Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 188, NWS Philadelphia/Mount Holly

August 9, 2009Camden County, Gloucester County, Salem County, New Jersey; 4 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 9, 2009, 6:10 PM EDT for Camden County, Gloucester County, Salem County, New Jersey; 4 counties in Pennsylvania. It was in force for 80 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: Aug 9, 2009, 6:10 PM EDT (22:10 UTC)
Expired: Aug 9, 2009, 7:30 PM EDT
In force: 80 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Camden County, NJ, Gloucester County, NJ, Salem County, NJ, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 81 km from the middle of the area, began a volume at 22:14 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 9, 6:25 PM EDT	TSTM WND DMG	Media, PA	A COUPLE OF TREES KNOCKED DOWN COUNTYWIDE.
Aug 9, 6:40 PM EDT	TSTM WND DMG	2 N Beckett, NJ	TREE FELL DOWN ONTO INTERSTATE 295 IN LOGAN TOWNSHIP.
Aug 9, 6:44 PM EDT	TSTM WND DMG	Penns Grove, NJ	TREES AND WIRES DOWNED IN NW SALEM COUNTY.

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
Aug 9, 3:18 PM EDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 10.2 hours before the alert went out and 199 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: 255 J/kg
Mixed-layer CIN: -88 J/kg
Mixed-layer LCL: 1087 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 243 m²/s²
0-3 km storm-relative helicity: 282 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 6.6

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 092210
SVRPHI
NJC007-015-033-PAC029-045-091-101-092330-
/O.NEW.KPHI.SV.W.0188.090809T2210Z-090809T2330Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
610 PM EDT SUN AUG 9 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EAST CENTRAL CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
  DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
  SOUTHEASTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
  PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF PHILADELPHIA...
  WESTERN CAMDEN COUNTY IN SOUTHERN NEW JERSEY...
  THIS INCLUDES THE CITY OF CAMDEN...
  GLOUCESTER COUNTY IN SOUTHERN NEW JERSEY...
  SALEM COUNTY IN SOUTHERN NEW JERSEY...

* UNTIL 730 PM EDT

* AT 606 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS UP
  TO 70 MPH.  THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
  FROM 12 MILES NORTHWEST OF PLYMOUTH MEETING TO 15 MILES WEST OF
  WESTTOWN...OR ALONG A LINE EXTENDING FROM 18 MILES NORTH OF WEST
  CHESTER TO 12 MILES WEST OF WEST CHESTER...AND MOVING SOUTHEAST AT
  35 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  PLYMOUTH MEETING AND WESTTOWN AROUND 625 PM EDT...
  TROUT LAKE...NEWTOWN SQUARE...GRADYVILLE AND CONCORDVILLE AROUND
  630 PM EDT...
  CHESTNUT HILL...ELAM...CHELSEA AND NARBERTH AROUND 635 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS A HISTORY OF PRODUCING DESTRUCTIVE WINDS. NUMEROUS
TREES AND WIRES HAVE BEEN KNOCKED DOWN IN CHESTER AND BERKS COUNTIES.
SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY AWAY FROM 
WINDOWS AND TREES.

IN ADDITION TO DAMAGING WINDS...HEAVY RAIN WILL OCCUR
WITH THESE STORMS AND CAUSE LOW-LYING AND POOR DRAINAGE FLOODING.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
SUNDAY EVENING FOR NORTHERN DELAWARE AND NORTHEAST MARYLAND AND NEW
JERSEY AND EASTERN PENNSYLVANIA. A SEVERE THUNDERSTORM WATCH ALSO
REMAINS IN EFFECT UNTIL 1100 PM EDT SUNDAY EVENING FOR SOUTHERN
DELAWARE AND NORTHEASTERN MARYLAND.

&&

LAT...LON 3953 7521 3955 7524 3943 7542 3942 7548
      3946 7555 3950 7557 3957 7553 3962 7558
      3980 7542 3984 7552 3984 7565 3987 7566
      4021 7516 4008 7503 4002 7500 3999 7507
      3991 7496 3977 7488
TIME...MOT...LOC 2209Z 313DEG 30KT 4019 7546 3995 7580

$$

TFG

1 follow-up statement

000 
WWUS51 KPHI 092259
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
659 PM EDT SUN AUG 9 2009

PAC029-045-091-101-092308-
/O.CAN.KPHI.SV.W.0188.000000T0000Z-090809T2330Z/
DELAWARE PA-PHILADELPHIA PA-CHESTER PA-MONTGOMERY PA-
659 PM EDT SUN AUG 9 2009

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN MONTGOMERY...EAST
CENTRAL CHESTER...PHILADELPHIA AND DELAWARE COUNTIES IS CANCELLED...

