Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 31, NWS Philadelphia/Mount Holly

April 28, 20115 counties in Pennsylvania; 4 counties in New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 28, 2011, 10:25 AM EDT for 5 counties in Pennsylvania; 4 counties in New Jersey. It was in force for 50 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: Apr 28, 2011, 10:25 AM EDT (14:25 UTC)
Expired: Apr 28, 2011, 11:15 AM EDT
In force: 50 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Hunterdon County, NJ, Morris County, NJ, Sussex County, NJ, Warren County, NJ, Bucks County, PA, Carbon County, PA, Lehigh County, PA, Monroe County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 136 km from the middle of the area, began a volume at 14:25 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
Apr 28, 10:50 AM EDT	TSTM WND DMG	Springfield Twp, PA	WIRES DOWN IN SPRINGFIELD TOWNSHIP.
Apr 28, 11:00 AM EDT	FUNNEL CLOUD	Alexandria Twp, NJ	A FUNNEL CLOUD SPOTTED IN ALEXANDRIA TOWNSHIP.
Apr 28, 11:10 AM EDT	TSTM WND DMG	Alexandria Twp, NJ	TREES AND POWER LINES DOWN.

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
Apr 28, 9:45 AM EDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 2.4 hours before the alert went out and 178 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: 211 J/kg
Mixed-layer CIN: -85 J/kg
Mixed-layer LCL: 513 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 346 m²/s²
0-3 km storm-relative helicity: 324 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.

813 
WUUS51 KPHI 281425
SVRPHI
NJC019-027-037-041-PAC017-025-077-089-095-281515-
/O.NEW.KPHI.SV.W.0031.110428T1425Z-110428T1515Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1025 AM EDT THU APR 28 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EAST CENTRAL LEHIGH COUNTY IN EASTERN PENNSYLVANIA...
  THIS INCLUDES THE CITY OF ALLENTOWN...
  NORTHAMPTON COUNTY IN EASTERN PENNSYLVANIA...
  THIS INCLUDES THE CITY OF EASTON...
  EXTREME SOUTHEASTERN CARBON COUNTY IN NORTHEAST PENNSYLVANIA...
  EASTERN MONROE COUNTY IN NORTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF MOUNT POCONO...
  WESTERN MORRIS COUNTY IN NORTHERN NEW JERSEY...
  NORTHWESTERN HUNTERDON COUNTY IN NORTHWEST NEW JERSEY...
  SUSSEX COUNTY IN NORTHWEST NEW JERSEY...
  THIS INCLUDES THE CITY OF NEWTON...
  WARREN COUNTY IN NORTHWEST NEW JERSEY...
  NORTH CENTRAL BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 1115 AM EDT

* AT 1020 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS 
  TO 60 MPH. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING FROM 6 
  MILES NORTHEAST OF SKYTOP TO STORMVILLE TO 6 MILES SOUTH OF        
  ALLENTOWN...OR ALONG A LINE EXTENDING FROM 16 MILES NORTHEAST OF   
  MOUNT POCONO TO 14 MILES SOUTH OF MOUNT POCONO TO 6 MILES SOUTH    
  OF ALLENTOWN...AND MOVING NORTHEAST AT 50 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  PLEASANT VALLEY...TATAMY...HELLERTOWN AND EAST BANGOR AROUND 1030
  AM EDT...
  PIPERSVILLE...BEDMINSTER...SPRINGTOWN AND FORKS AROUND 1035 AM
  EDT...
  REVERE AND OTTSVILLE AROUND 1040 AM EDT...

  SOME OF THESE STORMS HAVE HAD A HISTORY OF PRODUCING WIND DAMAGE   
  IN EASTERN PENNSYLVANIA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

SOME OF THESE SEVERE THUNDERSTORMS MAY CONTAIN LITTLE OR NO 
LIGHTNING. DO NOT WAIT FOR THUNDER BEFORE TAKING COVER. SEEK SHELTER 
IMMEDIATELY INSIDE A STURDY STRUCTURE AND STAY AWAY FROM WINDOWS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 400 PM EDT
THURSDAY AFTERNOON FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND
AND NEW JERSEY AND EASTERN PENNSYLVANIA.

