New Jersey, 2016

Flash Flooding and Flooding in New Jersey, July 30 to 31, 2016

July 30 to 31, 2016 · NWS PHI · 77 events in 9 counties and zones

Several clusters of thunderstorms associated with several shortwaves and a cold front became nearly stationary over Mercer County on the 29th and Hunderdon County on the morning of the 30th. Heavy rainfall over 5 inches occurred in these areas.

Where it happened

Every event with a place to put it. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

Open the live radar over this ground

The toll

Deaths
0
Injuries
0
Property damage
$3.1 million
Crop damage
None recorded
Events
77

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS PHI wrote it up.

Several clusters of thunderstorms associated with several shortwaves and a cold front became nearly stationary over Mercer County on the 29th and Hunderdon County on the morning of the 30th. Heavy rainfall over 5 inches occurred in these areas. The persistent heavy rain resulted in severe flash flooding including a state of emergency being issued in West Windsor Twp. Thousands were left without power as a result of the storms. The Monmouth county fair and New Jersey Balloon festival were cancelled due to weather on 7/31.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Philadelphia/Mount Holly wrote its last area forecast discussion before the first event at Jul 30, 8:11 AM EST, 5 hours 44 minutes earlier.

Area forecast discussion, Jul 30, 8:11 AM EST, 5 hours 44 minutes before
Area Forecast Discussion
National Weather Service Mount Holly NJ
911 AM EDT SAT JUL 30 2016

.SYNOPSIS...
As a weak frontal boundary remains near our area today into early
next week, a few weak low pressure systems will track along it.
High pressure will build across our area Tuesday through Wednesday
before shifting offshore Thursday, then a cold front is scheduled
to arrive Friday night.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

We are anticipating a break in the potential for showers in our
forecast area until about noontime when the HRRR and RAP both show
a quick uptick in shower and thunderstorm coverage across the
region. Showers and thunderstorms are expected to become more
numerous during the afternoon as an impulse traveling in the mid
level flow begins to approach from the west. An isolated strong to
severe storm this afternoon can not be ruled out across Delmarva
with an environment marked with 1000-2000 J/KG Surface and mixed
layer CAPE coupled with about 30 knots of 0-6 km bulk shear. A
developing south to southeast surface flow will draw additional
moisture into our region. Precipitable water values are forecast
to increase to around 2.0 to 2.1 inches. As a result, the rain may
become heavy at times.

We are expecting an increase in overall cloud cover today and
temperatures should not get above the 80s.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
We continue to expect showers and scattered thunderstorms for
tonight as a couple of mid level impulses affect our region and as
a warm front approaches from the southwest and south. We will keep
the mention of rain, heavy at times, due to additional low level
moisture advecting into our region on a southeasterly flow off the
ocean.

Overnight minimum temperatures are forecast to be in the upper
60s in the Poconos and far northern New Jersey and mainly in the
lower 70s in the rest of our region.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
The synoptic setup is comprised of general troughing in the
Northeast to start that then becomes more amplified during early
next week. This should shift offshore midweek as some ridging
starts to migrate eastward from the Plains. The ridge axis may not
arrive until Friday, therefore a cooler airmass is for a few days
next week. We used a model blend for Sunday into Tuesday, then
mostly went with the 00z WPC guidance. Some adjustments were then
made however following additional collaboration with our
neighboring offices.

For Sunday and Monday...A couple of short waves will move across
our region as a frontal boundary remains in the vicinity. The
result will be some showers and thunderstorms. While the specific
timing of the short waves is less certain, the more widespread
convective activity should occur during peak heating and
potentially be more focused initially along a weak surface
convergence zone. The PW values are forecast to be around 2.00
inches and therefore locally torrential downpours can occur. While
any flood threat should be localized Sunday, weak low-level flow
may result in slow movers and back building of any thunderstorms.
Any robust convection may produce quite a bit of lightning.
Overall, the severe weather threat looks rather low at this time.
For Monday, an upper-level trough sharpens and with some cooling
aloft and increase in the wind fields, a few locally stronger
storms may occur during the afternoon.

For Tuesday through Thursday...A cold front should be south and
east of our area to start Tuesday, as high pressure builds in.
This surface high is forecast to be in place through Wednesday
before it shifts offshore Thursday. We are anticipating some
lowering of the dew points and also the temperatures. Some return
flow however starts to develop on Thursday, which should allow the
dew points to inch back up some.

For Friday...High pressure to our south and east will yield to a
warm front lifting well to our north. This will help assist in a
more south-southwest flow as a cold front approaches in the
afternoon, then the front should start settling across our area at
night. An area of warm air advection ahead of the front will allow
for afternoon temperatures to approach 90 degrees especially from
the Interstate 95 corridor on south and east. The overall timing
of the front will govern any convective threat as it appears that
a lee side trough may not be present. We carried slight chance to
low chance pops from west to east Friday afternoon and night.

&&

.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

VFR,however, showers and scattered thunderstorms are expected to
be on the increase as the day progresses. Ceilings and visibility
values are anticipated to lower to MVFR and perhaps IFR tonight as
a warm front approaches from the southwest and south.

