Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 77, NWS Philadelphia/Mount Holly

June 30, 2015Chester County, Delaware County, Philadelphia County, Pennsylvania; Gloucester County, Salem County, New Jersey; New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 30, 2015, 3:43 PM EDT for Chester County, Delaware County, Philadelphia County, Pennsylvania; Gloucester County, Salem County, New Jersey; New Castle County, Delaware. It was in force for 47 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 30, 2015, 3:43 PM EDT (19:43 UTC)
Expired: Jun 30, 2015, 4:30 PM EDT
In force: 47 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties New Castle County, DE, Gloucester County, NJ, Salem County, NJ, Chester County, PA, Delaware County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 104 km from the middle of the area, began a volume at 19:42 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
Jun 30, 4:10 PM EDT	TSTM WND DMG	Talleyville, DE	A FEW TREES DOWN IN NEW CASTLE COUNTY.

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
Jun 30, 1:21 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 7.7 hours before the alert went out and 56 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: 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.

293 
WUUS51 KPHI 301943
SVRPHI
DEC003-NJC015-033-PAC029-045-101-302030-
/O.NEW.KPHI.SV.W.0077.150630T1943Z-150630T2030Z/

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

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ  HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN NEW CASTLE COUNTY IN NORTHERN DELAWARE...
  NORTHWESTERN SALEM COUNTY IN SOUTHERN NEW JERSEY...
  NORTHWESTERN GLOUCESTER COUNTY IN SOUTHERN NEW JERSEY...
  DELAWARE COUNTY IN SOUTHEASTERN PENNSYLVANIA...
  SOUTHEASTERN CHESTER COUNTY IN SOUTHEASTERN PENNSYLVANIA...
  SOUTHWESTERN PHILADELPHIA COUNTY IN SOUTHEASTERN PENNSYLVANIA...

* UNTIL 430 PM EDT

* AT 343 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 HOCKESSIN...OR 7 MILES NORTH
  OF NEWARK...AND MOVING NORTHEAST AT 30 MPH.

* LOCATIONS IMPACTED INCLUDE...
  WILMINGTON...NEWARK...CHESTER...WESTTOWN...FOLCROFT...SWARTHMORE...
  ELSMERE...PAULSBORO...KENNETT SQUARE...NEWPORT...ARDEN...
  PHILADELPHIA INTERNATIONAL AIRPORT...PHILADELPHIA INTERNATIONAL
  ARPT...ELAM...NORTH STAR...TALLEYVILLE...BROOMALL...STANTON...
  NETHER PROVIDENCE TOWNSHIP AND HOCKESSIN.

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 3969 7568 3971 7577 3979 7571 3984 7583
      4004 7540 3986 7522
TIME...MOT...LOC 1943Z 236DEG 25KT 3978 7572 

$$

HEAVENER

1 follow-up statement

241 
WWUS51 KPHI 302005
SVSPHI

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

DEC003-NJC015-033-PAC029-045-101-302030-
/O.CON.KPHI.SV.W.0077.000000T0000Z-150630T2030Z/
NEW CASTLE DE-SALEM NJ-GLOUCESTER NJ-DELAWARE PA-CHESTER PA-
PHILADELPHIA PA-
405 PM EDT TUE JUN 30 2015

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM EDT
FOR NORTHEASTERN NEW CASTLE...NORTHWESTERN SALEM...NORTHWESTERN
GLOUCESTER...DELAWARE...SOUTHEASTERN CHESTER AND SOUTHWESTERN
PHILADELPHIA COUNTIES...

AT 405 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 TALLEYVILLE...OR NEAR WILMINGTON...
MOVING NORTHEAST AT 30 MPH.

LOCATIONS IMPACTED INCLUDE...
WILMINGTON...CHESTER...WESTTOWN...FOLCROFT...SWARTHMORE...ELSMERE...
PAULSBORO...ARDEN...PHILADELPHIA INTERNATIONAL AIRPORT...PHILADELPHIA
INTERNATIONAL ARPT...ELAM...TALLEYVILLE...BROOMALL...NETHER
PROVIDENCE TOWNSHIP...CHELSEA...CHEYNEY...GREENVILLE...LIMA...CHESTER
TOWNSHIP AND CONCORDVILLE.

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.

