Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 115, NWS Philadelphia/Mount Holly

June 22, 2011Bucks County, Montgomery County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 22, 2011, 2:53 PM EDT for Bucks County, Montgomery County, Philadelphia County, Pennsylvania. It was in force for 67 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
Jun 22, 2011, 2:53 PM EDT (18:53 UTC)
Expired
Jun 22, 2011, 4:00 PM EDT
In force
67 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Bucks County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 66 km from the middle of the area, began a volume at 18:55 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
Jun 22, 3:12 PM EDTTSTM WND DMGLansdale, PAWIRES DOWN IN LANSDALE
Jun 22, 3:29 PM EDTTSTM WND DMGHorsham, PATREES DOWN IN HORSHAM
Jun 22, 3:30 PM EDTTSTM WND DMGWarrington, PATHREE AREAS IN WARRINGTON WITH TREES DOWN

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

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 6.9 hours before the alert went out and 117 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, Phillips Aaf/Abe, MD at 12:00Z on 2011-06-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 356 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, Phillips Aaf/Abe, MD at 12:00Z on 2011-06-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 156 square meters per square second.1939587897117136Sfc1 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
356 J/kg
Mixed-layer CIN
-109 J/kg
Mixed-layer LCL
887 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
156 m²/s²
0-3 km storm-relative helicity
169 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

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

261 
WUUS51 KPHI 221853
SVRPHI
PAC017-091-101-222000-
/O.NEW.KPHI.SV.W.0115.110622T1853Z-110622T2000Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
253 PM EDT WED JUN 22 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...
  MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
  NORTHERN PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 400 PM EDT

* AT 251 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
  COLLEGEVILLE...OR 20 MILES NORTHEAST OF WEST CHESTER...AND MOVING
  EAST AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  LANSDALE...HATFIELD AND SOUDERTON AROUND 310 PM EDT...
  FRICKS AROUND 320 PM EDT...
  CHALFONT AROUND 325 PM EDT...
  DOYLESTOWN AND HATBORO AROUND 335 PM EDT...
  IVYLAND AROUND 340 PM EDT...
  RICHBORO AROUND 350 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CLOUD TO GROUND 
LIGHTNING IS DEVELOPING WITH THIS STORM. MOVE INDOORS IMMEDIATELY! 
LIGHTNING IS ONE OF NATURES GREATEST KILLERS. REMEMBER...IF YOU CAN 
HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE STRUCK BY LIGHTNING.

&&

LAT...LON 4012 7476 4012 7483 4007 7488 4006 7495
      4003 7498 4009 7546 4013 7548 4013 7552
      4016 7551 4015 7554 4031 7558 4048 7507
      4042 7506 4040 7502 4040 7497 4034 7495
      4015 7472
TIME...MOT...LOC 1853Z 259DEG 20KT 4021 7542

$$

MPD
2 follow-up statements
802 
WWUS51 KPHI 221919
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
319 PM EDT WED JUN 22 2011

PAC017-091-101-222000-
/O.CON.KPHI.SV.W.0115.000000T0000Z-110622T2000Z/
PHILADELPHIA PA-MONTGOMERY PA-BUCKS PA-
319 PM EDT WED JUN 22 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 400 PM EDT
FOR BUCKS...EASTERN MONTGOMERY AND NORTHEASTERN PHILADELPHIA
COUNTIES...

AT 316 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING HAIL UP TO GOLF 
BALL SIZE ...AND DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS 
LOCATED NEAR MONTGOMERYVILLE...OR 17 MILES NORTH OF 
PHILADELPHIA...MOVING EAST AT 25 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  HORSHAM BY 325 PM EDT...
  DOYLESTOWN AND WARMINSTER HEIGHTS BY 330 PM EDT...
  IVYLAND BY 335 PM EDT...
  RICHBORO AND CHURCHVILLE BY 345 PM EDT...
  NEWTOWN GRANT AND VILLAGE SHIRES BY 350 PM EDT...
  NEWTOWN AND NEW HOPE BY 355 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...FREQUENT CLOUD TO 
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. THIS IS A DANGEROUS 
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.

&&

LAT...LON 4012 7476 4012 7483 4007 7488 4006 7495
      4003 7498 4012 7533 4036 7542 4048 7507
      4042 7506 4040 7502 4040 7497 4034 7495
      4015 7472
TIME...MOT...LOC 1918Z 259DEG 20KT 4025 7520

$$

GORSE
447 
WWUS51 KPHI 221946
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
346 PM EDT WED JUN 22 2011

PAC091-101-221954-
/O.CAN.KPHI.SV.W.0115.000000T0000Z-110622T2000Z/
PHILADELPHIA PA-MONTGOMERY PA-
346 PM EDT WED JUN 22 2011

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN MONTGOMERY AND
NORTHEASTERN PHILADELPHIA COUNTIES IS CANCELLED...

THE SEVERE THUNDERSTORM THAT PROMPTED THE WARNING HAS MOVED OUT OF 
MONTGOMERY COUNTY AND INTO BUCKS COUNTY. THIS STORM IS EXPECTED TO 
REMAIN NORTH OF PHILADELPHIA COUNTY. THEREFORE, THE WARNING HAS BEEN 
CANCELLED.

LAT...LON 4015 7472 4021 7515 4042 7523 4048 7507
      4042 7506 4040 7502 4040 7497 4034 7495
TIME...MOT...LOC 1944Z 262DEG 23KT 4027 7495

$$

PAC017-222000-
/O.CON.KPHI.SV.W.0115.000000T0000Z-110622T2000Z/
BUCKS PA-
346 PM EDT WED JUN 22 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 400 PM EDT
FOR CENTRAL BUCKS COUNTY...

AT 342 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 NEWTOWN GRANT...OR 12 MILES WEST OF TRENTON...MOVING
EAST AT 25 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  WOODBOURNE BY 350 PM EDT...
  WOODSIDE AND 7 MILES NORTH OF FAIRLESS HILLS BY 355 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. 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.

&&

LAT...LON 4015 7472 4021 7515 4042 7523 4048 7507
      4042 7506 4040 7502 4040 7497 4034 7495
TIME...MOT...LOC 1944Z 262DEG 23KT 4027 7495

$$

GORSE

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 21, 9:37 PM EDTAreal Flood AdvisoryPHIMonroe116 min
Jun 22, 2:15 AM EDTSpecial Weather StatementPHIBerks, Chester, Delaware60 min
Jun 22, 2:57 AM EDTSpecial Weather StatementPHIDelaware63 min
Jun 22, 3:05 AM EDTAreal Flood AdvisoryPHIChester, Delaware115 min
Jun 22, 4:13 AM EDTSpecial Weather StatementPHICarbon92 min
Jun 22, 6:32 AM EDTSpecial Weather StatementPHIDelaware, Philadelphia58 min
Jun 22, 8:00 AM EDTSpecial Weather StatementPHIDelaware, Philadelphia60 min
Jun 22, 1:48 PM EDTSpecial Weather StatementPHIBerks57 min
Jun 22, 4:09 PM EDTSpecial Weather StatementPHIMonroe66 min
Jun 22, 4:37 PM EDTSevere Thunderstorm WarningPHIMonroe, Northampton53 min

Nearby

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