Alert archive / New Jersey / Flash Flood Warnings in 2018

Flash Flood Warning 6, NWS Philadelphia/Mount Holly

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

NWS Philadelphia/Mount Holly issued this flash flood warning at May 27, 2018, 6:12 AM EDT for Mercer County, Middlesex County, Somerset County, New Jersey. It was in force for 4 hr. 23 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, 6:12 AM EDT (10:12 UTC)
Expired: May 27, 2018, 10:15 AM EDT
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Mercer County, NJ, Middlesex County, NJ, Somerset County, NJ

The radar

The Philadelphia radar (KDIX), 55 km from the middle of the area, began a volume at 10:14 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

Time	Report	Where	Remark
May 27, 7:00 AM EDT	FLASH FLOOD	Cranbury Twp, NJ	THE PETTY ROAD BRIDGE WAS WASHED OUT AT CEDAR BROOK.
May 27, 7:00 AM EDT	FLASH FLOOD	East Windsor Twp, NJ	WATER RESCUES. FLOODING ON THE ONE MILE ROAD EXTENSTION. ROUTE 130 WAS CLOSED IN BOTH DIRECTIONS AT DUTCH NECK ROAD AND ROUTE 571.
May 27, 7:10 AM EDT	FLOOD	Monroe Twp, NJ	SHERIFF'S OFFICE REPORTS FLOODING IN MONROE AND NEARBY CRANBERRY TWP. REPORTS AROUND 7:10 AM.
May 27, 7:18 AM EDT	FLOOD	East Windsor Twp, NJ	FLOODING ON 80 ONE MILE ROAD EXTENSTION IN EAST WINDSOR, NJ. ROUTE 130 IS BEING CLOSED IN BOTH DIRECTIONS AT DUTCH NECK RD AND ROUTE 571.
May 27, 8:00 AM EDT	FLOOD	Princeton, NJ	RISING WATER ALONG RIVER ROAD. DEBRIS ALONG ROAD EDGE. ROAD CLOSURE EXPECTED.
May 27, 8:00 AM EDT	FLASH FLOOD	Hopewell Twp, NJ	NJ 29 CLOSED IN BOTH DIRECTIONS DUE TO FLOODING AT PLEASANT VALLEY RD. ALL LANES CLOSED.
May 27, 8:00 AM EDT	FLASH FLOOD	Lawrence Twp, NJ	PRINCETON PIKE CLOSED BETWEEN FACKLER ROAD AND LEWISVILLE ROAD DUE TO FLOODING.
May 27, 8:00 AM EDT	FLASH FLOOD	Lawrence Twp, NJ	PRINCETON PIKE CLOSED BETWEEN GRAF AVENUE AND FAIRFIELD AVENUE DUE TO HEAVY FLOODING.
May 27, 8:00 AM EDT	FLASH FLOOD	Princeton, NJ	MERCER ROAD BETWEEN PROVINCELINE AND HUTCHINSON DRIVE IS FLOODING. ROAD CLOSURE EXPECTED.
May 27, 8:00 AM EDT	FLASH FLOOD	Princeton, NJ	QUAKER ROAD CLOSED BETWEEN NASSAU PARK AND MERCER ROAD.
May 27, 8:00 AM EDT	HEAVY RAIN 5.04	3 E West Amwell Twp, NJ	RAINFALL OCCURRED IN THE PAST 2.5 HR
May 27, 8:00 AM EDT	HEAVY RAIN 5.54	2 N Mercerville-Hamilto, NJ	RAINFALL IN THE PAST THREE HOURS
May 27, 8:00 AM EDT	HEAVY RAIN 6	2 N Mercerville-Hamilto, NJ
May 27, 8:20 AM EDT	HEAVY RAIN 3.13	Kendall Park, NJ
May 27, 8:26 AM EDT	HEAVY RAIN 2.2	Skillman, NJ	1.64 IN 1 HOUR FROM 5:50 AM-6:50 AM.
May 27, 8:29 AM EDT	HEAVY RAIN 2.29	Lawrenceville, NJ
May 27, 8:29 AM EDT	HEAVY RAIN 2.41	Princeton, NJ
May 27, 8:29 AM EDT	HEAVY RAIN 3.16	Hopewell, NJ
May 27, 8:45 AM EDT	HEAVY RAIN 6	East Windsor Twp, NJ	AS OF 8:45 AM. MANY ROADS IMPASSABLE DUE TO HIGH WATER.
May 27, 9:50 AM EDT	FLOOD	South Brunswick, NJ	FLOODING ON US 1 IN BOTH DIRECTIONS AT RAYMOND RD. 1 LANE CLOSED.
May 27, 10:11 AM EDT	FLOOD	Princeton, NJ	MERCER ROAD BETWEEN PROVINCELINE AND HUTCHINSON DRIVE IS FLOODING. ROAD CLOSURE EXPECTED.
May 27, 10:11 AM EDT	FLOOD	Princeton, NJ	QUAKER ROAD CLOSED BETWEEN NASSAU PARK AND MERCER ROAD.
May 27, 10:11 AM EDT	FLOOD	Princeton, NJ	RISING WATER ALONG RIVER ROAD. DEBRIS ALONG ROAD EDGE. ROAD CLOSURE EXPECTED.

