoon and Wednesday evening. The heavy
rain could result in flooding of roadways and areas of poor drainage.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

ANZ430-431-450>455-311915-
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-
310 PM EDT Tue Jul 30 2019

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

.DAY ONE...This afternoon and tonight.

There is a low probability for widespread hazardous weather.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Wind gusts in excess of 35 knots are possible with any thunderstorms
on Wednesday afternoon and Wednesday evening.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

Special Weather Statement
National Weather Service Mount Holly NJ
1045 PM EDT Tue Jul 30 2019

PAZ060-310330-
Berks-
1045 PM EDT Tue Jul 30 2019

...A STRONG THUNDERSTORM WILL AFFECT NORTHWESTERN BERKS COUNTY...

At 1045 PM EDT, a strong thunderstorm was located over Avon, or over
Myerstown, moving northeast at 30 mph.

Wind gusts up to 50 mph and pea size hail are possible with this
storm.

Locations impacted include...
Hamburg, Womelsdorf, Bernville and Strausstown.

If outdoors, consider seeking shelter inside a building.

LAT...LON 4052 7634 4052 7625 4058 7605 4057 7602
      4064 7599 4058 7589 4036 7620 4039 7627
      4049 7643
TIME...MOT...LOC 0245Z 222DEG 27KT 4038 7637

CMS

Special Weather Statement
National Weather Service Mount Holly NJ
1138 PM EDT Tue Jul 30 2019

PAZ054-060-061-310430-
Lehigh-Berks-Carbon-
1138 PM EDT Tue Jul 30 2019

...A STRONG THUNDERSTORM WILL AFFECT NORTH CENTRAL BERKS...
NORTHWESTERN LEHIGH AND SOUTHWESTERN CARBON COUNTIES...

At 1137 PM EDT, a strong thunderstorm was located over Wanamakers, or
10 miles south of Tamaqua, moving northeast at 15 mph.

Wind gusts up to 50 mph and pea size hail are possible with this
storm.

Locations impacted include...
Lehighton, Palmerton, Jim Thorpe, Nesquehoning, Lenhartsville, New
Mahoning, Wanamakers, New Tripoli, Jordan Valley, Lansford, Summit
Hill, Bowmanstown, Parryville, Weissport and Weissport East.

If outdoors, consider seeking shelter inside a building.

LAT...LON 4063 7600 4065 7598 4069 7587 4070 7583
      4074 7576 4081 7587 4086 7594 4091 7593
      4080 7561 4054 7583 4061 7601
TIME...MOT...LOC 0337Z 204DEG 15KT 4066 7590

CMS

Special Weather Statement
National Weather Service Mount Holly NJ
1206 AM EDT Wed Jul 31 2019

PAZ054-055-061-062-310445-
Lehigh-Monroe-Northampton-Carbon-
1206 AM EDT Wed Jul 31 2019

...A STRONG THUNDERSTORM WILL AFFECT NORTH CENTRAL LEHIGH...CARBON...
SOUTHWESTERN MONROE AND WESTERN NORTHAMPTON COUNTIES...

At 1206 AM EDT, a strong thunderstorm was located over Palmerton, or
over Lehighton, moving northeast at 25 mph.

Wind gusts up to 50 mph and pea size hail are possible with this
storm.

Locations impacted include...
Lehighton, Palmerton, Jim Thorpe, Slatington, Nesquehoning,
Walnutport, Brodheadsville, Kunkletown, Gilbert, Pocono Raceway, Lake
Harmony, Rossland, Berlinsville, Albrightsville, Emerald,
Kresgeville, Sun Valley, Jonas, Meckesville and Danielsville.

If outdoors, consider seeking shelter inside a building.

LAT...LON 4071 7568 4086 7586 4112 7557 4091 7530
TIME...MOT...LOC 0406Z 224DEG 23KT 4081 7567

CMS