Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 92, NWS Philadelphia/Mount Holly

July 9, 20154 states

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 9, 2015, 7:29 PM EDT for 4 states. It was in force for 46 min. 3 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: Jul 9, 2015, 7:29 PM EDT (23:29 UTC)
Expired: Jul 9, 2015, 8:15 PM EDT
In force: 46 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

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

The radar

The Dover AFB radar (KDOX), 86 km from the middle of the area, began a volume at 23:28 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
Jul 9, 7:49 PM EDT	TSTM WND DMG	New Castle, DE	WIRES DOWN ON ROUTE 9 FROM LAMBSON LANE TO TERMINAL AVE
Jul 9, 7:50 PM EDT	TSTM WND DMG	2 N New Castle, DE	PARTIAL COLLAPSE OF THREE BUILDINGS.
Jul 9, 7:50 PM EDT	TORNADO	Minquadale, DE	EF-0 TORNADO WITH MAXIMUM WINDS OF 65 MPH CONFIRMED IN MINQUADALE. SEVERAL BUILDINGS DAMAGED.

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
Jul 9, 4:57 PM EDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 11.5 hours before the alert went out and 163 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: -194 J/kg
Mixed-layer LCL: 1091 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: -19 m²/s²
0-3 km storm-relative helicity: -2 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.

033 
WUUS51 KPHI 092329
SVRPHI
DEC001-003-MDC015-029-NJC033-PAC029-045-100015-
/O.NEW.KPHI.SV.W.0092.150709T2329Z-150710T0015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
729 PM EDT THU JUL 9 2015

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ  HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NEW CASTLE COUNTY IN NORTHERN DELAWARE...
  NORTHERN KENT COUNTY IN CENTRAL DELAWARE...
  NORTHEASTERN KENT COUNTY IN NORTHEASTERN MARYLAND...
  CECIL COUNTY IN NORTHEASTERN MARYLAND...
  NORTHWESTERN SALEM COUNTY IN SOUTHERN NEW JERSEY...
  SOUTHWESTERN DELAWARE COUNTY IN SOUTHEASTERN PENNSYLVANIA...
  SOUTHERN CHESTER COUNTY IN SOUTHEASTERN PENNSYLVANIA...

* UNTIL 815 PM EDT

* AT 728 PM EDT...DOPPLER RADAR INDICATED A LINE OF SEVERE
  THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 60
  MPH. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING FROM NEAR
  WEST CHESTER TO NEAR PORT PENN TO NEAR HAZLETTVILLE...AND MOVING
  EAST AT 50 MPH.

* LOCATIONS IMPACTED INCLUDE...
  WILMINGTON...NEWARK...MIDDLETOWN...WEST CHESTER...ELKTON...
  CALVERT...PENNSVILLE...WESTTOWN...SMYRNA...CARNEYS POINT...
  ELSMERE...KENNETT SQUARE...NEW CASTLE...PENNS GROVE...SALEM...
  OXFORD...NORTH EAST...CLAYTON...WEST GROVE AND RISING SUN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS...DEADLY
LIGHTNING AND VERY HEAVY RAIN. FOR YOUR PROTECTION...MOVE TO AN
INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME OR BUSINESS. HEAVY
RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE INTO AREAS WHERE WATER
COVERS THE ROAD.

&&

LAT...LON 3943 7600 3952 7598 3959 7611 3982 7603
      4003 7543 3961 7545 3966 7548 3958 7548
      3959 7546 3946 7554 3957 7551 3962 7557
      3972 7551 3969 7553 3962 7561 3942 7554
      3930 7560 3930 7617
TIME...MOT...LOC 2328Z 270DEG 53KT 4000 7561 3948 7561 3909 7561 

$$

FRANCK/GORSE

1 follow-up statement

863 
WWUS51 KPHI 100001
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
801 PM EDT THU JUL 9 2015

DEC001-003-MDC015-029-NJC033-PAC029-045-100015-
/O.CON.KPHI.SV.W.0092.000000T0000Z-150710T0015Z/
NEW CASTLE DE-KENT DE-KENT MD-CECIL MD-SALEM NJ-DELAWARE PA-
CHESTER PA-
801 PM EDT THU JUL 9 2015

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM EDT
FOR NEW CASTLE...NORTHERN KENT...NORTHEASTERN KENT...SOUTHEASTERN
CECIL...NORTHWESTERN SALEM...SOUTHWESTERN DELAWARE AND SOUTHEASTERN
CHESTER COUNTIES...

AT 800 PM EDT...DOPPLER RADAR INDICATED A LINE OF SEVERE
THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 60
MPH. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING FROM PALMYRA TO
VINELAND TO 7 MILES NORTHWEST OF GREEN CREEK...MOVING EAST AT 60 MPH.

LOCATIONS IMPACTED INCLUDE...
WILMINGTON...MIDDLETOWN...PENNSVILLE...SMYRNA...CARNEYS POINT...
ELSMERE...NEW CASTLE...PENNS GROVE...SALEM...CLAYTON...DELAWARE
CITY...NEWPORT...CECILTON...ARDEN...WILMINGTON MANOR...BOHEMIAS
MILLS...CHELSEA...HOPE CREEK...PORT PENN AND ELAM.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS...DEADLY LIGHTNING AND 
VERY HEAVY RAIN. FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON 
THE LOWEST FLOOR OF YOUR HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS 
QUICKLY SO DO NOT DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.

&&

LAT...LON 3939 7589 3944 7583 3955 7572 3968 7564
      3987 7560 4003 7543 3961 7545 3966 7548
      3958 7548 3959 7546 3946 7554 3957 7551
      3962 7557 3972 7551 3968 7554 3962 7561
      3942 7554 3930 7560 3930 7599
TIME...MOT...LOC 0000Z 270DEG 53KT 4000 7502 3948 7503 3909 7503 

$$

GORSE/FRANCK

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 9, 6:15 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Montgomery	45 min
Jul 9, 6:35 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh	40 min
Jul 9, 6:46 PM EDT	Areal Flood Advisory	PHI	Carbon, Lehigh, Monroe, Northampton	4 hr
Jul 9, 6:50 PM EDT	Severe Thunderstorm Warning	PHI	Chester	40 min
Jul 9, 6:57 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Lehigh, Montgomery	48 min
Jul 9, 7:12 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Lehigh, Northampton	48 min
Jul 9, 7:21 PM EDT	Areal Flood Advisory	PHI	Berks, Lehigh	4 hr
Jul 9, 7:39 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	66 min
Jul 9, 7:55 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Philadelphia	40 min
Jul 9, 7:56 PM EDT	Areal Flood Advisory	PHI	Bucks, Delaware, Montgomery, Philadelphia	4 hr
Jul 9, 7:38 PM EDT	Severe Thunderstorm Warning	PHI	Kent, New Castle	52 min
Jul 9, 7:44 PM EDT	Special Marine Warning	PHI		31 min
Jul 8, 9:15 PM EDT	Special Weather Statement	PHI	Cecil	30 min
Jul 8, 9:43 PM EDT	Special Weather Statement	PHI	Cecil	32 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2015 Severe Thunderstorm Warnings in Delaware, 2015 Severe Thunderstorm Warnings in Maryland, 2015 Every severe thunderstorm warning in 2015

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.