Alert archive / New Jersey / Flash Flood Warnings in 2018

Flash Flood Warning 76, NWS Philadelphia/Mount Holly

August 17, 20184 counties in New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 17, 2018, 11:30 PM EDT for 4 counties in New Jersey. It was in force for 4 hr. 5 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 17, 2018, 11:30 PM EDT (03:30 UTC)
Expired
Aug 18, 2018, 3:30 AM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Hunterdon County, NJ, Middlesex County, NJ, Morris County, NJ, Somerset County, NJ

The radar

The Philadelphia radar (KDIX), 80 km from the middle of the area, began a volume at 03:30 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 17, 11:45 PM EDTFLOOD1 N Pluckemin, NJREPORT OF MINOR FLOODING ON 287 NORTHBOUND AT MILE MARKER 22. TIME ESTIMATED FROM RADAR.
Aug 18, 12:00 AM EDTFLOOD1 S Pluckemin, NJCONSIDERABLE STREAM, ROAD, AND FIELD FLOODING. CHAMBERS BROOK OVERFLOWING. MEASURED 2.34 INCHES IN 3.5 HOURS.
Aug 18, 12:00 AM EDTHEAVY RAIN 2.38Somerset Airport, NJ1.62 INCHES MEASURED BETWEEN 11 PM AND MIDNIGHT.
Aug 18, 12:00 AM EDTHEAVY RAIN 2.521 Ne Green Knoll, NJHADS SENSOR AT MARTINSVILLE.
Aug 18, 12:08 AM EDTHEAVY RAIN 2.03Basking Ridge, NJ

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, 3.5 hours before the alert went out and 138 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 2018-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 802 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 2018-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 59 square meters per square second.1939Sfc1 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
802 J/kg
Mixed-layer CIN
-65 J/kg
Mixed-layer LCL
900 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
59 m²/s²
0-3 km storm-relative helicity
119 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

863 
WGUS51 KPHI 180330
FFWPHI
NJC019-023-027-035-180730-
/O.NEW.KPHI.FF.W.0076.180818T0330Z-180818T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
1130 PM EDT FRI AUG 17 2018

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Southeastern Morris County in northern New Jersey...
  East central Hunterdon County in northwestern New Jersey...
  Somerset County in northern New Jersey...
  North central Middlesex County in northern New Jersey...

* Until 330 AM EDT.

* At 1130 PM 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...
  Morristown, Somerville, Bridgewater, Madison, Middlesex, Florham
  Park, East Hanover, Bound Brook, Manville, Chatham, Mendham,
  Peapack And Gladstone, Far Hills, Flagtown, Martinsville,
  Millington, White House Station, Basking Ridge, South Plainfield
  and North Plainfield.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Move to higher ground now. Act quickly to protect your life.

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

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

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 4048 7475 4069 7479 4084 7438 4080 7435
      4076 7438 4075 7436 4067 7446 4066 7445
      4066 7441 4065 7440 4063 7442 4060 7446
      4060 7430

$$

MPS
2 follow-up statements
555 
WGUS71 KPHI 180423
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
1223 AM EDT SAT AUG 18 2018

NJC019-023-027-035-180730-
/O.CON.KPHI.FF.W.0076.000000T0000Z-180818T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Morris NJ-Hunterdon NJ-Somerset NJ-Middlesex NJ-
1223 AM EDT SAT AUG 18 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 330 AM EDT FOR
SOUTHEASTERN MORRIS...EAST CENTRAL HUNTERDON...SOMERSET AND NORTH
CENTRAL MIDDLESEX COUNTIES...

At 1222 AM EDT, Doppler radar indicated heavy rain fell across the 
warned area. Up to two inches of rain have already fallen. Flash 
flooding is already occurring. Many of the area rivers and streams 
are quickly rising in response to the heavy rain.

