Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 90, NWS Philadelphia/Mount Holly

August 13, 20134 states

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 13, 2013, 6:23 AM EDT for 4 states. It was in force for 67 min. 4 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: Aug 13, 2013, 6:23 AM EDT (10:23 UTC)
Expired: Aug 13, 2013, 7:30 AM EDT
In force: 67 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties New Castle County, DE, Cecil County, MD, Salem County, NJ, Chester County, PA, Delaware County, PA

The radar

The Dover AFB radar (KDOX), 98 km from the middle of the area, began a volume at 10:23 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
Aug 13, 6:50 AM EDT	TSTM WND DMG	Elkton, MD	20 TO 30 TREES DOWN 600 BLOCK KNOTTINGHAM ROAD
Aug 13, 6:55 AM EDT	TSTM WND GST 60	Newark, DE
Aug 13, 6:56 AM EDT	TSTM WND DMG	Bear, DE	TREES DOWN
Aug 13, 6:56 AM EDT	TSTM WND DMG	Newark, DE	TREES DOWN

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, 10.4 hours before the alert went out and 155 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: 1 J/kg
Mixed-layer CIN: -66 J/kg
Mixed-layer LCL: 1841 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 31 m²/s²
0-3 km storm-relative helicity: 84 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

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

216 
WUUS51 KPHI 131023
SVRPHI
DEC003-MDC015-NJC033-PAC029-045-131130-
/O.NEW.KPHI.SV.W.0090.130813T1023Z-130813T1130Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
623 AM EDT TUE AUG 13 2013

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHWESTERN DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
  NORTHERN NEW CASTLE COUNTY IN NORTHERN DELAWARE...
  NORTHERN CECIL COUNTY IN NORTHEAST MARYLAND...
  SOUTHERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
  NORTHWESTERN SALEM COUNTY IN SOUTHERN NEW JERSEY...

* UNTIL 730 AM EDT

* AT 618 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM. THE STORM WAS NEAR PERRYVILLE...MOVING
  NORTHEAST AT 30 MPH. THIS STORM IS CAPABLE OF PRODUCING ONE INCH
  DIAMETER HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH. 

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  FARMINGTON AND RISING SUN AROUND 630 AM EDT...
  NORTH EAST AND BAY VIEW AROUND 635 AM EDT...
  PLEASANT HILL AND LOMBARD AROUND 640 AM EDT...
  CHERRY HILL AND ANDORA AROUND 645 AM EDT...
  BARKSDALE AND FAIR HILL AROUND 650 AM EDT...
  APPLETON AND NEWARK AROUND 655 AM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DOPPLER RADAR HAS INDICATED SOME ROTATION WITHIN THIS STORM. WHILE
NOT IMMEDIATELY LIKELY...A TORNADO MAY STILL DEVELOP. IF A TORNADO IS
SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A STURDY
STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM ON THE LOWEST
FLOOR.

&&

LAT...LON 4002 7568 3971 7536 3964 7554 3965 7554
      3969 7552 3969 7553 3962 7560 3947 7600
      3952 7599 3955 7603 3955 7608 3957 7610
      3957 7609 3956 7608 3957 7608 3964 7616
      3966 7616
TIME...MOT...LOC 1023Z 241DEG 24KT 3958 7603

$$

KLINE

2 follow-up statements

413 
WWUS51 KPHI 131058
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
658 AM EDT TUE AUG 13 2013

MDC015-131107-
/O.CAN.KPHI.SV.W.0090.000000T0000Z-130813T1130Z/
CECIL MD-
658 AM EDT TUE AUG 13 2013

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN CECIL COUNTY IS
CANCELLED...

THE STORM THAT PROMPTED THE SEVERE THUNDERSTORM WARNING HAS MOVED OUT
OF THE AREA...THEREFORE THE SEVERE THUNDERSTORM WARNING HAS BEEN
CANCELLED.

LAT...LON 3998 7564 3971 7536 3964 7554 3969 7552
      3969 7553 3962 7560 3960 7563 3961 7574
      3962 7579 3972 7579 3972 7582 3978 7583
TIME...MOT...LOC 1057Z 241DEG 33KT 3972 7573 3963 7569

$$

DEC003-NJC033-PAC029-045-131130-
/O.CON.KPHI.SV.W.0090.000000T0000Z-130813T1130Z/
DELAWARE PA-NEW CASTLE DE-CHESTER PA-SALEM NJ-
658 AM EDT TUE AUG 13 2013

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 AM EDT
FOR NORTHWESTERN SALEM...SOUTH CENTRAL CHESTER...NORTHERN NEW CASTLE
AND SOUTHWESTERN DELAWARE COUNTIES...