The wind direction should favor the south for today and it will
likely become southeast for tonight. Speeds are forecast to be
mostly less than 10 knots.

Outlook...
Sunday and Monday...Potential for MVFR ceilings to start each
morning, otherwise VFR with scattered to broken cloud cover. Some
showers and thunderstorms will be around especially Sunday and
this will lead to mainly local and brief restrictions.

Tuesday and Wednesday...VFR overall as high pressure builds in.

&&

.MARINE...
The wind is expected to settle into the south and southeast for
today around 5 to 10 knots. The wind is forecast to favor the
southeast for tonight and speeds may increase to 10 to 15 knots as
a warm front approaches from the southwest and south.

Wave heights on our ocean waters are expected to be 2 to 3 feet
for today and tonight. Waves on Delaware Bay should be 2 feet or
less.

Showers and scattered thunderstorms are anticipated from this
afternoon into tonight.

Outlook...
Sunday through Wednesday...An onshore flow Sunday should increase
some especially across the northern coastal waters, with gusts to
about 20 knots. It appears at this point that that conditions
remain below advisory criteria. Otherwise, a weak pressure
gradient should keep winds and seas mainly below Small Craft
Advisory criteria through Wednesday. Main concern will be the
threat of some thunderstorms Sunday and Monday, however the
greatest concentration of storms may be inland.

Rip Currents...
For today, there is a low risk for the development of dangerous
rip currents along the coasts of New Jersey and Delaware. The wind
direction should favor the southeast at 5 to 10 MPH with wave
heights in the 2 to 3 foot range. We are anticipating a southerly
swell with a wave period around 6 seconds.

For Sunday, a low risk overall. However a moderate risk is
possible mainly along the northern New Jersey coast although this
will be dependent on the strength of an onshore flow.

&&

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

&&

Synopsis...Gorse
Near Term...Gaines/Iovino
Short Term...Iovino
Long Term...Gorse
Aviation...Gorse/Iovino
Marine...Gorse/Iovino
Hazardous weather outlook, Jul 30, 2:51 AM EST, 11 hours 4 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
351 AM EDT SAT JUL 30 2016

DEZ001>003-MDZ008-012-015-019-020-NJZ001-007>010-012-013-015>023-027-
PAZ054-055-060>062-070-071-101>106-310800-
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-
351 AM EDT SAT JUL 30 2016

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...TODAY AND TONIGHT.

SOME SHOWERS AND THUNDERSTORMS MAINLY THIS AFTERNOON AND TONIGHT
WILL PRODUCE HEAVY RAIN AT TIMES, POTENTIALLY LEADING TO LOCALIZED
FLOODING.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

SOME SHOWERS AND THUNDERSTORMS SUNDAY, ESPECIALLY IN THE
AFTERNOON, WILL PRODUCE HEAVY RAIN AT TIMES, POTENTIALLY LEADING
TO LOCALIZED FLOODING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

DEZ004-NJZ014-024>026-310800-
DELAWARE BEACHES-EASTERN MONMOUTH-ATLANTIC COASTAL CAPE MAY-
COASTAL ATLANTIC-COASTAL OCEAN-
351 AM EDT SAT JUL 30 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHERN DELAWARE...CENTRAL
NEW JERSEY AND SOUTHERN NEW JERSEY.

.DAY ONE...TODAY AND TONIGHT.

SOME SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND TONIGHT WILL
PRODUCE HEAVY RAIN AT TIMES, POTENTIALLY LEADING TO LOCALIZED
FLOODING.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

SOME SHOWERS AND THUNDERSTORMS SUNDAY, ESPECIALLY IN THE
AFTERNOON, WILL PRODUCE HEAVY RAIN AT TIMES, POTENTIALLY LEADING
TO LOCALIZED FLOODING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

ANZ430-431-450>455-310800-
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-
351 AM EDT SAT JUL 30 2016

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.

In the hours before

Special weather statement, Jul 30, 10:04 AM EST, 3 hours 51 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1104 AM EDT SAT JUL 30 2016

DEZ001-MDZ008-PAZ101-102-301600-
NEW CASTLE-CECIL-WESTERN CHESTER-EASTERN CHESTER-
1104 AM EDT SAT JUL 30 2016

...A STRONG THUNDERSTORM WILL AFFECT NORTHWESTERN NEW CASTLE...
CENTRAL CECIL AND SOUTHWESTERN CHESTER COUNTIES...

AT 1104 AM EDT...A STRONG THUNDERSTORM WAS OVER HAVRE DE GRACE...
MOVING NORTHEAST AT 20 MPH.

WIND GUSTS UP TO 30 MPH AND PEA SIZE HAIL ARE POSSIBLE WITH THIS
STORM.

LOCATIONS IMPACTED INCLUDE...
NEWARK...ELKTON...CALVERT...OXFORD...NORTH EAST...WEST GROVE...
RISING SUN...CHARLESTOWN...PLEASANT HILL...BLAKE...ANDORA...
HOMEVILLE...MOUNT VERNON...GLEN ROY...RICHARDSMERE...WOODLAWN...
LADENBERG...NORTH STAR...APPLETON AND CHERRY HILL.

