Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 78, NWS Philadelphia/Mount Holly

June 30, 20155 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 30, 2015, 3:45 PM EDT for 5 counties in Pennsylvania. It was in force for 45 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, 3:45 PM EDT (19:45 UTC)
Expired: Jun 30, 2015, 4:30 PM EDT
In force: 45 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 68 km from the middle of the area, began a volume at 19:47 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.

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, 7.8 hours before the alert went out and 117 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.

468 
WUUS51 KPHI 301945
SVRPHI
PAC017-029-045-091-101-302030-
/O.NEW.KPHI.SV.W.0078.150630T1945Z-150630T2030Z/

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

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ  HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTH CENTRAL DELAWARE COUNTY IN SOUTHEASTERN PENNSYLVANIA...
  NORTHEASTERN CHESTER COUNTY IN SOUTHEASTERN PENNSYLVANIA...
  CENTRAL BUCKS COUNTY IN SOUTHEASTERN PENNSYLVANIA...
  NORTHWESTERN PHILADELPHIA COUNTY IN SOUTHEASTERN PENNSYLVANIA...
  SOUTHEASTERN MONTGOMERY COUNTY IN SOUTHEASTERN PENNSYLVANIA...

* UNTIL 430 PM EDT

* AT 344 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 KING OF PRUSSIA...OR 13
  MILES NORTHEAST OF WEST CHESTER...AND MOVING NORTHEAST AT 45 MPH.

* LOCATIONS IMPACTED INCLUDE...
  PHILADELPHIA...EWING...NORRISTOWN...PHOENIXVILLE...LANSDALE...WEST
  NORRITON...EAST NORRITON...DOYLESTOWN...CONSHOHOCKEN...HATBORO...
  AMBLER...COLLEGEVILLE...JENKINTOWN...CHALFONT...NEW HOPE...
  YARDLEY...NEWTOWN...ABINGTON...LANGHORNE AND BRYN ATHYN.

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 3999 7544 4014 7557 4041 7500 4035 7494
      4033 7494 4032 7490 4020 7478
TIME...MOT...LOC 1944Z 240DEG 37KT 4008 7540 

$$

HEAVENER

2 follow-up statements

691 
WWUS51 KPHI 302008
SVSPHI

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

PAC045-101-302017-
/O.CAN.KPHI.SV.W.0078.000000T0000Z-150630T2030Z/
DELAWARE PA-PHILADELPHIA PA-
408 PM EDT TUE JUN 30 2015

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL DELAWARE AND
NORTHWESTERN PHILADELPHIA COUNTIES IS CANCELLED...
    
THE SEVERE THUNDERSTORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF 
THE WARNED AREA. THEREFORE THE WARNING HAS BEEN  CANCELLED.

LAT...LON 4007 7537 4021 7543 4041 7500 4035 7494
      4033 7494 4032 7490 4020 7478
TIME...MOT...LOC 2007Z 240DEG 37KT 4021 7510 

$$

PAC017-029-091-302030-
/O.CON.KPHI.SV.W.0078.000000T0000Z-150630T2030Z/
CHESTER PA-BUCKS PA-MONTGOMERY PA-
408 PM EDT TUE JUN 30 2015

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM EDT
FOR NORTHEASTERN CHESTER...CENTRAL BUCKS AND CENTRAL MONTGOMERY
COUNTIES...

AT 407 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 IVYLAND...OR 14 MILES NORTH OF
PHILADELPHIA...MOVING NORTHEAST AT 45 MPH.

LOCATIONS IMPACTED INCLUDE...
EWING...NORRISTOWN...LANSDALE...WEST NORRITON...EAST NORRITON...
DOYLESTOWN...CONSHOHOCKEN...HATBORO...AMBLER...CHALFONT...HATFIELD...
NEW HOPE...YARDLEY...NEWTOWN...LANGHORNE...BRYN ATHYN...IVYLAND...
PLYMOUTH MEETING...WILLOW GROVE AND WOODSIDE.

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 4007 7537 4021 7543 4041 7500 4035 7494
      4033 7494 4032 7490 4020 7478
TIME...MOT...LOC 2007Z 240DEG 37KT 4021 7510 

$$

HEAVENER

343 
WWUS51 KPHI 302026
SVSPHI

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

PAC017-029-091-302035-
/O.EXP.KPHI.SV.W.0078.000000T0000Z-150630T2030Z/
CHESTER PA-BUCKS PA-MONTGOMERY PA-
426 PM EDT TUE JUN 30 2015

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN CHESTER...CENTRAL
BUCKS AND CENTRAL MONTGOMERY COUNTIES WILL EXPIRE AT 430 PM EDT...
    
THE SEVERE THUNDERSTORM WHICH PROMPTED THE WARNING HAS WEAKENED. 
THEREFORE THE WARNING WILL BE ALLOWED TO EXPIRE.

LAT...LON 4007 7537 4021 7543 4041 7500 4035 7494
      4033 7494 4032 7490 4020 7478
TIME...MOT...LOC 2023Z 240DEG 37KT 4021 7510 

$$

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, 3:43 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Philadelphia	47 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

Nearby

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