Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 18, NWS Philadelphia/Mount Holly

May 29, 2012Berks County, Lehigh County, Northampton County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 29, 2012, 6:14 PM EDT for Berks County, Lehigh County, Northampton County, Pennsylvania. It was in force for 91 min. 4 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 29, 2012, 6:14 PM EDT (22:14 UTC)
Expired
May 29, 2012, 7:45 PM EDT
In force
91 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), 112 km from the middle of the area, began a volume at 22:16 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 29, 6:30 PM EDTTSTM WND DMGSouth Whitehall Twp, PAWIRES DOWN
May 29, 6:30 PM EDTTSTM WND DMGWilson, PAWIRES DOWN IN WILSON... BANGOR AND NAZARETH
May 29, 6:40 PM EDTTSTM WND DMGAllentown, PAWIRES DOWN
May 29, 6:50 PM EDTTSTM WND DMGAmity Twp, PAA FEW BRANCHES WIRES 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.

IssuedProductOfficeLasted
May 29, 1:03 PM EDTSevere Thunderstorm WatchSPC8 hr
May 29, 5:54 PM EDTSevere Thunderstorm WatchSPC3 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 10.2 hours before the alert went out and 127 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 2012-05-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 667 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 2012-05-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -39 square meters per square second.1939Sfc1 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
667 J/kg
Mixed-layer CIN
-217 J/kg
Mixed-layer LCL
1153 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
-39 m²/s²
0-3 km storm-relative helicity
-10 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.

987 
WUUS51 KPHI 292214
SVRPHI
PAC011-077-095-292345-
/O.NEW.KPHI.SV.W.0018.120529T2214Z-120529T2345Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
614 PM EDT TUE MAY 29 2012

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

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

* UNTIL 745 PM EDT

* AT 612 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
  LAURELDALE...OR NEAR READING...AND MOVING NORTHEAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  FLEETWOOD AROUND 630 PM EDT...
  LYONS AND KUTZTOWN AROUND 640 PM EDT...
  TOPTON AROUND 645 PM EDT...
  ANCIENT OAKS AROUND 700 PM EDT...
  EMMAUS AROUND 710 PM EDT...
  ALLENTOWN AROUND 715 PM EDT...

OTHER POTENTIALLY SEVERE THUNDERSTORMS IN LANCASTER COUNTY COULD 
ENTER SOUTHERN BERKS COUNTY AFTER 645 PM.

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.

THIS STORM HAS A HISTORY OF PRODUCING DESTRUCTIVE WINDS AND LARGE
DAMAGING HAIL. SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY
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
TUESDAY EVENING FOR NORTHEASTERN PENNSYLVANIA. A SEVERE THUNDERSTORM
WATCH ALSO REMAINS IN EFFECT UNTIL 1000 PM EDT TUESDAY EVENING FOR
NEW JERSEY AND SOUTHEASTERN PENNSYLVANIA.

&&

LAT...LON 4071 7551 4071 7520 4068 7520 4068 7518
      4061 7520 4050 7540 4042 7548 4044 7553
      4027 7567 4013 7587 4034 7619
TIME...MOT...LOC 2214Z 242DEG 24KT 4040 7595

$$

TFG
1 follow-up statement
854 
WWUS51 KPHI 292324
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
724 PM EDT TUE MAY 29 2012

PAC011-077-095-292345-
/O.CON.KPHI.SV.W.0018.000000T0000Z-120529T2345Z/
BERKS PA-LEHIGH PA-NORTHAMPTON PA-
724 PM EDT TUE MAY 29 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT
FOR SOUTH CENTRAL NORTHAMPTON...SOUTHEASTERN LEHIGH AND SOUTHEASTERN
BERKS COUNTIES...

AT 720 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING
WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE
EXTENDING FROM FREEMANSBURG TO BALLY TO 7 MILES SOUTH OF AMITY
GARDENS...OR ALONG A LINE EXTENDING FROM 7 MILES EAST OF ALLENTOWN TO
17 MILES SOUTH OF ALLENTOWN TO 14 MILES SOUTHEAST OF READING...MOVING
SOUTHEAST AT 25 MPH.

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.

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
TUESDAY EVENING FOR NORTHEASTERN PENNSYLVANIA.

&&

LAT...LON 4022 7585 4068 7539 4071 7520 4068 7520
      4068 7518 4065 7520 4061 7520 4051 7539
      4042 7548 4044 7553 4027 7567 4014 7587
TIME...MOT...LOC 2322Z 319DEG 24KT 4061 7534 4034 7551
          4016 7577

$$
 
TFG

The office that day

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

IssuedProductOfficeCountiesLasted
May 29, 12:29 PM EDTFlash Flood WatchPHIBerks, Carbon, Delaware, Lehigh, Monroe, Northampton and 1 more8 hr
May 29, 1:36 PM EDTSpecial Weather StatementPHIMonroe54 min
May 29, 1:50 PM EDTAreal Flood AdvisoryPHICarbon, Monroe115 min
May 29, 5:06 PM EDTSpecial Weather StatementPHIBerks, Carbon, Lehigh, Monroe, Northampton114 min
May 29, 5:25 PM EDTSevere Thunderstorm WarningPHIBerks, Carbon, Lehigh95 min
May 29, 5:45 PM EDTSevere Thunderstorm WarningPHIMonroe, Northampton75 min
May 29, 6:23 PM EDTFlash Flood WarningPHICarbon, Monroe112 min
May 29, 6:44 PM EDTAreal Flood AdvisoryPHIBerks, Bucks, Lehigh, Montgomery3 hr
May 29, 6:46 PM EDTSpecial Weather StatementPHIBucks, Chester, Delaware, Montgomery, Philadelphia89 min
May 29, 6:52 PM EDTSevere Thunderstorm WarningPHIBucks, Chester, Montgomery53 min
May 29, 7:34 PM EDTSpecial Weather StatementPHIDelaware, Philadelphia56 min
May 29, 7:35 PM EDTAreal Flood AdvisoryPHIBucks, Chester, Delaware, Montgomery, Philadelphia115 min
May 29, 7:44 PM EDTSpecial Weather StatementPHIBucks61 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2012Every severe thunderstorm warning in 2012

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.