Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2006

Severe Thunderstorm Warning 210, NWS Philadelphia/Mount Holly

July 27, 2006Delaware County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 27, 2006, 11:32 PM EDT for Delaware County, Montgomery County, Pennsylvania. It was in force for 88 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 27, 2006, 11:32 PM EDT (03:32 UTC)
Expired
Jul 28, 2006, 1:00 AM EDT
In force
88 min
Issued by
NWS Philadelphia/Mount Holly
Area
Counties, with a storm outline in the text

Counties Delaware County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 89 km from the middle of the area, began a volume at 03:35 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 nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 3.5 hours before the alert went out and 219 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 2006-07-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2366 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 00:00Z on 2006-07-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 64 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
2366 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
1305 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
64 m²/s²
0-3 km storm-relative helicity
110 m²/s²
Significant tornado parameter
0.4
Supercell composite
4.6

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 280332
SVRPHI
PAC045-091-280500-
/O.NEW.KPHI.SV.W.0210.060728T0332Z-060728T0500Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1132 PM EDT THU JUL 27 2006

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTH CENTRAL DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA
  SOUTHERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA

* UNTIL 100 AM EDT

* AT 1131 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED 20
  MILES WEST OF RADNOR TOWNSHIP...OR ABOUT 20 MILES NORTHWEST OF
  WILMINGTON...AND MOVING EAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  RADNOR TOWNSHIP BY 1220 AM EDT...
  NORRISTOWN BY 1230 AM EDT...
  PLYMOUTH MEETING BY 1235 AM EDT...
  9 MILES SOUTH OF LANSDALE BY 1245 AM EDT...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS 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 4031 7563 4018 7535 3988 7542 4019 7521
      4027 7523

$$

EBERWINE/MPD
1 follow-up statement
000 
WWUS51 KPHI 280416
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1214 AM EDT FRI JUL 28 2006

PAC045-091-280500-
/O.CON.KPHI.SV.W.0210.000000T0000Z-060728T0500Z/
DELAWARE PA-MONTGOMERY PA-
1214 AM EDT FRI JUL 28 2006

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 100 AM EDT 
FOR SOUTHERN MONTGOMERY AND DELAWARE COUNTIES...

AT 1213 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS 
LOCATED NEAR WILMINGTON...AND WAS MOVING NORTHEAST AT 35 MPH. IT WAS 
APPROACHING THE AREA FROM BOOTHWYN TO CHESTER HEIGHTS IN WESTERN 
DELAWARE COUNTY. 

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 4031 7563 4018 7535 3988 7542 4019 7521
      4027 7523

$$

MPD

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 27, 10:55 PM EDTSevere Thunderstorm WarningPHIChester65 min
Jul 28, 12:32 AM EDTSevere Thunderstorm WarningPHIPhiladelphia43 min
Jul 28, 12:40 AM EDTFlash Flood WarningPHIBucks, Montgomery, Philadelphia3 hr
Jul 28, 12:40 AM EDTSevere Thunderstorm WarningPHIBucks65 min
Jul 28, 2:28 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery, Philadelphia62 min
Jul 28, 2:49 PM EDTSevere Thunderstorm WarningPHIPhiladelphia56 min
Jul 28, 3:07 PM EDTSevere Thunderstorm WarningPHIBucks53 min
Jul 28, 4:03 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery57 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2006Every severe thunderstorm warning in 2006

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.