Alert archive / New Jersey / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 291, NWS Philadelphia/Mount Holly

August 21, 20115 counties in New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 21, 2011, 6:12 PM EDT for 5 counties in New Jersey. It was in force for 63 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
Aug 21, 2011, 6:12 PM EDT (22:12 UTC)
Expired
Aug 21, 2011, 7:15 PM EDT
In force
63 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Burlington County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Ocean County, NJ

The radar

The Philadelphia radar (KDIX), 32 km from the middle of the area, began a volume at 22:13 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 watch it was issued in

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

IssuedProductOfficeLasted
Aug 21, 12:52 PM EDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 10.2 hours before the alert went out and 147 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 2011-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 874 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 12:00Z on 2011-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 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
874 J/kg
Mixed-layer CIN
-29 J/kg
Mixed-layer LCL
857 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
116 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

542 
WUUS51 KPHI 212212
SVRPHI
NJC005-021-023-025-029-212315-
/O.NEW.KPHI.SV.W.0291.110821T2212Z-110821T2315Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
612 PM EDT SUN AUG 21 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN MERCER COUNTY IN CENTRAL NEW JERSEY...
  WESTERN MONMOUTH COUNTY IN CENTRAL NEW JERSEY...
  SOUTHERN MIDDLESEX COUNTY IN NORTHERN NEW JERSEY...
  NORTH CENTRAL BURLINGTON COUNTY IN SOUTHERN NEW JERSEY...
  NORTHWESTERN OCEAN COUNTY IN SOUTHERN NEW JERSEY...

* UNTIL 715 PM EDT

* AT 609 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  GEORGETOWN...AND MOVING EAST AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  ALLENTOWN AROUND 620 PM EDT...
  CREAM RIDGE AROUND 625 PM EDT...
  IMLAYSTOWN AND WOODRUFF AROUND 630 PM EDT...
  SIX FLAGS THEME PARK...CASSVILLE AND CLARKSBURG AROUND 640 PM
  EDT...
  JACKSONS MILLS AROUND 650 PM EDT...
  FREEWOOD ACRES AND ADELPHIA AROUND 700 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DOPPLER RADAR HAS INDICATED SOME WEAK ROTATION WITHIN THIS STORM.
WHILE NOT IMMEDIATELY LIKELY...A TORNADO MAY STILL DEVELOP. 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...DESTRUCTIVE 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.

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

&&

LAT...LON 4043 7418 4003 7417 3999 7469 4031 7476
TIME...MOT...LOC 2212Z 253DEG 22KT 4010 7463

$$

IOVINO
1 follow-up statement
011 
WWUS51 KPHI 212234
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
634 PM EDT SUN AUG 21 2011

NJC005-021-023-025-029-212315-
/O.CON.KPHI.SV.W.0291.000000T0000Z-110821T2315Z/
MERCER NJ-MIDDLESEX NJ-MONMOUTH NJ-OCEAN NJ-BURLINGTON NJ-
634 PM EDT SUN AUG 21 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM EDT
FOR NORTH CENTRAL BURLINGTON...NORTHERN OCEAN...WESTERN MONMOUTH...
SOUTHERN MIDDLESEX AND SOUTHEASTERN MERCER COUNTIES...

AT 632 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS 
LOCATED NEAR SIX FLAGS THEME PARK...MOVING EAST AT 25 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  CLARKSBURG AND CASSVILLE BY 640 PM EDT...
  JACKSONS MILLS BY 650 PM EDT...
  FREEWOOD ACRES...ADELPHIA...WEST FREEHOLD AND FREEHOLD BY 700 PM
  EDT...
  EAST FREEHOLD BY 705 PM EDT...
  HOWELL BY 710 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DOPPLER RADAR HAS INDICATED SOME WEAK ROTATION WITHIN THIS STORM.
WHILE NOT IMMEDIATELY LIKELY...A TORNADO MAY STILL DEVELOP. 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...DESTRUCTIVE 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.

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

&&

LAT...LON 4034 7461 4043 7418 4003 7417 3999 7469
TIME...MOT...LOC 2233Z 253DEG 22KT 4014 7447

$$

IOVINO

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 21, 3:24 AM EDTSmall Craft AdvisoryPHI30 hr
Aug 21, 3:28 AM EDTFlash Flood WatchPHIBurlington, Camden, Cumberland, Gloucester, Hunterdon, Mercer and 6 more17 hr
Aug 21, 8:41 AM EDTSpecial Weather StatementPHISalem64 min
Aug 21, 10:33 AM EDTSpecial Marine WarningPHI57 min
Aug 21, 11:07 AM EDTSpecial Marine WarningPHI83 min
Aug 21, 12:20 PM EDTSpecial Weather StatementPHIMorris55 min
Aug 21, 12:33 PM EDTSevere Thunderstorm WarningPHIMorris33 min
Aug 21, 12:39 PM EDTSpecial Weather StatementPHIBurlington, Camden66 min
Aug 21, 1:47 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Mercer58 min
Aug 21, 2:33 PM EDTAreal Flood AdvisoryPHIBurlington, Camden, Mercer117 min
Aug 21, 2:43 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Gloucester, Mercer62 min
Aug 21, 3:08 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean67 min
Aug 21, 3:21 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean54 min
Aug 21, 3:22 PM EDTSpecial Marine WarningPHI83 min
Aug 21, 3:46 PM EDTFlash Flood WarningPHIBurlington2 hr
Aug 21, 4:14 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean46 min
Aug 21, 4:26 PM EDTSpecial Marine WarningPHI57 min
Aug 21, 4:35 PM EDTAreal Flood AdvisoryPHIBurlington, Camden, Mercer, Middlesex, Monmouth, Ocean3 hr
Aug 21, 5:44 PM EDTSpecial Weather StatementPHIMercer61 min
Aug 21, 6:05 PM EDTFlash Flood WarningPHIBurlington6 hr
Aug 21, 6:20 PM EDTSpecial Weather StatementPHIHunterdon55 min
Aug 21, 6:54 PM EDTAreal Flood AdvisoryPHIHunterdon, Middlesex, Morris, Somerset, Sussex, Warren111 min
Aug 21, 7:08 PM EDTSpecial Weather StatementPHIHunterdon, Middlesex, Somerset52 min
Aug 21, 7:18 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean42 min
Aug 21, 7:21 PM EDTSpecial Marine WarningPHI84 min
Aug 21, 7:24 PM EDTFlash Flood WarningPHIMercer, Monmouth, Ocean5 hr
Aug 21, 7:35 PM EDTAreal Flood AdvisoryPHIBurlington, Mercer, Middlesex, Monmouth, Ocean115 min

Nearby

Severe Thunderstorm Warnings in New Jersey, 2011Every severe thunderstorm warning in 2011

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.