Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 71, NWS Philadelphia/Mount Holly

May 26, 2011Berks County, Lehigh County, Northampton County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 26, 2011, 8:50 PM EDT for Berks County, Lehigh County, Northampton County, Pennsylvania. It was in force for 55 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
May 26, 2011, 8:50 PM EDT (00:50 UTC)
Expired
May 26, 2011, 9:45 PM EDT
In force
55 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Berks County, PA, Lehigh County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 128 km from the middle of the area, began a volume at 00:51 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
May 26, 8:50 PM EDTTSTM WND DMGMaiden Creek, PALIMBS DOWN. POWER POLE DAMAGED.
May 26, 9:00 PM EDTTSTM WND DMG3 S Kutztown, PASEVERAL DOWNED TREES AND BRANCHES
May 26, 9:00 PM EDTTSTM WND DMGAlbany Twp, PASIDE OF UNUSED BARN BLOWN OUT... TWO ROOFS DAMAGED... TREES AND POWER LINES DOWN.
May 26, 9:00 PM EDTTSTM WND GST 61Topton, PA
May 26, 9:13 PM EDTHAIL 1Lehigh Twp, PA

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

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 0.8 hours before the alert went out and 226 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, Washington/Dulle, VA at 00:00Z on 2011-05-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 935 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, Washington/Dulle, VA at 00:00Z on 2011-05-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 185 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
935 J/kg
Mixed-layer CIN
-39 J/kg
Mixed-layer LCL
1937 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
185 m²/s²
0-3 km storm-relative helicity
146 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.9

Open this sounding in Storm Lab

The text

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

463 
WUUS51 KPHI 270050
SVRPHI
PAC011-077-095-270145-
/O.NEW.KPHI.SV.W.0071.110527T0050Z-110527T0145Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
850 PM EDT THU MAY 26 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN BERKS COUNTY IN EASTERN PENNSYLVANIA...
  THIS INCLUDES THE CITY OF READING...
  LEHIGH COUNTY IN EASTERN PENNSYLVANIA...
  THIS INCLUDES THE CITY OF ALLENTOWN...
  SOUTHWESTERN NORTHAMPTON COUNTY IN EASTERN PENNSYLVANIA...

* UNTIL 945 PM EDT

* AT 847 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
  KUTZTOWN...OR 14 MILES NORTH OF READING...AND MOVING EAST AT 45
  MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  TOPTON AROUND 855 PM EDT...
  CLAUSSVILLE AND ANCIENT OAKS AROUND 900 PM EDT...
  COFFEETOWN AROUND 905 PM EDT...
  ALLENTOWN AND NORTHAMPTON AROUND 910 PM EDT...
  BETHLEHEM AND BATH AROUND 915 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.

&&

LAT...LON 4056 7610 4084 7537 4059 7526 4043 7557
      4016 7591
TIME...MOT...LOC 0050Z 248DEG 48KT 4053 7580

$$

NIERENBERG
1 follow-up statement
413 
WWUS51 KPHI 270112
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
912 PM EDT THU MAY 26 2011

PAC011-270121-
/O.CAN.KPHI.SV.W.0071.000000T0000Z-110527T0145Z/
BERKS PA-
912 PM EDT THU MAY 26 2011

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN BERKS COUNTY IS
CANCELLED...

THE THUNDERSTORMS HAVE MOVED OUT OF THE AREA.

LAT...LON 4071 7569 4084 7537 4059 7526 4053 7538
      4051 7542 4045 7553
TIME...MOT...LOC 0111Z 248DEG 48KT 4063 7546

$$

PAC077-095-270145-
/O.CON.KPHI.SV.W.0071.000000T0000Z-110527T0145Z/
LEHIGH PA-NORTHAMPTON PA-
912 PM EDT THU MAY 26 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 PM EDT
FOR WESTERN NORTHAMPTON AND EASTERN LEHIGH COUNTIES...

AT 908 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 FULLERTON...OR NEAR ALLENTOWN...MOVING EAST AT 55 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  7 MILES SOUTH OF CHAPMAN BY 915 PM EDT...

LAT...LON 4071 7569 4084 7537 4059 7526 4053 7538
      4051 7542 4045 7553
TIME...MOT...LOC 0111Z 248DEG 48KT 4063 7546

$$

RPW

The office that day

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

IssuedProductOfficeCountiesLasted
May 26, 8:11 PM EDTSevere Thunderstorm WarningPHIBerks48 min
May 26, 8:46 PM EDTSevere Thunderstorm WarningPHIBerks, Carbon, Lehigh, Monroe, Northampton59 min
May 26, 9:44 PM EDTSevere Thunderstorm WarningPHIMonroe, Northampton61 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.