LAT...LON 3974 7612 3973 7610 3976 7606 3983 7604
      3987 7599 3991 7599 3976 7569 3939 7601
      3940 7603 3943 7599 3946 7601 3952 7598
      3955 7603 3955 7608 3967 7619
TIME...MOT...LOC 1504Z 212DEG 16KT 3954 7610

MEOLA
Special weather statement, Jul 30, 11:36 AM EST, 2 hours 19 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1236 PM EDT SAT JUL 30 2016

DEZ001-002-MDZ008-012-015-NJZ016-301730-
KENT-NEW CASTLE-CECIL-KENT-QUEEN ANNE'S-SALEM-
1236 PM EDT SAT JUL 30 2016

...AN AREA OF STRONG THUNDERSTORMS WILL AFFECT NEW CASTLE...
NORTHWESTERN KENT...NORTHERN KENT...CECIL...NORTHEASTERN QUEEN
ANNE'S...WESTERN SALEM AND SOUTHERN CHESTER COUNTIES...

AT 1235 PM EDT...AN AREA OF STRONG THUNDERSTORMS WAS NEAR CECILTON...
OR 10 MILES EAST OF ABERDEEN PROVING GROUND...MOVING NORTHEAST AT 20
MPH.

WIND GUSTS UP TO 30 MPH AND PEA SIZE HAIL ARE POSSIBLE WITH THIS
STORM.

LOCATIONS IMPACTED INCLUDE...
WILMINGTON...NEWARK...MIDDLETOWN...ELKTON...CALVERT...PENNSVILLE...
SMYRNA...ELSMERE...NEW CASTLE...CHESTERTOWN...NORTH EAST...CLAYTON...
DELAWARE CITY...CHARLESTOWN...NEWPORT...CHURCH HILL...CECILTON...
MILLINGTON...SUDLERSVILLE AND BETTERTON.

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY CAUSE
LOCALIZED FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

LAT...LON 3929 7617 3934 7616 3943 7599 3952 7598
      3955 7608 3961 7612 3972 7599 3972 7577
      3978 7574 3973 7551 3965 7556 3967 7551
      3958 7551 3959 7553 3956 7557 3954 7554
      3949 7559 3935 7551 3911 7603 3926 7622
TIME...MOT...LOC 1635Z 212DEG 16KT 3941 7594

MEOLA
Special weather statement, Jul 30, 11:51 AM EST, 2 hours 4 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1251 PM EDT SAT JUL 30 2016

NJZ009-015-PAZ105-106-301745-
HUNTERDON-MERCER-LOWER BUCKS-UPPER BUCKS-
1251 PM EDT SAT JUL 30 2016

...A STRONG THUNDERSTORM WILL AFFECT NORTHWESTERN MERCER...SOUTHERN
HUNTERDON AND EAST CENTRAL BUCKS COUNTIES...

AT 1250 PM EDT...A STRONG THUNDERSTORM WAS NEAR RICHBORO...OR 12
MILES WEST OF TRENTON...MOVING NORTHEAST AT 5 MPH.

WIND GUSTS UP TO 40 MPH AND PEA SIZE HAIL ARE POSSIBLE WITH THIS
STORM.

LOCATIONS IMPACTED INCLUDE...
EWING...DOYLESTOWN...PENNINGTON...NEW HOPE...YARDLEY...NEWTOWN...
WASHINGTON CROSSING...WOODSIDE...RICHBORO...
LAMBERTVILLE AND NEWTOWN GRANT.

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY CAUSE
LOCALIZED FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

LAT...LON 4021 7492 4032 7515 4038 7498 4036 7479
      4028 7477
TIME...MOT...LOC 1650Z 230DEG 5KT 4027 7498

MEOLA
Special weather statement, Jul 30, 12:55 PM EST, 1 hour before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
155 PM EDT SAT JUL 30 2016

NJZ008>010-301845-
SOMERSET-MORRIS-HUNTERDON-
155 PM EDT SAT JUL 30 2016

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN HUNTERDON...
NORTHWESTERN SOMERSET AND SOUTHWESTERN MORRIS COUNTIES...

AT 154 PM EDT...A STRONG THUNDERSTORM WAS NEAR FLEMINGTON...OR 11
MILES WEST OF SOMERVILLE...MOVING NORTHEAST AT 15 MPH.

LOCATIONS IMPACTED INCLUDE...
BRIDGEWATER...FLEMINGTON...HIGH BRIDGE...CLINTON...
PEAPACK AND GLADSTONE...LEBANON...CALIFON...FAR HILLS...
WHITE HOUSE STATION...CLOVERHILL...ANNANDALE AND RARITAN.

WIND GUSTS UP TO 35 MPH ARE POSSIBLE WITH THIS STORM.