AT 654 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING
WINDS IN EXCESS OF 60 MPH. THESE STORMS WERE LOCATED ALONG A LINE
EXTENDING FROM NEWARK TO BEAR...MOVING NORTHEAST AT 40 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
HOCKESSIN AND ASHLAND AROUND 705 AM EDT...
WILMINGTON MANOR AND NEW CASTLE AROUND 710 AM EDT...
TALLEYVILLE AND EDGEMOOR AROUND 715 AM EDT...
ELAM AND CLAYMONT AROUND 720 AM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DOPPLER RADAR HAS INDICATED SOME ROTATION WITHIN THIS STORM. WHILE
NOT IMMEDIATELY LIKELY...A TORNADO MAY DEVELOP. IF A TORNADO IS
SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A STURDY
STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM.

THIS STORM HAS A HISTORY OF PRODUCING DAMAGING WINDS AND LARGE HAIL.
SEEK SHELTER NOW INSIDE A STURDY STRUCTURE...AND STAY AWAY FROM
WINDOWS.

&&

LAT...LON 3998 7564 3971 7536 3964 7554 3969 7552
      3969 7553 3962 7560 3960 7563 3961 7574
      3962 7579 3972 7579 3972 7582 3978 7583
TIME...MOT...LOC 1057Z 241DEG 33KT 3972 7573 3963 7569

$$

FORECASTER:  DRAG

105 
WWUS51 KPHI 131122
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
722 AM EDT TUE AUG 13 2013

PAC029-045-131131-
/O.CAN.KPHI.SV.W.0090.000000T0000Z-130813T1130Z/
DELAWARE PA-CHESTER PA-
722 AM EDT TUE AUG 13 2013

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL CHESTER AND
SOUTHWESTERN DELAWARE COUNTIES IS CANCELLED...

THE STORM THAT PROMPTED THE SEVERE THUNDERSTORM WARNING HAS MOVED OUT
OF THE AREA...THEREFORE THE SEVERE THUNDERSTORM WARNING HAS BEEN
CANCELLED.

LAT...LON 3984 7556 3983 7549 3971 7536 3964 7554
      3969 7552 3969 7553 3979 7557
TIME...MOT...LOC 1121Z 241DEG 33KT 3988 7548 3974 7544

$$

DEC003-NJC033-131130-
/O.CON.KPHI.SV.W.0090.000000T0000Z-130813T1130Z/
NEW CASTLE DE-SALEM NJ-
722 AM EDT TUE AUG 13 2013

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 AM EDT
FOR NORTHWESTERN SALEM AND NORTHEASTERN NEW CASTLE COUNTIES...

AT 720 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING
WINDS IN EXCESS OF 60 MPH. THESE STORMS WERE LOCATED ALONG A LINE
EXTENDING FROM ARDEN TO PENNS GROVE...MOVING NORTHEAST AT 40 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
EDGEMOOR...CLAYMONT...BELLEFONTE...ARDENTOWN AND ARDENCROFT

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO DAMAGING WINDS...FREQUENT CLOUD TO GROUND LIGHTNING 
IS OCCURRING WITH THIS STORM AS WELL AS DRENCHING RAIN. MOVE INDOORS 
IMMEDIATELY! REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE 
ENOUGH TO BE STRUCK BY LIGHTNING.

&&

LAT...LON 3984 7556 3983 7549 3971 7536 3964 7554
      3969 7552 3969 7553 3979 7557
TIME...MOT...LOC 1121Z 241DEG 33KT 3988 7548 3974 7544