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM.  MOVE INDOORS
IMMEDIATELY. LIGHTNING IS ONE OF NATURES LEADING KILLERS. 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 7560 3979 7564 3991 7568 4004 7540
      3986 7522
TIME...MOT...LOC 2005Z 236DEG 25KT 3982 7553 

$$

HEAVENER

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 30, 10:01 AM EDT	Areal Flood Advisory	PHI	Carbon, Monroe	4 hr
Jun 30, 12:37 PM EDT	Areal Flood Advisory	PHI	Berks	4 hr
Jun 30, 12:47 PM EDT	Special Weather Statement	PHI	Berks	43 min
Jun 30, 1:08 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh	52 min
Jun 30, 1:47 PM EDT	Special Weather Statement	PHI	Lehigh	43 min
Jun 30, 1:48 PM EDT	Flash Flood Warning	PHI	Berks	4 hr
Jun 30, 1:55 PM EDT	Special Weather Statement	PHI	Chester	50 min
Jun 30, 2:00 PM EDT	Tornado Warning	PHI	Berks, Chester	30 min
Jun 30, 2:05 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Carbon, Lehigh, Monroe, Northampton	55 min
Jun 30, 2:13 PM EDT	Tornado Warning	PHI	Lehigh	32 min
Jun 30, 2:19 PM EDT	Special Weather Statement	PHI	Chester	26 min
Jun 30, 2:26 PM EDT	Areal Flood Advisory	PHI	Berks, Chester	4 hr
Jun 30, 2:34 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Montgomery	56 min
Jun 30, 2:41 PM EDT	Severe Thunderstorm Warning	PHI	Chester	49 min
Jun 30, 2:42 PM EDT	Tornado Warning	PHI	Lehigh, Northampton	33 min
Jun 30, 2:48 PM EDT	Special Weather Statement	PHI	Chester	57 min
Jun 30, 2:52 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Montgomery	38 min
Jun 30, 2:55 PM EDT	Flash Flood Warning	PHI	Berks, Lehigh, Northampton	4 hr
Jun 30, 3:00 PM EDT	Areal Flood Advisory	PHI	Bucks, Monroe, Northampton	4 hr
Jun 30, 3:00 PM EDT	Severe Thunderstorm Warning	PHI	Lehigh, Northampton	60 min
Jun 30, 3:08 PM EDT	Areal Flood Advisory	PHI	Chester	4 hr
Jun 30, 3:22 PM EDT	Tornado Warning	PHI	Chester, Delaware, Montgomery	23 min
Jun 30, 3:25 PM EDT	Severe Thunderstorm Warning	PHI	Chester	37 min
Jun 30, 3:31 PM EDT	Special Weather Statement	PHI	Lehigh	44 min
Jun 30, 3:37 PM EDT	Areal Flood Advisory	PHI	Carbon, Lehigh, Monroe, Northampton	4 hr
Jun 30, 3:45 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	45 min
Jun 30, 3:47 PM EDT	Severe Thunderstorm Warning	PHI	Northampton	43 min
Jun 30, 3:54 PM EDT	Flash Flood Watch	PHI	Berks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more	13 hr
Jun 30, 3:57 PM EDT	Areal Flood Advisory	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	4 hr
Jun 30, 4:22 PM EDT	Special Weather Statement	PHI	Monroe	23 min
Jun 30, 4:29 PM EDT	Special Weather Statement	PHI	Delaware, Philadelphia	31 min
Jun 30, 4:31 PM EDT	Special Weather Statement	PHI	Carbon	29 min
Jun 30, 4:58 PM EDT	Areal Flood Advisory	PHI	Delaware, Montgomery, Philadelphia	3 hr
Jun 30, 4:59 PM EDT	Special Weather Statement	PHI	Philadelphia	61 min
Jun 30, 5:03 PM EDT	Special Weather Statement	PHI	Monroe	27 min
Jun 30, 5:51 PM EDT	Special Weather Statement	PHI	Monroe	24 min
Jun 30, 6:03 PM EDT	Flash Flood Warning	PHI	Carbon, Monroe	11 hr
Jun 30, 6:28 PM EDT	Severe Thunderstorm Warning	PHI	Monroe, Northampton	47 min
Jun 30, 7:13 PM EDT	Severe Thunderstorm Warning	PHI	Monroe	62 min
Jun 30, 3:22 PM EDT	Special Marine Warning	PHI		23 min
Jun 30, 4:13 PM EDT	Special Weather Statement	PHI	Camden, Gloucester	32 min
Jun 30, 4:35 PM EDT	Special Weather Statement	PHI	Morris	25 min
Jun 30, 5:48 PM EDT	Special Weather Statement	PHI	Camden, Gloucester	57 min
Jun 30, 6:20 PM EDT	Special Weather Statement	PHI	Warren	25 min
Jun 30, 6:35 PM EDT	Small Craft Advisory	PHI		3 hr
Jun 30, 6:11 PM EDT	Special Weather Statement	PHI	Sussex	34 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2015 Severe Thunderstorm Warnings in New Jersey, 2015 Severe Thunderstorm Warnings in Delaware, 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.