HEAVY RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY CAUSE
PONDING ON ROADWAYS AND POOR DRAINAGE AREAS. DO NOT DRIVE YOUR
VEHICLE THROUGH HIGH WATER.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

LAT...LON 4045 7478 4051 7497 4075 7485 4067 7456
TIME...MOT...LOC 1754Z 206DEG 13KT 4056 7483

ROBERTSON
Special weather statement, Jul 30, 1:40 PM EST, 15 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
240 PM EDT SAT JUL 30 2016

NJZ001-007>010-301915-
SUSSEX-SOMERSET-MORRIS-HUNTERDON-WARREN-
240 PM EDT SAT JUL 30 2016

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT EAST CENTRAL WARREN...
NORTHEASTERN HUNTERDON...SOUTH CENTRAL SUSSEX...NORTHEASTERN SOMERSET
AND MORRIS COUNTIES...

AT 240 PM EDT...A LINE OF STRONG THUNDERSTORMS WAS ALONG A LINE
EXTENDING FROM NEAR BEATYESTOWN TO NEAR MORRISTOWN TO NEAR CLARK...
AND MOVING NORTHEAST AT 20 MPH.

WIND GUSTS UP TO 35 MPH ARE POSSIBLE WITH THIS STORM.

HEAVY RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY CAUSE
PONDING ON ROADWAYS AND POOR DRAINAGE AREAS. DO NOT DRIVE YOUR
VEHICLE THROUGH HIGH WATER.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

LOCATIONS IMPACTED INCLUDE...
MORRISTOWN...DOVER...MADISON...HOPATCONG...FLORHAM PARK...
EAST HANOVER...LINCOLN PARK...HACKETTSTOWN...CHATHAM...BOONTON...
WHARTON...ROCKAWAY...MORRIS PLAINS...MOUNT ARLINGTON...MENDHAM...
MOUNTAIN LAKES...STANHOPE...NETCONG...
PEAPACK AND GLADSTONE AND CHESTER.

LAT...LON 4090 7427 4091 7433 4083 7433 4076 7438
      4075 7436 4067 7446 4066 7445 4066 7440
      4062 7443 4070 7459 4074 7492 4096 7481
      4093 7429
TIME...MOT...LOC 1840Z 224DEG 15KT 4077 7483 4076 7452 4064 7436

ROBERTSON

The radar

The Philadelphia radar (KDIX), 94 km away, was scanning. The volume nearest the first event began at 18:55 UTC.

Open the radar archive at this moment

Event by event

60 heavy rain, 9 flash flood, 6 flood, 2 thunderstorm wind. Local standard time, as filed.

Thunderstorm Wind, Morris

When
July 30, 1:55 PM EST
Where
Morris County, 1.25 mi WSW of Morristown
Measured
52 kt (60 mph) estimated gust
Reported by
Broadcast Media
Coordinates
40.790, -74.490

Trees and wires down on Western Ave in Morristown due to thunderstorm winds.

Thunderstorm Wind, Morris

When
July 30, 2:05 PM EST
Where
Morris County, 1.48 mi NNW of Cedar Knolls
Measured
52 kt (60 mph) estimated gust
Reported by
CoCoRaHS
Coordinates
40.840, -74.460

Trees were taken down at the intersection of 202 and route 10 in Morris Plains due to thunderstorm winds.

Flood, Middlesex

When
July 30, 2:46 PM EST
Where
Middlesex County, 1.33 mi NNW of Cheesequake to 1.46 mi SSW of South Amboy Jct
Cause
Heavy Rain
Reported by
Social Media
Coordinates
40.447, -74.291

Street flooding reported near the old bridge park and ride. Photos show water about half way up to lights on cars driving through it. Water about six inches deep.

Flash Flood, Mercer

When
July 30, 3:04 PM EST to 5:04 PM EST
Where
Mercer County, 1.26 mi WNW of Dutch Neck to 1.25 mi N of Grovers Mills
Cause
Heavy Rain
Property damage
$1.0 million
Reported by
Social Media
Coordinates
40.290, -74.640

Multiple roads were flooded and impassable including US 1, Route 571, Washington and Alexander roads. Water rescues ongoing in Princeton. Canal Pointe Blvd also was closed due to flooding/ Several people were trapped in cars and needed to be rescued.

Flash Flood, Middlesex

When
July 30, 3:20 PM EST to 5:20 PM EST
Where
Middlesex County, Plainsboro to 1.29 mi SSW of Plainsboro
Cause
Heavy Rain
Property damage
$100,000
Reported by
Social Media
Coordinates
40.330, -74.600

Flash flooding occurring in Plainsboro. Water up to bumpers on cars.

Flash Flood, Mercer

When
July 30, 3:30 PM EST to 5:30 PM EST
Where
Mercer County, 0.21 mi WSW of Penns Neck to Penns Neck
Cause
Heavy Rain
Property damage
$1.0 million
Reported by
Broadcast Media
Coordinates
40.329, -74.634

The Princeton Junction train station inundated by flood waters with water up to the top of the tunnel. Four people were also rescued with a nearby home evacuated.