$$

FORECASTER:  DRAG

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 13, 2:45 AM EDT	Flash Flood Watch	PHI	Berks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more	9 hr
Aug 13, 5:15 AM EDT	Areal Flood Advisory	PHI	Berks, Chester, Montgomery	4 hr
Aug 13, 5:47 AM EDT	Flash Flood Warning	PHI	Chester	4 hr
Aug 13, 6:07 AM EDT	Areal Flood Advisory	PHI	Bucks, Lehigh, Northampton	7 hr
Aug 13, 6:07 AM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	53 min
Aug 13, 6:20 AM EDT	Areal Flood Advisory	PHI	Bucks, Delaware, Philadelphia	4 hr
Aug 13, 6:32 AM EDT	Tornado Warning	PHI	Chester	43 min
Aug 13, 6:36 AM EDT	Flash Flood Warning	PHI	Chester, Delaware, Montgomery	8 hr
Aug 13, 7:05 AM EDT	Severe Thunderstorm Warning	PHI	Delaware, Philadelphia	40 min
Aug 13, 7:14 AM EDT	Flash Flood Warning	PHI	Berks	4 hr
Aug 13, 7:42 AM EDT	Special Weather Statement	PHI	Philadelphia	48 min
Aug 13, 7:54 AM EDT	Flash Flood Warning	PHI	Delaware, Montgomery, Philadelphia	8 hr
Aug 13, 7:54 AM EDT	Special Weather Statement	PHI	Delaware, Philadelphia	66 min
Aug 13, 8:07 AM EDT	River Flood Warning	PHI	Chester	9 hr
Aug 13, 8:20 AM EDT	Flash Flood Warning	PHI	Bucks	8 hr
Aug 13, 9:50 AM EDT	Flash Flood Warning	PHI	Chester	4 hr
Aug 13, 11:22 AM EDT	River Flood Warning	PHI	Chester, Delaware	16 hr
Aug 13, 2:18 PM EDT	Areal Flood Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	9 hr
Aug 13, 7:11 AM EDT	Special Marine Warning	PHI		19 min
Aug 13, 7:16 AM EDT	Special Weather Statement	PHI	Camden, Gloucester, Salem	59 min
Aug 13, 7:22 AM EDT	Areal Flood Advisory	PHI	Camden, Gloucester, Salem	7 hr
Aug 13, 7:33 AM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Warren	7 hr
Aug 13, 7:51 AM EDT	Special Marine Warning	PHI		24 min
Aug 13, 7:57 AM EDT	Severe Thunderstorm Warning	PHI	Gloucester, Salem	48 min
Aug 13, 8:36 AM EDT	Special Weather Statement	PHI	Mercer	39 min
Aug 13, 8:44 AM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Gloucester, Salem	61 min
Aug 13, 8:59 AM EDT	Flash Flood Warning	PHI	Atlantic, Burlington, Camden, Gloucester	7 hr
Aug 13, 9:07 AM EDT	Special Weather Statement	PHI	Cumberland, Salem	38 min
Aug 13, 9:11 AM EDT	Special Weather Statement	PHI	Burlington	49 min
Aug 13, 9:22 AM EDT	Severe Thunderstorm Warning	PHI	Burlington, Ocean	38 min
Aug 13, 9:26 AM EDT	Special Weather Statement	PHI	Atlantic	34 min
Aug 13, 9:34 AM EDT	Special Marine Warning	PHI		56 min
Aug 13, 9:42 AM EDT	Flash Flood Warning	PHI	Atlantic, Burlington, Cape May, Cumberland, Hunterdon, Middlesex and 4 more	5 hr
Aug 13, 9:43 AM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Ocean	47 min
Aug 13, 9:49 AM EDT	Special Weather Statement	PHI	Atlantic, Cumberland	56 min
Aug 13, 10:01 AM EDT	Special Weather Statement	PHI	Monmouth	29 min
Aug 13, 10:04 AM EDT	Special Weather Statement	PHI	Ocean	41 min
Aug 13, 10:12 AM EDT	Tornado Warning	PHI	Ocean	33 min
Aug 13, 10:32 AM EDT	Severe Thunderstorm Warning	PHI	Ocean	28 min
Aug 13, 10:39 AM EDT	Special Marine Warning	PHI		66 min
Aug 13, 10:51 AM EDT	Special Weather Statement	PHI	Atlantic	54 min
Aug 13, 11:51 AM EDT	Special Marine Warning	PHI		84 min
Aug 13, 1:10 PM EDT	Special Marine Warning	PHI		65 min
Aug 13, 3:30 PM EDT	Small Craft Advisory	PHI		24 hr
Aug 13, 6:51 AM EDT	Areal Flood Advisory	PHI	New Castle	7 hr
Aug 13, 7:31 AM EDT	Special Weather Statement	PHI	New Castle	44 min
Aug 13, 8:37 AM EDT	River Flood Warning	PHI	New Castle	4 hr
Aug 13, 11:19 AM EDT	Special Weather Statement	PHI	Kent	56 min
Aug 13, 1:50 PM EDT	River Flood Warning	PHI	New Castle	119 min
Aug 13, 5:54 AM EDT	Areal Flood Advisory	PHI	Cecil	7 hr
Aug 13, 12:47 PM EDT	Areal Flood Advisory	PHI	Cecil	3 hr
Aug 13, 4:55 PM EDT	Special Weather Statement	PHI	Cecil	65 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2013 Severe Thunderstorm Warnings in New Jersey, 2013 Severe Thunderstorm Warnings in Delaware, 2013 Every severe thunderstorm warning in 2013

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.