Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 227, NWS Philadelphia/Mount Holly

September 18, 2012Delaware County, Philadelphia County, Pennsylvania; Camden County, Gloucester County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Sep 18, 2012, 5:12 PM EDT for Delaware County, Philadelphia County, Pennsylvania; Camden County, Gloucester County, New Jersey. It was in force for 78 min. 3 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: Sep 18, 2012, 5:12 PM EDT (21:12 UTC)
Expired: Sep 18, 2012, 6:30 PM EDT
In force: 78 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Camden County, NJ, Gloucester County, NJ, Delaware County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 65 km from the middle of the area, began a volume at 21:11 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
Sep 18, 5:35 PM EDT	TSTM WND DMG	Chester, PA	* 2 INJ * TREE DOWN WITH 2 FIREFIGHTERS INJURED.
Sep 18, 5:40 PM EDT	TSTM WND DMG	Norwood, PA	TREES DOWN.
Sep 18, 6:10 PM EDT	TSTM WND DMG	Deptford Twp, NJ	TREE DOWN ON A GARAGE.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Sep 18, 12:10 PM EDT	Tornado Watch	SPC	9 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 9.2 hours before the alert went out and 89 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: 330 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 519 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 265 m²/s²
0-3 km storm-relative helicity: 275 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 2.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

165 
WUUS51 KPHI 182112
SVRPHI
NJC007-015-PAC045-101-182230-
/O.NEW.KPHI.SV.W.0227.120918T2112Z-120918T2230Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
512 PM EDT TUE SEP 18 2012

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
  SOUTHERN PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...
  CAMDEN COUNTY IN SOUTHERN NEW JERSEY...
  THIS INCLUDES THE CITIES OF...GLOUCESTER CITY...CAMDEN...
  GLOUCESTER COUNTY IN SOUTHERN NEW JERSEY...

* UNTIL 630 PM EDT

* AT 510 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN
  EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
  ACROSS EXTREME SOUTHEASTERN PENNSYLVANIA AND NORTHERN
  DELAWARE...MOVING NORTHEAST AT 45 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  CHESTER AROUND 525 PM EDT...
  FOLCROFT...SWEDESBORO AND BECKETT AROUND 530 PM EDT...
  SOUTH PHILADELPHIA...PHILADELPHIA INTERNATIONAL AIRPORT...PAULSBORO
  AND GIBBSTOWN AROUND 535 PM EDT...
  WEST DEPTFORD AND BEN FRANKLIN BRIDGE AROUND 540 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. IF A TORNADO
IS SPOTTED... ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A STURDY
STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM.

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE 
IMMEDIATELY FOR DAMAGING WINDS...HAIL...AND DEADLY CLOUD TO GROUND 
LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...PREFERABLY 
INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

&&

LAT...LON 3963 7515 3967 7520 3966 7524 3972 7538
      3978 7540 3978 7543 3979 7541 3982 7544
      3984 7560 3992 7526 4002 7503 3999 7506
      3998 7501 3995 7502 3994 7498 3989 7493
      3979 7491 3979 7481 3973 7474
TIME...MOT...LOC 2111Z 246DEG 40KT 3983 7555 3950 7562

$$

IOVINO

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 18, 4:13 AM EDT	Coastal Flood Advisory	PHI	Delaware, Philadelphia	21 hr
Sep 18, 12:58 PM EDT	Areal Flood Advisory	PHI	Carbon, Monroe	93 min
Sep 18, 12:59 PM EDT	Special Weather Statement	PHI	Berks, Lehigh	46 min
Sep 18, 1:05 PM EDT	Areal Flood Advisory	PHI	Berks, Lehigh	115 min
Sep 18, 1:32 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh	43 min
Sep 18, 2:00 PM EDT	Special Weather Statement	PHI	Chester, Montgomery	60 min
Sep 18, 2:18 PM EDT	Special Weather Statement	PHI	Carbon, Monroe	57 min
Sep 18, 2:23 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Montgomery	30 min
Sep 18, 2:25 PM EDT	Flash Flood Warning	PHI	Carbon, Lehigh, Monroe, Northampton	4 hr
Sep 18, 2:52 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Lehigh, Northampton	17 min
Sep 18, 3:07 PM EDT	Areal Flood Warning	PHI	Berks, Lehigh	8 hr
Sep 18, 3:16 PM EDT	Special Weather Statement	PHI	Monroe	59 min
Sep 18, 3:24 PM EDT	Special Weather Statement	PHI	Berks, Carbon	51 min
Sep 18, 3:52 PM EDT	Special Weather Statement	PHI	Chester	53 min
Sep 18, 4:05 PM EDT	Areal Flood Advisory	PHI	Berks, Lehigh	55 min
Sep 18, 4:19 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Delaware, Montgomery	56 min
Sep 18, 4:23 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh, Monroe, Northampton	52 min
Sep 18, 4:26 PM EDT	Areal Flood Advisory	PHI	Bucks, Lehigh, Northampton	3 hr
Sep 18, 4:35 PM EDT	Areal Flood Advisory	PHI	Bucks, Chester, Lehigh, Montgomery	55 min
Sep 18, 5:01 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Delaware, Lehigh, Montgomery, Northampton and 1 more	59 min
Sep 18, 5:12 PM EDT	Areal Flood Advisory	PHI	Bucks, Chester, Delaware, Montgomery	63 min
Sep 18, 5:13 PM EDT	Severe Thunderstorm Warning	PHI	Monroe, Northampton	62 min
Sep 18, 6:00 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery, Philadelphia	60 min
Sep 18, 6:06 PM EDT	Areal Flood Advisory	PHI	Bucks, Montgomery, Philadelphia	54 min
Sep 18, 6:19 PM EDT	Areal Flood Warning	PHI	Carbon, Lehigh, Monroe, Northampton	16 hr
Sep 18, 6:54 PM EDT	Areal Flood Advisory	PHI	Bucks	111 min
Sep 17, 8:54 PM EDT	Rip Current Statement	PHI	Atlantic, Cape May, Monmouth, Ocean	23 hr
Sep 18, 4:21 PM EDT	Severe Thunderstorm Warning	PHI	Salem	69 min
Sep 18, 5:23 PM EDT	Severe Thunderstorm Warning	PHI	Salem	52 min
Sep 18, 6:02 PM EDT	Special Marine Warning	PHI		88 min
Sep 18, 6:46 PM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Camden, Cumberland, Gloucester, Salem	119 min
Sep 18, 6:52 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex, Monmouth, Morris, Somerset	53 min
Sep 18, 7:04 PM EDT	Special Weather Statement	PHI	Atlantic, Burlington, Cumberland	56 min
Sep 18, 7:16 PM EDT	Areal Flood Advisory	PHI	Cape May	59 min
Sep 18, 7:51 PM EDT	Special Weather Statement	PHI	Atlantic, Cape May, Ocean	54 min
Sep 18, 7:52 PM EDT	Special Marine Warning	PHI		77 min
Sep 18, 7:56 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Cape May, Ocean	64 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2012 Severe Thunderstorm Warnings in New Jersey, 2012 Every severe thunderstorm warning in 2012

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.