Flash Flood, Middlesex

When
July 30, 3:40 PM EST
Where
Middlesex County, 0.95 mi W of Kingston to 1.23 mi ENE of Kendall Park
Cause
Heavy Rain
Reported by
Public
Coordinates
40.382, -74.618

Widespread roadway flooding along route 1.Some roads in Deans were flooded including Deans Lane.

Heavy Rain, Middlesex

When
July 30, 4:30 PM EST
Where
Middlesex County, 1.72 mi ESE of Plainsboro
Reported by
CoCoRaHS
Coordinates
40.320, -74.570

Four and a half inches of heavy rain fell from thunderstorms.

Heavy Rain, Middlesex

When
July 30, 4:30 PM EST
Where
Middlesex County, Plainsboro
Reported by
Social Media
Coordinates
40.330, -74.600

Five and three quarters inches of heavy rain fell from thunderstorms.

Heavy Rain, Middlesex

When
July 30, 4:35 PM EST
Where
Middlesex County, 0.53 mi E of Cranbury
Reported by
Trained Spotter
Coordinates
40.320, -74.510

Just over four inches of heavy rain fell from thunderstorms.

Flash Flood, Mercer

When
July 30, 5:25 PM EST
Where
Mercer County, 0.42 mi ESE of Dutch Neck to 1.26 mi SSE of Grovers Mills
Cause
Heavy Rain
Property damage
$1.0 million
Reported by
Law Enforcement
Coordinates
40.277, -74.613

West Windsor Twp declared a state of emergency Due to widespread flash flooding, numerous water rescues occurred.

Heavy Rain, Middlesex

When
July 30, 5:40 PM EST
Where
Middlesex County, 3.49 mi N of Deans
Reported by
CoCoRaHS
Coordinates
40.450, -74.510

Four and a half inches inches of heavy rain fell from thunderstorms.

Heavy Rain, Middlesex

When
July 30, 6:10 PM EST
Where
Middlesex County, 1.72 mi ENE of Deans
Reported by
Mesonet
Coordinates
40.410, -74.490

Rainfall of 5.41 inches fell in 12 hours.

Heavy Rain, Mercer

When
July 30, 6:30 PM EST
Where
Mercer County, 0.87 mi SE of Ewing Township
Reported by
Mesonet
Coordinates
40.270, -74.770

Rainfall of 2.65 inches fell in 12 hours from thunderstorms.

Heavy Rain, Middlesex

When
July 30, 6:45 PM EST
Where
Middlesex County, 0.69 mi N of Cranbury
Reported by
Mesonet
Coordinates
40.330, -74.520

Two and a half inches of rain in 12 hours.

Heavy Rain, Somerset

When
July 30, 6:45 PM EST
Where
Somerset County, 2.1 mi NE of Clyde
Reported by
Mesonet
Coordinates
40.500, -74.490

Just over two inches of rain fell from thunderstorms.

Heavy Rain, Morris

When
July 30, 6:57 PM EST
Where
Morris County, 0.52 mi E of Butler
Reported by
Mesonet
Coordinates
41.000, -74.340

Just over two inches of rain fell in 12 hours from thunderstorms.

Heavy Rain, Middlesex

When
July 30, 9:45 PM EST
Where
Middlesex County, 2.22 mi ENE of Plainsboro
Reported by
Public
Coordinates
40.340, -74.560

Five and three quarters inches of heavy rainfall from thunderstorms was measured at the Simonson Farms in Cranbury Twp.

Heavy Rain, Monmouth

When
July 30, 9:50 PM EST
Where
Monmouth County, 1.05 mi E of Keyport
Reported by
Trained Spotter
Coordinates
40.430, -74.200

Just over two inches of heavy rain fell from thunderstorms.

Heavy Rain, Morris

When
July 31, 5:00 AM EST
Where
Morris County, 1.25 mi WSW of Morris Plains
Reported by
CoCoRaHS
Coordinates
40.810, -74.500

Just over two inches of rain fell from thunderstorms.

Heavy Rain, Somerset

When
July 31, 5:00 AM EST
Where
Somerset County, 1.38 mi S of East Millstone
Reported by
COOP Observer
Coordinates
40.480, -74.570

Just over two inches of heavy rain fell from thunderstorms.

Heavy Rain, Mercer

When
July 31, 5:30 AM EST
Where
Mercer County, 0.87 mi NE of Lawrenceville
Reported by
CoCoRaHS
Coordinates
40.310, -74.720

Just under four inches of rain fell in 24 hours from thunderstorms.

Heavy Rain, Hunterdon

When
July 31, 5:30 AM EST
Where
Hunterdon County, 0.69 mi N of Flemington
Reported by
CoCoRaHS
Coordinates
40.510, -74.850

Just over two inches of rain fell from thunderstorms.

Heavy Rain, Middlesex

When
July 31, 6:00 AM EST
Where
Middlesex County, 0.87 mi SW of Cliffwood Beach
Reported by
CoCoRaHS
Coordinates
40.460, -74.240

Just over three inches of heavy rain fell from thunderstorms.

