Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2008

Severe Thunderstorm Warning 57, NWS Philadelphia/Mount Holly

June 10, 2008Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 10, 2008, 7:02 PM EDT for Chester County, Pennsylvania. It was in force for 58 min. 2 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: Jun 10, 2008, 7:02 PM EDT (23:02 UTC)
Expired: Jun 10, 2008, 8:00 PM EDT
In force: 58 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

County Chester County, PA

The radar

The Philadelphia radar (KDIX), 127 km from the middle of the area, began a volume at 23:03 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

Time	Report	Where	Remark
Jun 10, 7:22 PM EDT	TSTM WND DMG	Coatesville, PA	TREES AND WIRES DOWN REPORTED COUNTY WIDE, ESPECIALLY IN THE NORTHERN HALF THROUGH 745 PM.
Jun 10, 7:30 PM EDT	TSTM WND DMG	Coatesville, PA	TREES AND WIRES DOWN REPORTED COUNTY WIDE.

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.

Issued	Product	Office	Lasted
Jun 10, 5:47 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 11.0 hours before the alert went out and 54 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1286 J/kg
Mixed-layer CIN: -135 J/kg
Mixed-layer LCL: 1568 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 6 m²/s²
0-3 km storm-relative helicity: 20 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 102303
SVRPHI
PAC029-110000-
/O.NEW.KPHI.SV.W.0057.080610T2302Z-080611T0000Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
702 PM EDT TUE JUN 10 2008

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 800 PM EDT

* AT 700 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE HAIL...AND    
  DAMAGING WINDS TO 60 MPH.  THIS STORM WAS LOCATED NEAR             
  GLENMOORE...OR ABOUT 21 MILES SOUTH OF READING...AND MOVING        
  NORTHEAST AT 40 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  PUGHTOWN AND CHESTER SPRINGS BY 710 PM...
  6 MILES SOUTHEAST OF CEDARVILLE BY 715 PM...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...FREQUENT 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.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 100 AM WEDNESDAY
MORNING FOR DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY AND
EASTERN PENNSYLVANIA.

LAT...LON 3978 7607 3985 7604 3988 7600 3992 7602
      3994 7600 3997 7600 4004 7595 4009 7595
      4025 7569 4006 7542 3998 7549 3973 7581
      3973 7613
TIME...MOT...LOC 2302Z 236DEG 35KT 4008 7576

$$

GORSE

1 follow-up statement

000 
WWUS51 KPHI 102317
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
716 PM EDT TUE JUN 10 2008

PAC029-110000-
/O.CON.KPHI.SV.W.0057.000000T0000Z-080611T0000Z/
CHESTER PA-
716 PM EDT TUE JUN 10 2008

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR CHESTER COUNTY...

AT 715 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE 
HAIL...AND DAMAGING WINDS TO 60 MPH. THIS STORM WAS LOCATED NEAR 
LIONVILLE...OR 22 MILES SOUTHEAST OF READING...MOVING NORTHEAST AT 
35 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  6 MILES NORTHWEST OF PAOLI AND 6 MILES NORTHWEST OF MALVERN BY 725
  PM EDT...
  CHESTERBROOK AND 7 MILES NORTHWEST OF DEVON-BERWYN BY 730 PM EDT...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...LARGE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 100 AM EDT
WEDNESDAY MORNING FOR DELAWARE AND NORTHEASTERN MARYLAND AND NEW
JERSEY AND EASTERN PENNSYLVANIA.

LAT...LON 3978 7607 3985 7604 3988 7600 3992 7602
      3994 7600 3997 7600 4004 7595 4009 7595
      4025 7569 4006 7542 3998 7549 3973 7581
      3973 7613
TIME...MOT...LOC 2316Z 245DEG 30KT 4009 7564

$$

GORSE

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 10, 5:47 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Monroe	58 min
Jun 10, 5:51 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh	54 min
Jun 10, 6:20 PM EDT	Severe Thunderstorm Warning	PHI	Monroe	40 min
Jun 10, 6:42 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh	59 min
Jun 10, 6:47 PM EDT	Flash Flood Warning	PHI	Berks, Lehigh	3 hr
Jun 10, 6:57 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Monroe, Northampton	48 min
Jun 10, 7:13 PM EDT	Severe Thunderstorm Warning	PHI	Monroe, Northampton	77 min
Jun 10, 7:36 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Montgomery	54 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2008 Every severe thunderstorm warning in 2008

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.