Alert archive / New Jersey / Flash Flood Warnings in 2018

Flash Flood Warning 63, NWS Philadelphia/Mount Holly

August 11, 20185 counties in New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 11, 2018, 2:46 PM EDT for 5 counties in New Jersey. It was in force for 3 hr. 1 report 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, 2:46 PM EDT (18:46 UTC)
Expired: Aug 11, 2018, 5:45 PM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

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

The radar

The Philadelphia radar (KDIX), 59 km from the middle of the area, began a volume at 18:49 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
Aug 11, 4:50 PM EDT	HEAVY RAIN 2.18	1 Wsw Blaziers Corner, 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 12:00Z, 6.8 hours before the alert went out and 148 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: 840 J/kg
Mixed-layer CIN: -19 J/kg
Mixed-layer LCL: 590 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 31 m²/s²
0-3 km storm-relative helicity: 76 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 1.9

Open this sounding in Storm Lab

The text

As transmitted.

261 
WGUS51 KPHI 111846
FFWPHI
NJC019-021-023-027-035-112145-
/O.NEW.KPHI.FF.W.0063.180811T1846Z-180811T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Mount Holly NJ has issued a

* Flash Flood Warning for...
  South central Morris County in northern New Jersey...
  Hunterdon County in northwestern New Jersey...
  Mercer County in central New Jersey...
  Somerset County in northern New Jersey...
  Middlesex County in northern New Jersey...

* Until 545 PM EDT.

* At 243 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain moving into the area from eastern Pennsylvania. 
  Rainfall rates over 2 inches per hour have been reported from some 
  of these storms. Flash flooding can be expected where these heavy 
  rain bands happen to establish themselves over north-central New 
  Jersey this afternoon. 
 
* Some locations that could experience flooding include...
  Trenton, New Brunswick, Perth Amboy, Somerville, Somerset, Edison,
  Old Bridge, East Brunswick, Bridgewater, South Brunswick,
  Sayreville, North Brunswick, Ewing, Middlesex, Princeton, Bound
  Brook, Manville, Byram, Jamesburg and Hightstown.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4042 7425 4020 7456 4017 7468 4019 7470
      4016 7472 4033 7494 4040 7497 4042 7506
      4052 7507 4085 7458 4071 7442 4067 7446
      4065 7440 4060 7445 4061 7431 4055 7425
      4050 7426 4050 7428 4046 7425

$$

jjm

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 11, 3:24 AM EDT	Flash Flood Watch	PHI	Atlantic, Burlington, Camden, Cumberland, Gloucester, Hunterdon and 9 more	20 hr
Aug 11, 4:26 AM EDT	Coastal Flood Advisory	PHI	Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 5 more	24 hr
Aug 11, 5:27 AM EDT	Areal Flood Advisory	PHI	Hunterdon, Morris, Warren	4 hr
Aug 11, 6:06 AM EDT	Areal Flood Advisory	PHI	Hunterdon, Warren	6 hr
Aug 11, 6:31 AM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset	7 hr
Aug 11, 7:16 AM EDT	Flash Flood Warning	PHI	Middlesex, Somerset	4 hr
Aug 11, 10:49 AM EDT	Areal Flood Advisory	PHI	Middlesex, Somerset	3 hr
Aug 11, 11:29 AM EDT	Areal Flood Advisory	PHI	Atlantic	4 hr
Aug 11, 11:46 AM EDT	Special Marine Warning	PHI		119 min
Aug 11, 11:55 AM EDT	Special Weather Statement	PHI	Burlington	35 min
Aug 11, 12:27 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester, Ocean	4 hr
Aug 11, 12:39 PM EDT	Special Weather Statement	PHI	Ocean	36 min
Aug 11, 12:55 PM EDT	Special Marine Warning	PHI		65 min
Aug 11, 1:07 PM EDT	Flash Flood Warning	PHI	Atlantic, Cape May	4 hr
Aug 11, 1:26 PM EDT	Special Marine Warning	PHI		2 hr
Aug 11, 1:42 PM EDT	Special Marine Warning	PHI		2 hr
Aug 11, 1:51 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden	39 min
Aug 11, 2:00 PM EDT	Flash Flood Warning	PHI	Warren	9 hr
Aug 11, 2:05 PM EDT	Special Weather Statement	PHI	Cape May	25 min
Aug 11, 2:06 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester	3 hr
Aug 11, 2:19 PM EDT	Special Marine Warning	PHI		86 min
Aug 11, 2:20 PM EDT	Areal Flood Advisory	PHI	Cape May, Cumberland	3 hr
Aug 11, 2:30 PM EDT	Flash Flood Warning	PHI	Hunterdon, Morris, Warren	3 hr
Aug 11, 2:58 PM EDT	Special Weather Statement	PHI	Cumberland	47 min
Aug 11, 3:06 PM EDT	Flash Flood Warning	PHI	Warren	4 hr
Aug 11, 3:13 PM EDT	Special Weather Statement	PHI	Hunterdon	47 min
Aug 11, 3:23 PM EDT	Areal Flood Advisory	PHI	Morris, Sussex	3 hr
Aug 11, 3:24 PM EDT	Special Weather Statement	PHI	Atlantic, Cumberland	51 min
Aug 11, 3:32 PM EDT	Flash Flood Warning	PHI	Atlantic	3 hr
Aug 11, 3:47 PM EDT	Flash Flood Warning	PHI	Morris	3 hr
Aug 11, 4:11 PM EDT	Special Marine Warning	PHI		2 hr
Aug 11, 4:28 PM EDT	Special Marine Warning	PHI		2 hr
Aug 11, 5:00 PM EDT	Areal Flood Advisory	PHI	Gloucester, Salem	3 hr
Aug 11, 5:26 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Morris, Warren	4 hr
Aug 11, 5:36 PM EDT	Areal Flood Warning	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset	4 hr
Aug 11, 6:11 PM EDT	Special Marine Warning	PHI		2 hr
Aug 11, 6:12 PM EDT	Flash Flood Warning	PHI	Salem	3 hr
Aug 11, 7:35 PM EDT	Areal Flood Advisory	PHI	Atlantic, Cumberland	3 hr
Aug 11, 7:46 PM EDT	River Flood Warning	PHI	Essex, Morris, Passaic	4 days

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.