Heavy Rain, Hunterdon

When
July 31, 6:00 AM EST
Where
Hunterdon County, 0.53 mi E of Frenchtown
Reported by
CoCoRaHS
Coordinates
40.530, -75.060

Heavy rain fell from thunderstorms.

Heavy Rain, Ocean

When
July 31, 6:00 AM EST
Where
Ocean County, 0.53 mi W of Gilford Park
Reported by
CoCoRaHS
Coordinates
39.950, -74.140

Heavy rain fell from thunderstorms.

Heavy Rain, Hunterdon

When
July 31, 6:00 AM EST
Where
Hunterdon County, 0.69 mi S of Allerton
Reported by
CoCoRaHS
Coordinates
40.610, -74.870

Heavy rain fell from thunderstorms.

Heavy Rain, Hunterdon

When
July 31, 6:00 AM EST
Where
Hunterdon County, 0.69 mi S of Landsdown
Reported by
CoCoRaHS
Coordinates
40.610, -74.920

Heavy rain fell from thunderstorms.

Heavy Rain, Middlesex

When
July 31, 6:00 AM EST
Where
Middlesex County, 1.38 mi N of East Brunswick
Reported by
CoCoRaHS
Coordinates
40.470, -74.400

Heavy rain fell from thunderstorms.

Heavy Rain, Morris

When
July 31, 6:00 AM EST
Where
Morris County, 0.52 mi E of Denville
Reported by
CoCoRaHS
Coordinates
40.880, -74.460

Heavy rain fell from thunderstorms.

Heavy Rain, Hunterdon

When
July 31, 6:00 AM EST
Where
Hunterdon County, 0.87 mi NE of Lebanon
Reported by
CoCoRaHS
Coordinates
40.640, -74.820

Heavy rain fell from thunderstorms.

Heavy Rain, Middlesex

When
July 31, 6:00 AM EST
Where
Middlesex County, 3.49 mi N of Deans
Reported by
CoCoRaHS
Coordinates
40.450, -74.510

Heavy rain fell from thunderstorms.

Heavy Rain, Middlesex

When
July 31, 6:00 AM EST
Where
Middlesex County, 1.26 mi ESE of Lakeridge
Reported by
CoCoRaHS
Coordinates
40.410, -74.250

Heavy rain fell from thunderstorms.

Heavy Rain, Hunterdon

When
July 31, 6:00 AM EST
Where
Hunterdon County, 0.69 mi S of Readington
Reported by
CoCoRaHS
Coordinates
40.560, -74.750

Heavy rain fell from thunderstorms.

Heavy Rain, Morris

When
July 31, 6:00 AM EST
Where
Morris County, 1.04 mi W of Boonton
Reported by
CoCoRaHS
Coordinates
40.900, -74.420

Heavy rain fell from thunderstorms.

Heavy Rain, Middlesex

When
July 31, 6:00 AM EST
Where
Middlesex County, 0.69 mi N of South River
Reported by
CoCoRaHS
Coordinates
40.440, -74.380

Heavy rain fell from thunderstorms.

Heavy Rain, Somerset

When
July 31, 6:00 AM EST
Where
Somerset County, 0.87 mi SE of Belle Mead
Reported by
CoCoRaHS
Coordinates
40.460, -74.640

Heavy rain fell from thunderstorms.

Heavy Rain, Somerset

When
July 31, 6:00 AM EST
Where
Somerset County, 2.1 mi NE of Griggstown
Reported by
CoCoRaHS
Coordinates
40.470, -74.590

Heavy rain fell from thunderstorms.

Heavy Rain, Somerset

When
July 31, 6:00 AM EST
Where
Somerset County, 1.05 mi E of Middle Bush
Reported by
CoCoRaHS
Coordinates
40.500, -74.510

Heavy rain fell from thunderstorms.

Heavy Rain, Warren

When
July 31, 6:00 AM EST
Where
Warren County, 0.87 mi SW of Riegelsville
Reported by
COOP Observer
Coordinates
40.590, -75.190

Heavy rain fell from thunderstorms.

Heavy Rain, Sussex

When
July 31, 6:10 AM EST
Where
Sussex County, 0.87 mi SW of Stockholm
Reported by
CoCoRaHS
Coordinates
41.090, -74.540

Heavy rain fell from thunderstorms.

Flood, Ocean

When
July 31, 6:30 AM EST
Where
Ocean County, 1.06 mi W of Whiting to 0.22 mi N of Whiting
Cause
Heavy Rain
Reported by
Law Enforcement
Coordinates
39.950, -74.400

Minor flooding occurred along route 530.

Heavy Rain, Morris

When
July 31, 6:30 AM EST
Where
Morris County, 0.87 mi SE of Powerville
Reported by
CoCoRaHS
Coordinates
40.910, -74.410

Heavy rain fell from thunderstorms.

Heavy Rain, Ocean

When
July 31, 6:51 AM EST
Where
Ocean County, 0.87 mi SW of Holly Park
Reported by
Mesonet
Coordinates
39.890, -74.160

Heavy rain fell from thunderstorms, 12 hour total.