THE LINE OF SEVERE THUNDERSTORMS HAS MOVED INTO NEW JERSEY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
SUNDAY EVENING FOR NORTHERN DELAWARE AND NORTHEAST MARYLAND AND NEW
JERSEY AND EASTERN PENNSYLVANIA. A SEVERE THUNDERSTORM WATCH ALSO
REMAINS IN EFFECT UNTIL 1100 PM EDT SUNDAY EVENING FOR SOUTHERN
DELAWARE AND NORTHEASTERN MARYLAND.

LAT...LON 3953 7521 3955 7524 3946 7538 3946 7541
      3943 7542 3942 7548 3946 7555 3950 7557
      3952 7554 3957 7553 3962 7558 3982 7540
      3983 7521 3991 7496 3980 7492 3977 7488
TIME...MOT...LOC 2258Z 334DEG 35KT 3980 7515 3956 7549

$$

NJC007-015-033-092330-
/O.CON.KPHI.SV.W.0188.000000T0000Z-090809T2330Z/
SALEM NJ-CAMDEN NJ-GLOUCESTER NJ-
659 PM EDT SUN AUG 9 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM EDT
FOR GLOUCESTER...CENTRAL CAMDEN AND SALEM COUNTIES...

AT 658 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING
WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE
EXTENDING FROM OAK VALLEY TO SALEM...OR ALONG A LINE EXTENDING FROM
10 MILES SOUTH OF CAMDEN TO 12 MILES SOUTH OF WILMINGTON...MOVING
SOUTHEAST AT 40 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  TURNERSVILLE...PITMAN...ALLOWAY AND 8 MILES WEST OF PINE HILL BY
  705 PM EDT...
  GLASSBORO AND 6 MILES WEST OF SICKLERVILLE BY 710 PM EDT...
  ELMER AND CLAYTON BY 715 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
SUNDAY EVENING FOR NORTHERN DELAWARE AND NORTHEAST MARYLAND AND NEW
JERSEY AND EASTERN PENNSYLVANIA. A SEVERE THUNDERSTORM WATCH ALSO
REMAINS IN EFFECT UNTIL 1100 PM EDT SUNDAY EVENING FOR SOUTHERN
DELAWARE AND NORTHEASTERN MARYLAND.

&&

LAT...LON 3953 7521 3955 7524 3946 7538 3946 7541
      3943 7542 3942 7548 3946 7555 3950 7557
      3952 7554 3957 7553 3962 7558 3982 7540
      3983 7521 3991 7496 3980 7492 3977 7488
TIME...MOT...LOC 2258Z 334DEG 35KT 3980 7515 3956 7549

$$

TFG

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 9, 9:23 AM EDT	Areal Flood Advisory	PHI	Camden, Gloucester	83 min
Aug 9, 10:33 AM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Ocean	69 min
Aug 9, 11:57 AM EDT	Flash Flood Watch	PHI	Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 10 more	11 hr
Aug 9, 1:56 PM EDT	Excessive Heat Warning	PHI	Burlington, Camden, Gloucester, Mercer	30 hr
Aug 9, 1:56 PM EDT	Heat Advisory	PHI	Atlantic, Burlington, Cape May, Cumberland, Hunterdon, Middlesex and 6 more	30 hr
Aug 9, 6:20 PM EDT	Special Marine Warning	PHI		115 min
Aug 9, 6:48 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Camden, Cumberland, Gloucester, Salem	72 min
Aug 9, 7:21 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Cape May, Cumberland, Ocean	69 min
Aug 9, 7:33 PM EDT	Special Marine Warning	PHI		87 min
Aug 9, 9:33 AM EDT	Areal Flood Warning	PHI	Philadelphia	51 min
Aug 9, 4:30 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Carbon, Lehigh, Monroe, Northampton	90 min
Aug 9, 5:17 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Montgomery	76 min
Aug 9, 5:53 PM EDT	Severe Thunderstorm Warning	PHI	Chester	82 min
Aug 9, 6:03 PM EDT	Areal Flood Advisory	PHI	Berks, Chester, Delaware, Montgomery, Philadelphia	117 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2009 Severe Thunderstorm Warnings in New Jersey, 2009 Every severe thunderstorm warning in 2009

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.