Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 54, NWS Philadelphia/Mount Holly

June 29, 2012Chester County, Pennsylvania; Cecil County, Maryland; New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 29, 2012, 4:46 AM EDT for Chester County, Pennsylvania; Cecil County, Maryland; New Castle County, Delaware. It was in force for 48 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
Jun 29, 2012, 4:46 AM EDT (08:46 UTC)
Expired
Jun 29, 2012, 5:34 AM EDT
In force
48 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties New Castle County, DE, Cecil County, MD, Chester County, PA

The radar

The Dover AFB radar (KDOX), 97 km from the middle of the area, began a volume at 08:46 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
Jun 29, 5:15 AM EDTTSTM WND DMGStanton, DESOME TREE LIMBS AND WIRES DOWN IN AND AROUND STANTON.

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
Jun 29, 4:34 AM EDTSevere Thunderstorm WatchSPC3 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 8.8 hours before the alert went out and 162 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 2012-06-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2012-06-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 132 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2494 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
132 m²/s²
0-3 km storm-relative helicity
317 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.

011 
WUUS51 KPHI 290846
SVRPHI
DEC003-MDC015-PAC029-290945-
/O.NEW.KPHI.SV.W.0054.120629T0846Z-120629T0945Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
446 AM EDT FRI JUN 29 2012

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN CECIL COUNTY IN NORTHEAST MARYLAND...
  THIS INCLUDES THE CITY OF ELKTON...
  NEW CASTLE COUNTY IN NORTHERN DELAWARE...
  THIS INCLUDES THE CITIES OF...WILMINGTON...NEWARK...MIDDLETOWN...
  SOUTHERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 545 AM EDT

* AT 443 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DESTRUCTIVE WINDS IN EXCESS OF 70 MPH.  THIS STORM WAS LOCATED NEAR
  GLEN ROY...OR 19 MILES SOUTHEAST OF LANCASTER...AND MOVING EAST AT
  30 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  OXFORD AND HOMEVILLE AROUND 455 AM EDT...
  LOMBARD AROUND 500 AM EDT...
  BLAKE AROUND 505 AM EDT...
  WEST GROVE AND FAIR HILL AROUND 510 AM EDT...
  KEMBLESVILLE AND APPLETON AROUND 515 AM EDT...
  LADENBERG AND GLEN WESTOVER AROUND 520 AM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

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 800 AM EDT FRIDAY
MORNING FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND AND SOUTHERN
NEW JERSEY AND SOUTHEAST PENNSYLVANIA.

&&

LAT...LON 3973 7619 3974 7610 3988 7600 3995 7599
      3981 7544 3972 7547 3971 7551 3962 7560
      3960 7560 3964 7557 3951 7555 3948 7558
      3945 7557 3935 7561 3969 7621
TIME...MOT...LOC 0846Z 282DEG 25KT 3980 7608

$$
 
TFG
2 follow-up statements
271 
WWUS51 KPHI 290926
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
526 AM EDT FRI JUN 29 2012

PAC029-290936-
/O.CAN.KPHI.SV.W.0054.000000T0000Z-120629T0945Z/
CHESTER PA-
526 AM EDT FRI JUN 29 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN CHESTER COUNTY IS
CANCELLED...

THE THUNDERSTORM IS IN DELMARVA.

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 800 AM EDT FRIDAY
MORNING FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND AND SOUTHERN
NEW JERSEY AND SOUTHEAST PENNSYLVANIA.

LAT...LON 3966 7595 3970 7590 3972 7585 3972 7578
      3980 7571 3984 7555 3981 7544 3972 7547
      3971 7551 3962 7560 3960 7560 3963 7557
      3952 7555 3948 7558 3945 7557 3935 7562
      3959 7597
TIME...MOT...LOC 0926Z 290DEG 30KT 3970 7568

$$

DEC003-MDC015-290945-
/O.CON.KPHI.SV.W.0054.000000T0000Z-120629T0945Z/
NEW CASTLE DE-CECIL MD-
526 AM EDT FRI JUN 29 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 545 AM EDT
FOR NORTHEASTERN CECIL AND NEW CASTLE COUNTIES...

AT 521 AM 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 PIKE CREEK...OR NEAR NEWARK...MOVING EAST AT 35 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  NEW CASTLE...WILMINGTON MANOR...WILMINGTON AND 9 MILES NORTH OF
  SAINT GEORGES BY 535 AM EDT...
  WILMINGTON...6 MILES NORTH OF DELAWARE CITY...7 MILES SOUTH OF
  EDGEMOOR AND 8 MILES SOUTH OF BELLEFONTE BY 540 AM 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 800 AM EDT FRIDAY
MORNING FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND AND SOUTHERN
NEW JERSEY AND SOUTHEAST PENNSYLVANIA.

&&

LAT...LON 3966 7595 3970 7590 3972 7585 3972 7578
      3980 7571 3984 7555 3981 7544 3972 7547
      3971 7551 3962 7560 3960 7560 3963 7557
      3952 7555 3948 7558 3945 7557 3935 7562
      3959 7597
TIME...MOT...LOC 0926Z 290DEG 30KT 3970 7568

$$

TFG
444 
WWUS51 KPHI 290934
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
534 AM EDT FRI JUN 29 2012

DEC003-MDC015-290944-
/O.CAN.KPHI.SV.W.0054.000000T0000Z-120629T0945Z/
NEW CASTLE DE-CECIL MD-
534 AM EDT FRI JUN 29 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN CECIL AND NEW
CASTLE COUNTIES IS CANCELLED...

THE SEVERE STORM IS EAST OF THE AREA.

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 800 AM EDT FRIDAY
MORNING FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND AND SOUTHERN
NEW JERSEY AND SOUTHEAST PENNSYLVANIA.

LAT...LON 3966 7595 3970 7590 3972 7585 3972 7578
      3980 7571 3984 7555 3981 7544 3972 7547
      3971 7551 3962 7560 3960 7560 3963 7557
      3952 7555 3948 7558 3945 7557 3935 7562
      3959 7597
TIME...MOT...LOC 0934Z 290DEG 30KT 3968 7560

$$

TFG

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 29, 3:51 AM EDTSpecial Weather StatementPHIBerks, Bucks, Chester, Delaware, Lehigh, Montgomery and 1 more54 min
Jun 29, 4:14 AM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Chester, Lehigh, Montgomery, Northampton76 min
Jun 29, 5:00 AM EDTSevere Thunderstorm WarningPHIBucks, Chester, Delaware, Montgomery, Philadelphia75 min
Jun 29, 5:23 AM EDTSevere Thunderstorm WarningPHICaroline, Cecil, Kent, Queen Anne's, Talbot67 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2012Severe Thunderstorm Warnings in Maryland, 2012Severe Thunderstorm Warnings in Delaware, 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.