Heavy Rain, Ocean

When
July 31, 7:00 AM EST
Where
Ocean County, 0.69 mi N of Island Hgts
Reported by
CoCoRaHS
Coordinates
39.940, -74.170

Heavy rain fell from thunderstorms.

Heavy Rain, Somerset

When
July 31, 7:00 AM EST
Where
Somerset County, 1.38 mi N of Griggstown
Reported by
CoCoRaHS
Coordinates
40.470, -74.620

Heavy rain fell from thunderstorms.

Heavy Rain, Middlesex

When
July 31, 7:00 AM EST
Where
Middlesex County, 0.87 mi SW of Highland Park
Reported by
CoCoRaHS
Coordinates
40.490, -74.440

Heavy rain fell from thunderstorms.

Heavy Rain, Mercer

When
July 31, 7:00 AM EST
Where
Mercer County, Slackwood
Reported by
CoCoRaHS
Coordinates
40.270, -74.730

Heavy rain fell from thunderstorms.

Heavy Rain, Hunterdon

When
July 31, 7:00 AM EST
Where
Hunterdon County, 0.69 mi N of Lebanon
Reported by
CoCoRaHS
Coordinates
40.640, -74.830

Heavy rain fell from thunderstorms.

Heavy Rain, Hunterdon

When
July 31, 7:00 AM EST
Where
Hunterdon County, 1.26 mi WSW of Three Bridges
Reported by
CoCoRaHS
Coordinates
40.510, -74.820

Heavy rain fell from thunderstorms.

Heavy Rain, Hunterdon

When
July 31, 7:00 AM EST
Where
Hunterdon County, 0.87 mi NW of Flemington
Reported by
COOP Observer
Coordinates
40.510, -74.860

Heavy rain fell from thunderstorms.

Heavy Rain, Middlesex

When
July 31, 7:00 AM EST
Where
Middlesex County, 1.26 mi WSW of Highland Park
Reported by
COOP Observer
Coordinates
40.490, -74.450

Heavy rain fell from thunderstorms.

Heavy Rain, Middlesex

When
July 31, 7:00 AM EST
Where
Middlesex County, 0.69 mi N of Camp Kilmer
Reported by
CoCoRaHS
Coordinates
40.540, -74.480

Heavy rain fell from thunderstorms.

Heavy Rain, Middlesex

When
July 31, 7:15 AM EST
Where
Middlesex County, 1.72 mi WNW of Cranbury
Reported by
CoCoRaHS
Coordinates
40.330, -74.550

Heavy rain fell from thunderstorms.

Heavy Rain, Somerset

When
July 31, 7:15 AM EST
Where
Somerset County, 2.1 mi NE of Clyde
Reported by
CoCoRaHS
Coordinates
40.500, -74.490

Heavy rain fell from thunderstorms.

Flood, Ocean

When
July 31, 7:30 AM EST
Where
Ocean County, 3.5 mi S of Island Beach to 3.15 mi S of Island Beach
Cause
Heavy Rain
Reported by
Trained Spotter
Coordinates
39.830, -74.090

The main road in Island Beach State park was flooded due to heavy rainfall.

Heavy Rain, Ocean

When
July 31, 7:42 AM EST
Where
Ocean County, 1.06 mi W of Toms River Arpt
Reported by
ASOS
Coordinates
39.930, -74.300

Heavy rain fell from thunderstorms.

Heavy Rain, Middlesex

When
July 31, 8:00 AM EST
Where
Middlesex County, 2.1 mi E of Deans
Reported by
Mesonet
Coordinates
40.400, -74.480

Heavy rain fell from thunderstorms.

Heavy Rain, Ocean

When
July 31, 8:00 AM EST
Where
Ocean County, Lanoka Harbor
Reported by
Social Media
Coordinates
39.870, -74.170

Heavy rain fell from thunderstorms.

Heavy Rain, Ocean

When
July 31, 8:00 AM EST
Where
Ocean County, Whiting
Reported by
Social Media
Coordinates
39.950, -74.380

Heavy rain fell from thunderstorms.

Heavy Rain, Ocean

When
July 31, 8:00 AM EST
Where
Ocean County, 3.19 mi SSE of Toms River Arpt
Reported by
CoCoRaHS
Coordinates
39.890, -74.250

Heavy rain fell from thunderstorms. Two a third inches of rain in two hours from 7-9 am.

Heavy Rain, Middlesex

When
July 31, 8:00 AM EST
Where
Middlesex County, 0.69 mi S of Kendall Park
Reported by
CoCoRaHS
Coordinates
40.410, -74.570

Heavy rain fell from thunderstorms.

Heavy Rain, Hunterdon

When
July 31, 8:00 AM EST
Where
Hunterdon County, 0.52 mi W of Jutland
Reported by
CoCoRaHS
Coordinates
40.620, -74.980

Heavy rain fell from thunderstorms.