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, 10.2 hours before the alert went out and 157 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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.

072 
WGUS51 KPHI 271012
FFWPHI
NJC021-023-035-271415-
/O.NEW.KPHI.FF.W.0006.180527T1012Z-180527T1415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Mercer County in central New Jersey...
  Southwestern Somerset County in northern New Jersey...
  Middlesex County in northern New Jersey...

* Until 1015 AM EDT.

* At 612 AM EDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to three 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, Old Bridge, East Brunswick, South Brunswick,
  Sayreville, Ewing, Princeton, Matawan, Jamesburg, Hightstown,
  Cranbury, Pennington, Hopewell, Rocky Hill, Washington Crossing,
  Skillman, Flagtown, Princeton Meadows, Windsor and Brownville.

Additional rainfall amounts of one to two inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 4040 7425 4028 7439 4023 7451 4029 7487
      4033 7494 4035 7486 4038 7487 4038 7481
      4042 7480 4043 7475 4051 7480 4051 7477
      4054 7475 4055 7462 4043 7458 4044 7446
      4051 7438 4045 7423

$$

JRK

1 follow-up statement

635 
WGUS71 KPHI 271152
FFSPHI

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

NJC021-023-035-271415-
/O.CON.KPHI.FF.W.0006.000000T0000Z-180527T1415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mercer NJ-Somerset NJ-Middlesex NJ-
752 AM EDT SUN MAY 27 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1015 AM EDT FOR
MERCER...SOUTHWESTERN SOMERSET AND MIDDLESEX COUNTIES...

At 750 AM EDT, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain over the warned area. Two to five 
inches of rain have already fallen. Several road closures due to 
flooding have been reported in the warned area. Area creeks and 
streams continue to rise sharply in response to the excess runoff. 
Flash flooding may be occurring or beginning shortly.

Some locations that could experience flooding include...
New Brunswick, Old Bridge, East Brunswick, South Brunswick,
Sayreville, Ewing, Princeton, Matawan, Jamesburg, Hightstown,
Cranbury, Pennington, Hopewell, Rocky Hill, Washington Crossing,
Skillman, Flagtown, Princeton Meadows, Windsor and Brownville.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4040 7425 4028 7439 4023 7451 4029 7487
      4033 7494 4035 7486 4038 7487 4038 7481
      4042 7480 4043 7475 4051 7480 4051 7477
      4054 7475 4055 7462 4043 7458 4044 7446
      4051 7438 4045 7423

$$

JRK

The office that day

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

Issued	Product	Office	Counties	Lasted
May 26, 11:38 PM EDT	Flash Flood Watch	PHI	Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 9 more	23 hr
May 27, 1:27 AM EDT	Special Marine Warning	PHI		2 hr
May 27, 1:46 AM EDT	Special Marine Warning	PHI		89 min
May 27, 1:58 AM EDT	Areal Flood Advisory	PHI	Monmouth	4 hr
May 27, 2:13 AM EDT	Areal Flood Advisory	PHI	Morris, Warren	4 hr
May 27, 4:13 AM EDT	Areal Flood Advisory	PHI	Middlesex, Somerset	4 hr
May 27, 4:28 AM EDT	Flash Flood Warning	PHI	Monmouth	4 hr
May 27, 4:39 AM EDT	Flash Flood Warning	PHI	Middlesex, Somerset	4 hr
May 27, 5:27 AM EDT	Areal Flood Advisory	PHI	Hunterdon	4 hr
May 27, 5:35 AM EDT	Areal Flood Advisory	PHI	Mercer, Middlesex, Monmouth	4 hr
May 27, 5:43 AM EDT	Flash Flood Warning	PHI	Monmouth	4 hr
May 27, 6:33 AM EDT	Flash Flood Warning	PHI	Hunterdon	4 hr
May 27, 7:30 AM EDT	Flash Flood Warning	PHI	Mercer	4 hr
May 27, 8:25 AM EDT	Areal Flood Warning	PHI	Monmouth	7 hr
May 27, 8:40 AM EDT	Areal Flood Warning	PHI	Middlesex, Somerset	4 hr
May 27, 9:05 AM EDT	River Flood Warning	PHI	Mercer	13 hr
May 27, 9:17 AM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester, Mercer, Monmouth, Ocean	3 hr
May 27, 10:02 AM EDT	Areal Flood Warning	PHI	Monmouth	6 hr
May 27, 10:19 AM EDT	Areal Flood Warning	PHI	Hunterdon, Mercer, Middlesex, Somerset	8 hr
May 27, 10:27 AM EDT	Areal Flood Warning	PHI	Hunterdon	8 hr
May 27, 11:18 AM EDT	Areal Flood Warning	PHI	Mercer	7 hr
May 27, 3:10 PM EDT	River Flood Warning	PHI	Somerset	46 hr
May 27, 3:22 PM EDT	Coastal Flood Advisory	PHI	Burlington, Camden, Gloucester, Mercer, Middlesex, Monmouth and 2 more	12 hr
May 27, 3:44 PM EDT	Areal Flood Warning	PHI	Monmouth	16 hr
May 27, 6:07 PM EDT	Areal Flood Warning	PHI	Mercer, Middlesex, Somerset	4 hr

Nearby

Flash Flood Warnings in New Jersey, 2018 Every 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.