&&

LAT...LON 4122 7444 4079 7470 4036 7514 4063 7556
      4125 7533 4126 7514 4124 7513 4116 7516
      4115 7509 4110 7505 4109 7501 4115 7491
      4127 7484 4131 7480 4135 7468
TIME...MOT...LOC 1422Z 240DEG 36KT 4132 7510 4095 7522
          4053 7545

$$

GORSE

1 follow-up statement

940 
WWUS51 KPHI 281450
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1050 AM EDT THU APR 28 2011

PAC025-281457-
/O.CAN.KPHI.SV.W.0031.000000T0000Z-110428T1515Z/
CARBON PA-
1050 AM EDT THU APR 28 2011

...THE SEVERE THUNDERSTORM WARNING FOR EXTREME SOUTHEASTERN CARBON
COUNTY IS CANCELLED...

THE LINE OF SEVERE THUNDERSTORMS HAVE MOVED EAST OF THE AREA.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 400 PM EDT
THURSDAY AFTERNOON FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND
AND NEW JERSEY AND EASTERN PENNSYLVANIA.

LAT...LON 4122 7444 4079 7470 4036 7514 4063 7556
      4064 7556 4115 7509 4110 7505 4109 7501
      4115 7491 4127 7484 4131 7480 4135 7468
TIME...MOT...LOC 1447Z 240DEG 36KT 4140 7477 4103 7490
          4062 7519

$$

NJC019-027-037-041-PAC017-077-089-095-281515-
/O.CON.KPHI.SV.W.0031.000000T0000Z-110428T1515Z/
SUSSEX NJ-WARREN NJ-MORRIS NJ-HUNTERDON NJ-LEHIGH PA-NORTHAMPTON PA-
BUCKS PA-MONROE PA-
1050 AM EDT THU APR 28 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1115 AM EDT
FOR SOUTHEASTERN MONROE...NORTH CENTRAL BUCKS...NORTHAMPTON...EAST
CENTRAL LEHIGH...NORTHWESTERN HUNTERDON...WESTERN MORRIS...WARREN AND
SUSSEX COUNTIES...

AT 1045 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER 
SIZE HAIL...AND DAMAGING WINDS TO 60 MPH. THESE STORMS WERE LOCATED 
ALONG A LINE EXTENDING FROM 9 MILES NORTH OF HAINESVILLE TO 
BLAIRSTOWN TO RIEGELSVILLE...OR ALONG A LINE EXTENDING FROM MONTAGUE 
TO 11 MILES WEST OF NEWTON TO 6 MILES SOUTH OF EASTON...MOVING 
NORTHEAST AT 50 MPH.

AS 1045 AM...THE MOST INTENSE STORM WAS MOVING INTO SOUTHERN 
NORTHAMPTON COUNTY AND UPPER BUCKS COUNTY. FREQUENT CLOUD TO GROUND 
LIGHTNING IS OCCURRING WITH THIS PARTICULAR STORM.

SEVERE THUNDERSTORMS WILL BE NEAR...
  OXFORD...BRASS CASTLE AND BLOOMSBURY BY 1055 AM EDT...
  PLEASANT VALLEY...HIGH POINT...WASHINGTON AND BRANCHVILLE BY 1100
  AM EDT...
  CLINTON...ANNANDALE AND HAMPTON BY 1105 AM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THESE ARE DANGEROUS STORMS. IF YOU ARE IN ITS PATH...PREPARE 
IMMEDIATELY FOR DAMAGING WINDS...LARGE 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 400 PM EDT
THURSDAY AFTERNOON FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND
AND NEW JERSEY AND EASTERN PENNSYLVANIA.

&&

LAT...LON 4122 7444 4079 7470 4036 7514 4063 7556
      4064 7556 4115 7509 4110 7505 4109 7501
      4115 7491 4127 7484 4131 7480 4135 7468
TIME...MOT...LOC 1447Z 240DEG 45KT 4140 7477 4103 7490
          4062 7519