Flood, Hunterdon

When
July 31, 8:35 AM EST
Where
Hunterdon County, 0.91 mi WSW of Pleasant Run to 1.26 mi W of Pleasant Run
Cause
Heavy Rain
Reported by
Trained Spotter
Coordinates
40.565, -74.796

Pleasant run has exceeded its banks and was spilling onto county road 629.

Heavy Rain, Ocean

When
July 31, 8:35 AM EST
Where
Ocean County, 2.11 mi SE of Forked River
Reported by
Social Media
Coordinates
39.810, -74.150

Heavy rain fell from thunderstorms.

Heavy Rain, Hunterdon

When
July 31, 9:00 AM EST
Where
Hunterdon County, 1.05 mi W of Pleasant Run
Reported by
Trained Spotter
Coordinates
40.570, -74.800

Heavy rain fell from thunderstorms from 2 pm on 7/20 through 10 am on 7/31.

Heavy Rain, Ocean

When
July 31, 9:30 AM EST
Where
Ocean County, 2.11 mi SE of Forked River
Reported by
Social Media
Coordinates
39.810, -74.150

Heavy rain fell from thunderstorms.

Flash Flood, Hunterdon

When
July 31, 9:35 AM EST
Where
Hunterdon County, 2.93 mi NE of Readington Arpt to 0.78 mi E of Readington Arpt
Cause
Heavy Rain
Reported by
911 Call Center
Coordinates
40.608, -74.688

Water rescues occurred in Readington Twp due to flash flooding.

Heavy Rain, Sussex

When
July 31, 9:45 AM EST
Where
Sussex County, 0.87 mi SE of Newton Arpt
Reported by
CoCoRaHS
Coordinates
41.020, -74.760

Heavy rain fell from thunderstorms.

Flash Flood, Hunterdon

When
July 31, 10:00 AM EST
Where
Hunterdon County, 0.79 mi S of Cherryville to 1.21 mi SSE of Cherryville
Cause
Heavy Rain
Reported by
Social Media
Coordinates
40.559, -74.899

Water rescues took place in Raritan twp along River Road and Old Croton Road. Numerous Roads were impassable including Cherry Hollow Road. Payne road in Clinton twp was also impassable.

Flood, Hunterdon

When
July 31, 10:00 AM EST
Where
Hunterdon County, 1.1 mi NNE of Reaville to 1.78 mi SW of Three Bridges
Cause
Heavy Rain
Reported by
Other Federal Agency
Coordinates
40.495, -74.814

The Neshanic river went over flood stage of 6.5 feet.

Flash Flood, Hunterdon

When
July 31, 10:45 AM EST
Where
Hunterdon County, 10.68 mi ESE of Centerville to 9.39 mi ESE of Readington Arpt
Cause
Heavy Rain
Reported by
Trained Spotter
Coordinates
40.467, -74.579

The South Branch of the Raritan River overflowed in Franklin twp, numerous water rescues.

Heavy Rain, Hunterdon

When
July 31, 11:00 AM EST
Where
Hunterdon County, 1.05 mi W of Pleasant Run
Reported by
Trained Spotter
Coordinates
40.570, -74.800

Heavy rain fell from thunderstorms. Total was 6 inches with three and a half inches falling in a couple of hours.

Heavy Rain, Hunterdon

When
July 31, 11:04 AM EST
Where
Hunterdon County, 0.87 mi NW of Flemington
Reported by
COOP Observer
Coordinates
40.510, -74.860

Heavy rain fell from thunderstorms on the morning hours of 7/31.

Flash Flood, Somerset

When
July 31, 11:15 AM EST
Where
Somerset County, 2.95 mi NNW of Neshanic Station to 3.5 mi SSE of Branchburg Park
Cause
Heavy Rain
Reported by
911 Call Center
Coordinates
40.562, -74.741

Roads impassable due to flooding.

Flood, Hunterdon

When
July 31, 1:53 PM EST
Where
Hunterdon County, 1.84 mi SW of Copper Hill to 0.87 mi SSE of Centerville
Cause
Heavy Rain
Reported by
Broadcast Media
Coordinates
40.462, -74.876

High water on Route 202 in Flemington.

Heavy Rain, Hunterdon

When
July 31, 2:10 PM EST
Where
Hunterdon County, 1.05 mi W of Pleasant Run
Reported by
Trained Spotter
Coordinates
40.570, -74.800

Total rainfall from thunderstorms was six and three quarter inches with over four inches falling in a couple of hours.

What these are

Thunderstorm Wind
Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.
Flood
Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.
Flash Flood
Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
Heavy Rain
Rainfall totals unusual for the place and season that did not produce a flood.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in New Jersey in 2016Every state in 2016This day in weather historyWarnings in New Jersey, July 2016

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 640950, 640949, 640915, 640910, 640911, 640912, 643599, 640921, 640923, 640922, 640913, 640924, 640925, 640931, 640926, 640927, 640928, 640930, 640929, 640932, 640933, 640934, 640935, 640936, 640937, 640938, 640939, 640940, 640941, 640942, 640943, 640944, 640945, 640946, 640947, 640948, 640953, 640954, 640955, 640956, and more.