Alert archive / New Jersey / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 166, NWS Philadelphia/Mount Holly

July 31, 20094 counties in Pennsylvania; 5 counties in New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 31, 2009, 4:31 PM EDT for 4 counties in Pennsylvania; 5 counties in New Jersey. It was in force for 59 min. 5 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
Jul 31, 2009, 4:31 PM EDT (20:31 UTC)
Expired
Jul 31, 2009, 5:30 PM EDT
In force
59 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Salem County, NJ, Bucks County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 36 km from the middle of the area, began a volume at 20:32 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

TimeReportWhereRemark
Jul 31, 4:53 PM EDTTSTM WND GST 58Stratford, NJ58 MPH WIND GUST ESTIMATED IN STRATFORD. TREES ALSO REPORTED DOWN.
Jul 31, 5:10 PM EDTTSTM WND DMGMedford Lakes, NJTREES REPORTED DOWN. ALSO, SOME SMALL HAIL.
Jul 31, 5:15 PM EDTTSTM WND DMGVoorhees, NJTREES AND WIRES REPORTED DOWN IN THE VOORHEES AREA.
Jul 31, 5:16 PM EDTTSTM WND DMGWenonah, NJTREE REPORTED DOWN ON A CAR IN WENOAH.
Jul 31, 5:17 PM EDTTSTM WND DMGWoodbury, NJTREES AND WIRES REPORTED DOWN COUNTYWIDE.

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.

IssuedProductOfficeLasted
Jul 31, 1:18 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 8.5 hours before the alert went out and 195 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-pSkew-T log-p diagram, Brookhaven, NY at 12:00Z on 2009-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 48 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 12:00Z on 2009-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 133 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
48 J/kg
Mixed-layer CIN
-90 J/kg
Mixed-layer LCL
1022 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
133 m²/s²
0-3 km storm-relative helicity
184 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.8

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 312031
SVRPHI
NJC001-005-007-015-033-PAC017-045-091-101-312130-
/O.NEW.KPHI.SV.W.0166.090731T2031Z-090731T2130Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
431 PM EDT FRI JUL 31 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...
  NORTHEASTERN DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
  SOUTHEASTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
  PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF PHILADELPHIA...
  EXTREME NORTH CENTRAL ATLANTIC COUNTY IN SOUTHERN NEW JERSEY...
  BURLINGTON COUNTY IN SOUTHERN NEW JERSEY...
  CAMDEN COUNTY IN SOUTHERN NEW JERSEY...
  THIS INCLUDES THE CITY OF CAMDEN...
  EASTERN GLOUCESTER COUNTY IN SOUTHERN NEW JERSEY...
  EAST CENTRAL SALEM COUNTY IN SOUTHERN NEW JERSEY...

* UNTIL 530 PM EDT

* AT 428 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
  OF 60 MPH.  THIS STORM WAS LOCATED NEAR MULLICA HILL...OR 14 MILES
  SOUTHWEST OF CAMDEN...AND MOVING EAST AT 40 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  WOODBURY HEIGHTS...DEPTFORD AND WOODBURY AROUND 440 PM EDT...
  TURNERSVILLE AND BELLMAWR AROUND 445 PM EDT...
  LINDENWOLD AND MAGNOLIA AROUND 450 PM EDT...
  VOORHEES...SPRINGDALE AND MARLTON LAKES AROUND 455 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT FRIDAY
EVENING FOR DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY AND
EASTERN PENNSYLVANIA.

