Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2006

Severe Thunderstorm Warning 245, NWS Philadelphia/Mount Holly

August 25, 2006Chester County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 25, 2006, 11:05 PM EDT for Chester County, Montgomery County, Pennsylvania. It was in force for 40 min. 1 report 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
Aug 25, 2006, 11:05 PM EDT (03:05 UTC)
Expired
Aug 25, 2006, 11:45 PM EDT
In force
40 min
Issued by
NWS Philadelphia/Mount Holly
Area
Counties, with a storm outline in the text

Counties Chester County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 104 km from the middle of the area, began a volume at 03:05 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
Aug 25, 11:40 PM EDTHAIL 17 S Kenilworth, PANICKEL TO QUARTER SIZE HAIL REPORTED ABOUT 7 MILES SOUTH OF KENILWORTH.

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, 3.1 hours before the alert went out and 210 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 2006-08-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 979 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 2006-08-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 104 square meters per square second.19395878Sfc1 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
979 J/kg
Mixed-layer CIN
-18 J/kg
Mixed-layer LCL
1772 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
104 m²/s²
0-3 km storm-relative helicity
192 m²/s²
Significant tornado parameter
0.1
Supercell composite
4.3

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 260305
SVRPHI
PAC029-091-260345-
/O.NEW.KPHI.SV.W.0245.060826T0305Z-060826T0345Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1105 PM EDT FRI AUG 25 2006

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA
  WESTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA

* UNTIL 1145 PM EDT

* AT 1101 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  POTTSTOWN...OR ABOUT 12 MILES EAST OF READING...AND MOVING
  SOUTHEAST AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  POTTSTOWN BY 1110 PM EDT...
  6 MILES SOUTHWEST OF SPRING MOUNT BY 1125 PM EDT...
  PHOENIXVILLE BY 1130 PM EDT...
  COLLEGEVILLE BY 1135 PM EDT...

LAT...LON 4035 7556 4016 7583 4000 7565 4021 7530

$$

EBERWINE
1 follow-up statement
000 
WWUS51 KPHI 260320
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1117 PM EDT FRI AUG 25 2006

PAC029-091-260345-
/O.CON.KPHI.SV.W.0245.000000T0000Z-060826T0345Z/
CHESTER PA-MONTGOMERY PA-
1117 PM EDT FRI AUG 25 2006

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1145 PM EDT
FOR WESTERN MONTGOMERY AND NORTHEASTERN CHESTER COUNTIES...

AT 1113 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
LOCATED NEAR KENILWORTH...OR ABOUT 18 MILES SOUTHEAST OF 
READING...MOVING SOUTHEAST AT 25 MPH.

THE STORM PRODUCED NICKEL SIZE HAIL IN BIRDSBORO BERKS COUNTY AND 
MAY BE PRODUCING A GOOD DEAL OF HAIL ALONG THE NORTHEASTERN CHESTER 
AND NORTHWESTER MONTGOMERY COUNTIES. 

THE SEVERE THUNDERSTORM WILL BE NEAR...
  PHOENIXVILLE...TRAPPE...6 MILES SOUTHWEST OF COLLEGEVILLE AND 7
  MILES NORTHEAST OF LIONVILLE BY 1125 PM EDT...
  7 MILES NORTHEAST OF EXTON AND 7 MILES SOUTHWEST OF EAGLEVILLE BY
  1130 PM EDT...

LAT...LON 4035 7556 4016 7583 4000 7565 4021 7530

$$

EBERWINE

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 25, 10:43 PM EDTSevere Thunderstorm WarningPHIBerks32 min
Aug 25, 11:43 PM EDTSevere Thunderstorm WarningPHIChester, Montgomery47 min
Aug 25, 11:53 PM EDTSevere Thunderstorm WarningPHIDelaware52 min
Aug 26, 12:00 AM EDTSevere Thunderstorm WarningPHIPhiladelphia45 min
Aug 26, 1:55 AM EDTSevere Thunderstorm WarningPHIBucks50 min
Aug 26, 2:12 AM EDTSevere Thunderstorm WarningPHICarbon, Lehigh48 min
Aug 26, 3:05 AM EDTSevere Thunderstorm WarningPHIBucks, Lehigh55 min
Aug 26, 3:30 AM EDTSevere Thunderstorm WarningPHIMontgomery45 min
Aug 26, 4:11 AM EDTSevere Thunderstorm WarningPHIPhiladelphia49 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.