Alert archive / New Jersey / Flash Flood Warnings in 2018

Flash Flood Warning 55, NWS Philadelphia/Mount Holly

August 11, 2018Middlesex County, Somerset County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 11, 2018, 7:16 AM EDT for Middlesex County, Somerset County, New Jersey. It was in force for 4 hr. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 11, 2018, 7:16 AM EDT (11:16 UTC)
Expired
Aug 11, 2018, 10:51 AM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Middlesex County, NJ, Somerset County, NJ

The radar

The Philadelphia radar (KDIX), 70 km from the middle of the area, began a volume at 11:15 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Aug 11, 8:19 AM EDTFLOOD1 Nnw Melrose, NJGARDEN STATE PARKWAY NORTHBOUND CLOSED AT EXIT 125 - CHEVALIER AVENUE. 2 RIGHT LANES BLOCKED DUE TO FLOODING.
Aug 11, 8:30 AM EDTFLOOD1 Nnw Melrose, NJGARDEN STATE PARKWAY NORTHBOUND CLOSED AT EXIT 125 - CHEVALIER AVENUE. 2 RIGHT LANES BLOCKED DUE TO FLOODING.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 11.3 hours before the alert went out and 134 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Brookhaven, NY at 00:00Z on 2018-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 155 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 00:00Z on 2018-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
155 J/kg
Mixed-layer CIN
-54 J/kg
Mixed-layer LCL
1448 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
53 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

As transmitted.

392 
WGUS51 KPHI 111116
FFWPHI
NJC023-035-111515-
/O.NEW.KPHI.FF.W.0055.180811T1116Z-180811T1515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
716 AM EDT SAT AUG 11 2018

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Southeastern Somerset County in northern New Jersey...
  Northeastern Middlesex County in northern New Jersey...

* Until 1115 AM EDT.

* At 715 AM EDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to two inches of rain have
  already fallen. Flash flooding is expected to begin shortly in the
  areas of heaviest rain.

* Some locations that could experience flooding include...
  New Brunswick, Perth Amboy, Somerset, Edison, East Brunswick,
  Middlesex, Bound Brook, Manville, Millstone, Colonia, Martinsville,
  Society Hill, North Brunswick Township, Woodbridge, South
  Plainfield, North Plainfield, Highland Park, Metuchen, Dunellen and
  Milltown.

Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area early this morning.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.

&&

LAT...LON 4050 7426 4050 7428 4048 7427 4045 7451
      4048 7458 4064 7459 4066 7453 4065 7451
      4067 7448 4066 7445 4066 7441 4063 7442
      4060 7446 4060 7426 4052 7425

$$

JRK
3 follow-up statements
731 
WGUS71 KPHI 111153
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
753 AM EDT SAT AUG 11 2018

NJC023-035-111515-
/O.CON.KPHI.FF.W.0055.000000T0000Z-180811T1515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Somerset NJ-Middlesex NJ-
753 AM EDT SAT AUG 11 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1115 AM EDT FOR
SOUTHEASTERN SOMERSET AND NORTHEASTERN MIDDLESEX COUNTIES...

At 750 AM EDT, emergency management reported flash flooding in North 
Plainfield with two water rescues along Route 22. Up to 2.5 inches 
of rain have already fallen. Flash flooding is already occurring.

Some locations that could experience flooding include...
New Brunswick, Perth Amboy, Somerset, Edison, East Brunswick,
Middlesex, Bound Brook, Manville, Millstone, Colonia, Martinsville,
Society Hill, North Brunswick Township, Woodbridge, South Plainfield,
North Plainfield, Highland Park, Metuchen, Dunellen and Milltown.

Additional rainfall amounts of less than 1 inch are possible in the 
warned area through mid morning.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.

Please report flooding to your local law enforcement agency when you
can do so safely.

&&

LAT...LON 4050 7426 4050 7428 4048 7427 4045 7451
      4048 7458 4064 7459 4066 7453 4065 7451
      4067 7448 4066 7445 4066 7441 4063 7442
      4060 7446 4060 7426 4052 7425

$$

JRK
398 
WGUS71 KPHI 111304
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
904 AM EDT SAT AUG 11 2018

NJC023-035-111515-
/O.CON.KPHI.FF.W.0055.000000T0000Z-180811T1515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Somerset NJ-Middlesex NJ-
904 AM EDT SAT AUG 11 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1115 AM EDT FOR
EAST CENTRAL SOMERSET AND NORTHEASTERN MIDDLESEX COUNTIES...

At 856 AM EDT, emergency management reported flash flooding that 
occurred just after 7 AM in North Plainfield with multiple water 
rescues along Route 22. Several creeks and streams continue to 
respond to the excess runoff from the earlier heavy rain. Green 
Brook near Plainfield continues to rise quickly and was approaching 
flood stage of 8.0 feet at 850 AM. Flooding along Green Brook will 
occur shortly.

Some locations that could experience flooding include...
New Brunswick, Perth Amboy, Somerset, Edison, Middlesex, Bound Brook,
Manville, Millstone, Colonia, Martinsville, Society Hill, Woodbridge,
South Plainfield, North Plainfield, Highland Park, Metuchen,
Dunellen, Watchung, South Bound Brook and Iselin.


Up to 2.5 inches of rain have already fallen. An additional brief 
heavy downpour is possible before 11 AM if the showers that are 
currently over eastern Pennsylvania move back into the warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around...don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.

Please report flooding to your local law enforcement agency when you
can do so safely.

