Alert archive / New Jersey / Special Weather Statements in 2018

Special Weather Statement, NWS Philadelphia/Mount Holly

September 18, 2018Camden County, Gloucester County, Salem County, New Jersey; Delaware County, Philadelphia County, Pennsylvania; New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this special weather statement at Sep 18, 2018, 4:13 AM EDT for Camden County, Gloucester County, Salem County, New Jersey; Delaware County, Philadelphia County, Pennsylvania; New Castle County, Delaware. It was in force for 92 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Sep 18, 2018, 4:13 AM EDT (08:13 UTC)
Expired: Sep 18, 2018, 5:45 AM EDT
In force: 92 min
Issued by: NWS Philadelphia/Mount Holly

Counties New Castle County, DE, Camden County, NJ, Gloucester County, NJ, Salem County, NJ, Delaware County, PA, Philadelphia County, PA

The radar

The Dover AFB radar (KDOX), 80 km from the middle of the area, began a volume at 08:15 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

Washington/Dulle, VA (KIAD), launched 00:00Z, 8.2 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: 709 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 587 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 178 m²/s²
0-3 km storm-relative helicity: 256 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 4.8

Open this sounding in Storm Lab

The text

As transmitted.

244 
WWUS81 KPHI 180813
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
413 AM EDT TUE SEP 18 2018

DEZ001-002-MDZ008-012-NJZ016>019-PAZ070-071-104-106-180945-
Kent-New Castle-Cecil-Kent-Northwestern
Burlington-Salem-Camden-Gloucester-Lower Bucks-Eastern
Montgomery-Delaware-Philadelphia-
413 AM EDT TUE SEP 18 2018

...A STRONG THUNDERSTORM WILL AFFECT NEW CASTLE...NORTHWESTERN
KENT...NORTHEASTERN KENT...SOUTHEASTERN CECIL...SALEM...CAMDEN...
GLOUCESTER...NORTHWESTERN BURLINGTON...SOUTHEASTERN MONTGOMERY...
SOUTH CENTRAL BUCKS...PHILADELPHIA AND DELAWARE COUNTIES...

At 412 AM EDT, a strong thunderstorm was located over Delaware City,
or 11 miles south of Wilmington, moving northeast at 35 mph.

Torrential rainfall is also occurring with this storm, and may cause 
localized flooding. Do not drive your vehicle through flooded 
roadways. Winds up to 40 mph are possible with this storm.

Locations impacted include...
Philadelphia, Camden, Wilmington, Newark, Middletown, Elkton,
Gloucester City, Cherry Hill, Bensalem, Evesham, Mount Laurel,
Chester, Willingboro, Deptford, Voorhees, Medford, West Deptford,
Glassboro, Lindenwold and Pennsville.

LAT...LON 3948 7600 4028 7505 3997 7462 3942 7545
      3946 7554 3957 7551 3962 7557 3966 7552
      3972 7551 3962 7561 3958 7556 3958 7557
      3946 7559 3942 7555 3937 7552 3921 7575
      3924 7575 3925 7582 3941 7601
TIME...MOT...LOC 0812Z 224DEG 30KT 3956 7555 

$$

Meola

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 18, 9:27 AM EDT	Flash Flood Watch	PHI	Burlington, Camden, Gloucester, Hunterdon, Mercer, Middlesex and 5 more	6 hr
Sep 18, 10:59 AM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Middlesex, Monmouth, Somerset	4 hr
Sep 18, 12:01 PM EDT	Flash Flood Warning	PHI	Mercer, Middlesex, Somerset	4 hr
Sep 18, 12:16 PM EDT	Special Weather Statement	PHI	Middlesex	29 min
Sep 18, 12:36 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester, Mercer, Middlesex, Monmouth and 2 more	3 hr
Sep 18, 1:20 PM EDT	Special Weather Statement	PHI	Burlington	25 min
Sep 18, 1:35 PM EDT	Special Marine Warning	PHI		55 min
Sep 18, 2:51 PM EDT	Special Marine Warning	PHI		38 min
Sep 18, 2:55 PM EDT	Special Weather Statement	PHI	Ocean	35 min
Sep 18, 3:02 PM EDT	Areal Flood Advisory	PHI	Burlington, Ocean	3 hr
Sep 18, 3:12 PM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Camden, Ocean	47 min
Sep 18, 3:47 PM EDT	Special Weather Statement	PHI	Ocean	28 min
Sep 18, 4:12 PM EDT	Special Weather Statement	PHI	Atlantic	33 min
Sep 18, 4:47 PM EDT	Areal Flood Advisory	PHI	Atlantic, Cape May, Cumberland, Ocean	2 hr
Sep 18, 5:17 PM EDT	Flash Flood Warning	PHI	Atlantic	113 min
Sep 18, 1:13 AM EDT	Special Weather Statement	PHI	Chester	62 min
Sep 18, 2:09 AM EDT	Special Weather Statement	PHI	Chester, Delaware, Montgomery, Philadelphia	81 min
Sep 18, 2:38 AM EDT	Areal Flood Advisory	PHI	Chester, Montgomery	4 hr
Sep 18, 6:27 AM EDT	Areal Flood Advisory	PHI	Carbon, Monroe	4 hr
Sep 18, 10:57 AM EDT	Areal Flood Advisory	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	3 hr
Sep 18, 5:26 PM EDT	Special Weather Statement	PHI	Sussex	34 min

Nearby

Special Weather Statements in New Jersey, 2018 Special Weather Statements in Pennsylvania, 2018 Special Weather Statements in Delaware, 2018 Every special weather statement 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.