Alert archive / New Jersey / Flash Flood Warnings in 2018

Flash Flood Warning 4, NWS Philadelphia/Mount Holly

May 27, 2018Middlesex County, Somerset County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at May 27, 2018, 4:39 AM EDT for Middlesex County, Somerset County, New Jersey. It was in force for 4 hr. 8 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
May 27, 2018, 4:39 AM EDT (08:39 UTC)
Expired
May 27, 2018, 8:45 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), 62 km from the middle of the area, began a volume at 08:42 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
May 27, 6:30 AM EDTFLASH FLOODNew Brunswick, NJFLOODING ON US 1 SB SOUTH OF NJ 18. RAMP CLOSED. TIME ESTIMATED FROM RADAR.
May 27, 6:30 AM EDTFLASH FLOODNorth Brunswick, NJUS 1 SB RAMP CLOSED DUE TO FLOODING AT RYDERS LANE.
May 27, 7:30 AM EDTFLOODNew Brunswick, NJFLOODING ON US 1 SB SOUTH OF NJ 18. RAMP CLOSED. TIME ESTIMATED FROM RADAR.
May 27, 7:30 AM EDTFLOODNorth Brunswick, NJUS 1 SB RAMP CLOSED DUE TO FLOODING AT RYDERS LANE.
May 27, 7:40 AM EDTFLASH FLOODFranklin Twp, NJBLACKWELLS MILLS ROAD CLOSED BETWEEN SOUTH MIDDLEBUSH AND VANCLEFF.
May 27, 7:40 AM EDTFLASH FLOODFranklin Twp, NJCANAL ROAD CLOSED BETWEEN ROUTE 518 AND COPERMINE ROAD.
May 27, 7:40 AM EDTFLASH FLOODFranklin Twp, NJFOXWOOD DRIVE CLOSED BETWEEN WINSTON DRIVE AND HUNT ROAD.
May 27, 7:40 AM EDTFLASH FLOODFranklin Twp, NJSOUTH MIDDLEBUSH ROAD CLOSED BETWEEN BENNETTS LANE AND HILL TOP.

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, 8.7 hours before the alert went out and 141 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 2018-05-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 861 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 2018-05-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 83 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
861 J/kg
Mixed-layer CIN
-92 J/kg
Mixed-layer LCL
1209 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
83 m²/s²
0-3 km storm-relative helicity
84 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

As transmitted.

608 
WGUS51 KPHI 270839
FFWPHI
NJC023-035-271245-
/O.NEW.KPHI.FF.W.0004.180527T0839Z-180527T1245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
439 AM EDT SUN MAY 27 2018

The National Weather Service in Mount Holly NJ has issued a

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

* Until 845 AM EDT.

* At 438 AM EDT, Doppler radar and automated rain gauges indicated
  thunderstorms producing heavy rain across the warned area. Up to 
  two inches of rain have already fallen with most of it fallen 
  within the past hour. Flash flooding is expected to begin shortly 
  in the areas of heaviest rain.

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

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 4052 7437 4045 7445 4043 7451 4043 7458
      4050 7461 4060 7453 4060 7434

$$

JRK
2 follow-up statements
210 
WGUS71 KPHI 271055
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
655 AM EDT SUN MAY 27 2018

NJC023-035-271245-
/O.CON.KPHI.FF.W.0004.000000T0000Z-180527T1245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Somerset NJ-Middlesex NJ-
655 AM EDT SUN MAY 27 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 845 AM EDT FOR
SOUTHEASTERN SOMERSET AND NORTHWESTERN MIDDLESEX COUNTIES...

At 653 AM EDT, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain over the warned area. Two to 
three inches of rain have already fallen. Flash flooding may be 
occurring or beginning shortly. Several area streams, including on 
the Middle Brook and Green Brook are rising sharply in response to 
the excess runoff. 

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

Additional rainfall amounts of one half inch are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

Stay away or be swept away. River banks and culverts can become
unstable and unsafe.