&&

LAT...LON 4050 7426 4050 7428 4048 7427 4047 7435
      4050 7436 4049 7447 4050 7452 4048 7458
      4064 7459 4066 7453 4065 7451 4067 7448
      4066 7445 4066 7441 4063 7442 4060 7446
      4060 7426 4052 7425

$$

JRK
781 
WGUS71 KPHI 111451
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1051 AM EDT SAT AUG 11 2018

NJC023-035-111459-
/O.CAN.KPHI.FF.W.0055.000000T0000Z-180811T1515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Somerset NJ-Middlesex NJ-
1051 AM EDT SAT AUG 11 2018

...THE FLASH FLOOD WARNING FOR EAST CENTRAL SOMERSET AND NORTHEASTERN
MIDDLESEX COUNTIES IS CANCELLED...

The heavy rain has ended and flood waters are receding. Flash 
flooding is no longer expected to pose a threat to life and 
property. However, minor flooding may linger for the next several 
hours in poor drainage areas. Please continue to heed any remaining 
road closures.

LAT...LON 4050 7426 4050 7428 4048 7427 4047 7435
      4050 7436 4049 7447 4050 7452 4048 7458
      4064 7459 4066 7453 4065 7451 4067 7448
      4066 7445 4066 7441 4063 7442 4060 7446
      4060 7426 4052 7425

$$

JRK

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 11, 3:24 AM EDTFlash Flood WatchPHIAtlantic, Burlington, Camden, Cumberland, Gloucester, Hunterdon and 9 more20 hr
Aug 11, 4:26 AM EDTCoastal Flood AdvisoryPHIAtlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 5 more24 hr
Aug 11, 5:27 AM EDTAreal Flood AdvisoryPHIHunterdon, Morris, Warren4 hr
Aug 11, 6:06 AM EDTAreal Flood AdvisoryPHIHunterdon, Warren6 hr
Aug 11, 6:31 AM EDTAreal Flood AdvisoryPHIHunterdon, Mercer, Middlesex, Morris, Somerset7 hr
Aug 11, 10:49 AM EDTAreal Flood AdvisoryPHIMiddlesex, Somerset3 hr
Aug 11, 11:29 AM EDTAreal Flood AdvisoryPHIAtlantic4 hr
Aug 11, 11:46 AM EDTSpecial Marine WarningPHI119 min
Aug 11, 11:55 AM EDTSpecial Weather StatementPHIBurlington35 min
Aug 11, 12:27 PM EDTAreal Flood AdvisoryPHIBurlington, Camden, Gloucester, Ocean4 hr
Aug 11, 12:39 PM EDTSpecial Weather StatementPHIOcean36 min
Aug 11, 12:55 PM EDTSpecial Marine WarningPHI65 min
Aug 11, 1:07 PM EDTFlash Flood WarningPHIAtlantic, Cape May4 hr
Aug 11, 1:26 PM EDTSpecial Marine WarningPHI2 hr
Aug 11, 1:42 PM EDTSpecial Marine WarningPHI2 hr
Aug 11, 1:51 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden39 min
Aug 11, 2:00 PM EDTFlash Flood WarningPHIWarren9 hr
Aug 11, 2:05 PM EDTSpecial Weather StatementPHICape May25 min
Aug 11, 2:06 PM EDTAreal Flood AdvisoryPHIBurlington, Camden, Gloucester3 hr
Aug 11, 2:19 PM EDTSpecial Marine WarningPHI86 min
Aug 11, 2:20 PM EDTAreal Flood AdvisoryPHICape May, Cumberland3 hr
Aug 11, 2:30 PM EDTFlash Flood WarningPHIHunterdon, Morris, Warren3 hr
Aug 11, 2:46 PM EDTFlash Flood WarningPHIHunterdon, Mercer, Middlesex, Morris, Somerset3 hr
Aug 11, 2:58 PM EDTSpecial Weather StatementPHICumberland47 min
Aug 11, 3:06 PM EDTFlash Flood WarningPHIWarren4 hr
Aug 11, 3:13 PM EDTSpecial Weather StatementPHIHunterdon47 min
Aug 11, 3:23 PM EDTAreal Flood AdvisoryPHIMorris, Sussex3 hr
Aug 11, 3:24 PM EDTSpecial Weather StatementPHIAtlantic, Cumberland51 min
Aug 11, 3:32 PM EDTFlash Flood WarningPHIAtlantic3 hr
Aug 11, 3:47 PM EDTFlash Flood WarningPHIMorris3 hr
Aug 11, 4:11 PM EDTSpecial Marine WarningPHI2 hr
Aug 11, 4:28 PM EDTSpecial Marine WarningPHI2 hr
Aug 11, 5:00 PM EDTAreal Flood AdvisoryPHIGloucester, Salem3 hr
Aug 11, 5:26 PM EDTAreal Flood AdvisoryPHIHunterdon, Morris, Warren4 hr
Aug 11, 5:36 PM EDTAreal Flood WarningPHIHunterdon, Mercer, Middlesex, Morris, Somerset4 hr
Aug 11, 6:11 PM EDTSpecial Marine WarningPHI2 hr
Aug 11, 6:12 PM EDTFlash Flood WarningPHISalem3 hr
Aug 11, 7:35 PM EDTAreal Flood AdvisoryPHIAtlantic, Cumberland3 hr
Aug 11, 7:46 PM EDTRiver Flood WarningPHIEssex, Morris, Passaic4 days

Nearby

Flash Flood Warnings in New Jersey, 2018Every flash flood warning in 2018

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.