Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 203, NWS Philadelphia/Mount Holly

July 29, 2011Berks County, Lehigh County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 29, 2011, 4:40 PM EDT for Berks County, Lehigh County, Pennsylvania. It was in force for 65 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
Jul 29, 2011, 4:40 PM EDT (20:40 UTC)
Expired
Jul 29, 2011, 5:45 PM EDT
In force
65 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Berks County, PA, Lehigh County, PA

The radar

The Philadelphia radar (KDIX), 145 km from the middle of the area, began a volume at 20:40 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
Jul 29, 2:40 PM EDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 8.7 hours before the alert went out and 212 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 12:00Z on 2011-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 529 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 12:00Z on 2011-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 78 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
529 J/kg
Mixed-layer CIN
-105 J/kg
Mixed-layer LCL
1236 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
78 m²/s²
0-3 km storm-relative helicity
128 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.

972 
WUUS51 KPHI 292040
SVRPHI
PAC011-077-292145-
/O.NEW.KPHI.SV.W.0203.110729T2040Z-110729T2145Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
440 PM EDT FRI JUL 29 2011

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...
  SOUTHERN LEHIGH COUNTY IN EASTERN PENNSYLVANIA...

* UNTIL 545 PM EDT

* AT 436 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 9 MILES
  NORTHWEST OF HAMBURG...OR 23 MILES SOUTHWEST OF LEHIGHTON...AND
  MOVING SOUTHEAST AT 40 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  HAMBURG AROUND 445 PM EDT...
  LENHARTSVILLE AND WANAMAKERS AROUND 455 PM EDT...
  KUTZTOWN AND LYONS AROUND 505 PM EDT...
  TOPTON AROUND 510 PM EDT...
  ANCIENT OAKS AROUND 515 PM EDT...
  EMMAUS AROUND 520 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 1100 PM EDT
FRIDAY EVENING FOR NEW JERSEY AND EASTERN PENNSYLVANIA.

&&

LAT...LON 4052 7637 4053 7623 4058 7609 4059 7607
      4059 7603 4064 7600 4069 7588 4053 7536
      4042 7549 4044 7553 4024 7570 4017 7584
      4050 7640
TIME...MOT...LOC 2040Z 293DEG 36KT 4064 7604

$$

JJM
1 follow-up statement
497 
WWUS51 KPHI 292101
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
501 PM EDT FRI JUL 29 2011

PAC011-077-292145-
/O.CON.KPHI.SV.W.0203.000000T0000Z-110729T2145Z/
BERKS PA-LEHIGH PA-
501 PM EDT FRI JUL 29 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 545 PM EDT
FOR SOUTHERN LEHIGH AND NORTHERN BERKS COUNTIES...

AT 457 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 LENHARTSVILLE...OR 18 MILES NORTH OF READING...MOVING
SOUTHEAST AT 30 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  KUTZTOWN AND 6 MILES NORTHEAST OF FLEETWOOD BY 515 PM EDT...
  LYONS BY 520 PM EDT...
  TOPTON BY 525 PM EDT...
  ALBURTIS AND ANCIENT OAKS BY 535 PM EDT...
  BALLY AND MACUNGIE BY 540 PM EDT...
  ZIONSVILLE BY 545 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 1100 PM EDT
FRIDAY EVENING FOR NEW JERSEY AND EASTERN PENNSYLVANIA.

&&

LAT...LON 4059 7607 4059 7603 4064 7600 4069 7588
      4053 7536 4042 7549 4044 7553 4028 7567
      4052 7622
TIME...MOT...LOC 2101Z 296DEG 24KT 4057 7589

$$

JJM

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 29, 3:44 PM EDTSpecial Weather StatementPHIBerks, Carbon, Lehigh, Monroe, Northampton2 hr
Jul 29, 5:56 PM EDTSpecial Weather StatementPHIBucks64 min
Jul 29, 6:05 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery55 min
Jul 29, 6:43 PM EDTSevere Thunderstorm WarningPHIPhiladelphia49 min
Jul 29, 7:03 PM EDTSevere Thunderstorm WarningPHIBucks46 min
Jul 29, 7:13 PM EDTSpecial Weather StatementPHIMontgomery62 min
Jul 29, 7:31 PM EDTSpecial Weather StatementPHIBucks, Montgomery, Philadelphia59 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.