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

&&

LAT...LON 4052 7437 4045 7445 4043 7451 4043 7458
      4050 7461 4060 7453 4060 7434

$$

JRK
230 
WGUS71 KPHI 271242
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
842 AM EDT SUN MAY 27 2018

NJC023-035-271250-
/O.EXP.KPHI.FF.W.0004.000000T0000Z-180527T1245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Somerset NJ-Middlesex NJ-
842 AM EDT SUN MAY 27 2018

...THE FLASH FLOOD WARNING FOR SOUTHEASTERN SOMERSET AND NORTHWESTERN
MIDDLESEX COUNTIES WILL EXPIRE AT 845 AM EDT...

The Flash Flood Warning has been converted to a Flood Warning. 
Runoff and flooding will continue throughout the morning, but the 
rapid rises the area experienced earlier has eased. A widespread one 
to three inches fell in a short period of time earlier this morning. 
More rain is expected throughout the morning, but it is not expected 
to be as intense. Creeks and streams, and rivers, like Middle Brook 
and Green Brook, have risen and will continue to do so as the rain 
continues to runoff.  

LAT...LON 4052 7437 4045 7445 4043 7451 4043 7458
      4050 7461 4060 7453 4060 7434

$$

Kruzdlo

The office that day

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

IssuedProductOfficeCountiesLasted
May 26, 11:38 PM EDTFlash Flood WatchPHIAtlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 9 more23 hr
May 27, 1:27 AM EDTSpecial Marine WarningPHI2 hr
May 27, 1:46 AM EDTSpecial Marine WarningPHI89 min
May 27, 1:58 AM EDTAreal Flood AdvisoryPHIMonmouth4 hr
May 27, 2:13 AM EDTAreal Flood AdvisoryPHIMorris, Warren4 hr
May 27, 4:13 AM EDTAreal Flood AdvisoryPHIMiddlesex, Somerset4 hr
May 27, 4:28 AM EDTFlash Flood WarningPHIMonmouth4 hr
May 27, 5:27 AM EDTAreal Flood AdvisoryPHIHunterdon4 hr
May 27, 5:35 AM EDTAreal Flood AdvisoryPHIMercer, Middlesex, Monmouth4 hr
May 27, 5:43 AM EDTFlash Flood WarningPHIMonmouth4 hr
May 27, 6:12 AM EDTFlash Flood WarningPHIMercer, Middlesex, Somerset4 hr
May 27, 6:33 AM EDTFlash Flood WarningPHIHunterdon4 hr
May 27, 7:30 AM EDTFlash Flood WarningPHIMercer4 hr
May 27, 8:25 AM EDTAreal Flood WarningPHIMonmouth7 hr
May 27, 8:40 AM EDTAreal Flood WarningPHIMiddlesex, Somerset4 hr
May 27, 9:05 AM EDTRiver Flood WarningPHIMercer13 hr
May 27, 9:17 AM EDTAreal Flood AdvisoryPHIBurlington, Camden, Gloucester, Mercer, Monmouth, Ocean3 hr
May 27, 10:02 AM EDTAreal Flood WarningPHIMonmouth6 hr
May 27, 10:19 AM EDTAreal Flood WarningPHIHunterdon, Mercer, Middlesex, Somerset8 hr
May 27, 10:27 AM EDTAreal Flood WarningPHIHunterdon8 hr
May 27, 11:18 AM EDTAreal Flood WarningPHIMercer7 hr
May 27, 3:10 PM EDTRiver Flood WarningPHISomerset46 hr
May 27, 3:22 PM EDTCoastal Flood AdvisoryPHIBurlington, Camden, Gloucester, Mercer, Middlesex, Monmouth and 2 more12 hr
May 27, 3:44 PM EDTAreal Flood WarningPHIMonmouth16 hr
May 27, 6:07 PM EDTAreal Flood WarningPHIMercer, Middlesex, Somerset4 hr

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.