Alert archive / New Jersey / Areal Flood Advisories in 2021

Areal Flood Advisory 67, NWS Philadelphia/Mount Holly

July 12, 2021Mercer County, Middlesex County, Monmouth County, New Jersey

NWS Philadelphia/Mount Holly issued this areal flood advisory at Jul 12, 2021, 2:20 PM EDT for Mercer County, Middlesex County, Monmouth County, New Jersey. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Jul 12, 2021, 2:20 PM EDT (18:20 UTC)
Expired: Jul 12, 2021, 5:00 PM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ

The radar

The Philadelphia radar (KDIX), 34 km from the middle of the area, began a volume at 18:20 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.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 6.3 hours before the alert went out and 170 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: 857 J/kg
Mixed-layer CIN: -57 J/kg
Mixed-layer LCL: 697 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 85 m²/s²
0-3 km storm-relative helicity: 114 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 2.4

Open this sounding in Storm Lab

The text

As transmitted.

800 
WGUS81 KPHI 121820
FLSPHI

Flood Advisory
National Weather Service Mount Holly NJ
220 PM EDT Mon Jul 12 2021

NJC021-023-025-122100-
/O.NEW.KPHI.FA.Y.0067.210712T1820Z-210712T2100Z/
/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mercer NJ-Middlesex NJ-Monmouth NJ-
220 PM EDT Mon Jul 12 2021

The National Weather Service in Mount Holly has issued a

* Flood Advisory for...
  Southeastern Mercer County in central New Jersey...
  Southwestern Monmouth County in central New Jersey...
  South Central Middlesex County in northern New Jersey...

* Until 500 PM EDT.

* At 220 PM EDT, Doppler radar indicated heavy rain due to 
  thunderstorms. Minor flooding is ongoing or expected to begin 
  shortly in the advisory area. Between 0.5 and 1 inch of rain has 
  already fallen in spots with another 1 to 2 inches possible.

* Some locations that may experience flooding include...
  Trenton, Manalapan, Ewing, Jamesburg, Hightstown, Cranbury, 
  Allentown, Roosevelt, Windsor, Twin Rivers, Imlaystown, and 
  Edinburg.

This includes the following highways...
	New Jersey Turnpike between exits 8 and 8A.
	Interstate 295 in New Jersey between mile markers 58 and 65.
	Interstate 195 in New Jersey between mile markers 0 and 15.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 4023 7479 4035 7444 4022 7431 4012 7458
      4014 7459 4014 7462 4015 7462 4017 7468
      4018 7470 4018 7471 4017 7471 4017 7470
      4015 7472 4016 7472 4017 7473 4018 7474
      4019 7475 4022 7477

$$

Iovino

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 12, 1:59 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden	3 hr
Jul 12, 2:12 PM EDT	Flash Flood Warning Emergency	PHI	Burlington	7 hr
Jul 12, 2:37 PM EDT	Flash Flood Warning	PHI	Mercer, Middlesex, Monmouth	93 min
Jul 12, 3:08 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean	67 min
Jul 12, 3:31 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex, Monmouth	41 min
Jul 12, 4:26 PM EDT	Special Marine Warning	PHI		2 hr
Jul 12, 4:33 PM EDT	Severe Thunderstorm Warning	PHI	Monmouth, Ocean	42 min
Jul 12, 4:52 PM EDT	Areal Flood Advisory	PHI	Monmouth, Ocean	98 min
Jul 12, 5:08 PM EDT	Areal Flood Advisory	PHI	Sussex	5 hr
Jul 12, 5:08 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Mercer	67 min
Jul 12, 5:26 PM EDT	Areal Flood Advisory	PHI	Camden	2 hr
Jul 12, 5:36 PM EDT	Special Weather Statement	PHI	Sussex	24 min
Jul 12, 5:41 PM EDT	Areal Flood Advisory	PHI	Burlington	83 min
Jul 12, 5:57 PM EDT	Severe Thunderstorm Warning	PHI	Morris, Sussex	63 min
Jul 12, 6:01 PM EDT	Flash Flood Warning	PHI	Camden	102 min
Jul 12, 6:08 PM EDT	Areal Flood Advisory	PHI	Morris	98 min
Jul 12, 6:43 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester	93 min
Jul 12, 6:52 PM EDT	Severe Thunderstorm Warning	PHI	Morris, Sussex	34 min
Jul 12, 7:00 PM EDT	Areal Flood Advisory	PHI	Gloucester, Salem	112 min
Jul 12, 7:06 PM EDT	Severe Thunderstorm Warning	PHI	Salem	69 min
Jul 12, 7:11 PM EDT	Flash Flood Warning	PHI	Morris, Sussex	35 min
Jul 12, 7:33 PM EDT	Special Marine Warning	PHI		58 min

Nearby

Areal Flood Advisories in New Jersey, 2021 Every areal flood advisory in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.