Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 111, NWS Philadelphia/Mount Holly

October 7, 2013New Castle County, Delaware; Chester County, Delaware County, Pennsylvania; Cecil County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Oct 7, 2013, 1:05 PM EDT for New Castle County, Delaware; Chester County, Delaware County, Pennsylvania; Cecil County, Maryland. It was in force for 25 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
Oct 7, 2013, 1:05 PM EDT (17:05 UTC)
Expired
Oct 7, 2013, 1:30 PM EDT
In force
25 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

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

The radar

The Dover AFB radar (KDOX), 111 km from the middle of the area, began a volume at 17:05 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
Oct 7, 1:10 PM EDTTSTM WND DMGNorth East, MDTREE TOPS SNAPPED ON HILLCREST LANE. TIME OF EVENT ESTIMATED FROM RADAR.
Oct 7, 1:10 PM EDTTSTM WND DMGNortheast Heights, MDDAMAGE TO CROPS

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
Oct 7, 8:56 AM EDTTornado WatchSPC8 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 5.1 hours before the alert went out and 49 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, Phillips Aaf/Abe, MD at 12:00Z on 2013-10-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 114 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, Phillips Aaf/Abe, MD at 12:00Z on 2013-10-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 149 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
114 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
584 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
149 m²/s²
0-3 km storm-relative helicity
196 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

141 
WUUS51 KPHI 071705
SVRPHI
DEC003-MDC015-PAC029-045-071730-
/O.NEW.KPHI.SV.W.0111.131007T1705Z-131007T1730Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
105 PM EDT MON OCT 7 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...

* UNTIL 130 PM EDT

* AT 104 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM. THE STORM WAS NEAR BAY VIEW...MOVING NORTHEAST
  AT 55 MPH. THIS STORM IS CAPABLE OF PRODUCING DAMAGING WINDS IN
  EXCESS OF 60 MPH. 

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  FAIR HILL AND PLEASANT HILL AROUND 110 PM EDT...
  KEMBLESVILLE AND GLEN WESTOVER AROUND 115 PM EDT...
  LADENBERG AND NORTH STAR AROUND 120 PM EDT...
  KENNETT SQUARE AND HOCKESSIN AROUND 125 PM EDT...
  ELAM AND WESTTOWN AROUND 130 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. IF A TORNADO
IS SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF SAFETY INSIDE A
STRONG BUILDING...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM.

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.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 500 PM EDT MONDAY AFTERNOON
FOR DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY AND EASTERN
PENNSYLVANIA.

&&

LAT...LON 3995 7558 3987 7537 3952 7597 3972 7616
TIME...MOT...LOC 1705Z 226DEG 47KT 3965 7597

$$

SZATKOWSKI
1 follow-up statement
802 
WWUS51 KPHI 071721
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
121 PM EDT MON OCT 7 2013

DEC003-MDC015-PAC029-045-071730-
/O.CON.KPHI.SV.W.0111.000000T0000Z-131007T1730Z/
DELAWARE PA-NEW CASTLE DE-CECIL MD-CHESTER PA-
121 PM EDT MON OCT 7 2013

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 130 PM EDT
FOR SOUTHERN CHESTER...NORTHEASTERN CECIL...NORTHERN NEW CASTLE AND
SOUTHWESTERN DELAWARE COUNTIES...

AT 118 PM 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 AVONDALE TO CHERRY HILL...MOVING NORTHEAST AT 60 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
ASHLAND AND WESTTOWN AROUND 130 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. 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.

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.

&&

LAT...LON 3995 7558 3987 7537 3957 7592 3980 7594
TIME...MOT...LOC 1721Z 227DEG 54KT 3989 7574 3964 7581

$$

FORECASTER:DRAG

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 7, 12:41 PM EDTSpecial Weather StatementPHINew Castle64 min
Oct 7, 1:37 PM EDTSpecial Weather StatementPHIKent, New Castle53 min
Oct 7, 2:18 PM EDTSevere Thunderstorm WarningPHIKent, Sussex57 min
Oct 7, 3:21 PM EDTSpecial Weather StatementPHISussex39 min
Oct 7, 11:31 AM EDTSpecial Weather StatementPHIBerks, Chester59 min
Oct 7, 11:50 AM EDTSevere Thunderstorm WarningPHIBerks40 min
Oct 7, 12:12 PM EDTSevere Thunderstorm WarningPHIBerks, Carbon, Lehigh, Monroe, Northampton63 min
Oct 7, 12:49 PM EDTSevere Thunderstorm WarningPHIBerks, Chester, Montgomery41 min
Oct 7, 1:30 PM EDTSpecial Weather StatementPHIMonroe, Northampton60 min
Oct 7, 1:33 PM EDTSpecial Weather StatementPHIBucks, Montgomery42 min
Oct 7, 1:59 PM EDTSevere Thunderstorm WarningPHIBucks46 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2013Severe Thunderstorm Warnings in Delaware, 2013Severe Thunderstorm Warnings in Maryland, 2013Every 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.