Some locations that could experience flooding include...
Morristown, Somerville, Bridgewater, Madison, Middlesex, Florham
Park, East Hanover, Bound Brook, Manville, Chatham, Mendham, Peapack
And Gladstone, Far Hills, Flagtown, Martinsville, Millington, White
House Station, Basking Ridge, South Plainfield and North Plainfield.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Move to higher ground now. Act quickly to protect your life.

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

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

&&

LAT...LON 4048 7475 4069 7479 4084 7438 4080 7435
      4076 7438 4075 7436 4067 7446 4066 7445
      4066 7441 4065 7440 4063 7442 4060 7446
      4060 7430

$$

MPS
402 
WGUS71 KPHI 180720
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
320 AM EDT SAT AUG 18 2018

NJC019-023-027-035-180730-
/O.EXP.KPHI.FF.W.0076.000000T0000Z-180818T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Morris NJ-Hunterdon NJ-Somerset NJ-Middlesex NJ-
320 AM EDT SAT AUG 18 2018

...THE FLASH FLOOD WARNING FOR SOUTHEASTERN MORRIS...EAST CENTRAL
HUNTERDON...SOMERSET AND NORTH CENTRAL MIDDLESEX COUNTIES WILL EXPIRE
AT 330 AM EDT...

The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed any remaining road closures.

LAT...LON 4048 7475 4069 7479 4084 7438 4080 7435
      4076 7438 4075 7436 4067 7446 4066 7445
      4066 7441 4065 7440 4063 7442 4060 7446
      4060 7430

$$

MPS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 17, 8:17 PM EDTSevere Thunderstorm WarningPHIHunterdon, Morris, Somerset, Sussex, Warren43 min
Aug 17, 8:47 PM EDTSevere Thunderstorm WarningPHIHunterdon, Mercer, Middlesex, Morris, Somerset, Sussex43 min
Aug 17, 8:48 PM EDTSpecial Weather StatementPHISussex27 min
Aug 17, 9:26 PM EDTSpecial Weather StatementPHIMercer, Middlesex, Somerset34 min
Aug 17, 10:59 PM EDTAreal Flood AdvisoryPHIHunterdon, Middlesex, Morris, Somerset, Warren75 min
Aug 17, 11:25 PM EDTSpecial Weather StatementPHISomerset35 min
Aug 17, 11:41 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Morris, Somerset34 min
Aug 17, 11:52 PM EDTSpecial Weather StatementPHIMiddlesex23 min
Aug 18, 12:56 AM EDTAreal Flood AdvisoryPHIGloucester, Salem4 hr
Aug 18, 2:37 AM EDTSpecial Weather StatementPHIOcean23 min
Aug 18, 2:38 AM EDTSpecial Marine WarningPHI52 min
Aug 18, 2:41 AM EDTSpecial Weather StatementPHIAtlantic, Cumberland34 min
Aug 18, 2:46 AM EDTSevere Thunderstorm WarningPHIOcean14 min
Aug 18, 3:15 AM EDTSpecial Marine WarningPHI30 min
Aug 18, 3:16 AM EDTFlash Flood WatchPHIBurlington, Camden, Gloucester, Hunterdon, Mercer, Middlesex and 7 more20 hr
Aug 18, 3:34 PM EDTSpecial Weather StatementPHISussex41 min
Aug 18, 3:40 PM EDTSmall Craft AdvisoryPHI45 hr
Aug 18, 4:14 PM EDTSpecial Weather StatementPHISussex46 min
Aug 18, 4:33 PM EDTSpecial Weather StatementPHIGloucester42 min
Aug 18, 5:16 PM EDTSpecial Weather StatementPHIBurlington, Camden44 min
Aug 18, 5:44 PM EDTAreal Flood AdvisoryPHIBurlington, Camden98 min
Aug 18, 5:55 PM EDTSpecial Weather StatementPHIBurlington35 min
Aug 18, 6:17 PM EDTSevere Thunderstorm WarningPHIBurlington, Ocean43 min
Aug 18, 6:31 PM EDTSpecial Marine WarningPHI119 min
Aug 18, 6:44 PM EDTSevere Thunderstorm WarningPHIOcean29 min

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.