$$

GORSE

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 28, 4:24 AM EDT	Special Weather Statement	PHI	Berks, Carbon, Lehigh, Northampton	66 min
Apr 28, 4:36 AM EDT	Severe Thunderstorm Warning	PHI	Berks, Carbon, Lehigh, Monroe, Northampton	54 min
Apr 28, 5:31 AM EDT	Special Weather Statement	PHI	Carbon, Monroe	59 min
Apr 28, 5:49 AM EDT	Special Weather Statement	PHI	Carbon	56 min
Apr 28, 5:58 AM EDT	Areal Flood Advisory	PHI	Berks, Carbon, Lehigh, Monroe, Northampton	3 hr
Apr 28, 6:12 AM EDT	Special Weather Statement	PHI	Chester, Delaware, Philadelphia	63 min
Apr 28, 6:18 AM EDT	Severe Thunderstorm Warning	PHI	Carbon, Monroe	57 min
Apr 28, 6:23 AM EDT	Special Weather Statement	PHI	Berks, Chester, Lehigh, Montgomery	52 min
Apr 28, 6:56 AM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Delaware, Lehigh, Montgomery and 2 more	34 min
Apr 28, 7:06 AM EDT	Flash Flood Warning	PHI	Carbon, Monroe	6 hr
Apr 28, 7:35 AM EDT	Special Weather Statement	PHI	Bucks	55 min
Apr 28, 8:17 AM EDT	Special Weather Statement	PHI	Berks	58 min
Apr 28, 8:55 AM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh	65 min
Apr 28, 8:59 AM EDT	Areal Flood Advisory	PHI	Berks, Lehigh	4 hr
Apr 28, 9:11 AM EDT	Special Weather Statement	PHI	Carbon, Monroe	49 min
Apr 28, 9:33 AM EDT	Severe Thunderstorm Warning	PHI	Carbon, Lehigh, Monroe, Northampton	57 min
Apr 28, 10:00 AM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Lehigh, Montgomery	60 min
Apr 28, 10:48 AM EDT	Areal Flood Advisory	PHI	Bucks, Chester, Montgomery, Northampton	3 hr
Apr 28, 10:57 AM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Lehigh, Montgomery, Northampton	63 min
Apr 28, 10:58 AM EDT	Tornado Warning	PHI	Bucks, Northampton	32 min
Apr 28, 11:11 AM EDT	Severe Thunderstorm Warning	PHI	Northampton	64 min
Apr 28, 12:03 PM EDT	Special Weather Statement	PHI	Montgomery, Philadelphia	57 min
Apr 28, 12:11 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Delaware, Montgomery	31 min
Apr 28, 12:42 PM EDT	Special Weather Statement	PHI	Delaware	63 min
Apr 28, 12:45 PM EDT	Special Weather Statement	PHI	Bucks, Delaware, Montgomery, Philadelphia	60 min
Apr 28, 1:23 PM EDT	Areal Flood Advisory	PHI	Philadelphia	103 min
Apr 28, 9:00 AM EDT	Special Weather Statement	PHI	Monmouth	60 min
Apr 28, 9:02 AM EDT	Special Marine Warning	PHI		26 min
Apr 28, 10:10 AM EDT	Gale Warning	PHI		5 hr
Apr 28, 11:15 AM EDT	Areal Flood Advisory	PHI	Mercer, Middlesex, Morris, Somerset	4 hr
Apr 28, 11:22 AM EDT	Tornado Warning	PHI	Hunterdon, Morris, Sussex, Warren	23 min
Apr 28, 11:45 AM EDT	Tornado Warning	PHI	Morris	30 min
Apr 28, 12:06 PM EDT	Special Marine Warning	PHI		43 min
Apr 28, 12:29 PM EDT	Special Weather Statement	PHI	Camden, Gloucester, Salem	61 min
Apr 28, 12:34 PM EDT	Special Weather Statement	PHI	Cumberland	56 min
Apr 28, 12:38 PM EDT	Special Weather Statement	PHI	Hunterdon, Morris, Somerset	52 min
Apr 28, 1:13 PM EDT	Special Weather Statement	PHI	Atlantic, Cape May	62 min
Apr 28, 1:44 PM EDT	Special Marine Warning	PHI		91 min
Apr 28, 2:02 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Gloucester	41 min
Apr 28, 2:11 PM EDT	Areal Flood Advisory	PHI	Burlington, Monmouth, Ocean	94 min
Apr 28, 2:27 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Monmouth, Ocean	41 min
Apr 28, 2:42 PM EDT	Special Marine Warning	PHI		63 min
Apr 28, 2:55 PM EDT	Special Weather Statement	PHI	Monmouth	65 min
Apr 28, 5:04 PM EDT	Special Weather Statement	PHI	Cape May	56 min
Apr 28, 6:03 PM EDT	Special Marine Warning	PHI		57 min
Apr 28, 6:22 PM EDT	Special Weather Statement	PHI	Cape May	53 min
Apr 28, 6:37 PM EDT	Special Marine Warning	PHI		53 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2011 Severe Thunderstorm Warnings in New Jersey, 2011 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.