&&

LAT...LON 3959 7517 4002 7538 4030 7490 4015 7472
      4016 7470 4011 7463 3986 7444 3977 7439
TIME...MOT...LOC 2031Z 250DEG 34KT 3977 7522

$$

AMC
1 follow-up statement
000 
WWUS51 KPHI 312105
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
505 PM EDT FRI JUL 31 2009

NJC001-005-007-015-021-029-033-PAC017-045-091-101-312130-
/O.CON.KPHI.SV.W.0166.000000T0000Z-090731T2130Z/
SALEM NJ-CAMDEN NJ-GLOUCESTER NJ-MERCER NJ-DELAWARE PA-
PHILADELPHIA PA-MONTGOMERY PA-BUCKS PA-OCEAN NJ-ATLANTIC NJ-
BURLINGTON NJ-
505 PM EDT FRI JUL 31 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM EDT
FOR BURLINGTON...EXTREME NORTH CENTRAL ATLANTIC...WEST CENTRAL
OCEAN...SOUTHEASTERN BUCKS...SOUTHEASTERN MONTGOMERY...
PHILADELPHIA...NORTHEASTERN DELAWARE...WEST CENTRAL MERCER...EASTERN
GLOUCESTER...CAMDEN AND EAST CENTRAL SALEM COUNTIES...

AT 504 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DESTRUCTIVE WINDS
IN EXCESS OF 70 MPH.  THIS STORM WAS LOCATED NEAR MEDFORD LAKES...OR
17 MILES EAST OF CAMDEN...MOVING EAST AT 40 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  TABERNACLE BY 510 PM EDT...
  LEISURETOWNE...PEMBERTON HEIGHTS AND 6 MILES SOUTH OF PEMBERTON BY
  515 PM EDT...
  9 MILES SOUTH OF WRIGHTSTOWN BY 520 PM EDT...
  PRESIDENTIAL LAKES...COUNTRY LAKE ESTATES...BROWNS MILLS AND 7
  MILES NORTH OF CHATSWORTH BY 525 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT FRIDAY
EVENING FOR DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY AND
EASTERN PENNSYLVANIA.

&&

LAT...LON 3959 7517 4002 7538 4030 7490 4015 7472
      4016 7470 4011 7463 3986 7444 3977 7439
TIME...MOT...LOC 2105Z 256DEG 34KT 3987 7479

$$

AMC

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 31, 2:13 PM EDTFlash Flood WarningPHICarbon, Monroe4 hr
Jul 31, 3:04 PM EDTFlash Flood WarningPHIBucks, Chester, Montgomery3 hr
Jul 31, 3:36 PM EDTSevere Thunderstorm WarningPHIChester, Delaware54 min
Jul 31, 3:40 PM EDTSevere Thunderstorm WarningPHIChester65 min
Jul 31, 4:03 PM EDTSevere Thunderstorm WarningPHIChester, Delaware57 min
Jul 31, 4:08 PM EDTFlash Flood WarningPHIBucks, Chester, Delaware, Montgomery, Philadelphia3 hr
Jul 31, 2:36 PM EDTFlash Flood WarningPHIHunterdon, Morris, Sussex, Warren4 hr
Jul 31, 4:23 PM EDTSpecial Marine WarningPHI67 min
Jul 31, 4:39 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 2 more96 min
Jul 31, 4:56 PM EDTFlash Flood WarningPHIHunterdon, Mercer, Middlesex, Monmouth, Morris, Somerset114 min
Jul 31, 5:07 PM EDTFlash Flood WarningPHIAtlantic, Burlington, Camden, Cumberland, Gloucester, Salem3 hr
Jul 31, 5:10 PM EDTTornado WarningPHIBurlington, Ocean21 min
Jul 31, 5:14 PM EDTSpecial Marine WarningPHI2 hr
Jul 31, 5:15 PM EDTSevere Thunderstorm WarningPHIAtlantic, Ocean60 min
Jul 31, 5:16 PM EDTSpecial Marine WarningPHI119 min
Jul 31, 5:31 PM EDTFlash Flood WarningPHIBurlington, Monmouth, Ocean4 hr
Jul 31, 5:48 PM EDTAreal Flood AdvisoryPHIAtlantic, Burlington, Cape May, Cumberland, Ocean3 hr

Nearby

Severe Thunderstorm Warnings in New Jersey, 2009Severe Thunderstorm Warnings in Pennsylvania, 2009Every 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.