Alert archive / New Jersey / Flash Flood Warnings in 2019

Flash Flood Warning 61, NWS Philadelphia/Mount Holly

July 18, 2019Hunterdon County, Middlesex County, Somerset County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 18, 2019, 6:01 PM EDT for Hunterdon County, 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: Jul 18, 2019, 6:01 PM EDT (22:01 UTC)
Expired: Jul 18, 2019, 10:00 PM 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, Somerset County, NJ

The radar

The Philadelphia radar (KDIX), 65 km from the middle of the area, began a volume at 22:04 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
Jul 18, 6:30 PM EDT	FLASH FLOOD	Green Brook Twp, NJ	FLOODING ON US-22W IN GREEN BROOK. RIGHT LANE AND SHOULDER CLOSED WITH CONDITIONS STILL DETERIORATING.
Jul 18, 7:00 PM EDT	FLASH FLOOD	Montgomery Twp, NJ	ROUTE 206 IN MONTGOMERY CLOSED DUE TO FLOODING. TIME OF REPORT ESTIMATED.

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 12:00Z, 10.0 hours before the alert went out and 140 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: 414 J/kg
Mixed-layer CIN: -31 J/kg
Mixed-layer LCL: 465 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: 81 m²/s²
0-3 km storm-relative helicity: 121 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

989 
WGUS51 KPHI 182201
FFWPHI
NJC019-023-035-190200-
/O.NEW.KPHI.FF.W.0061.190718T2201Z-190719T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
601 PM EDT Thu Jul 18 2019

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  Southeastern Hunterdon County in northwestern New Jersey...
  Somerset County in northern New Jersey...
  Northern Middlesex County in northern New Jersey...

* Until 1000 PM EDT.

* At 600 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Up to two inches of rain has 
  already fallen in a short amount of time. Flash flooding is 
  expected to begin shortly in the areas of heaviest rain.


* Some locations that could experience flooding include...
  New Brunswick, Perth Amboy, Somerville, Somerset, Edison, East
  Brunswick, Bridgewater, Sayreville, North Brunswick, Carteret,
  Middlesex, Bound Brook, Manville, Lebanon, Millstone, Skillman,
  Flagtown, Colonia, Belle Mead and Martinsville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 4056 7421 4055 7425 4050 7426 4050 7428
      4047 7427 4040 7474 4042 7475 4042 7480
      4039 7480 4038 7485 4064 7483 4067 7440
      4063 7442 4060 7446 4061 7431 4059 7429
      4059 7420

$$

Robertson54

2 follow-up statements

380 
WGUS71 KPHI 190033
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
833 PM EDT Thu Jul 18 2019

NJC019-023-190041-
/O.CAN.KPHI.FF.W.0061.000000T0000Z-190719T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-Middlesex NJ-
833 PM EDT Thu Jul 18 2019

...THE FLASH FLOOD WARNING FOR SOUTHEASTERN HUNTERDON AND NORTHERN
MIDDLESEX COUNTIES IS CANCELLED...

The heavy rain has ended. Flash flooding is no longer expected to 
pose a threat. Please continue to heed any remaining road closures 
as the water may be slow to recede in some areas.

LAT...LON 4063 7442 4060 7446 4057 7453 4044 7454
      4040 7473 4048 7478 4063 7469

$$

NJC035-190200-
/O.CON.KPHI.FF.W.0061.000000T0000Z-190719T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Somerset NJ-
833 PM EDT Thu Jul 18 2019

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1000 PM EDT FOR
CENTRAL SOMERSET COUNTY...

At 831 PM EDT, Doppler radar indicated two to three inches of rain 
from earlier thunderstorms. Flooding has occurred with high water on 
roads in several areas, including Green Brook and Montgomery

Some locations that could experience flooding include...
Somerville, Bridgewater, Middlesex, Bound Brook, Manville, Millstone,
Skillman, Flagtown, Belle Mead, Martinsville, North Plainfield,
Raritan and South Bound Brook.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 4063 7442 4060 7446 4057 7453 4044 7454
      4040 7473 4048 7478 4063 7469

$$

Robertson

303 
WGUS71 KPHI 190153
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
953 PM EDT Thu Jul 18 2019

NJC035-190203-
/O.EXP.KPHI.FF.W.0061.000000T0000Z-190719T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Somerset NJ-
953 PM EDT Thu Jul 18 2019

...THE FLASH FLOOD WARNING FOR CENTRAL SOMERSET COUNTY WILL EXPIRE AT
1000 PM EDT...

The heavy rain has ended. Flash flooding is no longer expected to 
pose a threat. Please continue to heed any remaining road closures 
as the water may be slow to recede in some areas.

LAT...LON 4063 7442 4060 7446 4057 7453 4044 7454
      4040 7473 4048 7478 4063 7469

$$

Robertson

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 8:01 PM EDT	Areal Flood Advisory	PHI	Warren	88 min
Jul 17, 8:10 PM EDT	Special Marine Warning	PHI		95 min
Jul 17, 8:15 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Gloucester, Hunterdon, Mercer and 1 more	45 min
Jul 17, 8:39 PM EDT	Areal Flood Advisory	PHI	Morris, Sussex	3 hr
Jul 17, 8:40 PM EDT	Special Weather Statement	PHI	Atlantic, Burlington, Mercer, Middlesex, Monmouth, Ocean	65 min
Jul 17, 8:43 PM EDT	Special Marine Warning	PHI		92 min
Jul 17, 8:50 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex, Monmouth, Somerset	40 min
Jul 17, 8:55 PM EDT	Areal Flood Advisory	PHI	Mercer, Middlesex, Somerset	49 min
Jul 17, 9:02 PM EDT	Flash Flood Warning	PHI	Mercer, Middlesex, Somerset	3 hr
Jul 17, 9:19 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex, Monmouth, Ocean	41 min
Jul 17, 9:44 PM EDT	Special Marine Warning	PHI		61 min
Jul 17, 10:41 PM EDT	Special Marine Warning	PHI		49 min
Jul 17, 11:12 PM EDT	Areal Flood Warning	PHI	Somerset	3 hr
Jul 18, 1:30 PM EDT	Areal Flood Advisory	PHI	Gloucester	4 hr
Jul 18, 2:13 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester, Ocean	4 hr
Jul 18, 2:24 PM EDT	Areal Flood Advisory	PHI	Salem	3 hr
Jul 18, 2:47 PM EDT	Flash Flood Warning	PHI	Burlington, Ocean	4 hr
Jul 18, 3:48 PM EDT	Areal Flood Advisory	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean	4 hr
Jul 18, 3:59 PM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Camden, Gloucester, Ocean, Salem	3 hr
Jul 18, 4:19 PM EDT	Flash Flood Warning	PHI	Atlantic, Burlington, Ocean	3 hr
Jul 18, 4:30 PM EDT	Areal Flood Advisory	PHI	Hunterdon	4 hr
Jul 18, 4:52 PM EDT	Special Marine Warning	PHI		53 min
Jul 18, 4:53 PM EDT	Areal Flood Advisory	PHI	Mercer, Middlesex, Monmouth, Somerset	4 hr
Jul 18, 4:56 PM EDT	Areal Flood Advisory	PHI	Cumberland, Gloucester, Salem	3 hr
Jul 18, 5:13 PM EDT	Flash Flood Warning	PHI	Mercer, Middlesex, Monmouth, Somerset	3 hr
Jul 18, 5:57 PM EDT	Areal Flood Advisory	PHI	Cumberland, Salem	2 hr

Nearby

Flash Flood Warnings in New Jersey, 2019 Every flash flood warning in 2019

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.