Alert archive / New Jersey / Areal Flood Warnings in 2021

Areal Flood Warning 10, NWS Philadelphia/Mount Holly

July 17, 2021Hunterdon County, New Jersey

NWS Philadelphia/Mount Holly issued this areal flood warning at Jul 17, 2021, 11:08 PM EDT for Hunterdon County, New Jersey. It was in force for 12 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: Jul 17, 2021, 11:08 PM EDT (03:08 UTC)
Expired: Jul 18, 2021, 11:37 AM EDT
In force: 12 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

County Hunterdon County, NJ

The radar

The Philadelphia radar (KDIX), 71 km from the middle of the area, began a volume at 03:10 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, 5:45 AM EDT	HEAVY RAIN 5.02	2 Sse Stanton, NJ	UPDATES PREVIOUS HEAVY RAIN REPORT FROM 2 SSE STANTON.

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, 3.1 hours before the alert went out and 177 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: 1431 J/kg
Mixed-layer CIN: -48 J/kg
Mixed-layer LCL: 988 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 26 m²/s²
0-3 km storm-relative helicity: 54 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.6

Open this sounding in Storm Lab

The text

As transmitted.

003 
WGUS41 KPHI 180308
FLWPHI

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service Mount Holly NJ
1108 PM EDT Sat Jul 17 2021

NJC019-181300-
/O.NEW.KPHI.FA.W.0010.210718T0308Z-210718T1300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-
1108 PM EDT Sat Jul 17 2021

The National Weather Service in Mount Holly has issued a

* Flood Warning for...
  Southeastern Hunterdon County in northwestern New Jersey...

* Until 900 AM EDT Sunday.

* At 1108 PM EDT, rainfall totals were between 4 and 6 inches in 
  much of central and southern Hunterdon County. While little 
  additional rainfall is expected overnight, runoff from the heavy 
  rain will continue to cause flooding in the area until Sunday 
  morning.

* Some locations that are experiencing flooding include...
  Byram, Flemington, New Hope, Stockton, Sand Brook, Sergeantsville, 
  White House Station, Lumberville, and Lambertville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Motorists should not attempt to drive around barricades or drive 
cars through flooded areas.

&&

LAT...LON 4050 7506 4065 7478 4061 7471 4059 7472
      4058 7471 4051 7477 4051 7480 4042 7475
      4042 7481 4038 7480 4038 7487 4035 7486
      4034 7494 4040 7497 4041 7499 4040 7503
      4042 7506 4046 7507 4048 7506

$$

Iovino

2 follow-up statements

005 
WGUS41 KPHI 181256
FLWPHI

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Flood Warning
National Weather Service Mount Holly NJ
856 AM EDT Sun Jul 18 2021

NJC019-181600-
/O.EXT.KPHI.FA.W.0010.000000T0000Z-210718T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-
856 AM EDT Sun Jul 18 2021

The National Weather Service in Mount Holly has extended the

* Flood Warning for...
  Southeastern Hunterdon County in northwestern New Jersey...

* Until noon EDT.

* At 856 AM EDT, County officials reported numerous closed roads in 
  the warned area due to thunderstorms and heavy rains from last 
  night. Flooding is ongoing. Between 4 and 6 inches of rain fell 
  across the area last night and early this morning.

* Some locations that will experience flooding include...
  Byram, Flemington, New Hope, Stockton, Sand Brook, Sergeantsville, 
  White House Station, Lumberville, and Lambertville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4050 7506 4065 7478 4061 7471 4059 7472
      4058 7471 4051 7477 4051 7480 4042 7475
      4042 7481 4038 7480 4038 7487 4035 7486
      4034 7494 4040 7497 4041 7499 4040 7503
      4042 7506 4046 7507 4048 7506

$$

PO

965 
WGUS81 KPHI 181537
FLSPHI

Flood Statement
National Weather Service Mount Holly NJ
1137 AM EDT Sun Jul 18 2021

NJC019-181547-
/O.CAN.KPHI.FA.W.0010.000000T0000Z-210718T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hunterdon NJ-
1137 AM EDT Sun Jul 18 2021

...FLOOD WARNING IS CANCELLED FOR SOUTHEASTERN HUNTERDON COUNTY...

Flood waters have receded. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

LAT...LON 4050 7506 4065 7478 4061 7471 4059 7472
      4058 7471 4051 7477 4051 7480 4042 7475
      4042 7481 4038 7480 4038 7487 4035 7486
      4034 7494 4040 7497 4041 7499 4040 7503
      4042 7506 4046 7507 4048 7506

$$

Iovino

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 8:00 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Mercer, Monmouth	45 min
Jul 17, 8:09 PM EDT	Flash Flood Warning	PHI	Mercer, Somerset	4 hr
Jul 17, 8:35 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Gloucester	40 min
Jul 17, 8:36 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean, Somerset	54 min
Jul 17, 8:46 PM EDT	Special Marine Warning	PHI		59 min
Jul 17, 8:53 PM EDT	Areal Flood Advisory	PHI	Mercer, Middlesex, Monmouth	3 hr
Jul 17, 9:25 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester, Salem	2 hr
Jul 17, 9:27 PM EDT	Severe Thunderstorm Warning	PHI	Gloucester, Salem	48 min
Jul 17, 9:30 PM EDT	Severe Thunderstorm Warning	PHI	Cape May	29 min
Jul 17, 9:36 PM EDT	Flash Flood Warning	PHI	Camden, Gloucester, Salem	2 hr
Jul 17, 9:44 PM EDT	Special Marine Warning	PHI		61 min
Jul 17, 9:48 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Gloucester, Mercer, Salem	42 min
Jul 17, 10:21 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean	54 min
Jul 17, 10:22 PM EDT	Tornado Warning	PHI	Burlington, Monmouth, Ocean	23 min
Jul 17, 10:27 PM EDT	Special Weather Statement	PHI	Burlington, Camden	33 min
Jul 17, 10:38 PM EDT	Tornado Warning	PHI	Burlington, Monmouth, Ocean	16 min
Jul 17, 10:43 PM EDT	Flash Flood Warning	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean	79 min
Jul 17, 10:47 PM EDT	Special Marine Warning	PHI		118 min
Jul 17, 10:51 PM EDT	Special Marine Warning	PHI		114 min
Jul 17, 11:07 PM EDT	Special Weather Statement	PHI	Middlesex	38 min
Jul 17, 11:11 PM EDT	Special Weather Statement	PHI	Monmouth, Ocean	34 min
Jul 17, 11:20 PM EDT	Special Marine Warning	PHI		115 min
Jul 17, 11:26 PM EDT	Areal Flood Warning	PHI	Somerset	10 hr
Jul 18, 2:41 AM EDT	Areal Flood Warning	PHI	Mercer	4 hr
Jul 18, 3:48 AM EDT	River Flood Warning	PHI	Mercer	3 hr
Jul 18, 9:08 AM EDT	Areal Flood Warning	PHI	Somerset	2 hr
Jul 18, 11:03 AM EDT	River Flood Warning	PHI	Middlesex, Somerset	88 min

Nearby

Areal Flood Warnings in New Jersey, 2021 Every areal flood warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.