Alert archive / Delaware / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 76, NWS Philadelphia/Mount Holly

June 30, 2015New Castle County, Delaware; Chester County, Pennsylvania; Cecil County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 30, 2015, 3:25 PM EDT for New Castle County, Delaware; Chester County, Pennsylvania; Cecil County, Maryland. It was in force for 37 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jun 30, 2015, 3:25 PM EDT (19:25 UTC)
Expired
Jun 30, 2015, 4:02 PM EDT
In force
37 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), 109 km from the middle of the area, began a volume at 19:27 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jun 30, 1:21 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 7.4 hours before the alert went out and 25 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 2015-06-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 600 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 2015-06-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 128 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
600 J/kg
Mixed-layer CIN
-45 J/kg
Mixed-layer LCL
728 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
128 m²/s²
0-3 km storm-relative helicity
128 m²/s²
Significant tornado parameter
0.3
Supercell composite
2.9

Open this sounding in Storm Lab

The text

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

820 
WUUS51 KPHI 301925
SVRPHI
DEC003-MDC015-PAC029-302030-
/O.NEW.KPHI.SV.W.0076.150630T1925Z-150630T2030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
325 PM EDT TUE JUN 30 2015

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ  HAS ISSUED A

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

* UNTIL 430 PM EDT

* AT 325 PM EDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM
  CAPABLE OF PRODUCING QUARTER SIZE HAIL AND DAMAGING WINDS IN EXCESS
  OF 60 MPH. THIS STORM WAS LOCATED OVER HAVRE DE GRACE...OR NEAR
  ABERDEEN...AND MOVING NORTHEAST AT 25 MPH.

* LOCATIONS IMPACTED INCLUDE...
  NEWARK...ELKTON...CALVERT...OXFORD...NORTH EAST...WEST GROVE...
  RISING SUN...CHARLESTOWN...BLAKE...PLEASANT HILL...ANDORA...
  HOMEVILLE...MOUNT VERNON...GLEN ROY...RICHARDSMERE...WOODLAWN...
  LADENBERG...NORTH STAR...APPLETON AND CHERRY HILL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS...LARGE HAIL...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.

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...FREQUENT CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY. REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE
ENOUGH TO BE STRUCK BY LIGHTNING.

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

&&

LAT...LON 3972 7614 3974 7612 3973 7610 3974 7610
      3976 7606 3983 7604 3987 7599 3990 7600
      3980 7568 3946 7597 3947 7600 3952 7598
      3955 7603 3955 7608 3966 7618
TIME...MOT...LOC 1925Z 207DEG 20KT 3956 7609 

$$

HEAVENER
2 follow-up statements
170 
WWUS51 KPHI 301949
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
349 PM EDT TUE JUN 30 2015

DEC003-MDC015-PAC029-302030-
/O.CON.KPHI.SV.W.0076.000000T0000Z-150630T2030Z/
NEW CASTLE DE-CECIL MD-CHESTER PA-
349 PM EDT TUE JUN 30 2015

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM EDT
FOR NORTHWESTERN NEW CASTLE...CENTRAL CECIL AND SOUTH CENTRAL CHESTER
COUNTIES...

AT 349 PM EDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM CAPABLE
OF PRODUCING QUARTER SIZE HAIL AND DAMAGING WINDS IN EXCESS OF 60
MPH. THIS STORM WAS LOCATED NEAR OXFORD...OR 12 MILES NORTHWEST OF
NEWARK...MOVING NORTHEAST AT 25 MPH.

LOCATIONS IMPACTED INCLUDE...
NEWARK...ELKTON...CALVERT...OXFORD...NORTH EAST...WEST GROVE...RISING
SUN...BLAKE...PLEASANT HILL...ANDORA...LADENBERG...NORTH STAR...
APPLETON...CHERRY HILL...BAY VIEW...LOMBARD...KEMBLESVILLE...
FARMINGTON...BARKSDALE AND WEST NOTTINGHAM.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS...DESTRUCTIVE HAIL...
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.

IF YOU ARE IN THE PATH OF THIS STORM...PREPARE IMMEDIATELY FOR LARGE
HAIL AND DAMAGING WINDS. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING AND AWAY FROM WINDOWS.

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

&&

LAT...LON 3975 7603 3987 7591 3980 7568 3959 7586
      3959 7594 3960 7603 3967 7610
TIME...MOT...LOC 1949Z 207DEG 20KT 3982 7592 

$$

HEAVENER
029 
WWUS51 KPHI 302002
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
402 PM EDT TUE JUN 30 2015

DEC003-MDC015-PAC029-302012-
/O.CAN.KPHI.SV.W.0076.000000T0000Z-150630T2030Z/
NEW CASTLE DE-CECIL MD-CHESTER PA-
402 PM EDT TUE JUN 30 2015

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN NEW CASTLE...
CENTRAL CECIL AND SOUTH CENTRAL CHESTER COUNTIES IS CANCELLED...
                
THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY.
THEREFORE THE WARNING HAS BEEN CANCELLED.

LAT...LON 3975 7603 3987 7591 3980 7568 3959 7586
      3959 7594 3960 7603 3967 7610
TIME...MOT...LOC 1959Z 207DEG 20KT 3990 7587 

$$

HEAVENER

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 30, 3:08 PM EDTAreal Flood AdvisoryPHINew Castle4 hr
Jun 30, 3:43 PM EDTSevere Thunderstorm WarningPHINew Castle47 min
Jun 30, 3:54 PM EDTFlash Flood WatchPHINew Castle13 hr
Jun 30, 3:57 PM EDTAreal Flood AdvisoryPHINew Castle4 hr
Jun 30, 6:11 PM EDTSpecial Weather StatementPHISussex34 min
Jun 30, 10:01 AM EDTAreal Flood AdvisoryPHICarbon, Monroe4 hr
Jun 30, 12:37 PM EDTAreal Flood AdvisoryPHIBerks4 hr
Jun 30, 12:47 PM EDTSpecial Weather StatementPHIBerks43 min
Jun 30, 1:08 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh52 min
Jun 30, 1:47 PM EDTSpecial Weather StatementPHILehigh43 min
Jun 30, 1:48 PM EDTFlash Flood WarningPHIBerks4 hr
Jun 30, 1:55 PM EDTSpecial Weather StatementPHIChester50 min
Jun 30, 2:00 PM EDTTornado WarningPHIBerks, Chester30 min
Jun 30, 2:05 PM EDTSevere Thunderstorm WarningPHIBerks, Carbon, Lehigh, Monroe, Northampton55 min
Jun 30, 2:13 PM EDTTornado WarningPHILehigh32 min
Jun 30, 2:19 PM EDTSpecial Weather StatementPHIChester26 min
Jun 30, 2:26 PM EDTAreal Flood AdvisoryPHIBerks, Chester4 hr
Jun 30, 2:34 PM EDTSevere Thunderstorm WarningPHIBerks, Chester, Montgomery56 min
Jun 30, 2:41 PM EDTSevere Thunderstorm WarningPHIChester49 min
Jun 30, 2:42 PM EDTTornado WarningPHILehigh, Northampton33 min
Jun 30, 2:48 PM EDTSpecial Weather StatementPHIChester57 min
Jun 30, 2:52 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery38 min
Jun 30, 2:55 PM EDTFlash Flood WarningPHIBerks, Lehigh, Northampton4 hr
Jun 30, 3:00 PM EDTAreal Flood AdvisoryPHIBucks, Monroe, Northampton4 hr
Jun 30, 3:00 PM EDTSevere Thunderstorm WarningPHILehigh, Northampton60 min
Jun 30, 3:22 PM EDTTornado WarningPHIChester, Delaware, Montgomery23 min
Jun 30, 3:31 PM EDTSpecial Weather StatementPHILehigh44 min
Jun 30, 3:37 PM EDTAreal Flood AdvisoryPHICarbon, Lehigh, Monroe, Northampton4 hr
Jun 30, 3:45 PM EDTSevere Thunderstorm WarningPHIBucks, Chester, Delaware, Montgomery, Philadelphia45 min
Jun 30, 3:47 PM EDTSevere Thunderstorm WarningPHINorthampton43 min
Jun 30, 4:22 PM EDTSpecial Weather StatementPHIMonroe23 min
Jun 30, 4:29 PM EDTSpecial Weather StatementPHIDelaware, Philadelphia31 min
Jun 30, 4:31 PM EDTSpecial Weather StatementPHICarbon29 min
Jun 30, 4:58 PM EDTAreal Flood AdvisoryPHIDelaware, Montgomery, Philadelphia3 hr
Jun 30, 4:59 PM EDTSpecial Weather StatementPHIPhiladelphia61 min
Jun 30, 5:03 PM EDTSpecial Weather StatementPHIMonroe27 min
Jun 30, 5:51 PM EDTSpecial Weather StatementPHIMonroe24 min
Jun 30, 6:03 PM EDTFlash Flood WarningPHICarbon, Monroe11 hr
Jun 30, 6:28 PM EDTSevere Thunderstorm WarningPHIMonroe, Northampton47 min
Jun 30, 7:13 PM EDTSevere Thunderstorm WarningPHIMonroe62 min
Jun 30, 2:34 PM EDTSpecial Weather StatementPHICecil26 min
Jun 30, 4:06 PM EDTSpecial Weather StatementPHIKent39 min
Jun 30, 4:32 PM EDTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's, Talbot43 min
Jun 30, 5:14 PM EDTSpecial Weather StatementPHIQueen Anne's31 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2015Severe Thunderstorm Warnings in Pennsylvania, 2015Severe Thunderstorm Warnings in Maryland, 2015Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.